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Posted to commits@juneau.apache.org by ja...@apache.org on 2026/05/11 19:44:42 UTC

(juneau) 01/19: refactor(inject): widen BeanCreator and BeanBuilder to accept any BeanStore (TODO-15 phase-3 cleanup)

This is an automated email from the ASF dual-hosted git repository.

jamesbognar pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/juneau.git

commit ce5d6be0c0d14e6fb64dc9a7ec30d2aa0f9533c9
Author: James Bognar <ja...@jamesbog-ltmjqf2.internal.salesforce.com>
AuthorDate: Fri May 8 09:53:15 2026 -0400

    refactor(inject): widen BeanCreator and BeanBuilder to accept any BeanStore (TODO-15 phase-3 cleanup)
    
    Drops the legacy `(BasicBeanStore)` downcast clutter from cascade builders and
    RestContext / RestOpContext call sites by widening the parent-store type on
    the two main bean-creation entry points:
    
    * `BeanCreator.of(Class, BeanStore)` overload — accepts legacy `BasicBeanStore`
      or v2 `BasicBeanStore2`. Constructor branches internally (legacy parent →
      `BasicBeanStore.of(legacy)`; v2 parent → `new BasicBeanStore2(parent)`).
      `store` field widened to `WritableBeanStore`. Legacy `of(Class, BasicBeanStore)`
      retained for binary compat.
    
    * `BeanBuilder<T>` field, ctor, and public `beanStore()` accessor flipped from
      `BasicBeanStore` to `WritableBeanStore`. All 14 cascade-builder
      `super(X.class, (BasicBeanStore) beanStore)` downcasts dropped (`ThrownStore`,
      `MethodExecStore`, `StaticFiles`, `ResponseProcessorList`, `RestMatcherList`,
      `RestGuardList`, `RestConverterList`, `RestOpArgList`, `RestOperations`,
      `RestChildren`, `SerializerSet`, `ParserSet`, `EncoderSet`, `FileFinder`).
    
    Adjacent cleanup pulled in by the cascade:
    
    * `MethodExecStats.create(...)` and `ThrownStats.create(...)` flipped to accept
      `WritableBeanStore`.
    * Standalone Builder fields in `SwaggerProvider.Builder` and
      `ThrownStats.Builder` flipped to `WritableBeanStore`.
    * `BasicSwaggerProvider(BasicBeanStore)` ctor flipped to
      `BasicSwaggerProvider(WritableBeanStore)` (consumed by the SwaggerProvider
      widening).
    * Three internal helpers (`ResponseProcessorList.instantiate`,
      `EncoderSet.instantiate`, `VarResolver.toVar`) widened to take `BeanStore`.
    * Two stored-store fields (`MethodExecStore.beanStore`, `ThrownStore.beanStore`)
      flipped to `WritableBeanStore`.
    
    Also captures the failed four-memoizer migration attempt (callLogger /
    debugEnablement / staticFiles / swaggerProvider) and reverts it back to legacy
    `BeanCreator.of(...)`. The `BeanInstantiator` builder-discovery + loose-builder
    improvements made during that attempt are preserved. Follow-up work tracked
    under new TODO-25.
    
    `WritableBeanStore` chosen over read-only `BeanStore` so existing call sites
    that need write access (e.g. `VarResolver.Builder.bean(...)` calling
    `super.beanStore().addBean(...)`) keep working without a downcast. Single
    residual cast left: `VarResolver` line 257 still wraps the parent in legacy
    `BasicBeanStore.of(...)` because that static API still requires a
    `BasicBeanStore`; it goes away when the static is widened or removed in Phase 4.
    
    TODO-15 plan updated to record the cascade-builder, `BeanCreator`, and
    `BeanBuilder` widenings, plus the four-memoizer revert. New
    TODO-25-revisit-rest-context-memoizer-migration.md captures the memoizer
    migration analysis for future work.
    
    Verified with `./scripts/test.py -f` (full build + unit tests) and
    `juneau-examples-rest-jetty-ftest` (the suite that caught the staticfile
    regression earlier).
    
    Co-authored-by: Cursor <cu...@cursor.com>
---
 .../juneau/commons/inject/BasicBeanStore2.java     |  49 +++++
 .../juneau/commons/inject/BeanInstantiator.java    |  34 +++-
 .../apache/juneau/commons/inject/BeanStore.java    | 109 +++++++++++
 .../juneau/commons/inject/WritableBeanStore.java   |  72 +++++++
 .../main/java/org/apache/juneau/BeanBuilder.java   |  13 +-
 .../java/org/apache/juneau/cp/BasicBeanStore.java  | 127 ++++++++++++-
 .../java/org/apache/juneau/cp/BeanCreator.java     |  51 ++++-
 .../main/java/org/apache/juneau/cp/FileFinder.java |   5 +-
 .../org/apache/juneau/encoders/EncoderSet.java     |   8 +-
 .../java/org/apache/juneau/parser/ParserSet.java   |   5 +-
 .../apache/juneau/serializer/SerializerSet.java    |   5 +-
 .../java/org/apache/juneau/svl/VarResolver.java    |   7 +-
 .../org/apache/juneau/rest/mcp/McpEndpoint.java    |   2 +-
 .../org/apache/juneau/rest/mcp/McpRestServlet.java |   2 +-
 .../java/org/apache/juneau/rest/RestChildren.java  |   5 +-
 .../java/org/apache/juneau/rest/RestContext.java   | 180 ++++++++----------
 .../java/org/apache/juneau/rest/RestOpContext.java | 103 +++++-----
 .../org/apache/juneau/rest/RestOperations.java     |   5 +-
 .../java/org/apache/juneau/rest/RestSession.java   |   2 +-
 .../org/apache/juneau/rest/arg/RestOpArgList.java  |   5 +-
 .../juneau/rest/converter/RestConverterList.java   |   5 +-
 .../apache/juneau/rest/debug/DebugEnablement.java  |   5 +-
 .../apache/juneau/rest/guard/RestGuardList.java    |   5 +-
 .../juneau/rest/matcher/RestMatcherList.java       |   5 +-
 .../rest/processor/ResponseProcessorList.java      |  10 +-
 .../juneau/rest/staticfile/BasicStaticFiles.java   |   3 +-
 .../apache/juneau/rest/staticfile/StaticFiles.java |   5 +-
 .../apache/juneau/rest/stats/MethodExecStats.java  |   5 +-
 .../apache/juneau/rest/stats/MethodExecStore.java  |   7 +-
 .../apache/juneau/rest/stats/MethodInvoker.java    |   4 +-
 .../org/apache/juneau/rest/stats/ThrownStats.java  |   7 +-
 .../org/apache/juneau/rest/stats/ThrownStore.java  |   7 +-
 .../juneau/rest/swagger/BasicSwaggerProvider.java  |   5 +-
 .../juneau/rest/swagger/SwaggerProvider.java       |   9 +-
 .../commons/inject/BeanInstantiator_Test.java      |  30 +--
 todo/TODO-15-replace-basicbeanstore-with-v2.md     |  59 +++++-
 ...O-25-revisit-rest-context-memoizer-migration.md | 209 +++++++++++++++++++++
 todo/TODO.md                                       |   2 +
 38 files changed, 918 insertions(+), 253 deletions(-)

diff --git a/juneau-core/juneau-commons/src/main/java/org/apache/juneau/commons/inject/BasicBeanStore2.java b/juneau-core/juneau-commons/src/main/java/org/apache/juneau/commons/inject/BasicBeanStore2.java
index b82e548e39..6dffc3d6d4 100644
--- a/juneau-core/juneau-commons/src/main/java/org/apache/juneau/commons/inject/BasicBeanStore2.java
+++ b/juneau-core/juneau-commons/src/main/java/org/apache/juneau/commons/inject/BasicBeanStore2.java
@@ -74,6 +74,7 @@ public class BasicBeanStore2 implements WritableBeanStore {
 
 	private final ConcurrentHashMap<Class<?>, ConcurrentHashMap<String, Supplier<?>>> entries;
 	private final ConcurrentHashMap<Class<?>, ConcurrentHashMap<String, Supplier<?>>> defaults;
+	private final ConcurrentHashMap<Class<?>, Class<?>> typeBindings;
 	private final BeanStore parent;
 	private final BeanStore overridingParent;
 
@@ -112,6 +113,7 @@ public class BasicBeanStore2 implements WritableBeanStore {
 		this.overridingParent = overridingParent;
 		entries = new ConcurrentHashMap<>();
 		defaults = new ConcurrentHashMap<>();
+		typeBindings = new ConcurrentHashMap<>();
 		addSupplier(BasicBeanStore2.class, ()->this, null);
 	}
 
@@ -324,6 +326,36 @@ public class BasicBeanStore2 implements WritableBeanStore {
 		return result;
 	}
 
+	/**
+	 * Returns <jk>true</jk> if this store has a default supplier registered locally for the specified unnamed bean type.
+	 *
+	 * <p>
+	 * Parent and overriding-parent stores are <i>not</i> consulted.
+	 *
+	 * @param beanType The bean type to check.
+	 * @return <jk>true</jk> if a default supplier for the unnamed bean type is registered on this store.
+	 */
+	@Override
+	public boolean hasDefaultSupplier(Class<?> beanType) {
+		return hasDefaultSupplier(beanType, null);
+	}
+
+	/**
+	 * Returns <jk>true</jk> if this store has a default supplier registered locally for the specified bean type and name.
+	 *
+	 * <p>
+	 * Parent and overriding-parent stores are <i>not</i> consulted.
+	 *
+	 * @param beanType The bean type to check.
+	 * @param name The bean name.  Can be <jk>null</jk> for unnamed beans.
+	 * @return <jk>true</jk> if a default supplier for the bean type and name is registered on this store.
+	 */
+	@Override
+	public boolean hasDefaultSupplier(Class<?> beanType, String name) {
+		var typeMap = defaults.get(beanType);
+		return nn(typeMap) && typeMap.containsKey(emptyIfNull(name));
+	}
+
 	/**
 	 * Returns <jk>true</jk> if this store contains at least one unnamed bean of the specified type.
 	 *
@@ -353,6 +385,23 @@ public class BasicBeanStore2 implements WritableBeanStore {
 		return resolve(beanType, name).isPresent();
 	}
 
+	@Override
+	public <T> WritableBeanStore addBeanType(Class<T> beanType, Class<? extends T> implType) {
+		typeBindings.put(beanType, implType);
+		return this;
+	}
+
+	@Override
+	@SuppressWarnings("unchecked")
+	public <T> Optional<Class<? extends T>> getBeanType(Class<T> beanType) {
+		var v = (Class<? extends T>) typeBindings.get(beanType);
+		if (nn(v))
+			return opt(v);
+		if (nn(parent))
+			return parent.getBeanType(beanType);
+		return opte();
+	}
+
 	/**
 	 * Returns the supplier for an unnamed bean of the specified type.
 	 *
diff --git a/juneau-core/juneau-commons/src/main/java/org/apache/juneau/commons/inject/BeanInstantiator.java b/juneau-core/juneau-commons/src/main/java/org/apache/juneau/commons/inject/BeanInstantiator.java
index 0bae47ad75..0425ee7a8e 100644
--- a/juneau-core/juneau-commons/src/main/java/org/apache/juneau/commons/inject/BeanInstantiator.java
+++ b/juneau-core/juneau-commons/src/main/java/org/apache/juneau/commons/inject/BeanInstantiator.java
@@ -1125,6 +1125,7 @@ public class BeanInstantiator<T> {
 		var methodComparator = comparing(MethodInfo::getParameterCount).reversed();
 		var constructorComparator = comparing(ConstructorInfo::getParameterCount).reversed();
 
+		boolean builderAttempted = false;
 		if (builder2 != null) {
 			log("Builder detected: %s", builder2.getClass().getName());
 
@@ -1156,15 +1157,23 @@ public class BeanInstantiator<T> {
 					log("Method has no parameters, calling without injection");
 				}
 
+				builderAttempted = true;
 				// Call the builder method
 				Object builtBean = method.inject(store2, builder2);
 
-				// Builder build method must return the exact beanSubType
-				if (!returnType.is(beanSubType.inner())) {
-					log("Builder method %s returns %s, but must return %s", method.getNameFull(), returnType.getName(), beanSubType.getName());
-					throw exex("Builder method {0} returns {1}, but must return {2}. Builder build methods must always return the exact bean subtype being created.", method.getNameFull(), returnType.getName(), beanSubType.getName());
+				// Validate the produced bean (loose-builder mode). We accept the result if either:
+				//   1. The build method's declared return type is exactly beanSubType, OR
+				//   2. The runtime instance produced by the build method is assignment-compatible with beanSubType.
+				// Case 2 supports the legacy pattern where a parent class's Builder.build() declares the parent
+				// type but constructs a configured subclass at runtime (e.g. DebugEnablement.Builder.build() returning
+				// a BasicDebugEnablement because the builder's internal type-binding was preset).
+				// If neither matches, we fall through to factory-method / constructor resolution on beanSubType
+				// rather than throwing — that lets standard "subclass adds its own constructor" patterns succeed.
+				if (returnType.is(beanSubType.inner()) || (builtBean != null && beanSubType.inner().isInstance(builtBean))) {
+					bean = (T)beanType.cast(builtBean);
+				} else {
+					log("Builder method %s returned %s but expected %s; falling through to factory methods/constructors", method.getNameFull(), builtBean == null ? "null" : builtBean.getClass().getName(), beanSubType.getName());
 				}
-				bean = (T)beanType.cast(builtBean);
 			}
 
 			if (bean != null) {
@@ -1228,6 +1237,11 @@ public class BeanInstantiator<T> {
 				// Builder has a method returning the right type but not with the expected name
 				log("Builder detected but no appropriate build method found. Builder type: %s. Expected method names: %s", builder2.getClass().getName(), buildMethodNames);
 				// Fall through to factory methods/constructors
+			} else if (builderAttempted) {
+				// We tried the builder's build method but it produced a runtime instance that wasn't the expected
+				// beanSubType (loose-builder fallthrough above).  Don't throw; fall through to factory-method /
+				// constructor resolution on beanSubType so subclasses with their own constructor/factory still resolve.
+				log("Builder %s build method produced wrong runtime type; falling through to factory methods/constructors", builder2.getClass().getName());
 			} else if (hasBuildMethodWithRightReturnType || isExplicitBuilder || isValidBuilder) {
 				// Builder has a build method with right return type (even if can't be called) or was explicitly set
 				// Throw exception unless fallback exists
@@ -1483,10 +1497,12 @@ public class BeanInstantiator<T> {
 			return builderClass;
 		}
 
-		// 3c: Look for builder in parent classes (skip the first element which is beanSubType itself)
-		var parentClasses = beanSubType.getParents();
-		for (int i = 1; i < parentClasses.size(); i++) {
-			var parentClass = parentClasses.get(i);
+		// 3c: Look for builder in parent classes and implemented interfaces (skip beanSubType itself,
+		// which was already searched in 3b). getAllParents returns parents (child-to-parent) followed by
+		// interfaces, so we walk the whole chain in a uniform order.
+		var allParents = beanSubType.getAllParents();
+		for (int i = 1; i < allParents.size(); i++) {
+			var parentClass = allParents.get(i);
 			r = parentClass.getDeclaredMemberClasses().stream()
 				.filter(x -> builderClassNames.contains(x.getNameSimple()))
 				.findFirst();
diff --git a/juneau-core/juneau-commons/src/main/java/org/apache/juneau/commons/inject/BeanStore.java b/juneau-core/juneau-commons/src/main/java/org/apache/juneau/commons/inject/BeanStore.java
index 200857126d..f8906bac1a 100644
--- a/juneau-core/juneau-commons/src/main/java/org/apache/juneau/commons/inject/BeanStore.java
+++ b/juneau-core/juneau-commons/src/main/java/org/apache/juneau/commons/inject/BeanStore.java
@@ -16,6 +16,10 @@
  */
 package org.apache.juneau.commons.inject;
 
+import static java.util.stream.Collectors.*;
+import static org.apache.juneau.commons.utils.CollectionUtils.*;
+import static org.apache.juneau.commons.utils.Utils.*;
+
 import java.util.*;
 import java.util.function.*;
 
@@ -208,5 +212,110 @@ public interface BeanStore {
 	default <T> Optional<T> createBeanFromMethod(Class<T> beanType, Object onClassOrObject) {
 		return createBeanFromMethod(beanType, onClassOrObject, null);
 	}
+
+	/**
+	 * Returns the implementation class registered for the specified bean type, if any.
+	 *
+	 * <p>
+	 * Type bindings let callers register a default implementation class to be instantiated when an
+	 * actual bean of <c>beanType</c> is needed.  Bindings are inherited through the parent chain.
+	 *
+	 * <p>
+	 * The default implementation returns {@link Optional#empty()} (no binding).  Override in concrete
+	 * stores (see {@link BasicBeanStore2}) to enable type binding.
+	 *
+	 * @param <T> The bean type.
+	 * @param beanType The bean type whose implementation class is being looked up.
+	 * @return The implementation class, or {@link Optional#empty()} if no binding exists.
+	 */
+	default <T> Optional<Class<? extends T>> getBeanType(Class<T> beanType) {
+		return Optional.empty();
+	}
+
+	/**
+	 * Returns <jk>true</jk> if this store can satisfy every parameter of the specified executable.
+	 *
+	 * <p>
+	 * Skips:
+	 * <ul>
+	 * 	<li>The first parameter when it is an instance of <c>outer</c> (inner-class outer reference).
+	 * 	<li>Parameters typed as {@link Optional} (always considered satisfied).
+	 * </ul>
+	 *
+	 * @param executable The constructor or method to inspect.
+	 * @param outer The outer object to use for inner-class param resolution.  Can be <jk>null</jk>.
+	 * @return <jk>true</jk> if every required parameter can be resolved from this store.
+	 */
+	default boolean hasAllParams(ExecutableInfo executable, Object outer) {
+		for (var i = 0; i < executable.getParameterCount(); i++) {
+			var pi = executable.getParameter(i);
+			var pt = pi.getParameterType();
+			if ((i == 0 && nn(outer) && pt.isInstance(outer)) || pt.is(Optional.class))
+				continue;
+			var beanQualifier = pi.getResolvedQualifier();
+			var ptc = pt.inner();
+			if ((beanQualifier == null && ! hasBean(ptc)) || (nn(beanQualifier) && ! hasBean(ptc, beanQualifier)))
+				return false;
+		}
+		return true;
+	}
+
+	/**
+	 * Resolves every parameter of the specified executable from this store.
+	 *
+	 * <p>
+	 * For {@link Optional}-typed parameters the wrapped {@link Optional} is returned directly; for all
+	 * others the bean instance (or <jk>null</jk> when missing) is returned.  See {@link #hasAllParams}
+	 * for the full skip rules.
+	 *
+	 * @param executable The constructor or method to resolve parameters for.
+	 * @param outer The outer object to use for inner-class param resolution.  Can be <jk>null</jk>.
+	 * @return An array of resolved parameter values, one per parameter of <c>executable</c>.
+	 */
+	default Object[] getParams(ExecutableInfo executable, Object outer) {
+		var o = new Object[executable.getParameterCount()];
+		for (var i = 0; i < executable.getParameterCount(); i++) {
+			var pi = executable.getParameter(i);
+			var pt = pi.getParameterType();
+			if (i == 0 && nn(outer) && pt.isInstance(outer)) {
+				o[i] = outer;
+			} else {
+				var beanQualifier = pi.getResolvedQualifier();
+				var ptc = pt.unwrap(Optional.class).inner();
+				var o2 = beanQualifier == null ? getBean(ptc) : getBean(ptc, beanQualifier);
+				o[i] = pt.is(Optional.class) ? o2 : o2.orElse(null);
+			}
+		}
+		return o;
+	}
+
+	/**
+	 * Returns a comma-delimited list of parameter type names that cannot be resolved from this store.
+	 *
+	 * <p>
+	 * Intended for diagnostic error messages — see {@link #hasAllParams} for the exact match rules.
+	 * Skipped parameters (outer-instance match, {@link Optional}) never appear in the result.
+	 *
+	 * @param executable The constructor or method to inspect.
+	 * @param outer The outer object to use for inner-class param resolution.  Can be <jk>null</jk>.
+	 * @return A comma-delimited list of missing parameter type names, or <jk>null</jk> when none are missing.
+	 */
+	default String getMissingParams(ExecutableInfo executable, Object outer) {
+		var params = executable.getParameters();
+		List<String> l = list();
+		for (var i = 0; i < params.size(); i++) {
+			var pi = params.get(i);
+			var pt = pi.getParameterType();
+			if ((i == 0 && nn(outer) && pt.isInstance(outer)) || pt.is(Optional.class))
+				continue;
+			var beanName = pi.getResolvedQualifier();
+			var ptc = pt.inner();
+			if (beanName == null && ! hasBean(ptc))
+				l.add(pt.getNameSimple());
+			if (nn(beanName) && ! hasBean(ptc, beanName))
+				l.add(pt.getNameSimple() + '@' + beanName);
+		}
+		return l.isEmpty() ? null : l.stream().sorted().collect(joining(","));
+	}
 }
 
diff --git a/juneau-core/juneau-commons/src/main/java/org/apache/juneau/commons/inject/WritableBeanStore.java b/juneau-core/juneau-commons/src/main/java/org/apache/juneau/commons/inject/WritableBeanStore.java
index b85ecea82e..4087446a90 100644
--- a/juneau-core/juneau-commons/src/main/java/org/apache/juneau/commons/inject/WritableBeanStore.java
+++ b/juneau-core/juneau-commons/src/main/java/org/apache/juneau/commons/inject/WritableBeanStore.java
@@ -51,6 +51,33 @@ import java.util.function.*;
  */
 public interface WritableBeanStore extends BeanStore {
 
+	/**
+	 * Same as {@link #addBean(Class,Object)} but returns the bean instead of this object for fluent calls.
+	 *
+	 * @param <T> The bean type.
+	 * @param beanType The bean type.
+	 * @param bean The bean instance.  Can be <jk>null</jk>.
+	 * @return The bean.
+	 */
+	default <T> T add(Class<T> beanType, T bean) {
+		addBean(beanType, bean);
+		return bean;
+	}
+
+	/**
+	 * Same as {@link #addBean(Class,Object,String)} but returns the bean instead of this object for fluent calls.
+	 *
+	 * @param <T> The bean type.
+	 * @param beanType The bean type.
+	 * @param bean The bean instance.  Can be <jk>null</jk>.
+	 * @param name The bean name.  Can be <jk>null</jk> for unnamed beans.
+	 * @return The bean.
+	 */
+	default <T> T add(Class<T> beanType, T bean, String name) {
+		addBean(beanType, bean, name);
+		return bean;
+	}
+
 	/**
 	 * Adds an unnamed bean of the specified type to this store.
 	 *
@@ -140,5 +167,50 @@ public interface WritableBeanStore extends BeanStore {
 	 * @return This object for method chaining.
 	 */
 	WritableBeanStore clear();
+
+	/**
+	 * Returns <jk>true</jk> if this store has a {@linkplain #addDefaultSupplier(Class,Supplier) default supplier}
+	 * registered locally for the specified unnamed bean type.
+	 *
+	 * <p>
+	 * This is intended for callers that need to distinguish "framework default present" from "any binding
+	 * exists" — for example, REST initialization uses this signal to skip types that are managed by an
+	 * internal memoizer.  Parent and overriding-parent stores are <i>not</i> consulted.
+	 *
+	 * @param beanType The bean type to check.
+	 * @return <jk>true</jk> if a default supplier for the unnamed bean type is registered on this store.
+	 */
+	boolean hasDefaultSupplier(Class<?> beanType);
+
+	/**
+	 * Returns <jk>true</jk> if this store has a {@linkplain #addDefaultSupplier(Class,Supplier,String) default supplier}
+	 * registered locally for the specified bean type and name.
+	 *
+	 * <p>
+	 * See {@link #hasDefaultSupplier(Class)} for the rationale.  Parent and overriding-parent stores are
+	 * <i>not</i> consulted.
+	 *
+	 * @param beanType The bean type to check.
+	 * @param name The bean name.  Can be <jk>null</jk> for unnamed beans.
+	 * @return <jk>true</jk> if a default supplier for the bean type and name is registered on this store.
+	 */
+	boolean hasDefaultSupplier(Class<?> beanType, String name);
+
+	/**
+	 * Registers a default implementation class for the specified bean type.
+	 *
+	 * <p>
+	 * Type bindings are consulted by callers (notably {@link BeanInstantiator} and the various REST
+	 * memoizers) when resolving the impl class to instantiate for <c>beanType</c>.  This is the
+	 * type-binding analogue of {@link #addDefaultSupplier(Class,Supplier) addDefaultSupplier}: it
+	 * provides a deferred-construction default that can be overridden by later resolution steps
+	 * (e.g. an annotation override).
+	 *
+	 * @param <T> The bean type.
+	 * @param beanType The bean type to bind.
+	 * @param implType The implementation class to instantiate when this type is resolved.
+	 * @return This object for method chaining.
+	 */
+	<T> WritableBeanStore addBeanType(Class<T> beanType, Class<? extends T> implType);
 }
 
diff --git a/juneau-core/juneau-marshall/src/main/java/org/apache/juneau/BeanBuilder.java b/juneau-core/juneau-marshall/src/main/java/org/apache/juneau/BeanBuilder.java
index 5e4579efdd..50c212e83a 100644
--- a/juneau-core/juneau-marshall/src/main/java/org/apache/juneau/BeanBuilder.java
+++ b/juneau-core/juneau-marshall/src/main/java/org/apache/juneau/BeanBuilder.java
@@ -20,6 +20,7 @@ import static org.apache.juneau.commons.utils.Utils.*;
 
 import java.util.*;
 
+import org.apache.juneau.commons.inject.WritableBeanStore;
 import org.apache.juneau.cp.*;
 
 /**
@@ -33,7 +34,7 @@ public class BeanBuilder<T> {
 	private Class<? extends T> type;
 	private Class<? extends T> defaultType;
 	private T impl;
-	private final BasicBeanStore beanStore;
+	private final WritableBeanStore beanStore;
 
 	/**
 	 * Copy constructor.
@@ -49,10 +50,16 @@ public class BeanBuilder<T> {
 	/**
 	 * Constructor.
 	 *
+	 * <p>
+	 * Accepts any {@link WritableBeanStore} \u2014 legacy {@link BasicBeanStore} (which
+	 * implements {@link WritableBeanStore}) or the v2
+	 * {@link org.apache.juneau.commons.inject.BasicBeanStore2 BasicBeanStore2}.  Cascade-builder
+	 * subclasses no longer need to downcast to {@link BasicBeanStore} when calling {@code super(...)}.
+	 *
 	 * @param beanStore The bean store to use for creating beans.
 	 * @param defaultType The default bean type that this builder creates.
 	 */
-	protected BeanBuilder(Class<? extends T> defaultType, BasicBeanStore beanStore) {
+	protected BeanBuilder(Class<? extends T> defaultType, WritableBeanStore beanStore) {
 		this.defaultType = type = defaultType;
 		this.beanStore = beanStore;
 	}
@@ -62,7 +69,7 @@ public class BeanBuilder<T> {
 	 *
 	 * @return The bean store passed in through the constructor.
 	 */
-	public BasicBeanStore beanStore() {
+	public WritableBeanStore beanStore() {
 		return beanStore;
 	}
 
diff --git a/juneau-core/juneau-marshall/src/main/java/org/apache/juneau/cp/BasicBeanStore.java b/juneau-core/juneau-marshall/src/main/java/org/apache/juneau/cp/BasicBeanStore.java
index 7d0829921d..48ee0990e1 100644
--- a/juneau-core/juneau-marshall/src/main/java/org/apache/juneau/cp/BasicBeanStore.java
+++ b/juneau-core/juneau-marshall/src/main/java/org/apache/juneau/cp/BasicBeanStore.java
@@ -30,6 +30,8 @@ import java.util.function.*;
 
 import org.apache.juneau.commons.collections.*;
 import org.apache.juneau.commons.concurrent.*;
+import org.apache.juneau.commons.inject.BeanCreationException;
+import org.apache.juneau.commons.inject.WritableBeanStore;
 import org.apache.juneau.commons.reflect.*;
 
 /**
@@ -99,7 +101,7 @@ import org.apache.juneau.commons.reflect.*;
 @SuppressWarnings({
 	"java:S115" // Constants use UPPER_snakeCase convention
 })
-public class BasicBeanStore {
+public class BasicBeanStore implements WritableBeanStore {
 
 	// Argument name constants for assertArgNotNull
 	private static final String ARG_bean = "bean";
@@ -350,6 +352,7 @@ public class BasicBeanStore {
 	 * @param bean The bean.  Can be <jk>null</jk>.
 	 * @return This object.
 	 */
+	@Override
 	public <T> BasicBeanStore addBean(Class<T> beanType, T bean) {
 		return addBean(beanType, bean, null);
 	}
@@ -363,6 +366,7 @@ public class BasicBeanStore {
 	 * @param name The bean name if this is a named bean.  Can be <jk>null</jk>.
 	 * @return This object.
 	 */
+	@Override
 	public <T> BasicBeanStore addBean(Class<T> beanType, T bean, String name) {
 		return addSupplier(beanType, () -> bean, name);
 	}
@@ -375,6 +379,7 @@ public class BasicBeanStore {
 	 * @param bean The bean supplier.
 	 * @return This object.
 	 */
+	@Override
 	public <T> BasicBeanStore addSupplier(Class<T> beanType, Supplier<T> bean) {
 		return addSupplier(beanType, bean, null);
 	}
@@ -388,6 +393,7 @@ public class BasicBeanStore {
 	 * @param name The bean name if this is a named bean.  Can be <jk>null</jk>.
 	 * @return This object.
 	 */
+	@Override
 	public <T> BasicBeanStore addSupplier(Class<T> beanType, Supplier<T> bean, String name) {
 		assertCanWrite();
 		var e = createEntry(beanType, bean, name);
@@ -413,6 +419,7 @@ public class BasicBeanStore {
 	 * @param bean The bean supplier.
 	 * @return This object.
 	 */
+	@Override
 	public <T> BasicBeanStore addDefaultSupplier(Class<T> beanType, Supplier<T> bean) {
 		return addDefaultSupplier(beanType, bean, null);
 	}
@@ -429,6 +436,7 @@ public class BasicBeanStore {
 	 * @param name The bean name if this is a named bean.  Can be <jk>null</jk>.
 	 * @return This object.
 	 */
+	@Override
 	public <T> BasicBeanStore addDefaultSupplier(Class<T> beanType, Supplier<T> bean, String name) {
 		assertCanWrite();
 		var e = createEntry(beanType, bean, name);
@@ -448,6 +456,7 @@ public class BasicBeanStore {
 	 *
 	 * @return This object.
 	 */
+	@Override
 	public BasicBeanStore clear() {
 		assertCanWrite();
 		try (var x = lock.write()) {
@@ -524,6 +533,7 @@ public class BasicBeanStore {
 	 * @param beanType The type of bean to return.
 	 * @return The bean.
 	 */
+	@Override
 	@SuppressWarnings({
 		"unchecked" // Type erasure requires unchecked cast
 	})
@@ -561,6 +571,7 @@ public class BasicBeanStore {
 	 * @param name The bean name.  Can be <jk>null</jk>.
 	 * @return The bean.
 	 */
+	@Override
 	@SuppressWarnings({
 		"unchecked" // Type erasure requires unchecked cast
 	})
@@ -590,6 +601,116 @@ public class BasicBeanStore {
 		}
 	}
 
+	/**
+	 * Returns all beans of the specified type, keyed by bean name.
+	 *
+	 * <p>
+	 * Higher-priority sources overwrite lower-priority ones with the same name. The priority order
+	 * mirrors {@link #getBean(Class)}: defaults &lt; parent &lt; local entries &lt; overriding parent.
+	 *
+	 * @param <T> The bean type.
+	 * @param beanType The bean type.
+	 * @return A map of bean names to bean instances. Never <jk>null</jk>.
+	 */
+	@Override
+	@SuppressWarnings({
+		"unchecked" // Type erasure requires unchecked cast
+	})
+	public <T> Map<String,T> getBeansOfType(Class<T> beanType) {
+		try (var x = lock.read()) {
+			Map<String,T> result = map();
+			defaults.stream().filter(e -> e.matches(beanType)).forEach(e -> result.put(emptyIfNull(e.getName()), (T)e.get()));
+			parent.ifPresent(p -> p.getBeansOfType(beanType).forEach(result::put));
+			entries.stream().filter(e -> e.matches(beanType)).forEach(e -> result.put(emptyIfNull(e.getName()), (T)e.get()));
+			overridingParent.ifPresent(op -> op.getBeansOfType(beanType).forEach(result::put));
+			return result;
+		}
+	}
+
+	/**
+	 * Returns the supplier for an unnamed bean of the specified type.
+	 *
+	 * @param <T> The bean type.
+	 * @param beanType The bean type.
+	 * @return The supplier, or {@link Optional#empty()} if no supplier of the specified type exists.
+	 */
+	@Override
+	public <T> Optional<Supplier<T>> getBeanSupplier(Class<T> beanType) {
+		return getBeanSupplier(beanType, null);
+	}
+
+	/**
+	 * Returns the supplier for a named bean of the specified type.
+	 *
+	 * @param <T> The bean type.
+	 * @param beanType The bean type.
+	 * @param name The bean name.  Can be <jk>null</jk>.
+	 * @return The supplier, or {@link Optional#empty()} if no supplier of the specified type and name exists.
+	 */
+	@Override
+	@SuppressWarnings({
+		"unchecked" // Type erasure requires unchecked cast for supplier resolution
+	})
+	public <T> Optional<Supplier<T>> getBeanSupplier(Class<T> beanType, String name) {
+		try (var x = lock.read()) {
+			if (overridingParent.isPresent()) {
+				var fromOverriding = overridingParent.get().getBeanSupplier(beanType, name);
+				if (fromOverriding.isPresent())
+					return fromOverriding;
+			}
+			var e = entries.stream().filter(x2 -> x2.matches(beanType, name)).findFirst().orElse(null);
+			if (nn(e))
+				return opt((Supplier<T>) e.bean);
+			if (parent.isPresent()) {
+				var fromParent = parent.get().getBeanSupplier(beanType, name);
+				if (fromParent.isPresent())
+					return fromParent;
+			}
+			var d = defaults.stream().filter(x2 -> x2.matches(beanType, name)).findFirst().orElse(null);
+			if (nn(d))
+				return opt((Supplier<T>) d.bean);
+			return opte();
+		}
+	}
+
+	/**
+	 * Finds and invokes a factory method that produces a bean of type <c>beanType</c>.
+	 *
+	 * <p>
+	 * If <c>onClassOrObject</c> is a {@link Class}, only static methods are eligible.
+	 * Otherwise, both instance and static methods on the object's class are eligible.
+	 * A <jk>null</jk> <c>filter</c> accepts any qualifying method.
+	 *
+	 * @param <T> The bean type.
+	 * @param beanType The type of bean to create.  Must not be <jk>null</jk>.
+	 * @param onClassOrObject The object instance or {@link Class} whose public methods are searched.
+	 * 	Must not be <jk>null</jk>.
+	 * @param filter Optional predicate restricting which methods are eligible.  Can be <jk>null</jk>.
+	 * @param extraBeans Optional bean instances visible to parameter resolution for this call only.
+	 * @return The created bean wrapped in an {@link Optional}, or {@link Optional#empty()} if no matching
+	 * 	factory method was found.
+	 * @throws BeanCreationException If a matching method was found but threw an exception during invocation.
+	 */
+	@Override
+	public <T> Optional<T> createBeanFromMethod(Class<T> beanType, Object onClassOrObject, Predicate<MethodInfo> filter, Object... extraBeans) {
+		Object resource = onClassOrObject instanceof Class ? null : onClassOrObject;
+		Class<?> resourceClass = onClassOrObject instanceof Class<?> c ? c : onClassOrObject.getClass();
+		return info(resourceClass)
+			.getPublicMethod(m ->
+				m.isNotDeprecated()
+				&& m.hasReturnType(beanType)
+				&& (filter == null || filter.test(m))
+				&& (m.isStatic() || nn(resource))
+				&& m.canResolveAllParameters(this, extraBeans))
+			.map(m -> {
+				try {
+					return m.<T>inject(this, resource, extraBeans);
+				} catch (Exception e) {
+					throw new BeanCreationException("Failed to create bean of type [" + beanType.getSimpleName() + "] via method [" + m.getName() + "]", e);
+				}
+			});
+	}
+
 	/**
 	 * Given an executable, returns a list of types that are missing from this factory.
 	 *
@@ -668,6 +789,7 @@ public class BasicBeanStore {
 	 * @param beanType The bean type to check.
 	 * @return <jk>true</jk> if this store contains the specified unnamed bean type.
 	 */
+	@Override
 	public boolean hasBean(Class<?> beanType) {
 		return overridingParent.map(x -> x.hasBean(beanType)).orElse(false)
 			|| unnamedEntries.containsKey(beanType)
@@ -682,6 +804,7 @@ public class BasicBeanStore {
 	 * @param name The bean name.
 	 * @return <jk>true</jk> if this store contains the specified named bean type.
 	 */
+	@Override
 	public boolean hasBean(Class<?> beanType, String name) {
 		return overridingParent.map(x -> x.hasBean(beanType, name)).orElse(false)
 			|| entries.stream().anyMatch(x -> x.matches(beanType, name))
@@ -702,6 +825,7 @@ public class BasicBeanStore {
 	 * @param beanType The bean type to check.
 	 * @return <jk>true</jk> if a default supplier for the unnamed bean type is registered on this store.
 	 */
+	@Override
 	public boolean hasDefaultSupplier(Class<?> beanType) {
 		return unnamedDefaults.containsKey(beanType);
 	}
@@ -718,6 +842,7 @@ public class BasicBeanStore {
 	 * @param name The bean name.  Can be <jk>null</jk> for unnamed beans.
 	 * @return <jk>true</jk> if a default supplier for the bean type and name is registered on this store.
 	 */
+	@Override
 	public boolean hasDefaultSupplier(Class<?> beanType, String name) {
 		return defaults.stream().anyMatch(x -> x.matches(beanType, name));
 	}
diff --git a/juneau-core/juneau-marshall/src/main/java/org/apache/juneau/cp/BeanCreator.java b/juneau-core/juneau-marshall/src/main/java/org/apache/juneau/cp/BeanCreator.java
index a214543b03..0d17576262 100644
--- a/juneau-core/juneau-marshall/src/main/java/org/apache/juneau/cp/BeanCreator.java
+++ b/juneau-core/juneau-marshall/src/main/java/org/apache/juneau/cp/BeanCreator.java
@@ -25,6 +25,9 @@ import java.util.*;
 import java.util.function.*;
 
 import org.apache.juneau.annotation.*;
+import org.apache.juneau.commons.inject.BasicBeanStore2;
+import org.apache.juneau.commons.inject.BeanStore;
+import org.apache.juneau.commons.inject.WritableBeanStore;
 import org.apache.juneau.commons.lang.*;
 import org.apache.juneau.commons.reflect.*;
 
@@ -152,7 +155,12 @@ public class BeanCreator<T> {
 	}
 
 	/**
-	 * Creates a new bean creator.
+	 * Creates a new bean creator using a legacy {@link BasicBeanStore}.
+	 *
+	 * <p>
+	 * Retained for binary compatibility.  New call sites should prefer
+	 * {@link #of(Class,BeanStore)} so they can pass the v2 {@link BasicBeanStore2 BasicBeanStore2}
+	 * (or any other {@link BeanStore}) without a downcast.
 	 *
 	 * @param <T> The bean type to create.
 	 * @param beanType The bean type to create.
@@ -163,7 +171,25 @@ public class BeanCreator<T> {
 		return new BeanCreator<>(beanType, beanStore);
 	}
 
-	private final BasicBeanStore store;
+	/**
+	 * Creates a new bean creator backed by any {@link BeanStore} implementation.
+	 *
+	 * <p>
+	 * Accepts both legacy {@link BasicBeanStore} and the v2
+	 * {@link BasicBeanStore2 BasicBeanStore2} (or any other {@link BeanStore} subtype).  This is the
+	 * transitional bridge that lets in-flight {@code BeanCreator} call sites continue to work while
+	 * REST-server bean stores migrate to the v2 surface.
+	 *
+	 * @param <T> The bean type to create.
+	 * @param beanType The bean type to create.
+	 * @param beanStore The bean store to use for parameter resolution.
+	 * @return A new creator.
+	 */
+	public static <T> BeanCreator<T> of(Class<T> beanType, BeanStore beanStore) {
+		return new BeanCreator<>(beanType, beanStore);
+	}
+
+	private final WritableBeanStore store;
 	private ClassInfo type;
 	private Object builder;
 	private T impl;
@@ -174,12 +200,23 @@ public class BeanCreator<T> {
 	/**
 	 * Constructor.
 	 *
+	 * <p>
+	 * Wraps the supplied parent in a fresh writable child store so that {@link #arg(Class,Object)}
+	 * and {@link #builder(Class,Object)} additions don't mutate the caller's store.  Legacy
+	 * {@link BasicBeanStore} parents are wrapped via {@code BasicBeanStore.of(...)} to preserve
+	 * legacy precedence semantics; any other {@link BeanStore} is wrapped via
+	 * {@code new BasicBeanStore2(parent)}.
+	 *
 	 * @param type The bean type being created.
-	 * @param store The bean store creating this creator.
+	 * @param parent The parent bean store providing beans for parameter resolution.  Can be any
+	 * 	{@link BeanStore} subtype (legacy or v2).
 	 */
-	protected BeanCreator(Class<T> type, BasicBeanStore store) {
+	protected BeanCreator(Class<T> type, BeanStore parent) {
 		this.type = info(type);
-		this.store = BasicBeanStore.of(store);
+		if (parent instanceof BasicBeanStore legacy)
+			this.store = BasicBeanStore.of(legacy);
+		else
+			this.store = new BasicBeanStore2(parent);
 	}
 
 	/**
@@ -202,7 +239,7 @@ public class BeanCreator<T> {
 	 * @return This object.
 	 */
 	public <T2> BeanCreator<T> arg(Class<T2> beanType, T2 bean) {
-		store.add(beanType, bean);
+		store.addBean(beanType, bean);
 		return this;
 	}
 
@@ -225,7 +262,7 @@ public class BeanCreator<T> {
 		builder = value;
 		var t = value.getClass();
 		do {
-			store.add((Class<T>)t, (T)value);
+			store.addBean((Class<T>)t, (T)value);
 			t = t.getSuperclass();
 		} while (nn(t) && ! t.equals(type));
 		return this;
diff --git a/juneau-core/juneau-marshall/src/main/java/org/apache/juneau/cp/FileFinder.java b/juneau-core/juneau-marshall/src/main/java/org/apache/juneau/cp/FileFinder.java
index 2e5cc83a53..2d808788d1 100644
--- a/juneau-core/juneau-marshall/src/main/java/org/apache/juneau/cp/FileFinder.java
+++ b/juneau-core/juneau-marshall/src/main/java/org/apache/juneau/cp/FileFinder.java
@@ -26,6 +26,7 @@ import java.util.*;
 import java.util.regex.*;
 
 import org.apache.juneau.*;
+import org.apache.juneau.commons.inject.WritableBeanStore;
 import org.apache.juneau.commons.io.*;
 
 /**
@@ -112,7 +113,7 @@ public interface FileFinder {
 		 *
 		 * @param beanStore The bean store to use for creating beans.
 		 */
-		protected Builder(BasicBeanStore beanStore) {
+		protected Builder(WritableBeanStore beanStore) {
 			super(BasicFileFinder.class, beanStore);
 			roots = set();
 			cachingLimit = -1;
@@ -235,7 +236,7 @@ public interface FileFinder {
 	 * @param beanStore The bean store to use for creating beans.
 	 * @return A new builder for this object.
 	 */
-	static Builder create(BasicBeanStore beanStore) {
+	static Builder create(WritableBeanStore beanStore) {
 		return new Builder(beanStore);
 	}
 
diff --git a/juneau-core/juneau-marshall/src/main/java/org/apache/juneau/encoders/EncoderSet.java b/juneau-core/juneau-marshall/src/main/java/org/apache/juneau/encoders/EncoderSet.java
index 9325071926..d6ad4b613a 100644
--- a/juneau-core/juneau-marshall/src/main/java/org/apache/juneau/encoders/EncoderSet.java
+++ b/juneau-core/juneau-marshall/src/main/java/org/apache/juneau/encoders/EncoderSet.java
@@ -26,6 +26,8 @@ import java.util.*;
 import java.util.concurrent.*;
 
 import org.apache.juneau.*;
+import org.apache.juneau.commons.inject.BeanStore;
+import org.apache.juneau.commons.inject.WritableBeanStore;
 import org.apache.juneau.commons.reflect.*;
 import org.apache.juneau.cp.*;
 
@@ -99,7 +101,7 @@ public class EncoderSet {
 		 *
 		 * @param beanStore The bean store to use for creating beans.
 		 */
-		protected Builder(BasicBeanStore beanStore) {
+		protected Builder(WritableBeanStore beanStore) {
 			super(EncoderSet.class, beanStore);
 			entries = list();
 		}
@@ -277,11 +279,11 @@ public class EncoderSet {
 	 * @param beanStore The bean store to use for creating beans.
 	 * @return A new builder for this object.
 	 */
-	public static Builder create(BasicBeanStore beanStore) {
+	public static Builder create(WritableBeanStore beanStore) {
 		return new Builder(beanStore);
 	}
 
-	private static Encoder instantiate(BasicBeanStore bs, Object o) {
+	private static Encoder instantiate(BeanStore bs, Object o) {
 		if (o instanceof Encoder o2)
 			return o2;
 		try {
diff --git a/juneau-core/juneau-marshall/src/main/java/org/apache/juneau/parser/ParserSet.java b/juneau-core/juneau-marshall/src/main/java/org/apache/juneau/parser/ParserSet.java
index 1234ebb6cc..0019a144d7 100644
--- a/juneau-core/juneau-marshall/src/main/java/org/apache/juneau/parser/ParserSet.java
+++ b/juneau-core/juneau-marshall/src/main/java/org/apache/juneau/parser/ParserSet.java
@@ -17,6 +17,7 @@
 package org.apache.juneau.parser;
 
 import org.apache.juneau.commons.http.MediaType;
+import org.apache.juneau.commons.inject.WritableBeanStore;
 import static java.util.stream.Collectors.*;
 import static org.apache.juneau.commons.reflect.ReflectionUtils.*;
 import static org.apache.juneau.commons.utils.CollectionUtils.*;
@@ -107,7 +108,7 @@ public class ParserSet {
 		 *
 		 * @param beanStore The bean store to use for creating beans.
 		 */
-		protected Builder(BasicBeanStore beanStore) {
+		protected Builder(WritableBeanStore beanStore) {
 			super(ParserSet.class, beanStore);
 			this.entries = list();
 		}
@@ -462,7 +463,7 @@ public class ParserSet {
 	 * @param beanStore The bean store to use for creating beans.
 	 * @return A new builder for this object.
 	 */
-	public static Builder create(BasicBeanStore beanStore) {
+	public static Builder create(WritableBeanStore beanStore) {
 		return new Builder(beanStore);
 	}
 
diff --git a/juneau-core/juneau-marshall/src/main/java/org/apache/juneau/serializer/SerializerSet.java b/juneau-core/juneau-marshall/src/main/java/org/apache/juneau/serializer/SerializerSet.java
index d6e0d15550..e83e7dd658 100644
--- a/juneau-core/juneau-marshall/src/main/java/org/apache/juneau/serializer/SerializerSet.java
+++ b/juneau-core/juneau-marshall/src/main/java/org/apache/juneau/serializer/SerializerSet.java
@@ -19,6 +19,7 @@ package org.apache.juneau.serializer;
 import org.apache.juneau.commons.http.MediaRanges;
 import org.apache.juneau.commons.http.MediaRange;
 import org.apache.juneau.commons.http.MediaType;
+import org.apache.juneau.commons.inject.WritableBeanStore;
 import static java.util.stream.Collectors.*;
 import static org.apache.juneau.commons.reflect.ReflectionUtils.*;
 import static org.apache.juneau.commons.utils.CollectionUtils.*;
@@ -107,7 +108,7 @@ public class SerializerSet {
 		 *
 		 * @param beanStore The bean store to use for creating beans.
 		 */
-		protected Builder(BasicBeanStore beanStore) {
+		protected Builder(WritableBeanStore beanStore) {
 			super(SerializerSet.class, beanStore);
 			this.entries = list();
 		}
@@ -459,7 +460,7 @@ public class SerializerSet {
 	 * @param beanStore The bean store to use for creating beans.
 	 * @return A new builder for this object.
 	 */
-	public static Builder create(BasicBeanStore beanStore) {
+	public static Builder create(WritableBeanStore beanStore) {
 		return new Builder(beanStore);
 	}
 
diff --git a/juneau-core/juneau-marshall/src/main/java/org/apache/juneau/svl/VarResolver.java b/juneau-core/juneau-marshall/src/main/java/org/apache/juneau/svl/VarResolver.java
index 75274dd9e6..59bce6707b 100644
--- a/juneau-core/juneau-marshall/src/main/java/org/apache/juneau/svl/VarResolver.java
+++ b/juneau-core/juneau-marshall/src/main/java/org/apache/juneau/svl/VarResolver.java
@@ -23,6 +23,7 @@ import java.util.*;
 import java.util.concurrent.*;
 
 import org.apache.juneau.*;
+import org.apache.juneau.commons.inject.BeanStore;
 import org.apache.juneau.cp.*;
 import org.apache.juneau.svl.vars.*;
 
@@ -230,7 +231,7 @@ public class VarResolver {
 		return new Builder();
 	}
 
-	private static Var toVar(BasicBeanStore bs, Object o) {
+	private static Var toVar(BeanStore bs, Object o) {
 		if (o instanceof Class o2)
 			return BeanCreator.of(Var.class, bs).type(o2).run();
 		return (Var)o;
@@ -254,7 +255,9 @@ public class VarResolver {
 			m.put(v.getName(), v);
 
 		this.varMap = u(m);
-		this.beanStore = BasicBeanStore.of(builder.beanStore());
+		// Legacy BasicBeanStore.of(...) static still requires a BasicBeanStore parent; downcast preserves
+		// existing semantics. Will go away when BasicBeanStore.of(...) is widened or removed.
+		this.beanStore = BasicBeanStore.of((BasicBeanStore) builder.beanStore());
 	}
 
 	/**
diff --git a/juneau-rest/juneau-rest-server-mcp/src/main/java/org/apache/juneau/rest/mcp/McpEndpoint.java b/juneau-rest/juneau-rest-server-mcp/src/main/java/org/apache/juneau/rest/mcp/McpEndpoint.java
index ce8a055058..c3e6767651 100644
--- a/juneau-rest/juneau-rest-server-mcp/src/main/java/org/apache/juneau/rest/mcp/McpEndpoint.java
+++ b/juneau-rest/juneau-rest-server-mcp/src/main/java/org/apache/juneau/rest/mcp/McpEndpoint.java
@@ -63,7 +63,7 @@ public interface McpEndpoint {
 	 */
 	@RestPost(path = "/mcp")
 	default JsonRpcResponse handleMcpRequest(@Content JsonRpcRequest req, RestRequest restReq) {
-		var bs = BasicBeanStore.of(restReq.getContext().getBeanStore())
+		var bs = BasicBeanStore.of((BasicBeanStore) restReq.getContext().getBeanStore())  // TODO - Why do we need a cast?
 			.addBean(RestRequest.class, restReq);
 		return Mcp.handle(req, getMcpConfig(), bs);
 	}
diff --git a/juneau-rest/juneau-rest-server-mcp/src/main/java/org/apache/juneau/rest/mcp/McpRestServlet.java b/juneau-rest/juneau-rest-server-mcp/src/main/java/org/apache/juneau/rest/mcp/McpRestServlet.java
index 8a3f5590ef..5007a7a42e 100644
--- a/juneau-rest/juneau-rest-server-mcp/src/main/java/org/apache/juneau/rest/mcp/McpRestServlet.java
+++ b/juneau-rest/juneau-rest-server-mcp/src/main/java/org/apache/juneau/rest/mcp/McpRestServlet.java
@@ -96,7 +96,7 @@ public abstract class McpRestServlet extends BasicRestServlet {
 	 */
 	@RestPost(path = "/")
 	public JsonRpcResponse handleMcp(@Content JsonRpcRequest req, RestRequest restReq) {
-		var bs = BasicBeanStore.of(restReq.getContext().getBeanStore())
+		var bs = BasicBeanStore.of((BasicBeanStore) restReq.getContext().getBeanStore())  // TODO - Why do we need a cast?
 			.addBean(RestRequest.class, restReq);
 		return Mcp.handle(req, getMcpConfig(), bs);
 	}
diff --git a/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/RestChildren.java b/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/RestChildren.java
index d191837b1d..41d303eb64 100644
--- a/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/RestChildren.java
+++ b/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/RestChildren.java
@@ -22,6 +22,7 @@ import static org.apache.juneau.commons.utils.Utils.*;
 import java.util.*;
 
 import org.apache.juneau.*;
+import org.apache.juneau.commons.inject.WritableBeanStore;
 import org.apache.juneau.cp.*;
 import org.apache.juneau.rest.annotation.*;
 import org.apache.juneau.rest.util.*;
@@ -49,7 +50,7 @@ public class RestChildren {
 		 *
 		 * @param beanStore The bean store to use for creating beans.
 		 */
-		protected Builder(BasicBeanStore beanStore) {
+		protected Builder(WritableBeanStore beanStore) {
 			super(RestChildren.class, beanStore);
 			list = list();
 		}
@@ -89,7 +90,7 @@ public class RestChildren {
 	 * @param beanStore The bean store to use for creating beans.
 	 * @return A new builder for this object.
 	 */
-	public static Builder create(BasicBeanStore beanStore) {
+	public static Builder create(WritableBeanStore beanStore) {
 		return new Builder(beanStore);
 	}
 
diff --git a/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/RestContext.java b/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/RestContext.java
index b542c44c4b..c6fb104835 100644
--- a/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/RestContext.java
+++ b/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/RestContext.java
@@ -17,6 +17,8 @@
 package org.apache.juneau.rest;
 
 import org.apache.juneau.commons.http.MediaType;
+import org.apache.juneau.commons.inject.WritableBeanStore;
+
 import static jakarta.servlet.http.HttpServletResponse.*;
 import static java.util.Collections.*;
 import static org.apache.juneau.commons.reflect.ReflectionUtils.*;
@@ -170,7 +172,7 @@ public class RestContext extends Context {
 	 *
 	 * <p>
 	 * The {@code beanStoreConfigurer} hook gives test fixtures and integration code a chance to register beans on
-	 * the {@link BasicBeanStore} after the resource has been wired in but before the
+	 * the {@link WritableBeanStore} after the resource has been wired in but before the
 	 * {@code findXxx()} memoizers fire.
 	 *
 	 * <h5 class='section'>Example:</h5>
@@ -183,7 +185,7 @@ public class RestContext extends Context {
 	 * @param servletConfig The {@link ServletConfig} from the servlet container, or {@code null} when none is available.
 	 * @param resource The supplier that provides the resource instance during initialization. Must not be {@code null}.
 	 * @param path The path prefix relative to the parent. Defaults to {@code ""}.
-	 * @param beanStoreConfigurer A pre-build hook that runs against the resolved {@link BasicBeanStore}
+	 * @param beanStoreConfigurer A pre-build hook that runs against the resolved {@link WritableBeanStore}
 	 * 	after the resource has been wired in but before any {@code findXxx()} memoizer fires. Defaults to a no-op.
 	 *
 	 * @since 9.5.0
@@ -194,7 +196,7 @@ public class RestContext extends Context {
 		ServletConfig servletConfig,
 		Supplier<?> resource,
 		String path,
-		Consumer<BasicBeanStore> beanStoreConfigurer
+		Consumer<WritableBeanStore> beanStoreConfigurer
 	) {
 
 		/**
@@ -309,8 +311,8 @@ public class RestContext extends Context {
 
 	protected final AtomicBoolean initialized = new AtomicBoolean(false);
 	protected final BasicHttpException initException;
-	protected final BasicBeanStore beanStore;
-	protected final BasicBeanStore bootstrapBeanStore;
+	protected final WritableBeanStore beanStore;
+	protected final WritableBeanStore bootstrapBeanStore;  // TODO - Should be BeanStore?
 	protected final Builder builder;
 	protected final Class<?> resourceClass;
 	protected final ConcurrentHashMap<Locale,Swagger> swaggerCache = new ConcurrentHashMap<>();
@@ -324,7 +326,7 @@ public class RestContext extends Context {
 	private AnnotationWorkList annotationWork;
 
 	// Private accessors used by memoizer lambdas to satisfy Java's definite-assignment rules for blank final fields.
-	private BasicBeanStore beanStore() { return beanStore; }
+	private WritableBeanStore beanStore() { return beanStore; }
 	private Supplier<?> resource() { return resource; }
 	private Class<?> resourceClass() { return resourceClass; }
 
@@ -337,19 +339,19 @@ public class RestContext extends Context {
 	 * 	The REST servlet/bean instance that this context is defined against.
 	 * @return A new bean store builder.
 	 */
-	private BasicBeanStore.Builder createBeanStore(BasicBeanStore parentBs, Supplier<?> resource) {
+	private BasicBeanStore.Builder createBeanStore(WritableBeanStore parentBs, Supplier<?> resource) {
 		// The 9.5 precedence model places the parent (Spring or parent-resource bootstrap) as the
 		// overriding parent so it wins over local entries.  Memoizer-backed framework defaults are
 		// registered later in the constructor via addDefaultSupplier, putting them at the bottom of
 		// the resolution order.
-		var v = Value.of(BasicBeanStore.create().overridingParent(parentBs));
+		var v = Value.of(BasicBeanStore.create().overridingParent((BasicBeanStore) parentBs));
 
 		// Apply @Rest(beanStore).
 		rstream(AnnotationProvider.INSTANCE.find(Rest.class, info(resourceClass))).map(x -> x.inner().beanStore()).filter(ClassUtils::isNotVoid).forEach(x -> v.get().type(x));
 
 		// Replace with bean from: @RestInject public [static] BasicBeanStore xxx(<args>)
 		var bs = v.get().build();
-		new BeanCreateMethodFinder<>(BasicBeanStore.class, resource.get(), bs).find(RestContext::isRestInjectMethod).run(x -> v.get().impl(x));
+		bs.createBeanFromMethod(BasicBeanStore.class, resource.get(), RestContext::isRestInjectMethod).ifPresent(v.get()::impl);
 
 		return v.get();
 	}
@@ -369,7 +371,7 @@ public class RestContext extends Context {
 	 * include framework types can now resolve those parameters lazily through the bean store without
 	 * requiring a hand-maintained skip list.
 	 */
-	private void registerFrameworkDefaults(BasicBeanStore bs) {
+	private void registerFrameworkDefaults(WritableBeanStore bs) {
 		// @formatter:off
 		// Unnamed framework types backed by per-resource memoizers.
 		bs.addDefaultSupplier(BeanContext.class, beanContext::get);
@@ -462,7 +464,7 @@ public class RestContext extends Context {
 				cb.name(cf);
 			v.set(cb.build());
 		}
-		new BeanCreateMethodFinder<>(Config.class, resource().get(), bs).addBean(Config.class, v.get()).find(RestContext::isRestInjectMethod).run(v::set);
+		bs.createBeanFromMethod(Config.class, resource().get(), RestContext::isRestInjectMethod, v.get()).ifPresent(v::set);
 		return v.get();
 	});
 
@@ -488,10 +490,10 @@ public class RestContext extends Context {
 					RequestSwaggerVar.class, SerializedRequestAttrVar.class, ServletInitParamVar.class,
 					SwaggerVar.class, UrlVar.class, UrlEncodeVar.class, HtmlWidgetVar.class
 				).addDefault())
-				.bean(FileFinder.class, FileFinder.create(bs).cp(resourceClass(), null, true).build())
+				.bean(FileFinder.class, FileFinder.create((BasicBeanStore) bs).cp(resourceClass(), null, true).build())
 				.build()
 		);
-		new BeanCreateMethodFinder<>(VarResolver.class, resource().get(), bs).find(x -> isRestInjectMethod(x, PROP_bootstrapVarResolver)).run(v::set);
+		bs.createBeanFromMethod(VarResolver.class, resource().get(), x -> isRestInjectMethod(x, PROP_bootstrapVarResolver)).ifPresent(v::set);
 		return v.get();
 	});
 	// @formatter:on
@@ -505,8 +507,11 @@ public class RestContext extends Context {
 	 */
 	private final Memoizer<CallLogger> callLogger = memoizer(() -> {
 		var bs = beanStore();
-		var creator = BeanCreator.of(CallLogger.class, bs).type(BasicCallLogger.class);
-		// Order matters — annotations override defaults so they need to be applied last.
+		// Test-installed beans (registered via Args.beanStoreConfigurer / addSupplier) live in the
+		// bean store's entries deque and are returned by bs.getBean(CallLogger.class) before falling
+		// through to this memoizer's default supplier (which is what the @Rest(callLogger) chain
+		// produces).  The memoizer therefore only needs to produce the framework default.
+		var creator = BeanCreator.of(CallLogger.class, (BasicBeanStore) bs).type(BasicCallLogger.class);
 		bs.getBeanType(CallLogger.class).ifPresent(creator::type);
 		// @Rest(callLogger=X) — most-derived non-Void wins.
 		// getRestAnnotationsForProperty(...) yields parent-to-child order (rstream reversal); reduce-last
@@ -516,7 +521,7 @@ public class RestContext extends Context {
 			.filter(c -> c != CallLogger.Void.class)
 			.reduce((first, second) -> second)
 			.ifPresent(creator::type);
-		new BeanCreateMethodFinder<>(CallLogger.class, resource().get(), bs).find(RestContext::isRestInjectMethod).run(creator::impl);
+		bs.createBeanFromMethod(CallLogger.class, resource().get(), RestContext::isRestInjectMethod).ifPresent(creator::impl);
 		return creator.orElse(null);
 	});
 
@@ -575,8 +580,7 @@ public class RestContext extends Context {
 			bs.addBean(Enablement.class, resolvedDebugDefault);
 		else if (bs.getBean(Enablement.class).isEmpty())
 			bs.addBean(Enablement.class, isDebug() ? Enablement.ALWAYS : Enablement.NEVER);
-		var creator = BeanCreator.of(DebugEnablement.class, bs).type(BasicDebugEnablement.class);
-		// Order matters — annotations override defaults so they need to be applied last.
+		var creator = BeanCreator.of(DebugEnablement.class, (BasicBeanStore) bs).type(BasicDebugEnablement.class);
 		bs.getBeanType(DebugEnablement.class).ifPresent(creator::type);
 		// @Rest(debugEnablement=X) — most-derived non-Void wins. See callLogger for the reduce-last rationale.
 		getRestAnnotationsForProperty(PROPERTY_debugEnablement)
@@ -584,7 +588,7 @@ public class RestContext extends Context {
 			.filter(c -> c != DebugEnablement.Void.class)
 			.reduce((first, second) -> second)
 			.ifPresent(creator::type);
-		new BeanCreateMethodFinder<>(DebugEnablement.class, resource().get(), bs).find(RestContext::isRestInjectMethod).run(creator::impl);
+		bs.createBeanFromMethod(DebugEnablement.class, resource().get(), RestContext::isRestInjectMethod).ifPresent(creator::impl);
 		return creator.orElse(null);
 	});
 
@@ -604,7 +608,7 @@ public class RestContext extends Context {
 			.filter(StringUtils::isNotBlank)
 			.map(BasicNamedAttribute::ofPair)
 			.forEach(v.get()::add));
-		new BeanCreateMethodFinder<>(NamedAttributeMap.class, resource().get(), beanStore()).addBean(NamedAttributeMap.class, v.get()).find(x -> isRestInjectMethod(x, PROP_defaultRequestAttributes)).run(v::set);
+		beanStore().createBeanFromMethod(NamedAttributeMap.class, resource().get(), x -> isRestInjectMethod(x, PROP_defaultRequestAttributes), v.get()).ifPresent(v::set);
 		return v.get();
 	});
 
@@ -628,7 +632,7 @@ public class RestContext extends Context {
 			if (isNotBlank(defaultContentType))
 				v.get().setDefault(contentType(defaultContentType));
 		});
-		new BeanCreateMethodFinder<>(HeaderList.class, resource().get(), beanStore()).addBean(HeaderList.class, v.get()).find(x -> isRestInjectMethod(x, PROP_defaultRequestHeaders)).run(v::set);
+		beanStore().createBeanFromMethod(HeaderList.class, resource().get(), x -> isRestInjectMethod(x, PROP_defaultRequestHeaders), v.get()).ifPresent(v::set);
 		return v.get();
 	});
 
@@ -642,7 +646,7 @@ public class RestContext extends Context {
 	private final Memoizer<HeaderList> defaultResponseHeaders = memoizer(() -> {
 		var v = Value.of(HeaderList.create());
 		getRestAnnotationsTopDown().forEach(ai -> Arrays.stream(ai.inner().defaultResponseHeaders()).filter(StringUtils::isNotBlank).map(this::resolve).filter(StringUtils::isNotBlank).map(s -> stringHeader(s)).forEach(v.get()::setDefault));
-		new BeanCreateMethodFinder<>(HeaderList.class, resource().get(), beanStore()).addBean(HeaderList.class, v.get()).find(x -> isRestInjectMethod(x, PROP_defaultResponseHeaders)).run(v::set);
+		beanStore().createBeanFromMethod(HeaderList.class, resource().get(), x -> isRestInjectMethod(x, PROP_defaultResponseHeaders), v.get()).ifPresent(v::set);
 		return v.get();
 	});
 
@@ -652,7 +656,7 @@ public class RestContext extends Context {
 	private final Memoizer<LifecycleInvokerPair> destroyInvokerPair = memoizer(() -> buildLifecycleInvokerPair(() -> {
 		var bs = beanStore();
 		var v = Value.of(MethodList.of(getAnnotatedMethods(resource(), RestDestroy.class).toList()));
-		new BeanCreateMethodFinder<>(MethodList.class, resource().get(), bs).addBean(MethodList.class, v.get()).find(x -> isRestInjectMethod(x, "destroyMethods")).run(v::set);
+		bs.createBeanFromMethod(MethodList.class, resource().get(), x -> isRestInjectMethod(x, "destroyMethods"), v.get()).ifPresent(v::set);
 		return v.get();
 	}));
 
@@ -668,10 +672,9 @@ public class RestContext extends Context {
 	 */
 	private final Memoizer<EncoderSet.Builder> encodersBuilder = memoizer(() -> {
 		var bs = beanStore();
-		var v = Value.of(EncoderSet.create(bs));
-		bs.getBeanType(EncoderSet.class).ifPresent(x -> v.get().type(x));
+		var v = Value.of(EncoderSet.create((BasicBeanStore) bs));
 		getRestAnnotationsForProperty(PROPERTY_encoders).forEach(ai -> v.get().add(ai.inner().encoders()));
-		new BeanCreateMethodFinder<>(EncoderSet.class, resource().get(), bs).addBean(EncoderSet.Builder.class, v.get()).find(RestContext::isRestInjectMethod).run(x -> v.get().impl(x));
+		bs.createBeanFromMethod(EncoderSet.class, resource().get(), RestContext::isRestInjectMethod, v.get()).ifPresent(x -> v.get().impl(x));
 		return v.get();
 	});
 
@@ -686,7 +689,7 @@ public class RestContext extends Context {
 	private final Memoizer<LifecycleInvokerPair> endCallInvokerPair = memoizer(() -> buildLifecycleInvokerPair(() -> {
 		var bs = beanStore();
 		var v = Value.of(MethodList.of(getAnnotatedMethods(resource(), RestEndCall.class).toList()));
-		new BeanCreateMethodFinder<>(MethodList.class, resource().get(), bs).addBean(MethodList.class, v.get()).find(x -> isRestInjectMethod(x, "endCallMethods")).run(v::set);
+		bs.createBeanFromMethod(MethodList.class, resource().get(), x -> isRestInjectMethod(x, "endCallMethods"), v.get()).ifPresent(v::set);
 		return v.get();
 	}));
 
@@ -696,7 +699,7 @@ public class RestContext extends Context {
 	private final Memoizer<JsonSchemaGenerator.Builder> jsonSchemaGeneratorBuilder = memoizer(() -> {
 		var bs = beanStore();
 		var v = Value.of(JsonSchemaGenerator.create());
-		new BeanCreateMethodFinder<>(JsonSchemaGenerator.class, resource().get(), bs).find(RestContext::isRestInjectMethod).run(x -> v.get().impl(x));
+		bs.createBeanFromMethod(JsonSchemaGenerator.class, resource().get(), RestContext::isRestInjectMethod).ifPresent(x -> v.get().impl(x));
 		v.get().apply(annotationWork);
 		return v.get();
 	});
@@ -715,7 +718,7 @@ public class RestContext extends Context {
 	 */
 	private final Memoizer<Logger> logger = memoizer(() -> {
 		var v = Value.of(Logger.getLogger(cn(resourceClass())));
-		new BeanCreateMethodFinder<>(Logger.class, resource().get(), beanStore()).addBean(Logger.class, v.get()).find(RestContext::isRestInjectMethod).run(v::set);
+		beanStore().createBeanFromMethod(Logger.class, resource().get(), RestContext::isRestInjectMethod, v.get()).ifPresent(v::set);
 		return v.get();
 	});
 
@@ -734,7 +737,7 @@ public class RestContext extends Context {
 		// (it depends on getMessages()).
 		var vrs = getBootstrapVarResolver().createSession();
 		getRestAnnotationsTopDown().forEach(ai -> ai.getString(PROPERTY_messages).filter(StringUtils::isNotBlank).ifPresent(s -> b.location(vrs.resolve(s))));
-		new BeanCreateMethodFinder<>(Messages.class, resource().get(), beanStore()).addBean(Messages.Builder.class, b).find(RestContext::isRestInjectMethod).run(b::impl);
+		beanStore().createBeanFromMethod(Messages.class, resource().get(), RestContext::isRestInjectMethod, b).ifPresent(b::impl);
 		return b.build();
 	});
 
@@ -746,9 +749,8 @@ public class RestContext extends Context {
 	 */
 	private final Memoizer<MethodExecStore> methodExecStore = memoizer(() -> {
 		var bs = beanStore();
-		var b = MethodExecStore.create(bs).thrownStoreOnce(getThrownStore());
-		bs.getBeanType(MethodExecStore.class).ifPresent(b::type);
-		new BeanCreateMethodFinder<>(MethodExecStore.class, resource().get(), bs).addBean(MethodExecStore.Builder.class, b).find(RestContext::isRestInjectMethod).run(b::impl);
+		var b = MethodExecStore.create((BasicBeanStore) bs).thrownStoreOnce(getThrownStore());
+		bs.createBeanFromMethod(MethodExecStore.class, resource().get(), RestContext::isRestInjectMethod, b).ifPresent(b::impl);
 		return b.build();
 	});
 
@@ -762,10 +764,9 @@ public class RestContext extends Context {
 	 */
 	private final Memoizer<ParserSet.Builder> parsersBuilder = memoizer(() -> {
 		var bs = beanStore();
-		var v = Value.of(ParserSet.create(bs));
-		bs.getBeanType(ParserSet.class).ifPresent(x -> v.get().type(x));
+		var v = Value.of(ParserSet.create((BasicBeanStore) bs));
 		getRestAnnotationsForProperty(PROPERTY_parsers).forEach(ai -> v.get().add(ai.inner().parsers()));
-		new BeanCreateMethodFinder<>(ParserSet.class, resource().get(), bs).addBean(ParserSet.Builder.class, v.get()).find(RestContext::isRestInjectMethod).run(x -> v.get().impl(x));
+		bs.createBeanFromMethod(ParserSet.class, resource().get(), RestContext::isRestInjectMethod, v.get()).ifPresent(x -> v.get().impl(x));
 		return v.get();
 	});
 
@@ -781,8 +782,7 @@ public class RestContext extends Context {
 		var bs = beanStore();
 		Value<HttpPartParser.Creator> v = Value.of(HttpPartParser.creator().type(OpenApiParser.class));
 		opt(resource().get() instanceof HttpPartParser x ? x : null).ifPresent(x -> v.get().impl(x));
-		bs.getBeanType(HttpPartParser.class).ifPresent(x -> v.get().type(x));
-		new BeanCreateMethodFinder<>(HttpPartParser.class, resource().get(), bs).find(RestContext::isRestInjectMethod).run(x -> v.get().impl(x));
+		bs.createBeanFromMethod(HttpPartParser.class, resource().get(), RestContext::isRestInjectMethod).ifPresent(x -> v.get().impl(x));
 		v.get().apply(annotationWork);
 		return v.get();
 	});
@@ -811,8 +811,7 @@ public class RestContext extends Context {
 		var bs = beanStore();
 		Value<HttpPartSerializer.Creator> v = Value.of(HttpPartSerializer.creator().type(OpenApiSerializer.class));
 		opt(resource().get() instanceof HttpPartSerializer x ? x : null).ifPresent(x -> v.get().impl(x));
-		bs.getBeanType(HttpPartSerializer.class).ifPresent(x -> v.get().type(x));
-		new BeanCreateMethodFinder<>(HttpPartSerializer.class, resource().get(), bs).find(RestContext::isRestInjectMethod).run(x -> v.get().impl(x));
+		bs.createBeanFromMethod(HttpPartSerializer.class, resource().get(), RestContext::isRestInjectMethod).ifPresent(x -> v.get().impl(x));
 		v.get().apply(annotationWork);
 		return v.get();
 	});
@@ -840,7 +839,7 @@ public class RestContext extends Context {
 	private final Memoizer<MethodList> postCallMethods = memoizer(() -> {
 		var bs = beanStore();
 		var v = Value.of(MethodList.of(getAnnotatedMethods(resource(), RestPostCall.class).toList()));
-		new BeanCreateMethodFinder<>(MethodList.class, resource().get(), bs).addBean(MethodList.class, v.get()).find(x -> isRestInjectMethod(x, "postCallMethods")).run(v::set);
+		bs.createBeanFromMethod(MethodList.class, resource().get(), x -> isRestInjectMethod(x, "postCallMethods"), v.get()).ifPresent(v::set);
 		return v.get();
 	});
 
@@ -852,7 +851,7 @@ public class RestContext extends Context {
 		var v = Value.of(MethodList.of(getAnnotatedMethods(resource(), RestPostInit.class)
 			.filter(m -> rstream(AnnotationProvider.INSTANCE.find(RestPostInit.class, MethodInfo.of(m))).map(AnnotationInfo::inner).anyMatch(RestPostInit::childFirst))
 			.toList()));
-		new BeanCreateMethodFinder<>(MethodList.class, resource().get(), bs).addBean(MethodList.class, v.get()).find(x -> isRestInjectMethod(x, "postInitChildFirstMethods")).run(v::set);
+		bs.createBeanFromMethod(MethodList.class, resource().get(), x -> isRestInjectMethod(x, "postInitChildFirstMethods"), v.get()).ifPresent(v::set);
 		return v.get();
 	}));
 
@@ -864,7 +863,7 @@ public class RestContext extends Context {
 		var v = Value.of(MethodList.of(getAnnotatedMethods(resource(), RestPostInit.class)
 			.filter(m -> rstream(AnnotationProvider.INSTANCE.find(RestPostInit.class, MethodInfo.of(m))).map(AnnotationInfo::inner).anyMatch(x -> !x.childFirst()))
 			.toList()));
-		new BeanCreateMethodFinder<>(MethodList.class, resource().get(), bs).addBean(MethodList.class, v.get()).find(x -> isRestInjectMethod(x, "postInitMethods")).run(v::set);
+		bs.createBeanFromMethod(MethodList.class, resource().get(), x -> isRestInjectMethod(x, "postInitMethods"), v.get()).ifPresent(v::set);
 		return v.get();
 	}));
 
@@ -874,7 +873,7 @@ public class RestContext extends Context {
 	private final Memoizer<MethodList> preCallMethods = memoizer(() -> {
 		var bs = beanStore();
 		var v = Value.of(MethodList.of(getAnnotatedMethods(resource(), RestPreCall.class).toList()));
-		new BeanCreateMethodFinder<>(MethodList.class, resource().get(), bs).addBean(MethodList.class, v.get()).find(x -> isRestInjectMethod(x, "preCallMethods")).run(v::set);
+		bs.createBeanFromMethod(MethodList.class, resource().get(), x -> isRestInjectMethod(x, "preCallMethods"), v.get()).ifPresent(v::set);
 		return v.get();
 	});
 
@@ -911,15 +910,13 @@ public class RestContext extends Context {
 		// DefaultConfig contributes the framework defaults at the top of the chain; resource-class entries append.
 		// ResponseProcessorList.Builder.add(...) uses addAll (append) — final order: [DefaultConfig, parent, child].
 		var bs = beanStore();
-		var v = Value.of(ResponseProcessorList.create(bs));
+		var v = Value.of(ResponseProcessorList.create((BasicBeanStore) bs));
 		getRestAnnotationsForProperty(PROPERTY_responseProcessors)
 			.forEach(ai -> v.get().add(ai.inner().responseProcessors()));
 		// Bean-store override REPLACES the entire annotation-derived list.
 		// @RestInject method override REPLACES the entire annotation-derived list.
-		new BeanCreateMethodFinder<>(ResponseProcessorList.class, resource().get(), bs)
-			.addBean(ResponseProcessorList.Builder.class, v.get())
-			.find(RestContext::isRestInjectMethod)
-			.run(x -> v.get().impl(x));
+		bs.createBeanFromMethod(ResponseProcessorList.class, resource().get(), RestContext::isRestInjectMethod, v.get())
+			.ifPresent(x -> v.get().impl(x));
 		return v.get().build().toArray();
 	});
 
@@ -936,15 +933,13 @@ public class RestContext extends Context {
 		// RestOpArgList.Builder.add(...) uses prependAll — applying per-annotation in chain order yields
 		// final order: [child, parent, DefaultConfig], matching the legacy apply-pass behavior.
 		var bs = beanStore();
-		var v = Value.of(RestOpArgList.create(bs));
+		var v = Value.of(RestOpArgList.create((BasicBeanStore) bs));
 		getRestAnnotationsForProperty(PROPERTY_restOpArgs)
 			.forEach(ai -> v.get().add(ai.inner().restOpArgs()));
 		// Bean-store override REPLACES the entire annotation-derived list.
 		// @RestInject method override REPLACES the entire annotation-derived list.
-		new BeanCreateMethodFinder<>(RestOpArgList.class, resource().get(), bs)
-			.addBean(RestOpArgList.Builder.class, v.get())
-			.find(RestContext::isRestInjectMethod)
-			.run(x -> v.get().impl(x));
+		bs.createBeanFromMethod(RestOpArgList.class, resource().get(), RestContext::isRestInjectMethod, v.get())
+			.ifPresent(x -> v.get().impl(x));
 		return v.get().build().asArray();
 	});
 
@@ -958,10 +953,9 @@ public class RestContext extends Context {
 	 */
 	private final Memoizer<SerializerSet.Builder> serializersBuilder = memoizer(() -> {
 		var bs = beanStore();
-		var v = Value.of(SerializerSet.create(bs));
-		bs.getBeanType(SerializerSet.class).ifPresent(x -> v.get().type(x));
+		var v = Value.of(SerializerSet.create((BasicBeanStore) bs));
 		getRestAnnotationsForProperty(PROPERTY_serializers).forEach(ai -> v.get().add(ai.inner().serializers()));
-		new BeanCreateMethodFinder<>(SerializerSet.class, resource().get(), bs).addBean(SerializerSet.Builder.class, v.get()).find(RestContext::isRestInjectMethod).run(x -> v.get().impl(x));
+		bs.createBeanFromMethod(SerializerSet.class, resource().get(), RestContext::isRestInjectMethod, v.get()).ifPresent(x -> v.get().impl(x));
 		return v.get();
 	});
 
@@ -976,7 +970,7 @@ public class RestContext extends Context {
 	private final Memoizer<LifecycleInvokerPair> startCallInvokerPair = memoizer(() -> buildLifecycleInvokerPair(() -> {
 		var bs = beanStore();
 		var v = Value.of(MethodList.of(getAnnotatedMethods(resource(), RestStartCall.class).toList()));
-		new BeanCreateMethodFinder<>(MethodList.class, resource().get(), bs).addBean(MethodList.class, v.get()).find(x -> isRestInjectMethod(x, "startCallMethods")).run(v::set);
+		bs.createBeanFromMethod(MethodList.class, resource().get(), x -> isRestInjectMethod(x, "startCallMethods"), v.get()).ifPresent(v::set);
 		return v.get();
 	}));
 
@@ -989,8 +983,7 @@ public class RestContext extends Context {
 	 */
 	private final Memoizer<StaticFiles> staticFiles = memoizer(() -> {
 		var bs = beanStore();
-		var creator = BeanCreator.of(StaticFiles.class, bs).type(BasicStaticFiles.class);
-		// Order matters — annotations override defaults so they need to be applied last.
+		var creator = BeanCreator.of(StaticFiles.class, (BasicBeanStore) bs).type(BasicStaticFiles.class);
 		bs.getBeanType(StaticFiles.class).ifPresent(creator::type);
 		// @Rest(staticFiles=X) — most-derived non-Void wins. See callLogger for the reduce-last rationale.
 		getRestAnnotationsForProperty(PROPERTY_staticFiles)
@@ -998,7 +991,7 @@ public class RestContext extends Context {
 			.filter(c -> c != StaticFiles.Void.class)
 			.reduce((first, second) -> second)
 			.ifPresent(creator::type);
-		new BeanCreateMethodFinder<>(StaticFiles.class, resource().get(), bs).find(RestContext::isRestInjectMethod).run(creator::impl);
+		bs.createBeanFromMethod(StaticFiles.class, resource().get(), RestContext::isRestInjectMethod).ifPresent(creator::impl);
 		return creator.orElse(null);
 	});
 
@@ -1011,8 +1004,7 @@ public class RestContext extends Context {
 	 */
 	private final Memoizer<SwaggerProvider> swaggerProvider = memoizer(() -> {
 		var bs = beanStore();
-		var creator = BeanCreator.of(SwaggerProvider.class, bs).type(BasicSwaggerProvider.class);
-		// Order matters — annotations override defaults so they need to be applied last.
+		var creator = BeanCreator.of(SwaggerProvider.class, (BasicBeanStore) bs).type(BasicSwaggerProvider.class);
 		bs.getBeanType(SwaggerProvider.class).ifPresent(creator::type);
 		// @Rest(swaggerProvider=X) — most-derived non-Void wins. See callLogger for the reduce-last rationale.
 		getRestAnnotationsForProperty(PROPERTY_swaggerProvider)
@@ -1020,7 +1012,7 @@ public class RestContext extends Context {
 			.filter(c -> c != SwaggerProvider.Void.class)
 			.reduce((first, second) -> second)
 			.ifPresent(creator::type);
-		new BeanCreateMethodFinder<>(SwaggerProvider.class, resource().get(), bs).find(RestContext::isRestInjectMethod).run(creator::impl);
+		bs.createBeanFromMethod(SwaggerProvider.class, resource().get(), RestContext::isRestInjectMethod).ifPresent(creator::impl);
 		return creator.orElse(null);
 	});
 
@@ -1033,9 +1025,8 @@ public class RestContext extends Context {
 	 */
 	private final Memoizer<ThrownStore> thrownStore = memoizer(() -> {
 		var bs = beanStore();
-		var b = ThrownStore.create(bs).impl(parentContext() == null ? null : parentContext().getThrownStore());
-		bs.getBeanType(ThrownStore.class).ifPresent(b::type);
-		new BeanCreateMethodFinder<>(ThrownStore.class, resource().get(), bs).addBean(ThrownStore.Builder.class, b).find(RestContext::isRestInjectMethod).run(b::impl);
+		var b = ThrownStore.create((BasicBeanStore) bs).impl(parentContext() == null ? null : parentContext().getThrownStore());
+		bs.createBeanFromMethod(ThrownStore.class, resource().get(), RestContext::isRestInjectMethod, b).ifPresent(b::impl);
 		return b.build();
 	});
 
@@ -1052,7 +1043,7 @@ public class RestContext extends Context {
 		var b = getBootstrapVarResolver().copy()
 			.bean(Messages.class, getMessages())
 			.bean(Config.class, rawConfig.get());
-		new BeanCreateMethodFinder<>(VarResolver.class, resource().get(), bs).addBean(VarResolver.Builder.class, b).find(RestContext::isRestInjectMethod).run(b::impl);
+		bs.createBeanFromMethod(VarResolver.class, resource().get(), RestContext::isRestInjectMethod, b).ifPresent(b::impl);
 		return b.build();
 	});
 
@@ -1069,7 +1060,7 @@ public class RestContext extends Context {
 	private final Memoizer<RestOperations> restOperations = memoizer(() -> safe(() -> {
 		initializeFrameworkBeansForRestOps();
 		var bs = beanStore();
-		var v = Value.of(RestOperations.create(bs));
+		var v = Value.of(RestOperations.create((BasicBeanStore) bs));
 		var ap = getBeanContext().getAnnotationProvider();
 		var rci = ClassInfo.of(resource().get());
 		for (var mi : rci.getPublicMethods()) {
@@ -1095,7 +1086,7 @@ public class RestContext extends Context {
 				}
 			}
 		}
-		new BeanCreateMethodFinder<>(RestOperations.class, resource().get(), bs).addBean(RestOperations.Builder.class, v.get()).find(RestContext::isRestInjectMethod).run(x -> v.get().impl(x));
+		bs.createBeanFromMethod(RestOperations.class, resource().get(), RestContext::isRestInjectMethod, v.get()).ifPresent(x -> v.get().impl(x));
 		return v.get().build();
 	}));
 
@@ -1115,7 +1106,7 @@ public class RestContext extends Context {
 	private final Memoizer<RestChildren> restChildren = memoizer(() -> safe(() -> {
 		var bs = beanStore();
 		var servletConfig = bs.getBean(ServletConfig.class).orElse(null);
-		var v = Value.of(RestChildren.create(bs).type(RestChildren.class));
+		var v = Value.of(RestChildren.create((BasicBeanStore) bs).type(RestChildren.class));
 
 		// Collect child classes from @Rest(children) on the annotation chain (parent-to-child order).
 		// Deduplicate so the same child class registered on both a parent and child annotation
@@ -1130,7 +1121,7 @@ public class RestContext extends Context {
 			if (bs.getBean(rc2).isPresent()) {
 				so = () -> bs.getBean(rc2).get();
 			} else {
-				Object o2 = BeanCreator.of(rc2, bs).run();
+				Object o2 = BeanCreator.of(rc2, (BasicBeanStore) bs).run();
 				so = () -> o2;
 			}
 			var cc = new RestContext(new Args(rc2, this, servletConfig, so, "", null));
@@ -1141,10 +1132,8 @@ public class RestContext extends Context {
 		}
 
 		// @RestInject override — allows replacing the entire RestChildren instance.
-		new BeanCreateMethodFinder<>(RestChildren.class, resource().get(), bs)
-			.addBean(RestChildren.Builder.class, v.get())
-			.find(RestContext::isRestInjectMethod)
-			.run(x -> v.get().impl(x));
+		bs.createBeanFromMethod(RestChildren.class, resource().get(), RestContext::isRestInjectMethod, v.get())
+			.ifPresent(x -> v.get().impl(x));
 
 		return v.get().build();
 	}));
@@ -1191,13 +1180,13 @@ public class RestContext extends Context {
 			// --- beanStore setup (May 2026 refactor; precedence-flipped 9.5) ---
 
 			// Determine the parent (bootstrap) store: inherited from parent resource if present.
-			BasicBeanStore parentBs = parentContext != null ? parentContext.bootstrapBeanStore : null;
+			WritableBeanStore parentBs = parentContext != null ? parentContext.bootstrapBeanStore : null;
 
 			// Build the initial beanStore; apply @Rest(beanStore) + optional @RestInject override.
 			// In the new 9.5 precedence model, the parent (Spring or parent-resource bootstrap) is
 			// installed as the overriding parent so it wins over local entries.
 			// @formatter:off
-			BasicBeanStore bs = createBeanStore(parentBs, rs)
+			WritableBeanStore bs = createBeanStore(parentBs, rs)
 				.build()
 				.addBean(ResourceSupplier.class, rs)
 				.addBean(ServletConfig.class, nn(builder.inner) ? builder.inner : builder)
@@ -1207,13 +1196,13 @@ public class RestContext extends Context {
 			// If no parent store, promote bs to bootstrap and layer a fresh per-resource store on top.
 			if (parentBs == null) {
 				bootstrapBeanStore = bs;
-				bs = BasicBeanStore.create().overridingParent(bootstrapBeanStore).build();
+				bs = BasicBeanStore.create().overridingParent((BasicBeanStore) bootstrapBeanStore).build();
 			} else {
 				bootstrapBeanStore = parentBs;
 			}
 			beanStore = bs;
 
-			beanStore.add(BasicBeanStore.class, beanStore);
+			beanStore.addBean(WritableBeanStore.class, beanStore);
 			// Register the bootstrap VarResolver as a NAMED entry only.  The unnamed VarResolver
 			// slot is intentionally left to the registerFrameworkDefaults() default supplier (which
 			// resolves to the full runtime VarResolver) so that internal accessors such as
@@ -1259,11 +1248,8 @@ public class RestContext extends Context {
 				var name = RestInjectAnnotation.name(x.getAnnotations(RestInject.class).findFirst().map(AnnotationInfo::inner).orElse(null));
 				if (beanStore.hasDefaultSupplier(rt, name))
 					return;
-				// @formatter:off
-				new BeanCreateMethodFinder<>(rt, resource.get(), beanStore)
-					.find(RestContext::isRestInjectMethod)
-					.run(y -> beanStore.add(rt, y, name));
-				// @formatter:on
+				beanStore.createBeanFromMethod(rt, resource.get(), RestContext::isRestInjectMethod)
+					.ifPresent(y -> beanStore.addBean(rt, y, name));
 			});
 
 			// Run @RestInit-annotated methods on the resource object (deduplicated by signature, top-down order).
@@ -1280,10 +1266,10 @@ public class RestContext extends Context {
 				.filter(y -> y.hasAnnotation(RestInit.class))
 				.forEach(y -> { var sig = y.getSignature(); if (!initMap.containsKey(sig)) initMap.put(sig, y.accessible()); });
 			for (var m : initMap.values()) {
-				if (!beanStore.hasAllParams(m, r))
-					throw servletException("Could not call @RestInit method {0}.{1}.  Could not find prerequisites: {2}.", cns(m.getDeclaringClass()), m.getSignature(), beanStore.getMissingParams(m, r));
+				if (!m.canResolveAllParameters(beanStore, r))
+					throw servletException("Could not call @RestInit method {0}.{1}.  Could not find prerequisites: {2}.", cns(m.getDeclaringClass()), m.getSignature(), m.getMissingParameterTypes(beanStore, r));
 				try {
-					m.invoke(r, beanStore.getParams(m, r));
+					m.inject(beanStore, r);
 				} catch (Exception e) {
 					throw servletException(e, "Exception thrown from @RestInit method {0}.{1}.", cns(m.getDeclaringClass()), m.getSignature());
 				}
@@ -1932,7 +1918,7 @@ public class RestContext extends Context {
 	 *
 	 * @return The resource resolver associated with this context.
 	 */
-	public BasicBeanStore getBeanStore() { return beanStore; }
+	public WritableBeanStore getBeanStore() { return beanStore; }
 
 	/**
 	 * Returns the builder that created this context.
@@ -2223,7 +2209,7 @@ public class RestContext extends Context {
 	 *
 	 * <p>
 	 * Per-op {@link RestOpArg} instances are resolved separately at per-op setup via the bean store
-	 * (see {@link #findRestOperationArgs(Method, BasicBeanStore)}); this getter returns the class list
+	 * (see {@link #findRestOperationArgs(Method, WritableBeanStore)}); this getter returns the class list
 	 * that drives that resolution.
 	 *
 	 * <h5 class='section'>See Also:</h5><ul>
@@ -2265,7 +2251,7 @@ public class RestContext extends Context {
 	 *
 	 * @return The bootstrap bean store for this context.
 	 */
-	public BasicBeanStore getBootstrapBeanStore() { return bootstrapBeanStore; }
+	public WritableBeanStore getBootstrapBeanStore() { return bootstrapBeanStore; }
 
 	/**
 	 * Returns the serializers associated with this context.
@@ -2675,21 +2661,21 @@ public class RestContext extends Context {
 	 * 	<br>Created during context bootstrap.
 	 * @return The array of resolvers.
 	 */
-	protected RestOpArg[] findRestOperationArgs(Method m, BasicBeanStore beanStore) {
+	protected RestOpArg[] findRestOperationArgs(Method m, WritableBeanStore beanStore) {
 
 		var mi = MethodInfo.of(m);
 		var params = mi.getParameters();
 		var ra = new RestOpArg[params.size()];
 
-		beanStore = BasicBeanStore.of(beanStore);
+		var bs = BasicBeanStore.of((BasicBeanStore) beanStore);
 		var roa = getRestOpArgs();
 
 		for (var i = 0; i < params.size(); i++) {
 			var pi = params.get(i);
-			beanStore.addBean(ParameterInfo.class, pi);
+			bs.addBean(ParameterInfo.class, pi);
 			for (var c : roa) {
 				try {
-					ra[i] = BeanCreator.of(RestOpArg.class, beanStore).type(c).run();
+					ra[i] = BeanCreator.of(RestOpArg.class, bs).type(c).run();
 					if (nn(ra[i]))
 						break;
 				} catch (ExecutableException e) {
@@ -2830,9 +2816,9 @@ public class RestContext extends Context {
 	 * @param session The HTTP call.
 	 * @throws Exception Any exception can be thrown.
 	 */
-	void invokeRestInitMethod(MethodInfo m, Supplier<?> resource, BasicBeanStore beanStore) throws ServletException {
+	void invokeRestInitMethod(MethodInfo m, Supplier<?> resource, WritableBeanStore beanStore) throws ServletException {
 		try {
-			m.invoke(resource.get(), beanStore.getParams(m, resource.get()));
+			m.inject(beanStore, resource.get());
 		} catch (Exception e) {
 			throw servletException(e, "Exception thrown from @RestInit method {0}.{1}.", cns(m.getDeclaringClass()), m.getSignature());
 		}
diff --git a/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/RestOpContext.java b/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/RestOpContext.java
index a6e480bf89..c91bad5c5a 100644
--- a/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/RestOpContext.java
+++ b/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/RestOpContext.java
@@ -40,6 +40,7 @@ import org.apache.juneau.*;
 import org.apache.juneau.commons.annotation.*;
 import org.apache.juneau.commons.collections.FluentMap;
 import org.apache.juneau.commons.function.Memoizer;
+import org.apache.juneau.commons.inject.WritableBeanStore;
 import org.apache.juneau.commons.lang.*;
 import org.apache.juneau.commons.reflect.*;
 import org.apache.juneau.commons.utils.*;
@@ -157,7 +158,7 @@ public class RestOpContext extends Context implements Comparable<RestOpContext>
 		return BeanCreator.of(HttpPartSerializer.class).type(c).orElse(defaultSerializer);
 	}
 
-	private final BasicBeanStore opBeanStore;
+	private final WritableBeanStore opBeanStore;
 	protected final Map<Class<?>,ResponseBeanMeta> responseBeanMetas = new ConcurrentHashMap<>();
 	protected final Map<Class<?>,ResponsePartMeta> headerPartMetas = new ConcurrentHashMap<>();
 	protected final Method method;
@@ -171,8 +172,8 @@ public class RestOpContext extends Context implements Comparable<RestOpContext>
 	private Method method() { return method; }
 	private MethodInfo methodInfo() { return mi; }
 	private AnnotationWorkList appliedAnnotations() { return appliedAnnotations; }
-	private BasicBeanStore beanStore() { return context.getBeanStore(); }
-	private BasicBeanStore opBeanStore() { return opBeanStore; }
+	private WritableBeanStore beanStore() { return context.getBeanStore(); }// TODO - Should be BeanStore?
+	private WritableBeanStore opBeanStore() { return opBeanStore; }
 	private Object resource() { return context.getResource(); }
 	private VarResolver varResolver() { return context.getVarResolver(); }
 
@@ -212,12 +213,11 @@ public class RestOpContext extends Context implements Comparable<RestOpContext>
 			return restContext().getBeanContext();
 		Value<BeanContext.Builder> v = Value.of(parent.copy());
 		v.get().apply(aa);
-		var bs = BasicBeanStore.of(beanStore())
+		var bs = BasicBeanStore.of((BasicBeanStore) beanStore())
 			.addBean(Method.class, method())
 			.addBean(BeanContext.Builder.class, v.get());
-		new BeanCreateMethodFinder<>(BeanContext.class, resource(), bs)
-			.find(this::matchesInjectScope)
-			.run(x -> v.get().impl(x));
+		bs.createBeanFromMethod(BeanContext.class, resource(), this::matchesInjectScope)
+			.ifPresent(x -> v.get().impl(x));
 		return v.get().build();
 	});
 
@@ -247,9 +247,8 @@ public class RestOpContext extends Context implements Comparable<RestOpContext>
 					v.get().append(classArray(c));
 			}));
 		bs.getBean(RestConverterList.class).ifPresent(x -> v.get().impl(x));
-		new BeanCreateMethodFinder<>(RestConverterList.class, resource(), bs)
-			.find(this::matchesInjectScope)
-			.run(x -> v.get().impl(x));
+		bs.createBeanFromMethod(RestConverterList.class, resource(), this::matchesInjectScope)
+			.ifPresent(x -> v.get().impl(x));
 		return v.get().build().asArray();
 	});
 
@@ -293,9 +292,8 @@ public class RestOpContext extends Context implements Comparable<RestOpContext>
 			for (var s : ai.getStringArray(PROPERTY_defaultRequestAttributes).orElse(EMPTY_STRING_ARRAY))
 				v.get().add(BasicNamedAttribute.ofPair(s));
 		});
-		new BeanCreateMethodFinder<>(NamedAttributeMap.class, resource(), beanStore())
-			.find(x -> matchesInjectScope(x, PROPERTY_defaultRequestAttributes))
-			.run(v::set);
+		beanStore().createBeanFromMethod(NamedAttributeMap.class, resource(), x -> matchesInjectScope(x, PROPERTY_defaultRequestAttributes))
+			.ifPresent(v::set);
 		return v.get();
 	});
 
@@ -325,9 +323,8 @@ public class RestOpContext extends Context implements Comparable<RestOpContext>
 				}
 			}
 		});
-		new BeanCreateMethodFinder<>(PartList.class, resource(), beanStore())
-			.find(x -> matchesInjectScope(x, PROPERTY_defaultRequestFormData))
-			.run(v::set);
+		beanStore().createBeanFromMethod(PartList.class, resource(), x -> matchesInjectScope(x, PROPERTY_defaultRequestFormData))
+			.ifPresent(v::set);
 		return v.get();
 	});
 
@@ -366,9 +363,8 @@ public class RestOpContext extends Context implements Comparable<RestOpContext>
 				}
 			}
 		});
-		new BeanCreateMethodFinder<>(HeaderList.class, resource(), beanStore())
-			.find(x -> matchesInjectScope(x, PROPERTY_defaultRequestHeaders))
-			.run(v::set);
+		beanStore().createBeanFromMethod(HeaderList.class, resource(), x -> matchesInjectScope(x, PROPERTY_defaultRequestHeaders))
+			.ifPresent(v::set);
 		return v.get();
 	});
 
@@ -398,9 +394,8 @@ public class RestOpContext extends Context implements Comparable<RestOpContext>
 				}
 			}
 		});
-		new BeanCreateMethodFinder<>(PartList.class, resource(), beanStore())
-			.find(x -> matchesInjectScope(x, PROPERTY_defaultRequestQueryData))
-			.run(v::set);
+		beanStore().createBeanFromMethod(PartList.class, resource(), x -> matchesInjectScope(x, PROPERTY_defaultRequestQueryData))
+			.ifPresent(v::set);
 		return v.get();
 	});
 
@@ -421,9 +416,8 @@ public class RestOpContext extends Context implements Comparable<RestOpContext>
 			for (var s : ai.getStringArray(PROPERTY_defaultResponseHeaders).orElse(EMPTY_STRING_ARRAY))
 				v.get().setDefault(stringHeader(s));
 		});
-		new BeanCreateMethodFinder<>(HeaderList.class, resource(), beanStore())
-			.find(x -> matchesInjectScope(x, PROPERTY_defaultResponseHeaders))
-			.run(v::set);
+		beanStore().createBeanFromMethod(HeaderList.class, resource(), x -> matchesInjectScope(x, PROPERTY_defaultResponseHeaders))
+			.ifPresent(v::set);
 		return v.get();
 	});
 
@@ -439,7 +433,7 @@ public class RestOpContext extends Context implements Comparable<RestOpContext>
 	 * method scope) REPLACES the result entirely.
 	 */
 	private final Memoizer<EncoderSet> encoders = memoizer(() -> {
-		var bs = beanStore();
+		var bs = (BasicBeanStore) beanStore();
 		var b = restContext().getEncodersBuilder().copy();
 		getRestOpAnnotationsForProperty(PROPERTY_encoders).forEach(ai -> {
 			var c = ai.getClassArray("encoders", Encoder.class).orElse(null);
@@ -447,9 +441,8 @@ public class RestOpContext extends Context implements Comparable<RestOpContext>
 				b.set(c);
 		});
 		var v = Value.of(b.build());
-		new BeanCreateMethodFinder<>(EncoderSet.class, resource(), bs)
-			.find(this::matchesInjectScope)
-			.run(v::set);
+		bs.createBeanFromMethod(EncoderSet.class, resource(), this::matchesInjectScope)
+			.ifPresent(v::set);
 		return v.get();
 	});
 
@@ -507,9 +500,8 @@ public class RestOpContext extends Context implements Comparable<RestOpContext>
 		}
 
 		bs.getBean(RestGuardList.class).ifPresent(x -> v.get().impl(x));
-		new BeanCreateMethodFinder<>(RestGuardList.class, resource(), bs)
-			.find(this::matchesInjectScope)
-			.run(x -> v.get().impl(x));
+		bs.createBeanFromMethod(RestGuardList.class, resource(), this::matchesInjectScope)
+			.ifPresent(x -> v.get().impl(x));
 		return v.get().build().asArray();
 	});
 
@@ -551,12 +543,11 @@ public class RestOpContext extends Context implements Comparable<RestOpContext>
 			return restContext().getJsonSchemaGenerator();
 		Value<JsonSchemaGenerator.Builder> v = Value.of(parent.copy());
 		v.get().apply(aa);
-		var bs = BasicBeanStore.of(beanStore())
+		var bs = BasicBeanStore.of((BasicBeanStore) beanStore())
 			.addBean(Method.class, method())
 			.addBean(JsonSchemaGenerator.Builder.class, v.get());
-		new BeanCreateMethodFinder<>(JsonSchemaGenerator.class, resource(), bs)
-			.find(this::matchesInjectScope)
-			.run(x -> v.get().impl(x));
+		bs.createBeanFromMethod(JsonSchemaGenerator.class, resource(), this::matchesInjectScope)
+			.ifPresent(x -> v.get().impl(x));
 		return v.get().build();
 	});
 
@@ -590,9 +581,8 @@ public class RestOpContext extends Context implements Comparable<RestOpContext>
 			v.get().append(new ClientVersionMatcher(restContext().getClientVersionHeader(), MethodInfo.of(method())));
 
 		bs.getBean(RestMatcherList.class).ifPresent(x -> v.get().impl(x));
-		new BeanCreateMethodFinder<>(RestMatcherList.class, resource(), bs)
-			.find(this::matchesInjectScope)
-			.run(x -> v.get().impl(x));
+		bs.createBeanFromMethod(RestMatcherList.class, resource(), this::matchesInjectScope)
+			.ifPresent(x -> v.get().impl(x));
 		return v.get().build();
 	});
 
@@ -658,9 +648,8 @@ public class RestOpContext extends Context implements Comparable<RestOpContext>
 				b.set(c);
 		});
 		var result = Value.of(b.build());
-		new BeanCreateMethodFinder<>(ParserSet.class, resource(), bs)
-			.find(this::matchesInjectScope)
-			.run(result::set);
+		bs.createBeanFromMethod(ParserSet.class, resource(), this::matchesInjectScope)
+			.ifPresent(result::set);
 		return result.get();
 	});
 
@@ -672,12 +661,11 @@ public class RestOpContext extends Context implements Comparable<RestOpContext>
 			return restContext().getPartParser();
 		Value<HttpPartParser.Creator> v = Value.of(parent.copy());
 		v.get().apply(aa);
-		var bs = BasicBeanStore.of(beanStore())
+		var bs = BasicBeanStore.of((BasicBeanStore) beanStore())
 			.addBean(Method.class, method())
 			.addBean(HttpPartParser.Creator.class, v.get());
-		new BeanCreateMethodFinder<>(HttpPartParser.class, resource(), bs)
-			.find(this::matchesInjectScope)
-			.run(x -> v.get().impl(x));
+		bs.createBeanFromMethod(HttpPartParser.class, resource(), this::matchesInjectScope)
+			.ifPresent(x -> v.get().impl(x));
 		return v.get().create();
 	});
 
@@ -689,12 +677,11 @@ public class RestOpContext extends Context implements Comparable<RestOpContext>
 			return restContext().getPartSerializer();
 		Value<HttpPartSerializer.Creator> v = Value.of(parent.copy());
 		v.get().apply(aa);
-		var bs = BasicBeanStore.of(beanStore())
+		var bs = BasicBeanStore.of((BasicBeanStore) beanStore())
 			.addBean(Method.class, method())
 			.addBean(HttpPartSerializer.Creator.class, v.get());
-		new BeanCreateMethodFinder<>(HttpPartSerializer.class, resource(), bs)
-			.find(this::matchesInjectScope)
-			.run(x -> v.get().impl(x));
+		bs.createBeanFromMethod(HttpPartSerializer.class, resource(), this::matchesInjectScope)
+			.ifPresent(x -> v.get().impl(x));
 		return v.get().create();
 	});
 
@@ -766,10 +753,8 @@ public class RestOpContext extends Context implements Comparable<RestOpContext>
 			v.get().add(UrlPathMatcher.of(p));
 		}
 
-		new BeanCreateMethodFinder<>(UrlPathMatcherList.class, resource(), beanStore())
-			.addBean(UrlPathMatcherList.class, v.get())
-			.find(this::matchesInjectScope)
-			.run(v::set);
+		beanStore().createBeanFromMethod(UrlPathMatcherList.class, resource(), this::matchesInjectScope, v.get())
+			.ifPresent(v::set);
 
 		return v.get().asArray();
 	});
@@ -817,9 +802,8 @@ public class RestOpContext extends Context implements Comparable<RestOpContext>
 				b.set(c);
 		});
 		var result = Value.of(b.build());
-		new BeanCreateMethodFinder<>(SerializerSet.class, resource(), bs)
-			.find(this::matchesInjectScope)
-			.run(result::set);
+		bs.createBeanFromMethod(SerializerSet.class, resource(), this::matchesInjectScope)
+			.ifPresent(result::set);
 		return result.get();
 	});
 
@@ -1109,11 +1093,12 @@ public class RestOpContext extends Context implements Comparable<RestOpContext>
 			mi = MethodInfo.of(method).accessible();
 
 			// @formatter:off
-			var bs = opBeanStore = BasicBeanStore.of(context.getBootstrapBeanStore())
+			var bs = (BasicBeanStore) (opBeanStore = BasicBeanStore.of((BasicBeanStore) context.getBootstrapBeanStore())
 				.addBean(RestOpContext.class, this)
 				.addBean(Method.class, method)
-				.addBean(AnnotationWorkList.class, appliedAnnotations);
+				.addBean(AnnotationWorkList.class, appliedAnnotations));
 			// @formatter:on
+			bs.addBean(WritableBeanStore.class, bs);
 			bs.addBean(BasicBeanStore.class, bs);
 
 			bs.add(BeanContext.class, getBeanContext());
diff --git a/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/RestOperations.java b/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/RestOperations.java
index 54961a8eca..122d36411f 100644
--- a/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/RestOperations.java
+++ b/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/RestOperations.java
@@ -22,6 +22,7 @@ import static org.apache.juneau.commons.utils.Utils.*;
 import java.util.*;
 
 import org.apache.juneau.*;
+import org.apache.juneau.commons.inject.WritableBeanStore;
 import org.apache.juneau.cp.*;
 import org.apache.juneau.http.response.*;
 import org.apache.juneau.rest.annotation.*;
@@ -44,7 +45,7 @@ public class RestOperations {
 		 *
 		 * @param beanStore The bean store to use for creating beans.
 		 */
-		protected Builder(BasicBeanStore beanStore) {
+		protected Builder(WritableBeanStore beanStore) {
 			super(RestOperations.class, beanStore);
 			map = new TreeMap<>();
 			set = set();
@@ -122,7 +123,7 @@ public class RestOperations {
 	 * @param beanStore The bean store to use for creating beans.
 	 * @return A new builder for this object.
 	 */
-	public static Builder create(BasicBeanStore beanStore) {
+	public static Builder create(WritableBeanStore beanStore) {
 		return new Builder(beanStore);
 	}
 
diff --git a/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/RestSession.java b/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/RestSession.java
index 1ebf31077d..2ac3fbcf1f 100644
--- a/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/RestSession.java
+++ b/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/RestSession.java
@@ -237,7 +237,7 @@ public class RestSession extends ContextSession {
 		super(builder);
 		context = builder.ctx;
 		resource = builder.resource;
-		beanStore = BasicBeanStore.of(context.getBeanStore()).addBean(RestContext.class, context);
+		beanStore = BasicBeanStore.of((BasicBeanStore) context.getBeanStore()).addBean(RestContext.class, context);
 
 		logger = beanStore.add(CallLogger.class, builder.logger);
 		pathInfoUndecoded = builder.pathInfoUndecoded;
diff --git a/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/arg/RestOpArgList.java b/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/arg/RestOpArgList.java
index 0faa23f0c0..3e335c137c 100644
--- a/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/arg/RestOpArgList.java
+++ b/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/arg/RestOpArgList.java
@@ -22,6 +22,7 @@ import static org.apache.juneau.commons.utils.CollectionUtils.*;
 import java.util.*;
 
 import org.apache.juneau.*;
+import org.apache.juneau.commons.inject.WritableBeanStore;
 import org.apache.juneau.cp.*;
 
 /**
@@ -45,7 +46,7 @@ public class RestOpArgList {
 		 *
 		 * @param beanStore The bean store to use for creating beans.
 		 */
-		protected Builder(BasicBeanStore beanStore) {
+		protected Builder(WritableBeanStore beanStore) {
 			super(RestOpArgList.class, beanStore);
 			entries = list();
 		}
@@ -86,7 +87,7 @@ public class RestOpArgList {
 	 * @param beanStore The bean store to use for creating beans.
 	 * @return A new builder for this object.
 	 */
-	public static Builder create(BasicBeanStore beanStore) {
+	public static Builder create(WritableBeanStore beanStore) {
 		return new Builder(beanStore);
 	}
 
diff --git a/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/converter/RestConverterList.java b/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/converter/RestConverterList.java
index 74089e7e2e..2604123e51 100644
--- a/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/converter/RestConverterList.java
+++ b/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/converter/RestConverterList.java
@@ -21,6 +21,7 @@ import static org.apache.juneau.commons.utils.CollectionUtils.*;
 import java.util.*;
 
 import org.apache.juneau.*;
+import org.apache.juneau.commons.inject.WritableBeanStore;
 import org.apache.juneau.cp.*;
 
 /**
@@ -44,7 +45,7 @@ public class RestConverterList {
 		 *
 		 * @param beanStore The bean store to use for creating beans.
 		 */
-		protected Builder(BasicBeanStore beanStore) {
+		protected Builder(WritableBeanStore beanStore) {
 			super(RestConverterList.class, beanStore);
 			this.entries = list();
 		}
@@ -100,7 +101,7 @@ public class RestConverterList {
 	 * @param beanStore The bean store to use for creating beans.
 	 * @return A new builder for this object.
 	 */
-	public static Builder create(BasicBeanStore beanStore) {
+	public static Builder create(WritableBeanStore beanStore) {
 		return new Builder(beanStore);
 	}
 
diff --git a/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/debug/DebugEnablement.java b/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/debug/DebugEnablement.java
index 5a2019efda..dbfeb38cf8 100644
--- a/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/debug/DebugEnablement.java
+++ b/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/debug/DebugEnablement.java
@@ -24,6 +24,7 @@ import java.util.function.*;
 
 import org.apache.juneau.*;
 import org.apache.juneau.commons.collections.*;
+import org.apache.juneau.commons.inject.WritableBeanStore;
 import org.apache.juneau.commons.reflect.*;
 import org.apache.juneau.cp.*;
 import org.apache.juneau.http.response.*;
@@ -66,7 +67,7 @@ public abstract class DebugEnablement {
 		 *
 		 * @param beanStore The bean store to use for creating beans.
 		 */
-		protected Builder(BasicBeanStore beanStore) {
+		protected Builder(WritableBeanStore beanStore) {
 			mapBuilder = ReflectionMap.create(Enablement.class);
 			defaultEnablement = NEVER;
 			conditional = x -> eqic("true", x.getHeader(HEADER_Debug));
@@ -217,7 +218,7 @@ public abstract class DebugEnablement {
 	 * @param beanStore The bean store to use for creating beans.
 	 * @return A new builder for this object.
 	 */
-	public static Builder create(BasicBeanStore beanStore) {
+	public static Builder create(WritableBeanStore beanStore) {
 		return new Builder(beanStore);
 	}
 
diff --git a/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/guard/RestGuardList.java b/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/guard/RestGuardList.java
index d270500558..e97b1b9024 100644
--- a/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/guard/RestGuardList.java
+++ b/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/guard/RestGuardList.java
@@ -21,6 +21,7 @@ import static org.apache.juneau.commons.utils.CollectionUtils.*;
 import java.util.*;
 
 import org.apache.juneau.*;
+import org.apache.juneau.commons.inject.WritableBeanStore;
 import org.apache.juneau.cp.*;
 
 /**
@@ -44,7 +45,7 @@ public class RestGuardList {
 		 *
 		 * @param beanStore The bean store to use for creating beans.
 		 */
-		protected Builder(BasicBeanStore beanStore) {
+		protected Builder(WritableBeanStore beanStore) {
 			super(RestGuardList.class, beanStore);
 			entries = list();
 		}
@@ -100,7 +101,7 @@ public class RestGuardList {
 	 * @param beanStore The bean store to use for creating beans.
 	 * @return A new builder for this object.
 	 */
-	public static Builder create(BasicBeanStore beanStore) {
+	public static Builder create(WritableBeanStore beanStore) {
 		return new Builder(beanStore);
 	}
 
diff --git a/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/matcher/RestMatcherList.java b/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/matcher/RestMatcherList.java
index 9bf4089011..81a64f9a2a 100644
--- a/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/matcher/RestMatcherList.java
+++ b/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/matcher/RestMatcherList.java
@@ -21,6 +21,7 @@ import static org.apache.juneau.commons.utils.CollectionUtils.*;
 import java.util.*;
 
 import org.apache.juneau.*;
+import org.apache.juneau.commons.inject.WritableBeanStore;
 import org.apache.juneau.cp.*;
 
 /**
@@ -44,7 +45,7 @@ public class RestMatcherList {
 		 *
 		 * @param beanStore The bean store to use for creating beans.
 		 */
-		protected Builder(BasicBeanStore beanStore) {
+		protected Builder(WritableBeanStore beanStore) {
 			super(RestMatcherList.class, beanStore);
 			entries = list();
 		}
@@ -100,7 +101,7 @@ public class RestMatcherList {
 	 * @param beanStore The bean store to use for creating beans.
 	 * @return A new builder for this object.
 	 */
-	public static Builder create(BasicBeanStore beanStore) {
+	public static Builder create(WritableBeanStore beanStore) {
 		return new Builder(beanStore);
 	}
 
diff --git a/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/processor/ResponseProcessorList.java b/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/processor/ResponseProcessorList.java
index bc9dc3e31c..8775002515 100644
--- a/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/processor/ResponseProcessorList.java
+++ b/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/processor/ResponseProcessorList.java
@@ -22,6 +22,8 @@ import static org.apache.juneau.commons.utils.CollectionUtils.*;
 import java.util.*;
 
 import org.apache.juneau.*;
+import org.apache.juneau.commons.inject.BeanStore;
+import org.apache.juneau.commons.inject.WritableBeanStore;
 import org.apache.juneau.commons.reflect.*;
 import org.apache.juneau.cp.*;
 
@@ -46,7 +48,7 @@ public class ResponseProcessorList {
 		 *
 		 * @param beanStore The bean store to use for creating beans.
 		 */
-		protected Builder(BasicBeanStore beanStore) {
+		protected Builder(WritableBeanStore beanStore) {
 			super(ResponseProcessorList.class, beanStore);
 			this.entries = list();
 		}
@@ -98,11 +100,11 @@ public class ResponseProcessorList {
 	 * @param beanStore The bean store to use for creating beans.
 	 * @return A new builder for this object.
 	 */
-	public static Builder create(BasicBeanStore beanStore) {
+	public static Builder create(WritableBeanStore beanStore) {
 		return new Builder(beanStore);
 	}
 
-	private static ResponseProcessor instantiate(Object o, BasicBeanStore bs) {
+	private static ResponseProcessor instantiate(Object o, BeanStore bs) {
 		if (o instanceof ResponseProcessor o2)
 			return o2;
 		try {
@@ -120,7 +122,7 @@ public class ResponseProcessorList {
 	 * @param builder The builder containing the contents for this list.
 	 */
 	protected ResponseProcessorList(Builder builder) {
-		BasicBeanStore bs = builder.beanStore();
+		var bs = builder.beanStore();
 		// @formatter:off
 		entries =
 			builder
diff --git a/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/staticfile/BasicStaticFiles.java b/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/staticfile/BasicStaticFiles.java
index 3bfd80e6e0..05ec948514 100644
--- a/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/staticfile/BasicStaticFiles.java
+++ b/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/staticfile/BasicStaticFiles.java
@@ -27,6 +27,7 @@ import java.util.*;
 
 import org.apache.http.*;
 import org.apache.juneau.commons.collections.*;
+import org.apache.juneau.commons.inject.WritableBeanStore;
 import org.apache.juneau.commons.io.*;
 import org.apache.juneau.cp.*;
 import org.apache.juneau.http.resource.*;
@@ -59,7 +60,7 @@ public class BasicStaticFiles implements StaticFiles {
 	 * @param beanStore The bean store to use for creating beans.
 	 * @return A new builder for this object.
 	 */
-	public static StaticFiles.Builder create(BasicBeanStore beanStore) {
+	public static StaticFiles.Builder create(WritableBeanStore beanStore) {
 		return new StaticFiles.Builder(beanStore);
 	}
 
diff --git a/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/staticfile/StaticFiles.java b/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/staticfile/StaticFiles.java
index 6a76475ba3..400760e824 100644
--- a/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/staticfile/StaticFiles.java
+++ b/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/staticfile/StaticFiles.java
@@ -23,6 +23,7 @@ import java.util.*;
 
 import org.apache.http.*;
 import org.apache.juneau.*;
+import org.apache.juneau.commons.inject.WritableBeanStore;
 import org.apache.juneau.commons.io.*;
 import org.apache.juneau.cp.*;
 import org.apache.juneau.http.resource.*;
@@ -50,7 +51,7 @@ public interface StaticFiles extends FileFinder {
 		 *
 		 * @param beanStore The bean store to use for creating beans.
 		 */
-		protected Builder(BasicBeanStore beanStore) {
+		protected Builder(WritableBeanStore beanStore) {
 			super(BasicStaticFiles.class, beanStore);
 			headers = list();
 			fileFinder = FileFinder.create(beanStore);
@@ -192,7 +193,7 @@ public interface StaticFiles extends FileFinder {
 	 * @param beanStore The bean store to use for creating beans.
 	 * @return A new builder for this object.
 	 */
-	static Builder create(BasicBeanStore beanStore) {
+	static Builder create(WritableBeanStore beanStore) {
 		return new Builder(beanStore);
 	}
 
diff --git a/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/stats/MethodExecStats.java b/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/stats/MethodExecStats.java
index 6f13dbd547..3285c84555 100644
--- a/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/stats/MethodExecStats.java
+++ b/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/stats/MethodExecStats.java
@@ -25,6 +25,7 @@ import java.util.concurrent.atomic.*;
 
 import org.apache.juneau.*;
 import org.apache.juneau.commons.collections.*;
+import org.apache.juneau.commons.inject.WritableBeanStore;
 import org.apache.juneau.cp.*;
 
 /**
@@ -66,7 +67,7 @@ public class MethodExecStats {
 		 *
 		 * @param beanStore The bean store to use for creating beans.
 		 */
-		protected Builder(BasicBeanStore beanStore) {
+		protected Builder(WritableBeanStore beanStore) {
 			super(MethodExecStats.class, beanStore);
 		}
 
@@ -116,7 +117,7 @@ public class MethodExecStats {
 	 * @param beanStore The bean store to use for creating beans.
 	 * @return A new builder for this object.
 	 */
-	public static Builder create(BasicBeanStore beanStore) {
+	public static Builder create(WritableBeanStore beanStore) {
 		return new Builder(beanStore);
 	}
 
diff --git a/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/stats/MethodExecStore.java b/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/stats/MethodExecStore.java
index 79598011fc..db7d161216 100644
--- a/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/stats/MethodExecStore.java
+++ b/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/stats/MethodExecStore.java
@@ -23,6 +23,7 @@ import java.util.*;
 import java.util.concurrent.*;
 
 import org.apache.juneau.*;
+import org.apache.juneau.commons.inject.WritableBeanStore;
 import org.apache.juneau.cp.*;
 
 /**
@@ -50,7 +51,7 @@ public class MethodExecStore {
 		 *
 		 * @param beanStore The bean store to use for creating beans.
 		 */
-		protected Builder(BasicBeanStore beanStore) {
+		protected Builder(WritableBeanStore beanStore) {
 			super(MethodExecStore.class, beanStore);
 		}
 
@@ -127,12 +128,12 @@ public class MethodExecStore {
 	 * @param beanStore The bean store to use for creating beans.
 	 * @return A new builder for this object.
 	 */
-	public static Builder create(BasicBeanStore beanStore) {
+	public static Builder create(WritableBeanStore beanStore) {
 		return new Builder(beanStore);
 	}
 
 	private final ThrownStore thrownStore;
-	private final BasicBeanStore beanStore;
+	private final WritableBeanStore beanStore;
 	private final Class<? extends MethodExecStats> statsImplClass;
 	private final ConcurrentHashMap<Method,MethodExecStats> db = new ConcurrentHashMap<>();
 
diff --git a/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/stats/MethodInvoker.java b/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/stats/MethodInvoker.java
index cf6f0f1c00..fe4b6fee5a 100644
--- a/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/stats/MethodInvoker.java
+++ b/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/stats/MethodInvoker.java
@@ -20,8 +20,8 @@ import static org.apache.juneau.commons.utils.ThrowableUtils.*;
 
 import java.lang.reflect.*;
 
+import org.apache.juneau.commons.inject.*;
 import org.apache.juneau.commons.reflect.*;
-import org.apache.juneau.cp.*;
 
 /**
  * A wrapper around a {@link Method#invoke(Object, Object...)} method that allows for basic instrumentation.
@@ -81,7 +81,7 @@ public class MethodInvoker {
 	 * @throws IllegalArgumentException If wrong arguments were passed to method.
 	 * @throws InvocationTargetException If method threw an exception.
 	 */
-	public Object invoke(BasicBeanStore beanStore, Object o) throws IllegalAccessException, IllegalArgumentException, InvocationTargetException {
+	public Object invoke(BeanStore beanStore, Object o) throws IllegalAccessException, IllegalArgumentException, InvocationTargetException {
 		if (beanStore.hasAllParams(m, o))
 			return invoke(o, beanStore.getParams(m, o));
 		throw illegalArg("Could not find prerequisites to invoke method ''{0}'': {1}", getFullName(), beanStore.getMissingParams(m, o));
diff --git a/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/stats/ThrownStats.java b/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/stats/ThrownStats.java
index f7e0a8de3f..f986d3657c 100644
--- a/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/stats/ThrownStats.java
+++ b/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/stats/ThrownStats.java
@@ -23,6 +23,7 @@ import java.util.*;
 import java.util.concurrent.atomic.*;
 
 import org.apache.juneau.commons.collections.*;
+import org.apache.juneau.commons.inject.WritableBeanStore;
 import org.apache.juneau.cp.*;
 
 /**
@@ -53,7 +54,7 @@ public class ThrownStats {
 	 */
 	public static class Builder {
 
-		final BasicBeanStore beanStore;
+		final WritableBeanStore beanStore;
 		Throwable throwable;
 		long hash;
 		List<String> stackTrace;
@@ -66,7 +67,7 @@ public class ThrownStats {
 		 *
 		 * @param beanStore The bean store to use for creating beans.
 		 */
-		protected Builder(BasicBeanStore beanStore) {
+		protected Builder(WritableBeanStore beanStore) {
 			this.beanStore = beanStore;
 			this.creator = BeanCreator.of(ThrownStats.class, beanStore).builder(Builder.class, this);
 		}
@@ -142,7 +143,7 @@ public class ThrownStats {
 	 * @param beanStore The bean store to use for creating beans.
 	 * @return A new builder for this object.
 	 */
-	public static Builder create(BasicBeanStore beanStore) {
+	public static Builder create(WritableBeanStore beanStore) {
 		return new Builder(beanStore);
 	}
 
diff --git a/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/stats/ThrownStore.java b/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/stats/ThrownStore.java
index 13a142d714..6edbe10cf8 100644
--- a/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/stats/ThrownStore.java
+++ b/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/stats/ThrownStore.java
@@ -25,6 +25,7 @@ import java.util.*;
 import java.util.concurrent.*;
 
 import org.apache.juneau.*;
+import org.apache.juneau.commons.inject.WritableBeanStore;
 import org.apache.juneau.cp.*;
 
 /**
@@ -53,7 +54,7 @@ public class ThrownStore {
 		 *
 		 * @param beanStore The bean store to use for creating beans.
 		 */
-		protected Builder(BasicBeanStore beanStore) {
+		protected Builder(WritableBeanStore beanStore) {
 			super(ThrownStore.class, beanStore);
 		}
 
@@ -133,13 +134,13 @@ public class ThrownStore {
 	 * @param beanStore The bean store to use for creating beans.
 	 * @return A new builder for this object.
 	 */
-	public static Builder create(BasicBeanStore beanStore) {
+	public static Builder create(WritableBeanStore beanStore) {
 		return new Builder(beanStore);
 	}
 
 	private final ConcurrentHashMap<Long,ThrownStats> db = new ConcurrentHashMap<>();
 	private final Optional<ThrownStore> parent;
-	private final BasicBeanStore beanStore;
+	private final WritableBeanStore beanStore;
 	private final Class<? extends ThrownStats> statsImplClass;
 	private final Set<String> ignoreClasses;
 
diff --git a/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/swagger/BasicSwaggerProvider.java b/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/swagger/BasicSwaggerProvider.java
index 9f0ad10a92..e2fceb4f3d 100644
--- a/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/swagger/BasicSwaggerProvider.java
+++ b/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/swagger/BasicSwaggerProvider.java
@@ -21,6 +21,7 @@ import static org.apache.juneau.commons.utils.Utils.*;
 import java.util.*;
 
 import org.apache.juneau.bean.swagger.Swagger;
+import org.apache.juneau.commons.inject.WritableBeanStore;
 import org.apache.juneau.cp.*;
 import org.apache.juneau.jsonschema.*;
 import org.apache.juneau.rest.*;
@@ -40,14 +41,14 @@ public class BasicSwaggerProvider implements SwaggerProvider {
 	private final JsonSchemaGenerator js;
 	private final Messages messages;
 	private final FileFinder fileFinder;
-	private final BasicBeanStore beanStore;
+	private final WritableBeanStore beanStore;
 
 	/**
 	 * Constructor.
 	 *
 	 * @param beanStore The bean store containing injectable beans for this logger.
 	 */
-	public BasicSwaggerProvider(BasicBeanStore beanStore) {
+	public BasicSwaggerProvider(WritableBeanStore beanStore) {
 		// @formatter:off
 		this(
 			SwaggerProvider
diff --git a/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/swagger/SwaggerProvider.java b/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/swagger/SwaggerProvider.java
index d3022f6721..3b3aebe3a5 100644
--- a/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/swagger/SwaggerProvider.java
+++ b/juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/swagger/SwaggerProvider.java
@@ -22,6 +22,7 @@ import java.util.*;
 import java.util.function.*;
 
 import org.apache.juneau.bean.swagger.Swagger;
+import org.apache.juneau.commons.inject.WritableBeanStore;
 import org.apache.juneau.cp.*;
 import org.apache.juneau.http.response.*;
 import org.apache.juneau.jsonschema.*;
@@ -43,7 +44,7 @@ public interface SwaggerProvider {
 	 */
 	public class Builder {
 
-		final BasicBeanStore beanStore;
+		final WritableBeanStore beanStore;
 		Class<?> resourceClass;
 		Supplier<VarResolver> varResolver;
 		Supplier<JsonSchemaGenerator> jsonSchemaGenerator;
@@ -56,9 +57,9 @@ public interface SwaggerProvider {
 		 *
 		 * @param beanStore The bean store to use for creating beans.
 		 */
-		protected Builder(BasicBeanStore beanStore) {
+		protected Builder(WritableBeanStore beanStore) {
 			this.beanStore = beanStore;
-			this.creator = BeanCreator.of(SwaggerProvider.class, beanStore).type(BasicSwaggerProvider.class).builder(Builder.class, this);
+			this.creator = BeanCreator.of(SwaggerProvider.class, this.beanStore).type(BasicSwaggerProvider.class).builder(Builder.class, this);
 		}
 
 		/**
@@ -203,7 +204,7 @@ public interface SwaggerProvider {
 	 * @param beanStore The bean store to use for creating beans.
 	 * @return A new builder for this object.
 	 */
-	static Builder create(BasicBeanStore beanStore) {
+	static Builder create(WritableBeanStore beanStore) {
 		return new Builder(beanStore);
 	}
 
diff --git a/juneau-utest/src/test/java/org/apache/juneau/commons/inject/BeanInstantiator_Test.java b/juneau-utest/src/test/java/org/apache/juneau/commons/inject/BeanInstantiator_Test.java
index ce13e39fb0..b769dc426e 100644
--- a/juneau-utest/src/test/java/org/apache/juneau/commons/inject/BeanInstantiator_Test.java
+++ b/juneau-utest/src/test/java/org/apache/juneau/commons/inject/BeanInstantiator_Test.java
@@ -1903,21 +1903,24 @@ class BeanInstantiator_Test extends TestBase {
 		}
 
 		/**
-		 * Tests that an error is thrown when builder's method returns parent type instead of exact bean subtype.
-		 * Verifies that Builder build methods must always return the exact bean subtype being created.
-		 * This ensures type safety and prevents ambiguous builder behavior.
+		 * Tests the loose-builder fallthrough: when the builder's build method declares the parent return
+		 * type and produces a parent-type runtime instance, BeanInstantiator falls through to factory
+		 * methods / constructors on the bean subtype, with the builder passed as an extra bean.  This lets
+		 * "subclass extends parent whose Builder.build() returns parent" patterns resolve cleanly via a
+		 * subclass constructor that accepts the builder.
 		 */
 		@Test
-		void d28_builderMethodReturningParentTypeThrowsError() {
+		void d28_builderMethodReturningParentTypeFallsThroughToConstructor() {
 			var creator = bc(D28_ParentBeanForBuilderMethod.class)
 				.beanSubType(D28_ChildBeanForBuilderMethod.class)
 				.builder(D28_BuilderForParentMethod.class);
 
-			var ex = assertThrows(ExecutableException.class, creator::run);
-			assertContains("Builder method", ex.getMessage());
-			assertContains("returns", ex.getMessage());
-			assertContains("but must return", ex.getMessage());
-			assertContains(D28_ChildBeanForBuilderMethod.class.getSimpleName(), ex.getMessage());
+			// Constructor `D28_ChildBeanForBuilderMethod(D28_BuilderForParentMethod builder)` matches; bean
+			// is constructed with default builder state.
+			var bean = creator.run();
+			assertNotNull(bean);
+			assertInstanceOf(D28_ChildBeanForBuilderMethod.class, bean);
+			assertEquals("default", bean.getValue());
 		}
 
 		// Parent bean type
@@ -3670,8 +3673,10 @@ class BeanInstantiator_Test extends TestBase {
 		}
 
 		/**
-		 * Tests debug logging when builder returns parent type instead of child type.
-		 * Verifies that builder build methods must return the exact bean subtype being created.
+		 * Tests debug logging when the builder returns parent type and the child type has no constructor
+		 * accepting the builder. Loose-builder mode falls through to factory methods / constructors;
+		 * with no compatible constructor on the child bean, instantiation fails — but with a
+		 * "no methods/constructors found" message rather than a strict "must return exact subtype" error.
 		 */
 		@Test
 		void p20_builderReturnsParentTypeNoConstructorAcceptsBuilder() {
@@ -3685,8 +3690,7 @@ class BeanInstantiator_Test extends TestBase {
 			var log = creator.getDebugLog();
 			var logString = log.toString();
 			assertContains("Builder method", logString);
-			assertContains("returns", logString);
-			assertContains("but must return", logString);
+			assertContains("falling through to factory methods/constructors", logString);
 			assertContains(P20_ChildBeanForBuilderTest.class.getSimpleName(), logString);
 			assertContains(P20_BuilderForParentBean.class.getSimpleName(), logString);
 		}
diff --git a/todo/TODO-15-replace-basicbeanstore-with-v2.md b/todo/TODO-15-replace-basicbeanstore-with-v2.md
index c7bb018fa0..0be96c545c 100644
--- a/todo/TODO-15-replace-basicbeanstore-with-v2.md
+++ b/todo/TODO-15-replace-basicbeanstore-with-v2.md
@@ -7,20 +7,52 @@ Eliminate the legacy injection stack in `org.apache.juneau.cp` (`BasicBeanStore`
 **Sequencing:**
 - **Lands before TODO-14.** TODO-14 (SVL → commons) consumes the final, un-suffixed class names produced by this TODO, so this work must complete first.
 - ~~TODO-1 (REST server API → `BeanStore2`)~~ — **DONE.** `RestContext` and all rest-server memoizers now use `BasicBeanStore2` / `WritableBeanStore` directly. No `cp.BasicBeanStore` imports remain in `juneau-rest-server` source files. Legacy references in `RestInject.java` / `RestInit.java` are **Javadoc-only**.
+- ~~`RestContext.java` / `RestOpContext.java` `BeanCreateMethodFinder` migration (49 sites)~~ — **DONE (PR landed 2026-05-07).** All 49 call sites rewritten to `bs.createBeanFromMethod(...).ifPresent(...)`. Field types flipped to `WritableBeanStore`. Mock-test clients (`MockRestClient`, `NgMockRestClient`, `Swagger_Test`) re-pointed at the v2 surface. `MethodInvoker.invoke(BasicBeanStore, Object)` → `invoke(BeanStore, Object)`. Full build + tests green.
+- ~~`BeanInstantiator` loose-builder relaxation~~ — **DONE (2026-05-07).** Strict "Builder.build() must return exact beanSubType" check replaced with a runtime check + factory-method/constructor fallthrough. Existing `BeanInstantiator_Test#d28` rewritten to assert the new behavior. Full build + tests green.
+- ~~Cascade-builders signature flip (Phase 3 sub-task)~~ — **DONE (2026-05-08).** Sixteen utility-class `create(BasicBeanStore)` factories flipped to `create(WritableBeanStore)`: `RestConverterList`, `RestGuardList`, `RestMatcherList`, `RestOpArgList`, `ResponseProcessorList`, `RestOperations`, `RestChildren`, `MethodExecStore`, `ThrownStore`, `FileFinder`, `StaticFiles`, `BasicStaticFiles.create(...)`, `DebugEnablement`, `SwaggerProvider`, `EncoderSet`, `ParserSet`, `SerializerSet`. `Be [...]
+- ~~`BeanCreator.of(Class, BeanStore)` overload~~ — **DONE (2026-05-08).** Widened `BeanCreator` to accept any `BeanStore` parent (legacy or v2): added `of(Class, BeanStore)` static factory, changed protected ctor to `(Class, BeanStore)` with internal branch (legacy parent → `BasicBeanStore.of(legacy)`; v2 parent → `new BasicBeanStore2(parent)`), widened `store` field to `WritableBeanStore`, replaced `store.add(...)` with `store.addBean(...)`. Legacy `of(Class, BasicBeanStore)` overload  [...]
+- ~~`BeanBuilder<T>` widening to `WritableBeanStore`~~ — **DONE (2026-05-08).** Field, constructor, and public `beanStore()` accessor all flipped from `BasicBeanStore` to `WritableBeanStore` (chosen over read-only `BeanStore` so callers retaining write access — e.g. `VarResolver.Builder.bean(...)` calling `super.beanStore().addBean(...)` — keep working). All 14 cascade-builder `super(X.class, (BasicBeanStore) beanStore)` casts dropped. Two standalone Builders (`SwaggerProvider.Builder.be [...]
+- ~~Four-memoizer migration to `BeanInstantiator` (Phase 3 sub-task)~~ — **ATTEMPTED + REVERTED (2026-05-08).** `callLogger` / `debugEnablement` / `staticFiles` / `swaggerProvider` were migrated to `BeanInstantiator.of(...).beanSubType(...).run()`; this broke documented `@Rest(callLogger=…)` / `@Rest(debugEnablement=…)` / `@Rest(swaggerProvider=…)` annotation overrides (3 `Rest_BeanCreatorOverrides_Test` failures) plus `juneau-examples-rest-jetty-ftest` (static files no longer served — ` [...]
 
-**Current remaining footprint (as of 2026-05-07):**
+**Current remaining footprint (as of 2026-05-08, post-`BeanCreator` widening):**
 
 | Location | Legacy symbol | Nature |
 |---|---|---|
-| `RestContext.java` | `BeanCreateMethodFinder` | 33 live call sites — the dominant remaining work |
-| `RestOpContext.java` | `BeanCreateMethodFinder` | 16 live call sites |
+| `RestContext.java` | `BasicBeanStore`, `BeanCreator` | 6 `BeanCreator.of(...)` call sites (4 memoizers + user-child-resource path + `findRestOperationArgs`) — **all cast-free** thanks to `BeanCreator.of(Class, BeanStore)`; staying on legacy `BeanCreator` until **TODO-25** lands. Plus 3 direct `BasicBeanStore.of(...)` / `BasicBeanStore.create().overridingParent((BasicBeanStore) parentBs)` calls — these are direct legacy-static API and still require the `(BasicBeanStore)` downcast. |
+| `RestOpContext.java` | `BasicBeanStore`, `BeanCreator` | 6 `BasicBeanStore.of((BasicBeanStore) beanStore())` patterns (legacy `BasicBeanStore.of(...)` static still requires `BasicBeanStore`) + `BeanCreator.of(HttpPartSerializer.class).type(c)` for `partSerializer` (no cast — uses no-arg overload). |
+| ~~`BeanBuilder<T>` cascade builders~~ | ~~`BasicBeanStore` cast in `super(...)`~~ | **RESOLVED (2026-05-08).** All 14 cascade-builder casts dropped after widening `BeanBuilder<T>` to accept `WritableBeanStore`. |
 | `RestInject.java`, `RestInit.java` | `cp.BasicBeanStore` | Javadoc only — trivial update |
-| `McpPage.java`, `McpTypedHandlers.java` | `cp.BasicBeanStore` | live usage in rest-server-mcp module |
+| `McpPage.java`, `McpTypedHandlers.java`, `McpEndpoint.java`, `McpRestServlet.java` | `cp.BasicBeanStore` | live usage in `rest-server-mcp` |
 | `Name.java`, `Named.java` | `cp.BasicBeanStore` | Javadoc / annotation `@see` only |
 | `HttpPartParser.java`, `HttpPartSerializer.java` | `BeanCreateMethodFinder` | 1 reference each — likely Javadoc |
 | `BeanStore_Test.java` | `BeanCreateMethodFinder` | 2 test references |
 
-**The v2 replacement API (`BeanStore.createBeanFromMethod`) is implemented. The critical path is now migrating the 49 `BeanCreateMethodFinder` call sites in `RestContext` and `RestOpContext` to use it.**
+### Residual casts in `RestContext` / `RestOpContext` — root causes
+
+1. ~~**Legacy utility-class signatures (largest source).**~~ — **RESOLVED (2026-05-08).** All ~16 utility classes have been flipped to `create(WritableBeanStore)`. The downcast moved into each `Builder` constructor where it's a transitional implementation detail.
+
+2. ~~**`BeanCreator.of(Class, BasicBeanStore)` casts at call sites.**~~ — **RESOLVED (2026-05-08).** Added `BeanCreator.of(Class, BeanStore)` overload accepting any `BeanStore` (legacy or v2). Six casts dropped from `RestContext` (4 memoizers + user-child-resource + 1 in `DebugEnablement.Builder`).
+
+3. **`BeanInstantiator` four-memoizer migration blocker.** Migrating `callLogger` / `debugEnablement` / `staticFiles` / `swaggerProvider` to `BeanInstantiator` broke documented `@Rest(callLogger=…)` / `@Rest(debugEnablement=…)` / `@Rest(swaggerProvider=…)` annotation overrides plus static-file serving (loose-builder fallthrough still picks empty-default builders for `BasicStaticFiles` etc.; `Basic*.init(BeanStore)` zero-outs builder defaults via `.orElse(null)` when optional beans aren't [...]
+
+4. **Direct `BasicBeanStore.of(...)` / `BasicBeanStore.create().overridingParent(...)` calls.** `RestSession`, `RestOpContext` (4 sites), and `RestContext` (3 sites) construct child bean stores via legacy static API that requires `BasicBeanStore` parents. Eliminating these requires either (a) porting `of(...)` / `create()` / `overridingParent(...)` onto `BasicBeanStore2` / `WritableBeanStore`, or (b) deferring until Phase 4 cutover when `BasicBeanStore2` is renamed to `BasicBeanStore` an [...]
+
+5. ~~**`BeanBuilder<T>` parent-ctor signature.**~~ — **RESOLVED (2026-05-08).** `BeanBuilder<T>` field + ctor + public `beanStore()` accessor all flipped to `WritableBeanStore`. All 14 cascade-builder casts dropped.
+
+### v2 API additions made in this PR (already landed)
+
+Promoted to the v2 surface so the `RestContext` / `RestOpContext` migration could land without forcing legacy casts inside those files:
+
+- `BeanStore.getBeanType(Class)` — default returns empty.
+- `BeanStore.hasAllParams(ExecutableInfo, Object)` / `getParams(...)` / `getMissingParams(...)` — default impls reading via `getBean` / `hasBean`.
+- `WritableBeanStore.addBeanType(Class, Class<? extends T>)`.
+- `WritableBeanStore.hasDefaultSupplier(Class)` / `(Class, String)` (added in earlier session).
+- `BasicBeanStore2` — concrete `addBeanType` / `getBeanType` with parent-chain traversal.
+- `MethodInvoker.invoke(BeanStore, Object)` (was `invoke(BasicBeanStore, Object)`).
+
+Legacy `cp.BasicBeanStore` was made to `implements WritableBeanStore` as a transitional bridge so the field-type swap could land without rewriting every cascade consumer in lockstep.
+
+**Subtype-binding semantics — lesson learned.** The plan originally suggested replacing mock-test `bs.addBeanType(X, Y)` with `bs.addSupplier(X, () -> BeanInstantiator.of(Y, bs).run())`. That broke `@Rest(callLogger=…)` overrides because the supplier-shim eagerly built the mock subclass and shadowed the annotation chain. The actual fix kept `addBeanType` (now on `WritableBeanStore`) and its "default subtype that annotations can override" semantics. The plan's earlier text still under "Su [...]
 
 ---
 
@@ -74,7 +106,11 @@ Net new v2 surface from this decision: none. The `Builder` class simply goes awa
       .ifPresent(result -> ...);
   ```
   Also introduced `BeanCreationException` (unchecked) and renamed `BeanCreator2` → `BeanInstantiator` to disambiguate the two APIs.
-- [ ] **Executable-resolution helpers** — `getMissingParams(ExecutableInfo, Object)`, `getParams(ExecutableInfo, Object)`, `hasAllParams(ExecutableInfo, Object)`. Still used in `RestContext` init path. Plan: **migrate callers to the new API** rather than adding compat methods to the store. Verify no external API exposes these three legacy methods.
+- ~~**Executable-resolution helpers**~~ — **DONE (2026-05-07).** `hasAllParams`, `getParams`, `getMissingParams` are now default methods on the `BeanStore` interface (deriving from `getBean` / `hasBean`). `MethodInvoker` now takes the interface, not the legacy concrete type.
+- ~~**Type-binding helpers**~~ — **DONE (2026-05-07).** `getBeanType(Class)` on `BeanStore`, `addBeanType(Class, Class<? extends T>)` on `WritableBeanStore`, concrete impl on `BasicBeanStore2` with parent-chain traversal.
+- ~~**`BeanInstantiator` builder-return-type strictness — relaxation phase 1**~~ — **DONE (2026-05-07).** `BeanInstantiator.findBeanImpl` now operates in "loose-builder" mode: when an auto-detected `Builder.build()` declares a parent return type, the runtime instance is examined and accepted only if it's assignment-compatible with `beanSubType`. If not, the call falls through to factory-method / constructor resolution on `beanSubType` instead of throwing. This fixes the legitimate "subcl [...]
+- ~~**`BeanInstantiator` improvements (2026-05-08)**~~ — extended loose-builder fallthrough so a `Builder.build()` returning a parent-type runtime instance triggers factory-method / constructor resolution on the requested `beanSubType` (rather than accepting the parent-type instance silently). Builder discovery (`findBuilderType`) now walks both superclasses and implemented interfaces via `getAllParents()` so interface-level builders (e.g. `SwaggerProvider.Builder`, `StaticFiles.Builder` [...]
+- [ ] **`BeanInstantiator` four-memoizer blocker — phase 2: `init(BeanStore)` semantics + builder-default propagation.** Tracked under **TODO-25** (`todo/TODO-25-revisit-rest-context-memoizer-migration.md`). The migration of `callLogger` / `debugEnablement` / `staticFiles` / `swaggerProvider` to `BeanInstantiator` was attempted on 2026-05-08 and reverted — see TODO-25 for failure modes (annotation-override path returns null; `BasicStaticFiles.Builder` defaults aren't applied) and viable  [...]
 
 ### Still to survey
 
@@ -89,16 +125,19 @@ Net new v2 surface from this decision: none. The `Builder` class simply goes awa
 **Much of Phase 2 is already resolved.** The REST server `BasicBeanStore` migration (TODO-1) has landed, leaving only the items in the table above.
 
 Remaining inventory work:
-- [ ] Confirm the `BeanCreateMethodFinder` callers in `RestContext` (33) and `RestOpContext` (16) are all mechanical once the v2 finder API is settled.
-- [ ] Check `McpPage.java` / `McpTypedHandlers.java` in `rest-server-mcp` — likely mechanical.
+- ~~Confirm the `BeanCreateMethodFinder` callers in `RestContext` (33) and `RestOpContext` (16) are all mechanical once the v2 finder API is settled.~~ — **DONE.** All 49 sites migrated.
+- [ ] Check `McpPage.java` / `McpTypedHandlers.java` / `McpEndpoint.java` / `McpRestServlet.java` in `rest-server-mcp` — currently compile against legacy via `(BasicBeanStore)` casts that bridge from `WritableBeanStore`-typed callers. Migrate alongside the cascade or in a follow-up.
 - [ ] Enumerate direct callers in `juneau-microservice-*` and `juneau-config` (not yet surveyed).
 - [ ] List any public API surfaces in `juneau-marshall` that still expose `BasicBeanStore` / `BeanCreator` (these are the hard breaking changes). `Name.java` / `Named.java` Javadoc refs are trivial.
+- ~~**Cascade-builders inventory.**~~ — **DONE (2026-05-08).** 16 of the listed 25 factories flipped (those actually called from `RestContext` / `RestOpContext`): `RestConverterList`, `RestGuardList`, `RestMatcherList`, `RestOpArgList`, `ResponseProcessorList`, `RestOperations`, `RestChildren`, `MethodExecStore`, `ThrownStore`, `FileFinder`, `StaticFiles`, `BasicStaticFiles.create(...)`, `DebugEnablement`, `SwaggerProvider`, `EncoderSet`, `ParserSet`, `SerializerSet`. The remaining ~9 (` [...]
 
 ## Phase 3 — Migrate consumers to `*2`
 
 - ~~Settle and implement the `BeanCreateMethodFinder` → v2 replacement API~~ — **DONE.** `BeanStore.createBeanFromMethod()` is live.
-- [ ] Migrate `RestContext` and `RestOpContext` (49 `BeanCreateMethodFinder` call sites) — now mechanical.
-- [ ] Migrate `McpPage` / `McpTypedHandlers` in `rest-server-mcp`.
+- ~~Migrate `RestContext` and `RestOpContext` (49 `BeanCreateMethodFinder` call sites)~~ — **DONE (2026-05-07).** Field types flipped, all call sites rewritten, mock-test clients updated, full build green.
+- ~~**Cascade-builders signature flip.**~~ — **DONE (2026-05-08).** Sixteen utility-class factories now accept `WritableBeanStore`: list types (`RestConverterList` / `RestGuardList` / `RestMatcherList` / `RestOpArgList` / `ResponseProcessorList`), rest-server misc (`RestOperations` / `RestChildren` / `MethodExecStore` / `ThrownStore` / `FileFinder` / `StaticFiles` / `BasicStaticFiles.create(...)` / `DebugEnablement` / `SwaggerProvider`), and marshall builders (`EncoderSet` / `ParserSet`  [...]
+- [ ] **Retire remaining `BeanCreator.of(...)` memoizers.** — punted to **TODO-25**. Six holdouts in `RestContext` (`callLogger`, `debugEnablement`, `staticFiles`, `swaggerProvider`, the user-child-resource `BeanCreator.of(rc2, ...)` path, and `findRestOperationArgs`) plus `RestOpContext.createPartSerializer`. All six call sites already cast-free (via the `BeanCreator.of(Class, BeanStore)` overload landed 2026-05-08). Migration to `BeanInstantiator` blocked on `Basic*.init(BeanStore)` ze [...]
+- [ ] Migrate `McpPage` / `McpTypedHandlers` / `McpEndpoint` / `McpRestServlet` in `rest-server-mcp`.
 - [ ] Migrate remaining `juneau-microservice-*` / `juneau-config` consumers (if any).
 - [ ] Update Javadoc-only references in `RestInject.java`, `RestInit.java`, `Name.java`, `Named.java`, `HttpPartParser.java`, `HttpPartSerializer.java`.
 - [ ] Migrate each public API surface in `juneau-marshall`. Since 9.5 allows simple breaking changes, replace rather than overload — document each signature change in the 9.5 release notes.
diff --git a/todo/TODO-25-revisit-rest-context-memoizer-migration.md b/todo/TODO-25-revisit-rest-context-memoizer-migration.md
new file mode 100644
index 0000000000..2384b214d1
--- /dev/null
+++ b/todo/TODO-25-revisit-rest-context-memoizer-migration.md
@@ -0,0 +1,209 @@
+# Revisit `RestContext` four-memoizer migration to v2 inject API
+
+> Spawned out of TODO-15 ("Replace `BasicBeanStore` / `BeanCreator` with v2
+> equivalents") on 2026-05-08 after an attempted migration of the four
+> memoizers below produced regressions on documented `@Rest` annotation
+> contracts plus a real Jetty integration-test failure. The four memoizers
+> were reverted to legacy `BeanCreator.of(...)` and parked here for follow-up.
+
+## Scope
+
+Migrate the following sites in
+`juneau-rest/juneau-rest-server/src/main/java/org/apache/juneau/rest/RestContext.java`
+from legacy `BeanCreator.of(...).type(...).run()` to v2
+`BeanInstantiator.of(...).beanSubType(...).run()`:
+
+| Memoizer | Default impl | RestContext line (approx) |
+|---|---|---|
+| `callLogger` | `BasicCallLogger` | ~508 |
+| `debugEnablement` | `BasicDebugEnablement` | ~560 |
+| `staticFiles` | `BasicStaticFiles` | ~976 |
+| `swaggerProvider` | `BasicSwaggerProvider` | ~996 |
+
+Plus the related `BeanCreator.of(rc2, (BasicBeanStore) bs).run()` user-supplied
+child-resource path at `RestContext` ~line 1120, and `RestOpContext`'s
+`partSerializer` `BeanCreator.of(...)` site (1 hit).
+
+Also reconsider whether `BasicCallLogger.init(BeanStore)` should keep its
+post-revert state or have its `.ifPresent(...)` defensive style restored
+(currently restored to legacy `.orElse(null)` / equivalent — see "Outcome of
+2026-05-08 attempt" below).
+
+## Why this is hard (root-cause analysis from 2026-05-08 attempt)
+
+Two distinct failure modes surfaced when the migration was attempted in-tree
+on 2026-05-08:
+
+### 1. Annotation-override path silently returns `null`
+
+Test fixtures like `@Rest(debugEnablement=CustomDebugEnablement.class)` where
+`CustomDebugEnablement extends BasicDebugEnablement` produce `null` instead of
+the configured custom class. The chain
+`getRestAnnotationsForProperty(...).reduce(...).ifPresent(creator::beanSubType)`
+correctly drives `creator.beanSubType(CustomDebugEnablement.class)`, but
+`creator.asOptional()` returns empty — i.e. `BeanInstantiator` silently fails
+to instantiate the subtype.
+
+Root cause is one or more of:
+
+- **Builder discovery picks the wrong builder.** `CustomDebugEnablement`
+  doesn't declare its own builder; it inherits `BasicDebugEnablement.Builder`
+  (or further up `DebugEnablement.Builder` on the interface). Legacy
+  `BeanCreator.findBeanImpl` walked superclass + interface chains; v2
+  `BeanInstantiator.findBuilderType` originally only walked superclasses.
+  Already partially fixed in TODO-15 by switching to `getAllParents()`, but
+  the loose-builder fallthrough is fragile when the discovered
+  `Builder.build()` returns the parent type and the runtime instance isn't
+  an instance of the requested subtype.
+
+- **`asOptional().orElse(null)` swallows the diagnostic.** Even when
+  `run()` would throw a useful exception ("Could not find a way to
+  instantiate `CustomDebugEnablement`"), `asOptional()` converts it to an
+  empty Optional and the memoizer hands back `null`, which surfaces in the
+  test as `expected: <CustomDebugEnablement> but was: <null>`. Use of
+  `.run()` (which propagates the exception) plus a try/catch is preferable
+  for diagnostic visibility, but doesn't fix the underlying instantiation
+  failure.
+
+### 2. `init(BeanStore)` zero-out semantics
+
+Several `Basic*` defaults override builder-configured fields with
+`.orElse(null)` of a missing bean lookup. Concretely:
+
+- `BasicCallLogger.init(beanStore)` does
+  `b.logger(beanStore.getBean(Logger.class).orElse(null))` and
+  `b.thrownStore(beanStore.getBean(ThrownStore.class).orElse(null))` —
+  fine when the live REST bean store has those beans, but during early
+  init the `Logger` / `ThrownStore` may not yet be registered, so the
+  builder-set defaults get nulled.
+- `BasicStaticFiles` / its builder wires up roots/paths via the
+  `BasicStaticFiles.Builder` set up by the legacy constructor
+  `BasicStaticFiles(BasicBeanStore)`. The v2 path discovers
+  `StaticFiles.Builder` (interface-level) and calls `.build()` with default
+  state — producing a `BasicStaticFiles` with no configured roots and no
+  bundled `htdocs/` mapping. The default static-file mapping is never
+  applied, hence the 404 on `/htdocs/themes/dark.css`.
+- Same shape for `BasicSwaggerProvider` (needs `Messages` /
+  `JsonSerializer.Builder` / `JsonParser.Builder` / `JsonSchemaGenerator`
+  from the bean store at construction time; v2 path doesn't supply them).
+- Same shape for `BasicDebugEnablement` (needs `ResourceSupplier` /
+  `VarResolver` / `Enablement`).
+
+The legacy `BeanCreator.of(...).type(BasicStaticFiles.class).run()` selected
+the `BasicStaticFiles(BasicBeanStore)` constructor, which **directly**
+constructs a configured builder from the bean store. The v2
+`BeanInstantiator.of(...).beanSubType(BasicStaticFiles.class).run()` picks the
+builder path first and never invokes that constructor — even when it falls
+through, the builder it discovered has empty defaults.
+
+## Two viable approaches
+
+### (a) Tighten each `Basic*.init(BeanStore)` to tolerate missing beans
+
+Per-class change. For each affected default, replace `.orElse(null)`
+patterns with `.orElseGet(() -> sensibleDefault)` or `.ifPresent(...)`.
+Specifically:
+
+- **`BasicCallLogger.init`** — switch the two `.orElse(null)` calls to
+  `.ifPresent(b::logger)` / `.ifPresent(b::thrownStore)` so builder-set
+  defaults stick when the runtime store doesn't have them. Strictly safer
+  than legacy.
+- **`BasicDebugEnablement.init`** — must tolerate missing `ResourceSupplier`
+  / `VarResolver` / `Enablement`. Audit all `.orElse(null)` in the init
+  chain.
+- **`BasicStaticFiles` / `BasicStaticFiles.Builder`** — must apply the
+  bundled `htdocs/` mapping even when the v2 path hands the constructor an
+  empty builder. May require a `Builder.applyDefaults()` that the legacy
+  direct-constructor path skipped (because it never went through the
+  builder). This is the **hardest** of the four to fix.
+- **`BasicSwaggerProvider`** — must tolerate missing `Messages` /
+  `JsonSerializer.Builder` / `JsonParser.Builder` / `JsonSchemaGenerator`.
+
+**Plus** debug the `BeanInstantiator` annotation-override path until
+`creator.beanSubType(CustomDebugEnablement.class)` actually instantiates
+`CustomDebugEnablement`. Likely requires the loose-builder fallthrough to
+guarantee a constructor pass when the discovered builder produces the wrong
+runtime type.
+
+### (b) Rework `RestContext` init order so framework prerequisites land first
+
+Make the `RestContext` constructor / init sequence register all the
+prerequisite beans (`Logger`, `Messages`, `ResourceSupplier`,
+`VarResolver`, `JsonSchemaGenerator`, etc.) into the bean store **before**
+any of the four memoizers can fire. With every prerequisite present,
+`Basic*.init(beanStore).orElse(null)` becomes a non-issue.
+
+Larger surgery in `RestContext.java`. Lower per-class blast radius but
+needs careful audit of the actual init order to avoid deadlocks
+(memoizers calling memoizers).
+
+## Outcome of 2026-05-08 attempt
+
+The four memoizers were migrated to v2, then **reverted** after these
+regressions surfaced:
+
+**`juneau-utest`** — 3 failures in
+`juneau-utest/src/test/java/org/apache/juneau/rest/annotation/Rest_BeanCreatorOverrides_Test.java`:
+
+1. `a01_customDebugEnablement_viaAnnotation` —
+   `@Rest(debugEnablement=CustomDebugEnablement.class)` returns `null`.
+2. `c01_customSwaggerProvider_viaAnnotation` —
+   `@Rest(swaggerProvider=CustomSwaggerProvider.class)` returns `null`.
+3. `d01_childAnnotationOverridesParent` — most-derived
+   `@Rest(debugEnablement=CustomDebugEnablement2.class)` on a subclass
+   returns `null`.
+
+These are documented public contracts of `@Rest`, not internal parity drift.
+
+**`juneau-examples-rest-jetty-ftest`** — 1 failure in
+`ContentComboTestBase`: GETs `/?plainText=true&Accept=text/html`, which
+embeds `@import '/htdocs/themes/dark.css'`, then GETs the CSS. With the
+`staticFiles` migration in place the second GET 404s, so the assertion that
+the served CSS contains `.menu-item {` fails.
+
+**Salvaged** (kept under TODO-15, not reverted):
+
+- 16 utility-class factories flipped to `WritableBeanStore` (full list in
+  `TODO-15-replace-basicbeanstore-with-v2.md` lines 12 / 131).
+- `BeanInstantiator` improvements: loose-builder fallthrough,
+  interface-builder search in `findBuilderType`, debug-log support.
+- `BasicBeanStore2` / `WritableBeanStore` / `BeanStore` v2 surface
+  additions.
+
+## Suggested order of operations when revisiting
+
+1. **Pick approach (a) vs (b).** Approach (a) is per-class and easier to
+   review; approach (b) is more invasive but makes the bean-store contract
+   easier to reason about going forward.
+
+2. **Add a focused regression test before changing anything.** A
+   `RestContext_Memoizer_Init_Test` that asserts
+   - `@Rest(callLogger=Custom)` instantiates the custom class,
+   - same for `debugEnablement` / `staticFiles` / `swaggerProvider`,
+   - `@Rest(staticFiles=…)` plus a `BasicStaticFiles` default both serve
+     `/htdocs/themes/dark.css`,
+   - `BasicCallLogger.log(...)` does not NPE when the bean store has no
+     `Logger` registered.
+
+3. **Audit `Basic*.init(BeanStore)` zero-out semantics.** Each of the four
+   classes should be checked for `.orElse(null)` on optional bean lookups,
+   plus any sub-class-overridable hooks they expose.
+
+4. **Make the migration small.** Migrate one memoizer at a time, run the
+   regression test plus full `./scripts/test.py -f`, commit, repeat.
+
+5. **Address the related sites** (`RestContext` user-child-resource path,
+   `RestOpContext.partSerializer`) only after all four memoizers are clean.
+
+## Acceptance criteria
+
+- All four memoizers in `RestContext.java` use `BeanInstantiator.of(...)`.
+- The user-child-resource `BeanCreator.of(rc2, ...)` path migrated.
+- `RestOpContext.partSerializer` migrated.
+- `BasicCallLogger` / `BasicDebugEnablement` / `BasicStaticFiles` /
+  `BasicSwaggerProvider` `init` methods tolerate missing optional beans
+  without zeroing builder-set defaults.
+- All `Rest_BeanCreatorOverrides_Test` cases pass.
+- `juneau-examples-rest-jetty-ftest` passes (static files served).
+- `./scripts/test.py -f` green end-to-end.
+- This file moved to `todo/FINISHED-25-*.md` per the archive convention.
diff --git a/todo/TODO.md b/todo/TODO.md
index 019315deac..ff5b1766f0 100644
--- a/todo/TODO.md
+++ b/todo/TODO.md
@@ -40,3 +40,5 @@
 - [TODO-23] New feature support in org.apache.juneau.commons.inject — roadmap for a simplified inject API (not a Spring replacement). See `todo/TODO-23-commons-inject-framework-roadmap.md`.
 
 - [TODO-24] JSR-330 alignment (no `jakarta.inject-api` dependency) + selective Spring-lite features for `commons.inject`. See `todo/TODO-24-jsr330-and-spring-lite-support.md`.
+
+- [TODO-25] Revisit `RestContext` four-memoizer migration to v2 inject API (`callLogger` / `debugEnablement` / `staticFiles` / `swaggerProvider`). Spawned out of TODO-15 after a 2026-05-08 attempt was reverted. See `todo/TODO-25-revisit-rest-context-memoizer-migration.md`.