diff --git a/eslint.config.js b/eslint.config.js
index 90c31ebd..8e376ae9 100644
--- a/eslint.config.js
+++ b/eslint.config.js
@@ -10,21 +10,16 @@ export default [
     files: ['src/**/*.ts'],
     tsconfig: './src/tsconfig.json',
   }),
+  // Prevent non-vended-tools from importing vended-tools
+  noVendedToolsImports({
+    files: ['src/**/*.ts'],
+    ignores: ['src/vended-tools/**/*.ts'],
+  }),
   // Then unit-test rules to UTs
   unitTestRules({
     files: ['src/**/__tests__/**/*.ts'],
     tsconfig: './src/tsconfig.json',
   }),
-  // Apply SDK rules to vended_tool files
-  sdkRules({
-    files: ['vended_tools/**/*.ts'],
-    tsconfig: './vended_tools/tsconfig.json',
-  }),
-  // Then unit-test rules to UTs
-  unitTestRules({
-    files: ['vended_tools/**/__tests__/**/*.ts'],
-    tsconfig: './vended_tools/tsconfig.json',
-  }),
   // Apply UT rules to the integ tests
   unitTestRules({
     files: ['tests_integ/**/*.ts'],
@@ -122,3 +117,24 @@ function integTestRules(options) {
     },
   }
 }
+
+function noVendedToolsImports(options) {
+  return {
+    files: options.files,
+    ignores: options.ignores,
+    rules: {
+      'no-restricted-imports': [
+        'error',
+        {
+          patterns: [
+            {
+              group: ['**/vended-tools', '**/vended-tools/**'],
+              message:
+                'Core SDK files should not import from vended-tools. Vended tools are optional and independently importable.',
+            },
+          ],
+        },
+      ],
+    },
+  }
+}
diff --git a/package.json b/package.json
index c7c73c57..4829ac1c 100644
--- a/package.json
+++ b/package.json
@@ -23,24 +23,24 @@
       "default": "./dist/src/models/bedrock.js"
     },
     "./vended_tools/notebook": {
-      "types": "./dist/vended_tools/notebook/index.d.ts",
-      "default": "./dist/vended_tools/notebook/index.js"
+      "types": "./dist/src/vended-tools/notebook/index.d.ts",
+      "default": "./dist/src/vended-tools/notebook/index.js"
     },
     "./vended_tools/file_editor": {
-      "types": "./dist/vended_tools/file_editor/index.d.ts",
-      "default": "./dist/vended_tools/file_editor/index.js"
+      "types": "./dist/src/vended-tools/file_editor/index.d.ts",
+      "default": "./dist/src/vended-tools/file_editor/index.js"
     },
     "./vended_tools/http_request": {
-      "types": "./dist/vended_tools/http_request/index.d.ts",
-      "default": "./dist/vended_tools/http_request/index.js"
+      "types": "./dist/src/vended-tools/http_request/index.d.ts",
+      "default": "./dist/src/vended-tools/http_request/index.js"
     },
     "./vended_tools/bash": {
-      "types": "./dist/vended_tools/bash/index.d.ts",
-      "default": "./dist/vended_tools/bash/index.js"
+      "types": "./dist/src/vended-tools/bash/index.d.ts",
+      "default": "./dist/src/vended-tools/bash/index.js"
     }
   },
   "scripts": {
-    "build": "tsc --project src/tsconfig.json && tsc --project vended_tools/tsconfig.json",
+    "build": "tsc --project src/tsconfig.json",
     "check": "npm run lint && npm run format && npm run type-check && npm run test:coverage && npm run test:package",
     "clean": "rm -rf node_modules dist package-lock.json",
     "test": "vitest run --project unit-node",
@@ -55,11 +55,11 @@
     "test:all": "vitest run --project unit-node --project unit-browser",
     "test:all:coverage": "vitest run --coverage --project unit-node --project unit-browser",
     "test:package": "cd test/packages/esm-module && npm install && node esm.js && cd ../cjs-module && npm install && node cjs.js",
-    "lint": "eslint src tests_integ vended_tools",
-    "lint:fix": "eslint src tests_integ vended_tools --fix",
-    "format": "prettier --write src tests_integ vended_tools",
-    "format:check": "prettier --check src tests_integ vended_tools",
-    "type-check": "tsc --noEmit --project src/tsconfig.json && tsc --noEmit --project vended_tools/tsconfig.json && tsc --noEmit --project tests_integ/tsconfig.json",
+    "lint": "eslint src tests_integ",
+    "lint:fix": "eslint src tests_integ --fix",
+    "format": "prettier --write src tests_integ",
+    "format:check": "prettier --check src tests_integ",
+    "type-check": "tsc --noEmit --project src/tsconfig.json && tsc --noEmit --project tests_integ/tsconfig.json",
     "type-check:watch": "tsc --noEmit --watch",
     "prepare": "npm run build && husky"
   },
diff --git a/src/index.ts b/src/index.ts
index 5158d0aa..740b1fea 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -86,7 +86,6 @@ export type { ToolSpec, ToolUse, ToolResultStatus, ToolChoice } from './tools/ty
 
 // Tool interface and related types
 export type {
-  Tool,
   InvokableTool,
   ToolContext,
   ToolStreamEventData,
@@ -94,6 +93,9 @@ export type {
   ToolStreamGenerator,
 } from './tools/tool.js'
 
+// Tool base class
+export { Tool } from './tools/tool.js'
+
 // FunctionTool implementation
 export { FunctionTool } from './tools/function-tool.js'
 
diff --git a/vended_tools/bash/README.md b/src/vended-tools/bash/README.md
similarity index 100%
rename from vended_tools/bash/README.md
rename to src/vended-tools/bash/README.md
diff --git a/vended_tools/bash/__tests__/bash.test.ts b/src/vended-tools/bash/__tests__/bash.test.ts
similarity index 98%
rename from vended_tools/bash/__tests__/bash.test.ts
rename to src/vended-tools/bash/__tests__/bash.test.ts
index 744debf0..fd0ce261 100644
--- a/vended_tools/bash/__tests__/bash.test.ts
+++ b/src/vended-tools/bash/__tests__/bash.test.ts
@@ -1,9 +1,9 @@
 import { describe, it, expect, vi, afterEach } from 'vitest'
 import { bash } from '../index.js'
 import { BashTimeoutError, BashSessionError, type BashOutput } from '../index.js'
-import type { ToolContext } from '../../../src/index.js'
-import { AgentState } from '../../../src/agent/state.js'
-import { isNode } from '../../../src/__fixtures__/environment.js'
+import type { ToolContext } from '../../../index.js'
+import { AgentState } from '../../../agent/state.js'
+import { isNode } from '../../../__fixtures__/environment.js'
 
 // Skip all tests if not in Node.js environment
 describe.skipIf(!isNode || process.platform === 'win32')('bash tool', () => {
diff --git a/vended_tools/bash/bash.ts b/src/vended-tools/bash/bash.ts
similarity index 99%
rename from vended_tools/bash/bash.ts
rename to src/vended-tools/bash/bash.ts
index 8524aacf..994539f4 100644
--- a/vended_tools/bash/bash.ts
+++ b/src/vended-tools/bash/bash.ts
@@ -1,5 +1,5 @@
 /* eslint-env node */
-import { tool } from '../../src/tools/zod-tool.js'
+import { tool } from '../../tools/zod-tool.js'
 import { z } from 'zod'
 import { spawn, type ChildProcess } from 'child_process'
 import { Buffer } from 'buffer'
diff --git a/vended_tools/bash/index.ts b/src/vended-tools/bash/index.ts
similarity index 100%
rename from vended_tools/bash/index.ts
rename to src/vended-tools/bash/index.ts
diff --git a/vended_tools/bash/types.ts b/src/vended-tools/bash/types.ts
similarity index 100%
rename from vended_tools/bash/types.ts
rename to src/vended-tools/bash/types.ts
diff --git a/vended_tools/file_editor/README.md b/src/vended-tools/file_editor/README.md
similarity index 100%
rename from vended_tools/file_editor/README.md
rename to src/vended-tools/file_editor/README.md
diff --git a/vended_tools/file_editor/__tests__/file-editor.test.ts b/src/vended-tools/file_editor/__tests__/file-editor.test.ts
similarity index 99%
rename from vended_tools/file_editor/__tests__/file-editor.test.ts
rename to src/vended-tools/file_editor/__tests__/file-editor.test.ts
index 5f81233d..ca0d3ce5 100644
--- a/vended_tools/file_editor/__tests__/file-editor.test.ts
+++ b/src/vended-tools/file_editor/__tests__/file-editor.test.ts
@@ -1,7 +1,7 @@
 import { describe, it, expect, beforeEach, afterEach } from 'vitest'
 import { fileEditor } from '../file-editor.js'
-import type { ToolContext } from '../../../src/index.js'
-import { AgentState } from '../../../src/agent/state.js'
+import type { ToolContext } from '../../../index.js'
+import { AgentState } from '../../../agent/state.js'
 import { promises as fs } from 'fs'
 import * as path from 'path'
 import { tmpdir } from 'os'
diff --git a/vended_tools/file_editor/file-editor.ts b/src/vended-tools/file_editor/file-editor.ts
similarity index 99%
rename from vended_tools/file_editor/file-editor.ts
rename to src/vended-tools/file_editor/file-editor.ts
index 2a185e41..27aa51c0 100644
--- a/vended_tools/file_editor/file-editor.ts
+++ b/src/vended-tools/file_editor/file-editor.ts
@@ -1,4 +1,4 @@
-import { tool } from '../../src/tools/zod-tool.js'
+import { tool } from '../../tools/zod-tool.js'
 import { z } from 'zod'
 import type { IFileReader } from './types.js'
 import { promises as fs } from 'fs'
diff --git a/vended_tools/file_editor/index.ts b/src/vended-tools/file_editor/index.ts
similarity index 100%
rename from vended_tools/file_editor/index.ts
rename to src/vended-tools/file_editor/index.ts
diff --git a/vended_tools/file_editor/types.ts b/src/vended-tools/file_editor/types.ts
similarity index 100%
rename from vended_tools/file_editor/types.ts
rename to src/vended-tools/file_editor/types.ts
diff --git a/vended_tools/http_request/README.md b/src/vended-tools/http_request/README.md
similarity index 100%
rename from vended_tools/http_request/README.md
rename to src/vended-tools/http_request/README.md
diff --git a/vended_tools/http_request/__tests__/http-request.test.ts b/src/vended-tools/http_request/__tests__/http-request.test.ts
similarity index 100%
rename from vended_tools/http_request/__tests__/http-request.test.ts
rename to src/vended-tools/http_request/__tests__/http-request.test.ts
diff --git a/vended_tools/http_request/http-request.ts b/src/vended-tools/http_request/http-request.ts
similarity index 98%
rename from vended_tools/http_request/http-request.ts
rename to src/vended-tools/http_request/http-request.ts
index ec5bbe35..1caf4729 100644
--- a/vended_tools/http_request/http-request.ts
+++ b/src/vended-tools/http_request/http-request.ts
@@ -1,5 +1,5 @@
 /* eslint-env browser, node */
-import { tool } from '../../src/tools/zod-tool.js'
+import { tool } from '../../tools/zod-tool.js'
 import { z } from 'zod'
 
 /**
diff --git a/vended_tools/http_request/index.ts b/src/vended-tools/http_request/index.ts
similarity index 100%
rename from vended_tools/http_request/index.ts
rename to src/vended-tools/http_request/index.ts
diff --git a/vended_tools/http_request/types.ts b/src/vended-tools/http_request/types.ts
similarity index 100%
rename from vended_tools/http_request/types.ts
rename to src/vended-tools/http_request/types.ts
diff --git a/vended_tools/notebook/README.md b/src/vended-tools/notebook/README.md
similarity index 100%
rename from vended_tools/notebook/README.md
rename to src/vended-tools/notebook/README.md
diff --git a/vended_tools/notebook/__tests__/notebook.test.ts b/src/vended-tools/notebook/__tests__/notebook.test.ts
similarity index 99%
rename from vended_tools/notebook/__tests__/notebook.test.ts
rename to src/vended-tools/notebook/__tests__/notebook.test.ts
index 3f57e5eb..c6bf1ecd 100644
--- a/vended_tools/notebook/__tests__/notebook.test.ts
+++ b/src/vended-tools/notebook/__tests__/notebook.test.ts
@@ -1,8 +1,8 @@
 import { describe, it, expect } from 'vitest'
 import { notebook } from '../notebook.js'
 import type { NotebookState } from '../types.js'
-import type { ToolContext } from '../../../src/index.js'
-import { AgentState } from '../../../src/agent/state.js'
+import type { ToolContext } from '../../../index.js'
+import { AgentState } from '../../../agent/state.js'
 
 describe('notebook tool', () => {
   // Helper to create fresh state and context for each test
diff --git a/vended_tools/notebook/index.ts b/src/vended-tools/notebook/index.ts
similarity index 100%
rename from vended_tools/notebook/index.ts
rename to src/vended-tools/notebook/index.ts
diff --git a/vended_tools/notebook/notebook.ts b/src/vended-tools/notebook/notebook.ts
similarity index 99%
rename from vended_tools/notebook/notebook.ts
rename to src/vended-tools/notebook/notebook.ts
index 469d050b..2ba8d3ca 100644
--- a/vended_tools/notebook/notebook.ts
+++ b/src/vended-tools/notebook/notebook.ts
@@ -1,4 +1,4 @@
-import { tool } from '../../src/index.js'
+import { tool } from '../../index.js'
 import { z } from 'zod'
 import type { NotebookState } from './types.js'
 
diff --git a/vended_tools/notebook/types.ts b/src/vended-tools/notebook/types.ts
similarity index 100%
rename from vended_tools/notebook/types.ts
rename to src/vended-tools/notebook/types.ts
diff --git a/test/packages/cjs-module/cjs.js b/test/packages/cjs-module/cjs.js
index 4e1443cb..4324cd25 100644
--- a/test/packages/cjs-module/cjs.js
+++ b/test/packages/cjs-module/cjs.js
@@ -3,7 +3,13 @@
  * This script runs in a pure Node.js ES module environment.
  */
 
-const { Agent, BedrockModel, tool } = require('@strands-agents/sdk')
+const { Agent, BedrockModel, tool, Tool } = require('@strands-agents/sdk')
+
+const { notebook } = require('@strands-agents/sdk/vended_tools/notebook')
+const { fileEditor } = require('@strands-agents/sdk/vended_tools/file_editor')
+const { httpRequest } = require('@strands-agents/sdk/vended_tools/http_request')
+const { bash } = require('@strands-agents/sdk/vended_tools/bash')
+
 const { z } = require('zod')
 
 console.log('✓ Import from main entry point successful')
@@ -54,6 +60,19 @@ async function main() {
   if (agent.tools.length == 0) {
     throw new Error('Tool was not correctly added to the agent')
   }
+
+  const tools = {
+    notebook,
+    fileEditor,
+    httpRequest,
+    bash,
+  }
+
+  for (const tool of Object.values(tools)) {
+    if (!(tool instanceof Tool)) {
+      throw new Error(`Tool ${tool.name} isn't an instance of a tool`)
+    }
+  }
 }
 
 main().catch((error) => {
diff --git a/test/packages/esm-module/esm.js b/test/packages/esm-module/esm.js
index 5c9b4c8d..cb30ac90 100644
--- a/test/packages/esm-module/esm.js
+++ b/test/packages/esm-module/esm.js
@@ -3,7 +3,13 @@
  * This script runs in a pure Node.js ES module environment.
  */
 
-import { Agent, BedrockModel, tool } from '@strands-agents/sdk'
+import { Agent, BedrockModel, tool, Tool } from '@strands-agents/sdk'
+
+import { notebook } from '@strands-agents/sdk/vended_tools/notebook'
+import { fileEditor } from '@strands-agents/sdk/vended_tools/file_editor'
+import { httpRequest } from '@strands-agents/sdk/vended_tools/http_request'
+import { bash } from '@strands-agents/sdk/vended_tools/bash'
+
 import { z } from 'zod'
 
 console.log('✓ Import from main entry point successful')
@@ -53,3 +59,42 @@ const agent = new Agent({
 if (agent.tools.length == 0) {
   throw new Error('Tool was not correctly added to the agent')
 }
+
+async function validateScratchpad() {
+  let context = { agent: agent }
+  notebook.invoke(
+    {
+      mode: 'create',
+      name: 'scratchpad',
+      newStr: 'Content',
+    },
+    context
+  )
+
+  const result = await notebook.invoke(
+    {
+      mode: 'read',
+      name: 'scratchpad',
+    },
+    context
+  )
+
+  if (result !== 'Content') {
+    throw new Error(`Tool returned invalid response: ${result}`)
+  }
+
+  console.log('Notebook created successful')
+}
+
+const tools = {
+  notebook,
+  fileEditor,
+  httpRequest,
+  bash,
+}
+
+for (const tool of Object.values(tools)) {
+  if (!(tool instanceof Tool)) {
+    throw new Error(`Tool ${tool.name} isn't an instance of a tool`)
+  }
+}
diff --git a/tests_integ/bash.test.ts b/tests_integ/bash.test.ts
index 64221be8..73ba9ed8 100644
--- a/tests_integ/bash.test.ts
+++ b/tests_integ/bash.test.ts
@@ -1,6 +1,6 @@
 import { describe, it, expect } from 'vitest'
 import { Agent, BedrockModel } from '$/sdk/index.js'
-import { bash } from '../vended_tools/bash/index.js'
+import { bash } from '$/sdk/vended-tools/bash/index.js'
 import { getMessageText, shouldRunTests } from './__fixtures__/model-test-helpers.js'
 
 describe.skipIf(!(await shouldRunTests()) || process.platform === 'win32')(
diff --git a/tests_integ/file-editor.test.ts b/tests_integ/file-editor.test.ts
index 8b6d3110..ffa10c55 100644
--- a/tests_integ/file-editor.test.ts
+++ b/tests_integ/file-editor.test.ts
@@ -1,6 +1,6 @@
 import { describe, it, expect, beforeEach, afterEach } from 'vitest'
 import { Agent, BedrockModel } from '$/sdk/index.js'
-import { fileEditor } from '../vended_tools/file_editor/index.js'
+import { fileEditor } from '$/sdk/vended-tools/file_editor/index.js'
 import { collectGenerator } from '$/sdk/__fixtures__/model-test-helpers.js'
 import { shouldRunTests } from './__fixtures__/model-test-helpers.js'
 import { promises as fs } from 'fs'
diff --git a/tests_integ/notebook.test.ts b/tests_integ/notebook.test.ts
index 8cb7d22f..c091487f 100644
--- a/tests_integ/notebook.test.ts
+++ b/tests_integ/notebook.test.ts
@@ -1,7 +1,7 @@
 import { describe, it, expect } from 'vitest'
 import { Agent, BedrockModel } from '$/sdk/index.js'
 import type { AgentStreamEvent, AgentResult } from '$/sdk/index.js'
-import { notebook } from '../vended_tools/notebook/index.js'
+import { notebook } from '$/sdk/vended-tools/notebook/index.js'
 import { collectGenerator } from '$/sdk/__fixtures__/model-test-helpers.js'
 import { shouldRunTests } from './__fixtures__/model-test-helpers.js'
 
diff --git a/tests_integ/tsconfig.json b/tests_integ/tsconfig.json
index af7eda60..f086eed7 100644
--- a/tests_integ/tsconfig.json
+++ b/tests_integ/tsconfig.json
@@ -2,10 +2,9 @@
   "extends": "../tsconfig.base.json",
   "compilerOptions": {
     "paths": {
-      "$/sdk/*": ["../src/*"],
-      "$/vended/*": ["../vended_tools/*"]
+      "$/sdk/*": ["../src/*"]
     },
-    "types": ["vite/client", "vitest/importMeta"]
+    "types": ["vite/client", "vitest/importMeta", "@types/node"]
   },
-  "references": [{ "path": "../src/tsconfig.json" }, { "path": "../vended_tools/tsconfig.json" }]
+  "references": [{ "path": "../src/tsconfig.json" }]
 }
diff --git a/vended_tools/tsconfig.json b/vended_tools/tsconfig.json
deleted file mode 100644
index 2cd034ac..00000000
--- a/vended_tools/tsconfig.json
+++ /dev/null
@@ -1,7 +0,0 @@
-{
-  "extends": "../tsconfig.base.json",
-  "compilerOptions": {
-    "types": ["@types/node"]
-  },
-  "references": [{ "path": "../src/tsconfig.json" }]
-}
diff --git a/vitest.config.ts b/vitest.config.ts
index f08c9f81..c703d575 100644
--- a/vitest.config.ts
+++ b/vitest.config.ts
@@ -10,9 +10,9 @@ const __dirname = path.dirname(fileURLToPath(import.meta.url))
 
 // Conditionally exclude bash tool from coverage on Windows
 // since tests are skipped on Windows (bash not available)
-const coverageExclude = ['src/**/__tests__/**', 'src/**/__fixtures__/**', 'vended_tools/**/__tests__/**']
+const coverageExclude = ['src/**/__tests__/**', 'src/**/__fixtures__/**', 'src/vended-tools/**/__tests__/**']
 if (process.platform === 'win32') {
-  coverageExclude.push('vended_tools/bash/**')
+  coverageExclude.push('src/vended-tools/bash/**')
 }
 
 const getAwsCredentials: BrowserCommand<[], AwsCredentialIdentity> = async ({ testPath, provider }) => {
@@ -35,7 +35,7 @@ export default defineConfig({
     projects: [
       {
         test: {
-          include: ['src/**/__tests__/**/*.test.ts', 'vended_tools/**/__tests__/**/*.test.ts'],
+          include: ['src/**/__tests__/**/*.test.ts', 'src/vended-tools/**/__tests__/**/*.test.ts'],
           includeSource: ['src/**/*.{js,ts}'],
           name: { label: 'unit-node', color: 'green' },
           typecheck: {
@@ -47,8 +47,8 @@ export default defineConfig({
       },
       {
         test: {
-          include: ['src/**/__tests__/**/*.test.ts', 'vended_tools/**/__tests__/**/*.test.ts'],
-          exclude: ['vended_tools/file_editor/**/*.test.ts', 'vended_tools/bash/**/*.test.ts'],
+          include: ['src/**/__tests__/**/*.test.ts'],
+          exclude: ['src/vended-tools/file_editor/**/*.test.ts', 'src/vended-tools/bash/**/*.test.ts'],
           name: { label: 'unit-browser', color: 'cyan' },
           browser: {
             enabled: true,
@@ -66,7 +66,7 @@ export default defineConfig({
         test: {
           alias: {
             '$/sdk': path.resolve(__dirname, './src'),
-            '$/vended': path.resolve(__dirname, './vended_tools'),
+            '$/vended': path.resolve(__dirname, './src/vended-tools'),
           },
           include: ['tests_integ/**/*.test.ts'],
           exclude: ['tests_integ/**/*.browser.test.ts'],
@@ -83,7 +83,7 @@ export default defineConfig({
         test: {
           alias: {
             '$/sdk': path.resolve(__dirname, './src'),
-            '$/vended': path.resolve(__dirname, './vended_tools'),
+            '$/vended': path.resolve(__dirname, './src/vended-tools'),
           },
           include: ['tests_integ/**/*.browser.test.ts'],
           name: { label: 'integ-browser', color: 'yellow' },
@@ -117,7 +117,7 @@ export default defineConfig({
     coverage: {
       provider: 'v8',
       reporter: ['text', 'json', 'html'],
-      include: ['src/**/*.{ts,js}', 'vended_tools/**/*.{ts,js}'],
+      include: ['src/**/*.{ts,js}', 'src/vended-tools/**/*.{ts,js}'],
       exclude: coverageExclude,
       thresholds: {
         lines: 80,