diff --git a/.changeset/hip-sloths-jog.md b/.changeset/hip-sloths-jog.md
new file mode 100644
index 00000000..532de13e
--- /dev/null
+++ b/.changeset/hip-sloths-jog.md
@@ -0,0 +1,9 @@
+---
+'@storybook/mcp': minor
+---
+
+Replace the `source` property in the context with `request`.
+
+Now you don't pass in a source string that might be fetched or handled by your custom `manifestProvider`, but instead you pass in the whole web request. (This is automatically handled if you use the createStorybookMcpHandler() function).
+
+The default action is now to fetch the manifest from `../manifests/components.json` assuming the server is running at `./mcp`. Your custom `manifestProvider()`-function then also does not get a source string as an argument, but gets the whole web request, that you can use to get information about where to fetch the manifest from. It also gets a second argument, `path`, which it should use to determine which specific manifest to get from a built Storybook. (Currently always `./manifests/components.json`, but in the future it might be other paths too).
diff --git a/.github/copilot-instructions.md b/.github/copilot-instructions.md
index ed33bbc4..cadbb2f1 100644
--- a/.github/copilot-instructions.md
+++ b/.github/copilot-instructions.md
@@ -61,8 +61,14 @@ The `@storybook/mcp` package (in `packages/mcp`) is framework-agnostic:
 
 - Uses `tmcp` with HTTP transport and Valibot schema validation
 - Factory pattern: `createStorybookMcpHandler()` returns a request handler
-- Context-based: handlers accept `StorybookContext` to override source URLs and provide optional callbacks
+- Context-based: handlers accept `StorybookContext` which includes the HTTP `Request` object and optional callbacks
 - **Exports tools and types** for reuse by `addon-mcp` and other consumers
+- **Request-based manifest loading**: The `request` property in context is passed to tools, which use it to determine the manifest URL (defaults to same origin, replacing `/mcp` with the manifest path)
+- **Optional manifestProvider**: Custom function to override default manifest fetching behavior
+  - Signature: `(request: Request, path: string) => Promise<string>`
+  - Receives the `Request` object and a `path` parameter (currently always `'./manifests/components.json'`)
+  - The provider determines the base URL (e.g., mapping to S3 buckets) while the MCP server handles the path
+  - Returns the manifest JSON as a string
 - **Optional handlers**: `StorybookContext` supports optional handlers that are called at various points, allowing consumers to track usage or collect telemetry:
   - `onSessionInitialize`: Called when an MCP session is initialized
   - `onListAllComponents`: Called when the list-all-components tool is invoked
@@ -221,7 +227,8 @@ export { addMyTool, MY_TOOL_NAME } from './tools/my-tool.ts';
   - Checks `features.experimentalComponentsManifest` flag
   - Checks for `experimental_componentManifestGenerator` preset
   - Only registers `addListAllComponentsTool` and `addGetComponentDocumentationTool` when enabled
-- Context includes `source` URL pointing to `/manifests/components.json` endpoint
+- Context includes `request` (HTTP Request object) which tools use to determine manifest location
+- Default manifest URL is constructed from request origin, replacing `/mcp` with `/manifests/components.json`
 - **Optional handlers for tracking**:
   - `onSessionInitialize`: Called when an MCP session is initialized, receives context
   - `onListAllComponents`: Called when list tool is invoked, receives context and manifest
diff --git a/.github/instructions/mcp.instructions.md b/.github/instructions/mcp.instructions.md
index 81308a9f..4ca8918b 100644
--- a/.github/instructions/mcp.instructions.md
+++ b/.github/instructions/mcp.instructions.md
@@ -42,6 +42,59 @@ src/
 1. **Factory Pattern**: `createStorybookMcpHandler()` creates configured handler instances
 2. **Tool Registration**: Tools are added to the server using `server.tool()` method
 3. **Async Handler**: Returns a Promise-based request handler compatible with standard HTTP servers
+4. **Request-based Context**: The `Request` object is passed through context to tools, which use it to construct the manifest URL
+
+### Manifest Provider API
+
+The handler accepts a `StorybookContext` with the following key properties:
+
+- **`request`**: The HTTP `Request` object being processed (automatically passed by the handler)
+- **`manifestProvider`**: Optional custom function `(request: Request, path: string) => Promise<string>` to override default manifest fetching
+  - **Parameters**:
+    - `request`: The HTTP `Request` object to determine base URL, headers, routing, etc.
+    - `path`: The manifest path (currently always `'./manifests/components.json'`)
+  - **Responsibility**: The provider determines the "first part" of the URL (base URL/origin) by examining the request. The MCP server provides the path.
+  - Default behavior: Constructs URL from request origin, replacing `/mcp` with the provided path
+  - Return value should be the manifest JSON as a string
+
+**Example with custom manifestProvider (local filesystem):**
+
+```typescript
+import { createStorybookMcpHandler } from '@storybook/mcp';
+import { readFile } from 'node:fs/promises';
+
+const handler = await createStorybookMcpHandler({
+	manifestProvider: async (request, path) => {
+		// Custom logic: read from local filesystem
+		// The provider decides on the base path, MCP provides the manifest path
+		const basePath = '/path/to/manifests';
+		// Remove leading './' from path if present
+		const normalizedPath = path.replace(/^\.\//, '');
+		const fullPath = `${basePath}/${normalizedPath}`;
+		return await readFile(fullPath, 'utf-8');
+	},
+});
+```
+
+**Example with custom manifestProvider (S3 bucket mapping):**
+
+```typescript
+import { createStorybookMcpHandler } from '@storybook/mcp';
+
+const handler = await createStorybookMcpHandler({
+	manifestProvider: async (request, path) => {
+		// Map requests to different S3 buckets based on hostname
+		const url = new URL(request.url);
+		const bucket = url.hostname.includes('staging')
+			? 'staging-bucket'
+			: 'prod-bucket';
+		const normalizedPath = path.replace(/^\.\, '');
+		const manifestUrl = `https://${bucket}.s3.amazonaws.com/${normalizedPath}`;
+		const response = await fetch(manifestUrl);
+		return await response.text();
+	},
+});
+```
 
 ### Component Manifest and ReactDocgen Support
 
diff --git a/packages/addon-mcp/src/mcp-handler.ts b/packages/addon-mcp/src/mcp-handler.ts
index 12c12719..931cbbd9 100644
--- a/packages/addon-mcp/src/mcp-handler.ts
+++ b/packages/addon-mcp/src/mcp-handler.ts
@@ -96,8 +96,7 @@ export const mcpServerHandler = async ({
 		toolsets: getToolsets(webRequest, addonOptions),
 		origin: origin!,
 		disableTelemetry,
-		// Source URL for component manifest tools - points to the manifest endpoint
-		source: `${origin}/manifests/components.json`,
+		request: webRequest,
 		// Telemetry handlers for component manifest tools
 		...(!disableTelemetry && {
 			onListAllComponents: async ({ manifest }) => {
diff --git a/packages/mcp/bin.ts b/packages/mcp/bin.ts
index 80e0b6fa..6de06119 100644
--- a/packages/mcp/bin.ts
+++ b/packages/mcp/bin.ts
@@ -52,11 +52,15 @@ const args = parseArgs({
 
 transport.listen({
 	source: args.values.manifestPath,
-	manifestProvider: async (source) => {
-		if (source.startsWith('http://') || source.startsWith('https://')) {
-			const res = await fetch(source);
+	manifestProvider: async () => {
+		const { manifestPath } = args.values;
+		if (
+			manifestPath.startsWith('http://') ||
+			manifestPath.startsWith('https://')
+		) {
+			const res = await fetch(manifestPath);
 			return await res.text();
 		}
-		return await fs.readFile(source, 'utf-8');
+		return await fs.readFile(manifestPath, 'utf-8');
 	},
 });
diff --git a/packages/mcp/serve.ts b/packages/mcp/serve.ts
index 946b217d..9b965562 100644
--- a/packages/mcp/serve.ts
+++ b/packages/mcp/serve.ts
@@ -5,13 +5,16 @@ import { parseArgs } from 'node:util';
 
 async function serveMcp(port: number, manifestPath: string) {
 	const storybookMcpHandler = await createStorybookMcpHandler({
-		source: manifestPath,
-		manifestProvider: async (source) => {
-			if (source.startsWith('http://') || source.startsWith('https://')) {
-				const res = await fetch(source);
+		// Use the local fixture file via manifestProvider
+		manifestProvider: async () => {
+			if (
+				manifestPath.startsWith('http://') ||
+				manifestPath.startsWith('https://')
+			) {
+				const res = await fetch(manifestPath);
 				return await res.text();
 			}
-			return await fs.readFile(source, 'utf-8');
+			return await fs.readFile(manifestPath, 'utf-8');
 		},
 	});
 
diff --git a/packages/mcp/src/index.ts b/packages/mcp/src/index.ts
index 9d7282c3..252c3723 100644
--- a/packages/mcp/src/index.ts
+++ b/packages/mcp/src/index.ts
@@ -16,6 +16,9 @@ export {
 	GET_TOOL_NAME,
 } from './tools/get-component-documentation.ts';
 
+// Export manifest constants
+export { MANIFEST_PATH } from './utils/get-manifest.ts';
+
 // Export types for reuse
 export type { StorybookContext } from './types.ts';
 
@@ -94,7 +97,7 @@ export const createStorybookMcpHandler = async (
 
 	return (async (req, context) => {
 		return await transport.respond(req, {
-			source: context?.source ?? options.source,
+			request: req,
 			manifestProvider: context?.manifestProvider ?? options.manifestProvider,
 			onListAllComponents:
 				context?.onListAllComponents ?? options.onListAllComponents,
diff --git a/packages/mcp/src/tools/get-component-documentation.test.ts b/packages/mcp/src/tools/get-component-documentation.test.ts
index 891db65f..5ebcca0f 100644
--- a/packages/mcp/src/tools/get-component-documentation.test.ts
+++ b/packages/mcp/src/tools/get-component-documentation.test.ts
@@ -63,7 +63,10 @@ describe('getComponentDocumentationTool', () => {
 			},
 		};
 
-		const response = await server.receive(request);
+		const mockHttpRequest = new Request('https://example.com/mcp');
+		const response = await server.receive(request, {
+			custom: { request: mockHttpRequest },
+		});
 
 		expect(response.result).toMatchInlineSnapshot(`
 			{
@@ -102,7 +105,10 @@ describe('getComponentDocumentationTool', () => {
 			},
 		};
 
-		const response = await server.receive(request);
+		const mockHttpRequest = new Request('https://example.com/mcp');
+		const response = await server.receive(request, {
+			custom: { request: mockHttpRequest },
+		});
 
 		expect(response.result).toMatchInlineSnapshot(`
 			{
@@ -137,7 +143,10 @@ describe('getComponentDocumentationTool', () => {
 			},
 		};
 
-		const response = await server.receive(request);
+		const mockHttpRequest = new Request('https://example.com/mcp');
+		const response = await server.receive(request, {
+			custom: { request: mockHttpRequest },
+		});
 
 		expect(response.result).toMatchInlineSnapshot(`
 			{
@@ -167,14 +176,19 @@ describe('getComponentDocumentationTool', () => {
 			},
 		};
 
-		// Pass the handler in the context for this specific request
+		const mockHttpRequest = new Request('https://example.com/mcp');
+		// Pass the handler and request in the context for this specific request
 		await server.receive(request, {
-			custom: { onGetComponentDocumentation: handler },
+			custom: {
+				request: mockHttpRequest,
+				onGetComponentDocumentation: handler,
+			},
 		});
 
 		expect(handler).toHaveBeenCalledTimes(1);
 		expect(handler).toHaveBeenCalledWith({
 			context: expect.objectContaining({
+				request: mockHttpRequest,
 				onGetComponentDocumentation: handler,
 			}),
 			input: { componentId: 'button' },
@@ -232,7 +246,10 @@ describe('getComponentDocumentationTool', () => {
 			},
 		};
 
-		const response = await server.receive(request);
+		const mockHttpRequest = new Request('https://example.com/mcp');
+		const response = await server.receive(request, {
+			custom: { request: mockHttpRequest },
+		});
 
 		expect(response.result).toMatchInlineSnapshot(`
 			{
diff --git a/packages/mcp/src/tools/get-component-documentation.ts b/packages/mcp/src/tools/get-component-documentation.ts
index b454f84d..47949deb 100644
--- a/packages/mcp/src/tools/get-component-documentation.ts
+++ b/packages/mcp/src/tools/get-component-documentation.ts
@@ -29,7 +29,7 @@ export async function addGetComponentDocumentationTool(
 		async (input: GetComponentDocumentationInput) => {
 			try {
 				const manifest = await getManifest(
-					server.ctx.custom?.source,
+					server.ctx.custom?.request,
 					server.ctx.custom?.manifestProvider,
 				);
 
diff --git a/packages/mcp/src/tools/list-all-components.test.ts b/packages/mcp/src/tools/list-all-components.test.ts
index 12010976..5487e6d6 100644
--- a/packages/mcp/src/tools/list-all-components.test.ts
+++ b/packages/mcp/src/tools/list-all-components.test.ts
@@ -61,7 +61,10 @@ describe('listAllComponentsTool', () => {
 			},
 		};
 
-		const response = await server.receive(request);
+		const mockHttpRequest = new Request('https://example.com/mcp');
+		const response = await server.receive(request, {
+			custom: { request: mockHttpRequest },
+		});
 
 		expect(response.result).toMatchInlineSnapshot(`
 			{
@@ -115,7 +118,10 @@ describe('listAllComponentsTool', () => {
 			},
 		};
 
-		const response = await server.receive(request);
+		const mockHttpRequest = new Request('https://example.com/mcp');
+		const response = await server.receive(request, {
+			custom: { request: mockHttpRequest },
+		});
 
 		expect(response.result).toMatchInlineSnapshot(`
 			{
@@ -143,7 +149,10 @@ describe('listAllComponentsTool', () => {
 			},
 		};
 
-		const response = await server.receive(request);
+		const mockHttpRequest = new Request('https://example.com/mcp');
+		const response = await server.receive(request, {
+			custom: { request: mockHttpRequest },
+		});
 
 		expect(response.result).toMatchInlineSnapshot(`
 			{
@@ -171,12 +180,16 @@ describe('listAllComponentsTool', () => {
 			},
 		};
 
-		// Pass the handler in the context for this specific request
-		await server.receive(request, { custom: { onListAllComponents: handler } });
+		const mockHttpRequest = new Request('https://example.com/mcp');
+		// Pass the handler and request in the context for this specific request
+		await server.receive(request, {
+			custom: { request: mockHttpRequest, onListAllComponents: handler },
+		});
 
 		expect(handler).toHaveBeenCalledTimes(1);
 		expect(handler).toHaveBeenCalledWith({
 			context: expect.objectContaining({
+				request: mockHttpRequest,
 				onListAllComponents: handler,
 			}),
 			manifest: smallManifestFixture,
diff --git a/packages/mcp/src/tools/list-all-components.ts b/packages/mcp/src/tools/list-all-components.ts
index 48c1dd8e..d456581e 100644
--- a/packages/mcp/src/tools/list-all-components.ts
+++ b/packages/mcp/src/tools/list-all-components.ts
@@ -20,7 +20,7 @@ export async function addListAllComponentsTool(
 		async () => {
 			try {
 				const manifest = await getManifest(
-					server.ctx.custom?.source,
+					server.ctx.custom?.request,
 					server.ctx.custom?.manifestProvider,
 				);
 
diff --git a/packages/mcp/src/types.ts b/packages/mcp/src/types.ts
index cdac4c12..42b29e9e 100644
--- a/packages/mcp/src/types.ts
+++ b/packages/mcp/src/types.ts
@@ -3,19 +3,22 @@ import * as v from 'valibot';
 
 /**
  * Custom context passed to MCP server and tools.
- * Contains the source URL for getting component manifests.
+ * Contains the request object and optional manifest provider.
  */
 export interface StorybookContext extends Record<string, unknown> {
 	/**
-	 * The URL of the remote manifest to get component data from.
+	 * The incoming HTTP request being processed.
 	 */
-	source?: string;
+	request?: Request;
 	/**
 	 * Optional function to provide custom manifest retrieval logic.
-	 * If provided, this function will be called instead of using fetch.
-	 * The function receives the source URL and should return the manifest as a string.
+	 * If provided, this function will be called instead of the default fetch-based provider.
+	 * The function receives the request object and a path to the manifest file,
+	 * and should return the manifest as a string.
+	 * The default provider constructs the manifest URL from the request origin,
+	 * replacing /mcp with /manifests/components.json
 	 */
-	manifestProvider?: (source: string) => Promise<string>;
+	manifestProvider?: (request: Request, path: string) => Promise<string>;
 	/**
 	 * Optional handler called when list-all-components tool is invoked.
 	 * Receives the context and the component manifest.
diff --git a/packages/mcp/src/utils/get-manifest.test.ts b/packages/mcp/src/utils/get-manifest.test.ts
index 7c487f27..677d74e7 100644
--- a/packages/mcp/src/utils/get-manifest.test.ts
+++ b/packages/mcp/src/utils/get-manifest.test.ts
@@ -4,6 +4,15 @@ import type { ComponentManifestMap } from '../types';
 
 global.fetch = vi.fn();
 
+/**
+ * Helper function to create a mock Request object
+ */
+function createMockRequest(url: string): Request {
+	return new Request(url, {
+		method: 'POST',
+	});
+}
+
 describe('getManifest', () => {
 	beforeEach(() => {
 		// Reset the fetch mock between tests since we're checking call counts
@@ -11,14 +20,14 @@ describe('getManifest', () => {
 	});
 
 	describe('error cases', () => {
-		it('should throw ManifestGetError when url is not provided', async () => {
+		it('should throw ManifestGetError when request is not provided', async () => {
 			await expect(getManifest()).rejects.toThrow(ManifestGetError);
 			await expect(getManifest()).rejects.toThrow(
-				'The source URL is required, but was not part of the request context nor was a default source for the server set',
+				'The request is required but was not provided in the context',
 			);
 		});
 
-		it('should throw ManifestGetError when url is undefined', async () => {
+		it('should throw ManifestGetError when request is undefined', async () => {
 			await expect(getManifest(undefined)).rejects.toThrow(ManifestGetError);
 		});
 
@@ -29,12 +38,11 @@ describe('getManifest', () => {
 				statusText: 'Not Found',
 			});
 
-			await expect(
-				getManifest('https://example.com/manifest.json'),
-			).rejects.toThrow(ManifestGetError);
-			await expect(
-				getManifest('https://example.com/manifest.json'),
-			).rejects.toThrow('Failed to fetch manifest: 404 Not Found');
+			const request = createMockRequest('https://example.com/mcp');
+			await expect(getManifest(request)).rejects.toThrow(ManifestGetError);
+			await expect(getManifest(request)).rejects.toThrow(
+				'Failed to fetch manifest: 404 Not Found',
+			);
 		});
 
 		it('should throw ManifestGetError when fetch fails with 500', async () => {
@@ -44,9 +52,10 @@ describe('getManifest', () => {
 				statusText: 'Internal Server Error',
 			});
 
-			await expect(
-				getManifest('https://example.com/manifest.json'),
-			).rejects.toThrow('Failed to fetch manifest: 500 Internal Server Error');
+			const request = createMockRequest('https://example.com/mcp');
+			await expect(getManifest(request)).rejects.toThrow(
+				'Failed to fetch manifest: 500 Internal Server Error',
+			);
 		});
 
 		it('should throw ManifestGetError when content type is not JSON', async () => {
@@ -57,12 +66,9 @@ describe('getManifest', () => {
 				},
 			});
 
-			await expect(
-				getManifest('https://example.com/manifest.json'),
-			).rejects.toThrow(ManifestGetError);
-			await expect(
-				getManifest('https://example.com/manifest.json'),
-			).rejects.toThrow(
+			const request = createMockRequest('https://example.com/mcp');
+			await expect(getManifest(request)).rejects.toThrow(ManifestGetError);
+			await expect(getManifest(request)).rejects.toThrow(
 				'Invalid content type: expected application/json, got text/html',
 			);
 		});
@@ -76,12 +82,11 @@ describe('getManifest', () => {
 				text: vi.fn().mockResolvedValue('not valid json{'),
 			});
 
-			await expect(
-				getManifest('https://example.com/manifest.json'),
-			).rejects.toThrow(ManifestGetError);
-			await expect(
-				getManifest('https://example.com/manifest.json'),
-			).rejects.toThrow('Failed to get manifest:');
+			const request = createMockRequest('https://example.com/mcp');
+			await expect(getManifest(request)).rejects.toThrow(ManifestGetError);
+			await expect(getManifest(request)).rejects.toThrow(
+				'Failed to get manifest:',
+			);
 		});
 
 		it('should throw ManifestGetError when manifest schema is invalid', async () => {
@@ -98,8 +103,9 @@ describe('getManifest', () => {
 				),
 			});
 
+			const request = createMockRequest('https://example.com/mcp');
 			await expect(
-				getManifest('https://example.com/manifest.json'),
+				getManifest(request),
 			).rejects.toThrowErrorMatchingInlineSnapshot(
 				`[ManifestGetError: Failed to get manifest: Invalid key: Expected "v" but received undefined]`,
 			);
@@ -119,12 +125,11 @@ describe('getManifest', () => {
 				),
 			});
 
-			await expect(
-				getManifest('https://example.com/manifest.json'),
-			).rejects.toThrow(ManifestGetError);
-			await expect(
-				getManifest('https://example.com/manifest.json'),
-			).rejects.toThrow('No components found in the manifest');
+			const request = createMockRequest('https://example.com/mcp');
+			await expect(getManifest(request)).rejects.toThrow(ManifestGetError);
+			await expect(getManifest(request)).rejects.toThrow(
+				'No components found in the manifest',
+			);
 		});
 
 		it('should wrap network errors in ManifestGetError', async () => {
@@ -132,12 +137,11 @@ describe('getManifest', () => {
 				.fn()
 				.mockRejectedValue(new Error('Network connection failed'));
 
-			await expect(
-				getManifest('https://example.com/manifest.json'),
-			).rejects.toThrow(ManifestGetError);
-			await expect(
-				getManifest('https://example.com/manifest.json'),
-			).rejects.toThrow('Network connection failed');
+			const request = createMockRequest('https://example.com/mcp');
+			await expect(getManifest(request)).rejects.toThrow(ManifestGetError);
+			await expect(getManifest(request)).rejects.toThrow(
+				'Network connection failed',
+			);
 		});
 
 		it('should preserve ManifestGetError when already thrown', async () => {
@@ -147,12 +151,13 @@ describe('getManifest', () => {
 				statusText: 'Not Found',
 			});
 
+			const request = createMockRequest('https://example.com/mcp');
 			try {
-				await getManifest('https://example.com/manifest.json');
+				await getManifest(request);
 			} catch (error) {
 				expect(error).toBeInstanceOf(ManifestGetError);
 				expect((error as ManifestGetError).url).toBe(
-					'https://example.com/manifest.json',
+					'https://example.com/manifests/components.json',
 				);
 			}
 		});
@@ -180,11 +185,12 @@ describe('getManifest', () => {
 				text: vi.fn().mockResolvedValue(JSON.stringify(validManifest)),
 			});
 
-			const result = await getManifest('https://example.com/manifest.json');
+			const request = createMockRequest('https://example.com/mcp');
+			const result = await getManifest(request);
 
 			expect(result).toEqual(validManifest);
 			expect(global.fetch).toHaveBeenCalledExactlyOnceWith(
-				'https://example.com/manifest.json',
+				'https://example.com/manifests/components.json',
 			);
 		});
 	});
@@ -203,18 +209,17 @@ describe('getManifest', () => {
 				},
 			};
 
+			const request = createMockRequest('https://example.com/mcp');
 			const manifestProvider = vi
 				.fn()
 				.mockResolvedValue(JSON.stringify(validManifest));
 
-			const result = await getManifest(
-				'./fixtures/manifest.json',
-				manifestProvider,
-			);
+			const result = await getManifest(request, manifestProvider);
 
 			expect(result).toEqual(validManifest);
 			expect(manifestProvider).toHaveBeenCalledExactlyOnceWith(
-				'./fixtures/manifest.json',
+				request,
+				'./manifests/components.json',
 			);
 			// fetch should not be called when manifestProvider is used
 			expect(global.fetch).not.toHaveBeenCalled();
@@ -241,33 +246,36 @@ describe('getManifest', () => {
 				text: vi.fn().mockResolvedValue(JSON.stringify(validManifest)),
 			});
 
-			const result = await getManifest('https://example.com/manifest.json');
+			const request = createMockRequest('https://example.com/mcp');
+			const result = await getManifest(request);
 
 			expect(result).toEqual(validManifest);
 			expect(global.fetch).toHaveBeenCalledExactlyOnceWith(
-				'https://example.com/manifest.json',
+				'https://example.com/manifests/components.json',
 			);
 		});
 
 		it('should handle errors from manifestProvider', async () => {
+			const request = createMockRequest('https://example.com/mcp');
 			const manifestProvider = vi
 				.fn()
 				.mockRejectedValue(new Error('File not found'));
 
-			await expect(
-				getManifest('./fixtures/manifest.json', manifestProvider),
-			).rejects.toThrow(ManifestGetError);
-			await expect(
-				getManifest('./fixtures/manifest.json', manifestProvider),
-			).rejects.toThrow('Failed to get manifest: File not found');
+			await expect(getManifest(request, manifestProvider)).rejects.toThrow(
+				ManifestGetError,
+			);
+			await expect(getManifest(request, manifestProvider)).rejects.toThrow(
+				'Failed to get manifest: File not found',
+			);
 		});
 
 		it('should handle invalid JSON from manifestProvider', async () => {
+			const request = createMockRequest('https://example.com/mcp');
 			const manifestProvider = vi.fn().mockResolvedValue('not valid json{');
 
-			await expect(
-				getManifest('./fixtures/manifest.json', manifestProvider),
-			).rejects.toThrow(ManifestGetError);
+			await expect(getManifest(request, manifestProvider)).rejects.toThrow(
+				ManifestGetError,
+			);
 		});
 	});
 });
diff --git a/packages/mcp/src/utils/get-manifest.ts b/packages/mcp/src/utils/get-manifest.ts
index 45d108cc..e71a6506 100644
--- a/packages/mcp/src/utils/get-manifest.ts
+++ b/packages/mcp/src/utils/get-manifest.ts
@@ -1,6 +1,11 @@
 import { ComponentManifestMap } from '../types.ts';
 import * as v from 'valibot';
 
+/**
+ * The path to the component manifest file relative to the Storybook build
+ */
+export const MANIFEST_PATH = './manifests/components.json';
+
 /**
  * Error thrown when getting or parsing a manifest fails
  */
@@ -57,33 +62,34 @@ export const errorToMCPContent = (error: unknown): MCPErrorResult => {
 };
 
 /**
- * Gets a component manifest from a remote URL or using a custom provider
+ * Gets a component manifest from a request or using a custom provider
  *
- * @param url - The URL to get the manifest from
+ * @param request - The HTTP request to get the manifest for
  * @param manifestProvider - Optional custom function to get the manifest
  * @returns A promise that resolves to the parsed ComponentManifestMap
  * @throws {ManifestGetError} If getting the manifest fails or the response is invalid
  */
 export async function getManifest(
-	url?: string,
-	manifestProvider?: (source: string) => Promise<string>,
+	request?: Request,
+	manifestProvider?: (request: Request, path: string) => Promise<string>,
 ): Promise<ComponentManifestMap> {
+	if (!request) {
+		throw new ManifestGetError(
+			'The request is required but was not provided in the context',
+		);
+	}
 	try {
-		if (!url) {
-			throw new ManifestGetError(
-				'The source URL is required, but was not part of the request context nor was a default source for the server set',
-			);
-		}
-
-		// Use custom manifestProvider if provided, otherwise fallback to fetch
-		const manifestString = await (
-			manifestProvider ?? defaultFetchManifestProvider
-		)(url);
+		// Use custom manifestProvider if provided, otherwise fallback to default
+		const manifestString = await (manifestProvider ?? defaultManifestProvider)(
+			request,
+			MANIFEST_PATH,
+		);
 		const manifestData: unknown = JSON.parse(manifestString);
 
 		const manifest = v.parse(ComponentManifestMap, manifestData);
 
 		if (Object.keys(manifest.components).length === 0) {
+			const url = getManifestUrlFromRequest(request, MANIFEST_PATH);
 			throw new ManifestGetError(`No components found in the manifest`, url);
 		}
 
@@ -96,19 +102,39 @@ export async function getManifest(
 		// Wrap network errors and other unexpected errors
 		throw new ManifestGetError(
 			`Failed to get manifest: ${error instanceof Error ? error.message : String(error)}`,
-			url,
+			getManifestUrlFromRequest(request, MANIFEST_PATH),
 			error instanceof Error ? error : undefined,
 		);
 	}
 }
 
-async function defaultFetchManifestProvider(source: string): Promise<string> {
-	const response = await fetch(source);
+/**
+ * Constructs the manifest URL from a request by replacing /mcp with the provided path
+ */
+function getManifestUrlFromRequest(request: Request, path: string): string {
+	const url = new URL(request.url);
+	// Replace /mcp endpoint with the provided path (e.g., './manifests/components.json')
+	// Remove leading './' from path if present
+	const normalizedPath = path.replace(/^\.\//, '');
+	url.pathname = url.pathname.replace(/\/mcp\/?$/, `/${normalizedPath}`);
+	return url.toString();
+}
+
+/**
+ * Default manifest provider that fetches from the same origin as the request,
+ * replacing /mcp with the provided path
+ */
+async function defaultManifestProvider(
+	request: Request,
+	path: string,
+): Promise<string> {
+	const manifestUrl = getManifestUrlFromRequest(request, path);
+	const response = await fetch(manifestUrl);
 
 	if (!response.ok) {
 		throw new ManifestGetError(
 			`Failed to fetch manifest: ${response.status} ${response.statusText}`,
-			source,
+			manifestUrl,
 		);
 	}
 
@@ -116,7 +142,7 @@ async function defaultFetchManifestProvider(source: string): Promise<string> {
 	if (!contentType?.includes('application/json')) {
 		throw new ManifestGetError(
 			`Invalid content type: expected application/json, got ${contentType}`,
-			source,
+			manifestUrl,
 		);
 	}
 	return response.text();