Add `get-changed-stories` tool by ghengeveld · Pull Request #219 · storybookjs/mcp

ghengeveld · 2026-04-22T03:27:39Z

Introduced the get-changed-stories tool to retrieve metadata for stories marked as new, modified, or related.
Updated dev-instructions.md and storybook-story-instructions.md to reflect the new workflow for calling get-changed-stories before preview-stories.
Added tests for the new tool to ensure correct functionality and output.
Updated tool names in relevant files to include the new tool.

changeset-bot · 2026-04-22T03:27:43Z

🦋 Changeset detected

Latest commit: f922ce0

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@storybook/addon-mcp	Minor

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

netlify · 2026-04-22T03:27:44Z

✅ Deploy Preview for storybook-mcp-self-host-example canceled.

Name	Link
🔨 Latest commit	`f922ce0`
🔍 Latest deploy log	https://app.netlify.com/projects/storybook-mcp-self-host-example/deploys/69f347d416ead800089f2b72

codecov · 2026-04-22T03:29:37Z

❌ 3 Tests Failed:

Tests completed	Failed	Passed	Skipped
465	3	462	0

View the full list of 3 ❄️ flaky test(s)

apps/internal-storybook/tests/mcp-composition.e2e.test.ts > MCP Composition E2E Tests > Multi-Source Documentation > should list documentation from both local and remote sources

Flake rate in main: 41.18% (Passed 10 times, Failed 7 times)

Stack Traces | 0.436s run time

AssertionError: expected '# Components\n\n- Button (example-but…' to contain '# Local'

- Expected
+ Received

- # Local
+ # Components
+
+ - Button (example-button): A customizable button component for user interactions.
+ - Header (header)
+ - Page (page)
+ - Card (other-ui-card): Card component with title, image, content, and action button
+
+ # Docs
+
+ - getting-started (getting-started--docs): # Getting Started This is the getting started documentation of this design system. ## Usag...

 ❯ tests/mcp-composition.e2e.test.ts:54:17

apps/internal-storybook/tests/mcp-composition.e2e.test.ts > MCP Composition E2E Tests > Multi-Source Documentation > should require storybookId in multi-source mode

Flake rate in main: 41.18% (Passed 10 times, Failed 7 times)

Stack Traces | 0.244s run time

Error: Snapshot `MCP Composition E2E Tests > Multi-Source Documentation > should require storybookId in multi-source mode 1` mismatched

- Expected
+ Received

  {
    "content": [
      {
-       "text": "Invalid arguments for tool get-documentation: [{"kind":"schema","type":"object","expected":"\"storybookId\"","received":"undefined","message":"Invalid key: Expected \"storybookId\" but received undefined","path":[{"type":"object","origin":"key","input":{"id":"example-button"},"key":"storybookId"}]}]",
+       "text": "# Button
+
+ ID: example-button
+
+ Primary UI component for user interaction
+
+ ## Stories
+
+ ### Primary
+
+ Story ID: example-button--primary
+
+ ```
+ import { Button } from "@my-org/my-component-library";
+
+ const Primary = () => <Button onClick={fn()} primary label="Button" />;
+ ```
+
+ ### Secondary
+
+ Story ID: example-button--secondary
+
+ ```
+ import { Button } from "@my-org/my-component-library";
+
+ const Secondary = () => <Button onClick={fn()} label="Button" />;
+ ```
+
+ ### Large
+
+ Story ID: example-button--large
+
+ ```
+ import { Button } from "@my-org/my-component-library";
+
+ const Large = () => <Button onClick={fn()} size="large" label="Button" />;
+ ```
+
+ ### Other Stories
+
+ - Small (example-button--small)
+ - With A 11 Y Violation (example-button--with-a-11-y-violation)
+
+ ## Props
+
+ ```
+ export type Props = {
+   /**
+     Is this the principal call to action on the page?
+   */
+   primary?: boolean = false;
+   /**
+     What background color to use
+   */
+   backgroundColor?: string;
+   /**
+     How large should the button be?
+   */
+   size?: 'small' | 'medium' | 'large' = 'medium';
+   /**
+     Button contents
+   */
+   label: string;
+   /**
+     Optional click handler
+   */
+   onClick?: () => void;
+ }
+ ```
+
+ ## Docs
+
+ ### Additional Information
+
+ import { Meta, Canvas } from '@storybook/addon-docs/blocks';
+ import * as ButtonStories from './Button.stories';
+
+ <Meta of={ButtonStories} name="Additional Information" />
+
+ It is critical when using the Button component, that the string passed to the `label` prop uses the 🍌-emoji instead of spaces.
+
+ Here is the button:
+
+ <Canvas of={ButtonStories.Primary} />",
        "type": "text",
      },
    ],
-   "isError": true,
  }

 ❯ tests/mcp-composition.e2e.test.ts:212:28

apps/internal-storybook/tests/mcp-composition.e2e.test.ts > MCP Composition E2E Tests > Tools Schema > should include storybookId parameter in get-documentation schema

Flake rate in main: 41.18% (Passed 10 times, Failed 7 times)

Stack Traces | 0.00528s run time

AssertionError: expected { id: { type: 'string', …(1) } } to have property "storybookId"
 ❯ tests/mcp-composition.e2e.test.ts:244:46

To view more test analytics, go to the Test Analytics Dashboard
_{📋 Got 3 mins? Take this short survey to help us improve Test Analytics.}

Copilot

Pull request overview

Adds a new dev tool (get-changed-stories) to the @storybook/addon-mcp MCP server so agents can discover Storybook stories marked as new/modified/affected and then selectively call preview-stories for URLs.

Changes:

Introduces get-changed-stories tool + registers it in the addon MCP server.
Updates Storybook/agent instruction templates to call get-changed-stories before preview-stories.
Adds unit tests covering the new tool’s core behavior (filtering/sorting/fallbacks/error case).

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
packages/addon-mcp/src/tools/tool-names.ts	Adds the new tool name constant.
packages/addon-mcp/src/tools/get-storybook-story-instructions.ts	Injects the new tool name into the instructions template rendering.
packages/addon-mcp/src/tools/get-changed-stories.ts	Implements the new tool using Storybook’s status store + story index metadata.
packages/addon-mcp/src/tools/get-changed-stories.test.ts	Adds tests for filtering, sorting, fallbacks, and error behavior.
packages/addon-mcp/src/mcp-handler.ts	Registers the new tool in server initialization.
packages/addon-mcp/src/instructions/storybook-story-instructions.md	Updates workflow guidance to call `get-changed-stories` first.
packages/addon-mcp/src/instructions/dev-instructions.md	Updates dev workflow guidance to incorporate the new tool.

- Introduced the `get-changed-stories` tool to retrieve metadata for stories marked as new, modified, or affected. - Updated `dev-instructions.md` and `storybook-story-instructions.md` to reflect the new workflow for calling `get-changed-stories` before `preview-stories`. - Added tests for the new tool to ensure correct functionality and output. - Updated tool names in relevant files to include the new tool.

pkg-pr-new · 2026-04-22T10:02:34Z

npm i https://pkg.pr.new/storybookjs/mcp/@storybook/addon-mcp@219

npm i https://pkg.pr.new/storybookjs/mcp/@storybook/mcp@219

commit: f922ce0

- Updated the shutdown process in `stopStorybook` to handle SIGTERM and escalate to SIGKILL after a grace period. - Increased the `STARTUP_TIMEOUT` from 30 seconds to 60 seconds in multiple test files to accommodate longer startup times. - Introduced a check for remote source availability in MCP Composition tests to conditionally assert the presence of documentation components. - Added a utility function to handle browser launch errors in MCP Endpoint tests, ensuring proper error handling in test assertions.

Copilot

Pull request overview

Copilot reviewed 13 out of 16 changed files in this pull request and generated 4 comments.

Files not reviewed (3)

apps/internal-storybook/pnpm-lock.yaml: Language not supported
eval/pnpm-lock.yaml: Language not supported
packages/addon-mcp/pnpm-lock.yaml: Language not supported

codecov · 2026-04-22T20:02:42Z

Bundle Report

Bundle size has no change ✅

…nce tests - Updated the `get-changed-stories` tool to return optional story metadata fields (title, name, importPath). - Improved the output formatting to group stories by their status (new, modified, affected) with detailed inline snapshots in tests. - Refactored test cases to utilize helper functions for better readability and maintainability.

…tuses are found, enhancing performance and adding corresponding test case.

Extend get-changed-stories tests to cover getAll() and allStatuses/single-status fallback shapes so support for Storybook internal variants is protected from regressions. Made-with: Cursor

Remove hard line breaks from preview-link guidance and update instruction snapshots so tests assert semantic content instead of incidental whitespace. Made-with: Cursor

Remove hard-wrapped list formatting and switch the changed-stories fallback URL to a relative path so guidance stays correct across non-default Storybook origins. Made-with: Cursor

Copilot

Pull request overview

Copilot reviewed 14 out of 17 changed files in this pull request and generated 5 comments.

Files not reviewed (3)

apps/internal-storybook/pnpm-lock.yaml: Language not supported
eval/pnpm-lock.yaml: Language not supported
packages/addon-mcp/pnpm-lock.yaml: Language not supported

…is disabled

Copilot

Pull request overview

Copilot reviewed 17 out of 20 changed files in this pull request and generated 1 comment.

Files not reviewed (3)

apps/internal-storybook/pnpm-lock.yaml: Language not supported
eval/pnpm-lock.yaml: Language not supported
packages/addon-mcp/pnpm-lock.yaml: Language not supported

Copilot

Pull request overview

Copilot reviewed 16 out of 20 changed files in this pull request and generated 2 comments.

Files not reviewed (3)

apps/internal-storybook/pnpm-lock.yaml: Language not supported
eval/pnpm-lock.yaml: Language not supported
packages/addon-mcp/pnpm-lock.yaml: Language not supported

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Copilot

Pull request overview

Copilot reviewed 16 out of 19 changed files in this pull request and generated 1 comment.

Files not reviewed (3)

apps/internal-storybook/pnpm-lock.yaml: Language not supported
eval/pnpm-lock.yaml: Language not supported
packages/addon-mcp/pnpm-lock.yaml: Language not supported

Copilot

Pull request overview

Copilot reviewed 16 out of 19 changed files in this pull request and generated 4 comments.

Files not reviewed (3)

apps/internal-storybook/pnpm-lock.yaml: Language not supported
eval/pnpm-lock.yaml: Language not supported
packages/addon-mcp/pnpm-lock.yaml: Language not supported

…test.ts Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Copilot

Pull request overview

Copilot reviewed 16 out of 19 changed files in this pull request and generated 1 comment.

Files not reviewed (3)

apps/internal-storybook/pnpm-lock.yaml: Language not supported
eval/pnpm-lock.yaml: Language not supported
packages/addon-mcp/pnpm-lock.yaml: Language not supported

Copilot · 2026-04-30T12:19:53Z

+	typeId: string;
+	storyId: string;
+	title: string;
+	description: string;
+	data?: any;


The Status/StatusesByStoryIdAndTypeId typings are stricter than what the status-store objects actually provide (e.g. tests and likely runtime only include value/storyId). Because statusStore.getAll() is force-cast, these required fields (typeId, title, description) can mislead future code into assuming they exist. Consider modeling a minimal shape for this tool (e.g. { storyId: string; value: StatusValue }) or making the extra fields optional; also prefer unknown over any for data if it’s not used here.

Suggested change

typeId: string;

storyId: string;

title: string;

description: string;

data?: any;

storyId: string;

typeId?: string;

title?: string;

description?: string;

data?: unknown;

Copilot AI review requested due to automatic review settings April 22, 2026 03:27

ghengeveld requested review from JReinhold and valentinpalkovic April 22, 2026 03:27

Copilot started reviewing on behalf of ghengeveld April 22, 2026 03:28 View session

Copilot AI reviewed Apr 22, 2026

View reviewed changes

ghengeveld added 2 commits April 22, 2026 04:57

Update Storybook packages

aee78f6

ghengeveld force-pushed the get-changed-stories branch from bfe77f3 to aee78f6 Compare April 22, 2026 10:01

Copilot AI review requested due to automatic review settings April 22, 2026 14:16

Copilot started reviewing on behalf of ghengeveld April 22, 2026 14:16 View session

Copilot AI reviewed Apr 22, 2026

View reviewed changes

ghengeveld mentioned this pull request Apr 27, 2026

Docs: Update AI docs to include get-changed-stories tool storybookjs/storybook#34643

Open

ghengeveld added 6 commits April 28, 2026 11:05

Cleanup

63a1fb1

Implement early return in getChangedStories tool when no relevant sta…

0f33863

…tuses are found, enhancing performance and adding corresponding test case.

Add coverage for status-store compatibility paths.

7403d35

Extend get-changed-stories tests to cover getAll() and allStatuses/single-status fallback shapes so support for Storybook internal variants is protected from regressions. Made-with: Cursor

Normalize dev instruction markdown formatting.

85aa4f4

Remove hard line breaks from preview-link guidance and update instruction snapshots so tests assert semantic content instead of incidental whitespace. Made-with: Cursor

Refine story-linking fallback guidance in instructions.

8f1bce8

Remove hard-wrapped list formatting and switch the changed-stories fallback URL to a relative path so guidance stays correct across non-default Storybook origins. Made-with: Cursor

Copilot AI review requested due to automatic review settings April 28, 2026 13:20

Copilot started reviewing on behalf of ghengeveld April 28, 2026 13:21 View session

Add changeset

6684af6

ghengeveld force-pushed the get-changed-stories branch from acf59eb to 6684af6 Compare April 28, 2026 13:25

Copilot AI reviewed Apr 28, 2026

View reviewed changes

Formatting

46c2771

ghengeveld added 2 commits April 30, 2026 09:27

Do not include get-changed-stories instructions when changeDetection …

d2d0c5c

…is disabled

Handle Copilot review feedback

60ce580

Copilot AI review requested due to automatic review settings April 30, 2026 07:41

Copilot started reviewing on behalf of ghengeveld April 30, 2026 07:41 View session

Copilot AI reviewed Apr 30, 2026

View reviewed changes

Comment thread packages/addon-mcp/src/tools/get-changed-stories.ts Outdated

ghengeveld added 4 commits April 30, 2026 10:08

Upgrade to latest Storybook prerelease

ef1008d

Fix tool order

7eae68b

Revert e2e test changes

69a656d

Improve type

c7ff8dd

Copilot AI review requested due to automatic review settings April 30, 2026 08:39

Copilot AI reviewed Apr 30, 2026

View reviewed changes

Comment thread packages/addon-mcp/src/instructions/build-server-instructions.ts Outdated

Comment thread .changeset/icy-walls-exist.md

JReinhold approved these changes Apr 30, 2026

View reviewed changes

ghengeveld and others added 2 commits April 30, 2026 10:51

Omit changes for stories that are not in the index

27f434f

Update packages/addon-mcp/src/instructions/build-server-instructions.ts

1bae9bd

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Copilot AI review requested due to automatic review settings April 30, 2026 08:52

Copilot started reviewing on behalf of ghengeveld April 30, 2026 08:53 View session

Copilot AI reviewed Apr 30, 2026

View reviewed changes

Comment thread packages/addon-mcp/src/tools/get-changed-stories.ts

ghengeveld added 2 commits April 30, 2026 13:55

Update test to omit stories not in the index

80654ab

Add changeDetectionEnabled flag to buildServerInstructions tests

61787b2

Copilot AI review requested due to automatic review settings April 30, 2026 12:04

Copilot started reviewing on behalf of ghengeveld April 30, 2026 12:05 View session

Upgrade storybook

ca2c9fa

Copilot AI reviewed Apr 30, 2026

View reviewed changes

Comment thread apps/internal-storybook/tests/helpers.ts

Comment thread packages/addon-mcp/src/tools/get-changed-stories.ts

Comment thread packages/addon-mcp/src/tools/get-changed-stories.ts

Comment thread packages/addon-mcp/src/tools/get-storybook-story-instructions.test.ts

Update packages/addon-mcp/src/tools/get-storybook-story-instructions.…

f922ce0

…test.ts Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Copilot AI review requested due to automatic review settings April 30, 2026 12:15

Copilot started reviewing on behalf of ghengeveld April 30, 2026 12:15 View session

ghengeveld merged commit d4c7876 into main Apr 30, 2026
14 of 15 checks passed

ghengeveld deleted the get-changed-stories branch April 30, 2026 12:18

storybook-app-bot Bot mentioned this pull request Apr 30, 2026

Version Packages #223

Open

Copilot AI reviewed Apr 30, 2026

View reviewed changes

Conversation

ghengeveld commented Apr 22, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

changeset-bot Bot commented Apr 22, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

🦋 Changeset detected

Uh oh!

netlify Bot commented Apr 22, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

✅ Deploy Preview for storybook-mcp-self-host-example canceled.

Uh oh!

codecov Bot commented Apr 22, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

❌ 3 Tests Failed:

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Reviewed changes

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

pkg-pr-new Bot commented Apr 22, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

codecov Bot commented Apr 22, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Bundle Report

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Uh oh!

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Uh oh!

Uh oh!

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Uh oh!

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Uh oh!

Copilot AI Apr 30, 2026

ghengeveld commented Apr 22, 2026 •

edited

Loading

changeset-bot Bot commented Apr 22, 2026 •

edited

Loading

netlify Bot commented Apr 22, 2026 •

edited

Loading

codecov Bot commented Apr 22, 2026 •

edited

Loading

pkg-pr-new Bot commented Apr 22, 2026 •

edited

Loading

codecov Bot commented Apr 22, 2026 •

edited

Loading