diff --git a/packages/client/src/client/open-feature-client.ts b/packages/client/src/client/open-feature-client.ts
index e11fc400..7fb9c52c 100644
--- a/packages/client/src/client/open-feature-client.ts
+++ b/packages/client/src/client/open-feature-client.ts
@@ -6,7 +6,6 @@ import {
   EventHandler,
   FlagValue,
   FlagValueType,
-  Hook,
   HookContext,
   JsonValue,
   Logger,
@@ -22,6 +21,7 @@ import { OpenFeature } from '../open-feature';
 import { Provider } from '../provider';
 import { InternalEventEmitter } from '../events/internal/internal-event-emitter';
 import { Client } from './client';
+import { Hook } from '../hooks';
 
 type OpenFeatureClientOptions = {
   name?: string;
@@ -38,7 +38,7 @@ export class OpenFeatureClient implements Client {
     private readonly providerAccessor: () => Provider,
     private readonly emitterAccessor: () => InternalEventEmitter,
     private readonly globalLogger: () => Logger,
-    private readonly options: OpenFeatureClientOptions
+    private readonly options: OpenFeatureClientOptions,
   ) {}
 
   get metadata(): ClientMetadata {
@@ -76,12 +76,12 @@ export class OpenFeatureClient implements Client {
     return this;
   }
 
-  addHooks(...hooks: Hook<FlagValue>[]): this {
+  addHooks(...hooks: Hook[]): this {
     this._hooks = [...this._hooks, ...hooks];
     return this;
   }
 
-  getHooks(): Hook<FlagValue>[] {
+  getHooks(): Hook[] {
     return this._hooks;
   }
 
@@ -97,7 +97,7 @@ export class OpenFeatureClient implements Client {
   getBooleanDetails(
     flagKey: string,
     defaultValue: boolean,
-    options?: FlagEvaluationOptions
+    options?: FlagEvaluationOptions,
   ): EvaluationDetails<boolean> {
     return this.evaluate<boolean>(flagKey, this._provider.resolveBooleanEvaluation, defaultValue, 'boolean', options);
   }
@@ -109,7 +109,7 @@ export class OpenFeatureClient implements Client {
   getStringDetails<T extends string = string>(
     flagKey: string,
     defaultValue: T,
-    options?: FlagEvaluationOptions
+    options?: FlagEvaluationOptions,
   ): EvaluationDetails<T> {
     return this.evaluate<T>(
       flagKey,
@@ -117,7 +117,7 @@ export class OpenFeatureClient implements Client {
       this._provider.resolveStringEvaluation as () => EvaluationDetails<T>,
       defaultValue,
       'string',
-      options
+      options,
     );
   }
 
@@ -128,7 +128,7 @@ export class OpenFeatureClient implements Client {
   getNumberDetails<T extends number = number>(
     flagKey: string,
     defaultValue: T,
-    options?: FlagEvaluationOptions
+    options?: FlagEvaluationOptions,
   ): EvaluationDetails<T> {
     return this.evaluate<T>(
       flagKey,
@@ -136,14 +136,14 @@ export class OpenFeatureClient implements Client {
       this._provider.resolveNumberEvaluation as () => EvaluationDetails<T>,
       defaultValue,
       'number',
-      options
+      options,
     );
   }
 
   getObjectValue<T extends JsonValue = JsonValue>(
     flagKey: string,
     defaultValue: T,
-    options?: FlagEvaluationOptions
+    options?: FlagEvaluationOptions,
   ): T {
     return this.getObjectDetails(flagKey, defaultValue, options).value;
   }
@@ -151,7 +151,7 @@ export class OpenFeatureClient implements Client {
   getObjectDetails<T extends JsonValue = JsonValue>(
     flagKey: string,
     defaultValue: T,
-    options?: FlagEvaluationOptions
+    options?: FlagEvaluationOptions,
   ): EvaluationDetails<T> {
     return this.evaluate<T>(flagKey, this._provider.resolveObjectEvaluation, defaultValue, 'object', options);
   }
@@ -161,7 +161,7 @@ export class OpenFeatureClient implements Client {
     resolver: (flagKey: string, defaultValue: T, context: EvaluationContext, logger: Logger) => ResolutionDetails<T>,
     defaultValue: T,
     flagType: FlagValueType,
-    options: FlagEvaluationOptions = {}
+    options: FlagEvaluationOptions = {},
   ): EvaluationDetails<T> {
     // merge global, client, and evaluation context
 
@@ -224,26 +224,19 @@ export class OpenFeatureClient implements Client {
   }
 
   private beforeHooks(hooks: Hook[], hookContext: HookContext, options: FlagEvaluationOptions) {
+    Object.freeze(hookContext);
+    Object.freeze(hookContext.context);
+
     for (const hook of hooks) {
-      // freeze the hookContext
-      Object.freeze(hookContext);
-
-      // use Object.assign to avoid modification of frozen hookContext
-      Object.assign(hookContext.context, {
-        ...hookContext.context,
-        ...hook?.before?.(hookContext, Object.freeze(options.hookHints)),
-      });
+      hook?.before?.(hookContext, Object.freeze(options.hookHints));
     }
-
-    // after before hooks, freeze the EvaluationContext.
-    return Object.freeze(hookContext.context);
   }
 
   private afterHooks(
     hooks: Hook[],
     hookContext: HookContext,
     evaluationDetails: EvaluationDetails<FlagValue>,
-    options: FlagEvaluationOptions
+    options: FlagEvaluationOptions,
   ) {
     // run "after" hooks sequentially
     for (const hook of hooks) {
diff --git a/packages/client/src/evaluation/evaluation.ts b/packages/client/src/evaluation/evaluation.ts
index 8555dd53..05078724 100644
--- a/packages/client/src/evaluation/evaluation.ts
+++ b/packages/client/src/evaluation/evaluation.ts
@@ -1,7 +1,7 @@
-import { EvaluationDetails, Hook, HookHints, JsonValue } from '@openfeature/core';
+import { EvaluationDetails, BaseHook, HookHints, JsonValue } from '@openfeature/core';
 
 export interface FlagEvaluationOptions {
-  hooks?: Hook[];
+  hooks?: BaseHook[];
   hookHints?: HookHints;
 }
 
@@ -25,7 +25,7 @@ export interface Features {
   getBooleanDetails(
     flagKey: string,
     defaultValue: boolean,
-    options?: FlagEvaluationOptions
+    options?: FlagEvaluationOptions,
   ): EvaluationDetails<boolean>;
 
   /**
@@ -53,7 +53,7 @@ export interface Features {
   getStringDetails<T extends string = string>(
     flagKey: string,
     defaultValue: T,
-    options?: FlagEvaluationOptions
+    options?: FlagEvaluationOptions,
   ): EvaluationDetails<T>;
 
   /**
@@ -81,7 +81,7 @@ export interface Features {
   getNumberDetails<T extends number = number>(
     flagKey: string,
     defaultValue: T,
-    options?: FlagEvaluationOptions
+    options?: FlagEvaluationOptions,
   ): EvaluationDetails<T>;
 
   /**
@@ -107,12 +107,12 @@ export interface Features {
   getObjectDetails(
     flagKey: string,
     defaultValue: JsonValue,
-    options?: FlagEvaluationOptions
+    options?: FlagEvaluationOptions,
   ): EvaluationDetails<JsonValue>;
 
   getObjectDetails<T extends JsonValue = JsonValue>(
     flagKey: string,
     defaultValue: T,
-    options?: FlagEvaluationOptions
+    options?: FlagEvaluationOptions,
   ): EvaluationDetails<T>;
 }
diff --git a/packages/client/src/hooks/hook.ts b/packages/client/src/hooks/hook.ts
new file mode 100644
index 00000000..e824c149
--- /dev/null
+++ b/packages/client/src/hooks/hook.ts
@@ -0,0 +1,3 @@
+import { BaseHook, FlagValue } from '@openfeature/core';
+
+export type Hook = BaseHook<FlagValue, void, void>;
diff --git a/packages/client/src/hooks/index.ts b/packages/client/src/hooks/index.ts
new file mode 100644
index 00000000..1146a6d5
--- /dev/null
+++ b/packages/client/src/hooks/index.ts
@@ -0,0 +1 @@
+export * from './hook';
diff --git a/packages/client/src/index.ts b/packages/client/src/index.ts
index c6dfb63d..355cd9ce 100644
--- a/packages/client/src/index.ts
+++ b/packages/client/src/index.ts
@@ -3,4 +3,5 @@ export * from './provider';
 export * from './evaluation';
 export * from './open-feature';
 export * from './events';
+export * from './hooks';
 export * from '@openfeature/core';
diff --git a/packages/client/src/open-feature.ts b/packages/client/src/open-feature.ts
index cb27bd93..b2454bf0 100644
--- a/packages/client/src/open-feature.ts
+++ b/packages/client/src/open-feature.ts
@@ -2,6 +2,7 @@ import { EvaluationContext, ManageContext, OpenFeatureCommonAPI } from '@openfea
 import { Client, OpenFeatureClient } from './client';
 import { NOOP_PROVIDER, Provider } from './provider';
 import { OpenFeatureEventEmitter } from './events';
+import { Hook } from './hooks';
 
 // use a symbol as a key for the global singleton
 const GLOBAL_OPENFEATURE_API_KEY = Symbol.for('@openfeature/web-sdk/api');
@@ -11,7 +12,7 @@ type OpenFeatureGlobal = {
 };
 const _globalThis = globalThis as OpenFeatureGlobal;
 
-export class OpenFeatureAPI extends OpenFeatureCommonAPI<Provider> implements ManageContext<Promise<void>> {
+export class OpenFeatureAPI extends OpenFeatureCommonAPI<Provider, Hook> implements ManageContext<Promise<void>> {
   protected _events = new OpenFeatureEventEmitter();
   protected _defaultProvider: Provider = NOOP_PROVIDER;
   protected _createEventEmitter = () => new OpenFeatureEventEmitter();
@@ -49,7 +50,7 @@ export class OpenFeatureAPI extends OpenFeatureCommonAPI<Provider> implements Ma
         } catch (err) {
           this._logger?.error(`Error running context change handler of provider ${provider.metadata.name}:`, err);
         }
-      })
+      }),
     );
   }
 
@@ -75,7 +76,7 @@ export class OpenFeatureAPI extends OpenFeatureCommonAPI<Provider> implements Ma
       () => this.getProviderForClient(name),
       () => this.buildAndCacheEventEmitterForClient(name),
       () => this._logger,
-      { name, version }
+      { name, version },
     );
   }
 
diff --git a/packages/client/src/provider/provider.ts b/packages/client/src/provider/provider.ts
index 16a4bafe..f15b01e6 100644
--- a/packages/client/src/provider/provider.ts
+++ b/packages/client/src/provider/provider.ts
@@ -1,4 +1,5 @@
-import { CommonProvider, EvaluationContext, Hook, JsonValue, Logger, ResolutionDetails } from '@openfeature/core';
+import { CommonProvider, EvaluationContext, JsonValue, Logger, ResolutionDetails } from '@openfeature/core';
+import { Hook } from '../hooks';
 
 /**
  * Interface that providers must implement to resolve flag values for their particular
@@ -30,7 +31,7 @@ export interface Provider extends CommonProvider {
     flagKey: string,
     defaultValue: boolean,
     context: EvaluationContext,
-    logger: Logger
+    logger: Logger,
   ): ResolutionDetails<boolean>;
 
   /**
@@ -40,7 +41,7 @@ export interface Provider extends CommonProvider {
     flagKey: string,
     defaultValue: string,
     context: EvaluationContext,
-    logger: Logger
+    logger: Logger,
   ): ResolutionDetails<string>;
 
   /**
@@ -50,7 +51,7 @@ export interface Provider extends CommonProvider {
     flagKey: string,
     defaultValue: number,
     context: EvaluationContext,
-    logger: Logger
+    logger: Logger,
   ): ResolutionDetails<number>;
 
   /**
@@ -60,6 +61,6 @@ export interface Provider extends CommonProvider {
     flagKey: string,
     defaultValue: T,
     context: EvaluationContext,
-    logger: Logger
+    logger: Logger,
   ): ResolutionDetails<T>;
 }
diff --git a/packages/client/test/hooks.spec.ts b/packages/client/test/hooks.spec.ts
index 7f94f85c..72eeccf0 100644
--- a/packages/client/test/hooks.spec.ts
+++ b/packages/client/test/hooks.spec.ts
@@ -4,9 +4,9 @@ import {
   Client,
   FlagValueType,
   EvaluationContext,
-  Hook,
   GeneralError,
   OpenFeature,
+  Hook,
 } from '../src';
 
 const BOOLEAN_VALUE = true;
@@ -107,27 +107,6 @@ describe('Hooks', () => {
   });
 
   describe('Requirement 4.1.4', () => {
-    describe('before', () => {
-      it('evaluationContext must be mutable', (done) => {
-        client.getBooleanValue(FLAG_KEY, false, {
-          hooks: [
-            {
-              before: (hookContext) => {
-                try {
-                  // evaluation context is mutable in before, so this should work.
-                  hookContext.context.newBeforeProp = 'new!';
-                  expect(hookContext.context.newBeforeProp).toBeTruthy();
-                  done();
-                } catch (err) {
-                  done(err);
-                }
-              },
-            },
-          ],
-        });
-      });
-    });
-
     describe('after', () => {
       it('evaluationContext must be immutable', (done) => {
         client.getBooleanValue(FLAG_KEY, false, {
@@ -151,58 +130,6 @@ describe('Hooks', () => {
     });
   });
 
-  describe('4.3.2', () => {
-    it('"before" must run before flag resolution', async () => {
-      await client.getBooleanValue(FLAG_KEY, false, {
-        hooks: [
-          {
-            before: () => {
-              // add a prop to the context.
-              return { beforeRan: true };
-            },
-          },
-        ],
-      });
-
-      expect(MOCK_PROVIDER.resolveBooleanEvaluation).toHaveBeenCalledWith(
-        expect.anything(),
-        expect.anything(),
-        // ensure property was added by the time the flag resolution occurred.
-        expect.objectContaining({
-          beforeRan: true,
-        }),
-        expect.anything()
-      );
-    });
-  });
-
-  describe('Requirement 4.3.3', () => {
-    it('EvaluationContext must be passed to next "before" hook', (done) => {
-      client.getBooleanValue(FLAG_KEY, false, {
-        hooks: [
-          {
-            before: () => {
-              // add a prop to the context.
-              return { beforeRan: true };
-            },
-          },
-          {
-            before: (hookContext) => {
-              // ensure added prop exists in next hook
-              try {
-                expect(hookContext.context.beforeRan).toBeTruthy();
-                done();
-              } catch (err) {
-                done(err);
-              }
-              return { beforeRan: true };
-            },
-          },
-        ],
-      });
-    });
-  });
-
   describe('Requirement 4.3.5', () => {
     it('"after" must run after flag evaluation', (done) => {
       client.getBooleanValue(FLAG_KEY, false, {
diff --git a/packages/server/src/client/open-feature-client.ts b/packages/server/src/client/open-feature-client.ts
index 9020bbdb..35322269 100644
--- a/packages/server/src/client/open-feature-client.ts
+++ b/packages/server/src/client/open-feature-client.ts
@@ -6,7 +6,6 @@ import {
   EventHandler,
   FlagValue,
   FlagValueType,
-  Hook,
   HookContext,
   JsonValue,
   Logger,
@@ -16,13 +15,14 @@ import {
   ResolutionDetails,
   SafeLogger,
   StandardResolutionReasons,
-  statusMatchesEvent
+  statusMatchesEvent,
 } from '@openfeature/core';
 import { FlagEvaluationOptions } from '../evaluation';
 import { OpenFeature } from '../open-feature';
 import { Provider } from '../provider';
 import { Client } from './client';
 import { InternalEventEmitter } from '../events/internal/internal-event-emitter';
+import { Hook } from '../hooks';
 
 type OpenFeatureClientOptions = {
   name?: string;
@@ -41,7 +41,7 @@ export class OpenFeatureClient implements Client, ManageContext<OpenFeatureClien
     private readonly emitterAccessor: () => InternalEventEmitter,
     private readonly globalLogger: () => Logger,
     private readonly options: OpenFeatureClientOptions,
-    context: EvaluationContext = {}
+    context: EvaluationContext = {},
   ) {
     this._context = context;
   }
@@ -90,12 +90,12 @@ export class OpenFeatureClient implements Client, ManageContext<OpenFeatureClien
     return this._context;
   }
 
-  addHooks(...hooks: Hook<FlagValue>[]): OpenFeatureClient {
+  addHooks(...hooks: Hook[]): OpenFeatureClient {
     this._hooks = [...this._hooks, ...hooks];
     return this;
   }
 
-  getHooks(): Hook<FlagValue>[] {
+  getHooks(): Hook[] {
     return this._hooks;
   }
 
@@ -108,7 +108,7 @@ export class OpenFeatureClient implements Client, ManageContext<OpenFeatureClien
     flagKey: string,
     defaultValue: boolean,
     context?: EvaluationContext,
-    options?: FlagEvaluationOptions
+    options?: FlagEvaluationOptions,
   ): Promise<boolean> {
     return (await this.getBooleanDetails(flagKey, defaultValue, context, options)).value;
   }
@@ -117,7 +117,7 @@ export class OpenFeatureClient implements Client, ManageContext<OpenFeatureClien
     flagKey: string,
     defaultValue: boolean,
     context?: EvaluationContext,
-    options?: FlagEvaluationOptions
+    options?: FlagEvaluationOptions,
   ): Promise<EvaluationDetails<boolean>> {
     return this.evaluate<boolean>(
       flagKey,
@@ -125,7 +125,7 @@ export class OpenFeatureClient implements Client, ManageContext<OpenFeatureClien
       defaultValue,
       'boolean',
       context,
-      options
+      options,
     );
   }
 
@@ -133,7 +133,7 @@ export class OpenFeatureClient implements Client, ManageContext<OpenFeatureClien
     flagKey: string,
     defaultValue: T,
     context?: EvaluationContext,
-    options?: FlagEvaluationOptions
+    options?: FlagEvaluationOptions,
   ): Promise<T> {
     return (await this.getStringDetails<T>(flagKey, defaultValue, context, options)).value;
   }
@@ -142,7 +142,7 @@ export class OpenFeatureClient implements Client, ManageContext<OpenFeatureClien
     flagKey: string,
     defaultValue: T,
     context?: EvaluationContext,
-    options?: FlagEvaluationOptions
+    options?: FlagEvaluationOptions,
   ): Promise<EvaluationDetails<T>> {
     return this.evaluate<T>(
       flagKey,
@@ -151,7 +151,7 @@ export class OpenFeatureClient implements Client, ManageContext<OpenFeatureClien
       defaultValue,
       'string',
       context,
-      options
+      options,
     );
   }
 
@@ -159,7 +159,7 @@ export class OpenFeatureClient implements Client, ManageContext<OpenFeatureClien
     flagKey: string,
     defaultValue: T,
     context?: EvaluationContext,
-    options?: FlagEvaluationOptions
+    options?: FlagEvaluationOptions,
   ): Promise<T> {
     return (await this.getNumberDetails(flagKey, defaultValue, context, options)).value;
   }
@@ -168,7 +168,7 @@ export class OpenFeatureClient implements Client, ManageContext<OpenFeatureClien
     flagKey: string,
     defaultValue: T,
     context?: EvaluationContext,
-    options?: FlagEvaluationOptions
+    options?: FlagEvaluationOptions,
   ): Promise<EvaluationDetails<T>> {
     return this.evaluate<T>(
       flagKey,
@@ -177,7 +177,7 @@ export class OpenFeatureClient implements Client, ManageContext<OpenFeatureClien
       defaultValue,
       'number',
       context,
-      options
+      options,
     );
   }
 
@@ -185,7 +185,7 @@ export class OpenFeatureClient implements Client, ManageContext<OpenFeatureClien
     flagKey: string,
     defaultValue: T,
     context?: EvaluationContext,
-    options?: FlagEvaluationOptions
+    options?: FlagEvaluationOptions,
   ): Promise<T> {
     return (await this.getObjectDetails(flagKey, defaultValue, context, options)).value;
   }
@@ -194,7 +194,7 @@ export class OpenFeatureClient implements Client, ManageContext<OpenFeatureClien
     flagKey: string,
     defaultValue: T,
     context?: EvaluationContext,
-    options?: FlagEvaluationOptions
+    options?: FlagEvaluationOptions,
   ): Promise<EvaluationDetails<T>> {
     return this.evaluate<T>(flagKey, this._provider.resolveObjectEvaluation, defaultValue, 'object', context, options);
   }
@@ -205,12 +205,12 @@ export class OpenFeatureClient implements Client, ManageContext<OpenFeatureClien
       flagKey: string,
       defaultValue: T,
       context: EvaluationContext,
-      logger: Logger
+      logger: Logger,
     ) => Promise<ResolutionDetails<T>>,
     defaultValue: T,
     flagType: FlagValueType,
     invocationContext: EvaluationContext = {},
-    options: FlagEvaluationOptions = {}
+    options: FlagEvaluationOptions = {},
   ): Promise<EvaluationDetails<T>> {
     // merge global, client, and evaluation context
 
@@ -296,7 +296,7 @@ export class OpenFeatureClient implements Client, ManageContext<OpenFeatureClien
     hooks: Hook[],
     hookContext: HookContext,
     evaluationDetails: EvaluationDetails<FlagValue>,
-    options: FlagEvaluationOptions
+    options: FlagEvaluationOptions,
   ) {
     // run "after" hooks sequentially
     for (const hook of hooks) {
diff --git a/packages/server/src/evaluation/evaluation.ts b/packages/server/src/evaluation/evaluation.ts
index 979d7818..70af4bfd 100644
--- a/packages/server/src/evaluation/evaluation.ts
+++ b/packages/server/src/evaluation/evaluation.ts
@@ -1,4 +1,5 @@
-import { EvaluationContext, EvaluationDetails, Hook, HookHints, JsonValue } from '@openfeature/core';
+import { EvaluationContext, EvaluationDetails, HookHints, JsonValue } from '@openfeature/core';
+import { Hook } from '../hooks';
 
 export interface FlagEvaluationOptions {
   hooks?: Hook[];
@@ -18,7 +19,7 @@ export interface Features {
     flagKey: string,
     defaultValue: boolean,
     context?: EvaluationContext,
-    options?: FlagEvaluationOptions
+    options?: FlagEvaluationOptions,
   ): Promise<boolean>;
 
   /**
@@ -33,7 +34,7 @@ export interface Features {
     flagKey: string,
     defaultValue: boolean,
     context?: EvaluationContext,
-    options?: FlagEvaluationOptions
+    options?: FlagEvaluationOptions,
   ): Promise<EvaluationDetails<boolean>>;
 
   /**
@@ -49,14 +50,14 @@ export interface Features {
     flagKey: string,
     defaultValue: string,
     context?: EvaluationContext,
-    options?: FlagEvaluationOptions
+    options?: FlagEvaluationOptions,
   ): Promise<string>;
 
   getStringValue<T extends string = string>(
     flagKey: string,
     defaultValue: T,
     context?: EvaluationContext,
-    options?: FlagEvaluationOptions
+    options?: FlagEvaluationOptions,
   ): Promise<T>;
 
   /**
@@ -72,14 +73,14 @@ export interface Features {
     flagKey: string,
     defaultValue: string,
     context?: EvaluationContext,
-    options?: FlagEvaluationOptions
+    options?: FlagEvaluationOptions,
   ): Promise<EvaluationDetails<string>>;
 
   getStringDetails<T extends string = string>(
     flagKey: string,
     defaultValue: T,
     context?: EvaluationContext,
-    options?: FlagEvaluationOptions
+    options?: FlagEvaluationOptions,
   ): Promise<EvaluationDetails<T>>;
 
   /**
@@ -95,14 +96,14 @@ export interface Features {
     flagKey: string,
     defaultValue: number,
     context?: EvaluationContext,
-    options?: FlagEvaluationOptions
+    options?: FlagEvaluationOptions,
   ): Promise<number>;
 
   getNumberValue<T extends number = number>(
     flagKey: string,
     defaultValue: T,
     context?: EvaluationContext,
-    options?: FlagEvaluationOptions
+    options?: FlagEvaluationOptions,
   ): Promise<T>;
 
   /**
@@ -118,14 +119,14 @@ export interface Features {
     flagKey: string,
     defaultValue: number,
     context?: EvaluationContext,
-    options?: FlagEvaluationOptions
+    options?: FlagEvaluationOptions,
   ): Promise<EvaluationDetails<number>>;
 
   getNumberDetails<T extends number = number>(
     flagKey: string,
     defaultValue: T,
     context?: EvaluationContext,
-    options?: FlagEvaluationOptions
+    options?: FlagEvaluationOptions,
   ): Promise<EvaluationDetails<T>>;
 
   /**
@@ -141,14 +142,14 @@ export interface Features {
     flagKey: string,
     defaultValue: JsonValue,
     context?: EvaluationContext,
-    options?: FlagEvaluationOptions
+    options?: FlagEvaluationOptions,
   ): Promise<JsonValue>;
 
   getObjectValue<T extends JsonValue = JsonValue>(
     flagKey: string,
     defaultValue: T,
     context?: EvaluationContext,
-    options?: FlagEvaluationOptions
+    options?: FlagEvaluationOptions,
   ): Promise<T>;
 
   /**
@@ -164,13 +165,13 @@ export interface Features {
     flagKey: string,
     defaultValue: JsonValue,
     context?: EvaluationContext,
-    options?: FlagEvaluationOptions
+    options?: FlagEvaluationOptions,
   ): Promise<EvaluationDetails<JsonValue>>;
 
   getObjectDetails<T extends JsonValue = JsonValue>(
     flagKey: string,
     defaultValue: T,
     context?: EvaluationContext,
-    options?: FlagEvaluationOptions
+    options?: FlagEvaluationOptions,
   ): Promise<EvaluationDetails<T>>;
 }
diff --git a/packages/server/src/events/index.ts b/packages/server/src/events/index.ts
index 4377e48f..47d1dbc6 100644
--- a/packages/server/src/events/index.ts
+++ b/packages/server/src/events/index.ts
@@ -1 +1 @@
-export * from './open-feature-event-emitter';
\ No newline at end of file
+export * from './open-feature-event-emitter';
diff --git a/packages/server/src/hooks/hook.ts b/packages/server/src/hooks/hook.ts
new file mode 100644
index 00000000..606c2ed0
--- /dev/null
+++ b/packages/server/src/hooks/hook.ts
@@ -0,0 +1,7 @@
+import { BaseHook, EvaluationContext, FlagValue } from '@openfeature/core';
+
+export type Hook = BaseHook<
+  FlagValue,
+  Promise<EvaluationContext | Promise<void>> | EvaluationContext | void,
+  Promise<void> | void
+>;
diff --git a/packages/server/src/hooks/index.ts b/packages/server/src/hooks/index.ts
new file mode 100644
index 00000000..1146a6d5
--- /dev/null
+++ b/packages/server/src/hooks/index.ts
@@ -0,0 +1 @@
+export * from './hook';
diff --git a/packages/server/src/index.ts b/packages/server/src/index.ts
index d76d3dbd..c229d16f 100644
--- a/packages/server/src/index.ts
+++ b/packages/server/src/index.ts
@@ -4,4 +4,5 @@ export * from './evaluation';
 export * from './open-feature';
 export * from './transaction-context';
 export * from './events';
+export * from './hooks';
 export * from '@openfeature/core';
diff --git a/packages/server/src/open-feature.ts b/packages/server/src/open-feature.ts
index cdaa1793..bfcd87cd 100644
--- a/packages/server/src/open-feature.ts
+++ b/packages/server/src/open-feature.ts
@@ -14,6 +14,7 @@ import {
 } from './transaction-context';
 import { Client, OpenFeatureClient } from './client';
 import { OpenFeatureEventEmitter } from './events';
+import { Hook } from './hooks';
 
 // use a symbol as a key for the global singleton
 const GLOBAL_OPENFEATURE_API_KEY = Symbol.for('@openfeature/js-sdk/api');
@@ -24,13 +25,13 @@ type OpenFeatureGlobal = {
 const _globalThis = globalThis as OpenFeatureGlobal;
 
 export class OpenFeatureAPI
-  extends OpenFeatureCommonAPI<Provider>
+  extends OpenFeatureCommonAPI<Provider, Hook>
   implements ManageContext<OpenFeatureAPI>, ManageTransactionContextPropagator<OpenFeatureCommonAPI<Provider>>
 {
   protected _events = new OpenFeatureEventEmitter();
   protected _defaultProvider: Provider = NOOP_PROVIDER;
   protected _createEventEmitter = () => new OpenFeatureEventEmitter();
-  
+
   private _transactionContextPropagator: TransactionContextPropagator = NOOP_TRANSACTION_CONTEXT_PROPAGATOR;
 
   private constructor() {
@@ -100,7 +101,7 @@ export class OpenFeatureAPI
   getClient(
     nameOrContext?: string | EvaluationContext,
     versionOrContext?: string | EvaluationContext,
-    contextOrUndefined?: EvaluationContext
+    contextOrUndefined?: EvaluationContext,
   ): Client {
     const name = stringOrUndefined(nameOrContext);
     const version = stringOrUndefined(versionOrContext);
@@ -114,7 +115,7 @@ export class OpenFeatureAPI
       () => this.buildAndCacheEventEmitterForClient(name),
       () => this._logger,
       { name, version },
-      context
+      context,
     );
   }
 
@@ -127,7 +128,7 @@ export class OpenFeatureAPI
   }
 
   setTransactionContextPropagator(
-    transactionContextPropagator: TransactionContextPropagator
+    transactionContextPropagator: TransactionContextPropagator,
   ): OpenFeatureCommonAPI<Provider> {
     const baseMessage = 'Invalid TransactionContextPropagator, will not be set: ';
     if (typeof transactionContextPropagator?.getTransactionContext !== 'function') {
diff --git a/packages/server/src/provider/provider.ts b/packages/server/src/provider/provider.ts
index 83b23788..6e9ab0ce 100644
--- a/packages/server/src/provider/provider.ts
+++ b/packages/server/src/provider/provider.ts
@@ -1,4 +1,5 @@
-import { CommonProvider, EvaluationContext, Hook, JsonValue, Logger, ResolutionDetails } from '@openfeature/core';
+import { CommonProvider, EvaluationContext, JsonValue, Logger, ResolutionDetails } from '@openfeature/core';
+import { Hook } from '../hooks';
 
 /**
  * Interface that providers must implement to resolve flag values for their particular
@@ -22,7 +23,7 @@ export interface Provider extends CommonProvider {
     flagKey: string,
     defaultValue: boolean,
     context: EvaluationContext,
-    logger: Logger
+    logger: Logger,
   ): Promise<ResolutionDetails<boolean>>;
 
   /**
@@ -32,7 +33,7 @@ export interface Provider extends CommonProvider {
     flagKey: string,
     defaultValue: string,
     context: EvaluationContext,
-    logger: Logger
+    logger: Logger,
   ): Promise<ResolutionDetails<string>>;
 
   /**
@@ -42,7 +43,7 @@ export interface Provider extends CommonProvider {
     flagKey: string,
     defaultValue: number,
     context: EvaluationContext,
-    logger: Logger
+    logger: Logger,
   ): Promise<ResolutionDetails<number>>;
 
   /**
@@ -52,6 +53,6 @@ export interface Provider extends CommonProvider {
     flagKey: string,
     defaultValue: T,
     context: EvaluationContext,
-    logger: Logger
+    logger: Logger,
   ): Promise<ResolutionDetails<T>>;
 }
diff --git a/packages/server/test/hooks.spec.ts b/packages/server/test/hooks.spec.ts
index 849db312..4dd60dc9 100644
--- a/packages/server/test/hooks.spec.ts
+++ b/packages/server/test/hooks.spec.ts
@@ -167,7 +167,7 @@ describe('Hooks', () => {
         expect.objectContaining({
           beforeRan: true,
         }),
-        expect.anything()
+        expect.anything(),
       );
     });
   });
@@ -252,7 +252,7 @@ describe('Hooks', () => {
           [invocationPropToOverwrite434]: true,
           [hookProp434]: true,
         }),
-        expect.anything()
+        expect.anything(),
       );
     });
   });
@@ -903,7 +903,7 @@ describe('Hooks', () => {
             return new Promise<EvaluationContext>((resolve) =>
               setTimeout(() => {
                 resolve({ beforeRan: true });
-              }, 100)
+              }, 100),
             );
           }),
           after: jest.fn((hookContext) => {
@@ -940,7 +940,7 @@ describe('Hooks', () => {
             return new Promise<EvaluationContext>((resolve, reject) =>
               setTimeout(() => {
                 reject();
-              }, 100)
+              }, 100),
             );
           }),
           error: jest.fn(() => {
diff --git a/packages/server/test/logger.spec.ts b/packages/server/test/logger.spec.ts
index 08a539a5..93f69b49 100644
--- a/packages/server/test/logger.spec.ts
+++ b/packages/server/test/logger.spec.ts
@@ -1,4 +1,4 @@
-import { OpenFeature, Hook, Logger, Provider, DefaultLogger, SafeLogger } from '../src';
+import { OpenFeature, BaseHook, Logger, Provider, DefaultLogger, SafeLogger } from '../src';
 
 class MockedLogger implements Logger {
   error = jest.fn();
@@ -12,7 +12,7 @@ const AFTER_HOOK_LOG_MESSAGE = 'in after hook';
 const ERROR_HOOK_LOG_MESSAGE = 'in error hook';
 const FINALLY_HOOK_LOG_MESSAGE = 'in finally hook';
 
-const MOCK_HOOK: Hook = {
+const MOCK_HOOK: BaseHook = {
   before: jest.fn((hookContext) => hookContext.logger.info(BEFORE_HOOK_LOG_MESSAGE)),
   after: jest.fn((hookContext) => hookContext.logger.info(AFTER_HOOK_LOG_MESSAGE)),
   error: jest.fn((hookContext) => hookContext.logger.info(ERROR_HOOK_LOG_MESSAGE)),
@@ -93,7 +93,7 @@ describe('Logger', () => {
         const safeLogger = new SafeLogger({} as Logger);
 
         expect(errorSpy).toBeCalledWith(
-          expect.objectContaining({ message: 'The provided logger is missing the error method.' })
+          expect.objectContaining({ message: 'The provided logger is missing the error method.' }),
         );
         // Checking the private logger
         expect(safeLogger['logger']).toBeInstanceOf(DefaultLogger);
diff --git a/packages/shared/src/hooks/evaluation-lifecycle.ts b/packages/shared/src/hooks/evaluation-lifecycle.ts
index 9bb88632..37816902 100644
--- a/packages/shared/src/hooks/evaluation-lifecycle.ts
+++ b/packages/shared/src/hooks/evaluation-lifecycle.ts
@@ -1,4 +1,4 @@
-import { Hook } from './hook';
+import { BaseHook } from './hook';
 import { FlagValue } from '../evaluation';
 
 export interface EvaluationLifeCycle<T> {
@@ -9,16 +9,16 @@ export interface EvaluationLifeCycle<T> {
    * Hooks registered on the global API object run with all evaluations.
    * Hooks registered on the client run with all evaluations on that client.
    * @template T The type of the receiver
-   * @param {Hook<FlagValue>[]} hooks A list of hooks that should always run
+   * @param {BaseHook[]} hooks A list of hooks that should always run
    * @returns {T} The receiver (this object)
    */
-  addHooks(...hooks: Hook<FlagValue>[]): T;
+  addHooks(...hooks: BaseHook[]): T;
 
   /**
    * Access all the hooks that are registered on this receiver.
-   * @returns {Hook<FlagValue>[]} A list of the client hooks
+   * @returns {BaseHook<FlagValue>[]} A list of the client hooks
    */
-  getHooks(): Hook<FlagValue>[];
+  getHooks(): BaseHook[];
 
   /**
    * Clears all the hooks that are registered on this receiver.
diff --git a/packages/shared/src/hooks/hook.ts b/packages/shared/src/hooks/hook.ts
index 83b83c61..fe89f150 100644
--- a/packages/shared/src/hooks/hook.ts
+++ b/packages/shared/src/hooks/hook.ts
@@ -1,17 +1,14 @@
 import { BeforeHookContext, HookContext, HookHints } from './hooks';
-import { EvaluationContext, EvaluationDetails, FlagValue } from '../evaluation';
+import { EvaluationDetails, FlagValue } from '../evaluation';
 
-export interface Hook<T extends FlagValue = FlagValue> {
+export interface BaseHook<T extends FlagValue = FlagValue, BeforeHookReturn = unknown, HooksReturn = unknown> {
   /**
    * Runs before flag values are resolved from the provider.
    * If an EvaluationContext is returned, it will be merged with the pre-existing EvaluationContext.
    * @param hookContext
    * @param hookHints
    */
-  before?(
-    hookContext: BeforeHookContext,
-    hookHints?: HookHints
-  ): Promise<EvaluationContext | void> | EvaluationContext | void;
+  before?(hookContext: BeforeHookContext, hookHints?: HookHints): BeforeHookReturn;
 
   /**
    * Runs after flag values are successfully resolved from the provider.
@@ -22,8 +19,8 @@ export interface Hook<T extends FlagValue = FlagValue> {
   after?(
     hookContext: Readonly<HookContext<T>>,
     evaluationDetails: EvaluationDetails<T>,
-    hookHints?: HookHints
-  ): Promise<void> | void;
+    hookHints?: HookHints,
+  ): HooksReturn;
 
   /**
    * Runs in the event of an unhandled error or promise rejection during flag resolution, or any attached hooks.
@@ -31,7 +28,7 @@ export interface Hook<T extends FlagValue = FlagValue> {
    * @param error
    * @param hookHints
    */
-  error?(hookContext: Readonly<HookContext<T>>, error: unknown, hookHints?: HookHints): Promise<void> | void;
+  error?(hookContext: Readonly<HookContext<T>>, error: unknown, hookHints?: HookHints): HooksReturn;
 
   /**
    * Runs after all other hook stages, regardless of success or error.
@@ -39,5 +36,5 @@ export interface Hook<T extends FlagValue = FlagValue> {
    * @param hookContext
    * @param hookHints
    */
-  finally?(hookContext: Readonly<HookContext<T>>, hookHints?: HookHints): Promise<void> | void;
+  finally?(hookContext: Readonly<HookContext<T>>, hookHints?: HookHints): HooksReturn;
 }
diff --git a/packages/shared/src/open-feature.ts b/packages/shared/src/open-feature.ts
index dbf27452..f2d2b3e5 100644
--- a/packages/shared/src/open-feature.ts
+++ b/packages/shared/src/open-feature.ts
@@ -1,22 +1,22 @@
 import { GeneralError } from './errors';
-import { EvaluationContext, FlagValue } from './evaluation';
+import { EvaluationContext } from './evaluation';
 import { EventDetails, EventHandler, Eventing, ProviderEvents, statusMatchesEvent } from './events';
 import { GenericEventEmitter } from './events';
 import { isDefined } from './filter';
-import { EvaluationLifeCycle, Hook } from './hooks';
+import { EvaluationLifeCycle, BaseHook } from './hooks';
 import { DefaultLogger, Logger, ManageLogger, SafeLogger } from './logger';
 import { CommonProvider, ProviderMetadata, ProviderStatus } from './provider';
 import { objectOrUndefined, stringOrUndefined } from './type-guards';
 import { Paradigm } from './types';
 
-export abstract class OpenFeatureCommonAPI<P extends CommonProvider = CommonProvider>
+export abstract class OpenFeatureCommonAPI<P extends CommonProvider = CommonProvider, H extends BaseHook = BaseHook>
   implements Eventing, EvaluationLifeCycle<OpenFeatureCommonAPI<P>>, ManageLogger<OpenFeatureCommonAPI<P>>
 {
   protected abstract _createEventEmitter(): GenericEventEmitter;
   protected abstract _defaultProvider: P;
   protected abstract readonly _events: GenericEventEmitter;
 
-  protected _hooks: Hook[] = [];
+  protected _hooks: H[] = [];
   protected _context: EvaluationContext = {};
   protected _logger: Logger = new DefaultLogger();
 
@@ -30,12 +30,12 @@ export abstract class OpenFeatureCommonAPI<P extends CommonProvider = CommonProv
     this._runsOn = category;
   }
 
-  addHooks(...hooks: Hook<FlagValue>[]): this {
+  addHooks(...hooks: H[]): this {
     this._hooks = [...this._hooks, ...hooks];
     return this;
   }
 
-  getHooks(): Hook<FlagValue>[] {
+  getHooks(): H[] {
     return this._hooks;
   }
 
@@ -184,7 +184,7 @@ export abstract class OpenFeatureCommonAPI<P extends CommonProvider = CommonProv
     if (typeof provider.initialize === 'function' && provider.status === undefined) {
       const activeLogger = this._logger || console;
       activeLogger.warn(
-        `Provider ${providerName} implements 'initialize' but not 'status'. Please implement 'status'.`
+        `Provider ${providerName} implements 'initialize' but not 'status'. Please implement 'status'.`,
       );
     }
 
@@ -251,10 +251,11 @@ export abstract class OpenFeatureCommonAPI<P extends CommonProvider = CommonProv
     this._clientEvents.set(name, newEmitter);
 
     const clientProvider = this.getProviderForClient(name);
-    Object.values<ProviderEvents>(ProviderEvents).forEach((eventType) =>
-      clientProvider.events?.addHandler(eventType, async (details) => {
-        newEmitter.emit(eventType, { ...details, clientName: name, providerName: clientProvider.metadata.name });
-      })
+    Object.values<ProviderEvents>(ProviderEvents).forEach(
+      (eventType) =>
+        clientProvider.events?.addHandler(eventType, async (details) => {
+          newEmitter.emit(eventType, { ...details, clientName: name, providerName: clientProvider.metadata.name });
+        }),
     );
 
     return newEmitter;
@@ -280,7 +281,7 @@ export abstract class OpenFeatureCommonAPI<P extends CommonProvider = CommonProv
     oldProvider: P,
     newProvider: P,
     clientName: string | undefined,
-    emitters: (GenericEventEmitter | undefined)[]
+    emitters: (GenericEventEmitter | undefined)[],
   ) {
     this._clientEventHandlers
       .get(clientName)
@@ -321,7 +322,7 @@ export abstract class OpenFeatureCommonAPI<P extends CommonProvider = CommonProv
         } catch (err) {
           this.handleShutdownError(provider, err);
         }
-      })
+      }),
     );
   }