Update all documentation links from `modelcontextprotocol.github.io/ext-apps`
to the new custom domain across README.md, docs/, and example READMEs.
Add `cname` to the `peaceiris/actions-gh-pages` deploy action in
`.github/workflows/docs.yml` so the CNAME file persists across deploys.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
The term "external" is misleading for MCP Apps because developers
typically interpret it as "third-party." However, MCP App HTML runs in
a sandboxed iframe with no same-origin server, so *all* origins must be
declared—including where your own bundled JS/CSS is served from. Using
"network" instead avoids this confusion and aligns with the detailed
explanations in `patterns.md` and `spec.types.ts`.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Single quotes in `concurrently` commands work on Unix shells but not on
Windows Command Shell (`cmd.exe`), causing the `INPUT` environment
variable to not be set and npm scripts to fail with errors like:
'cross-env' is not recognized as an internal or external command
Error: INPUT environment variable is not set
Replace single quotes with escaped double quotes (`\"`) in npm scripts
in all example `package.json` files.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Adds a new section to the patterns guide explaining how to configure
Content Security Policy and CORS for MCP Apps that make network requests:
- CSP via `_meta.ui.csp` controls browser-side permissions (`connectDomains`,
`resourceDomains`)
- CORS via `_meta.ui.domain` provides a stable origin for API servers to
allowlist
Includes a type-checked example showing `computeAppDomainForClaude()` helper
that hashes an MCP server URL to create a stable `*.claudemcpcontent.com`
subdomain. Also adds `@see` links to `McpUiResourceMeta` and `McpUiResourceCsp`
in `registerAppResource` JSDoc.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
* docs: fix basic-host setup instructions in quickstart
Add missing root-level npm install and build steps before running
the basic-host example. Without these steps, the example fails because
it imports from dist/src/ which doesn't exist until the root package
is built.
Fixes setup failure when following quickstart tutorial.
* Update quickstart.md
Co-authored-by: Jonathan Hefner <jonathan@hefner.pro>
---------
Co-authored-by: Jonathan Hefner <jonathan@hefner.pro>
Clarifies when to use `localStorage` vs server-side storage for view state:
- Scope section intro to "recoverable" view state (easy to recreate)
- Add guidance for state representing user effort (bookmarks, annotations,
custom configurations) to use app-only tools instead
- Note that `viewUUID` should also be passed to app-only tools for scoping
- Clarify that example links are specifically for `localStorage` approach
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Document how to serve binary content (e.g., video) via MCP resources
as base64-encoded blobs. Includes server-side registration using the
`blob` field and client-side fetching with conversion to data URIs.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Documents the recommended approach for real-time dashboards that need to
poll server tools at regular intervals. Includes both Vanilla JS and
React examples with proper cleanup handling via `app.onteardown` and
`useEffect` cleanup functions respectively.
Also updates the "Tools that are private to Apps" section to mention
polling as a use case for app-only visibility.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Convert italic `_See example..._` text to `> [!NOTE]` callouts for better
visual prominence, and expand cross-references to include additional
relevant examples for each pattern.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
- Rename "host styling" section to "host context" and add safe area
insets handling
- Replace abstract `renderLoadingUI`/`renderFinalUI` example with
concrete code preview pattern for `ontoolinputpartial`
- Rename callback parameter `params` → `ctx` for clarity across all
`onhostcontextchanged` handlers
- Add CSS snippet for fullscreen border-radius handling
- Expand display mode example to show `availableDisplayModes` check
- Fix minor typos and wording consistency
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
The `extractRegion()` function in `sync-snippets.ts` used `indexOf()` to
find region markers like `//#region persistData`. This caused incorrect
matching when one region name was a prefix of another—searching for
`persistData` would match `//#region persistDataServer` first if it
appeared earlier in the file.
The fix detects the file's line ending style and appends it to region
markers, ensuring exact matches:
- `//#region persistData\n` no longer matches `//#region persistDataServer\n`
This corrects `docs/patterns.md` where the `persistData` code fence was
incorrectly showing server-side code instead of client-side localStorage
helpers.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
* chore: add stable spec release 2026-01-26
- Use git mv to copy specification from draft to specification/2026-01-26/apps.mdx (preserves history)
- Update status from 'Draft' to 'Stable (2026-01-26)'
- Add specification version table to README
- Update Resources section with links to both stable and draft specs
* chore: bump version to 1.0.0
- Update main package version from 0.4.2 to 1.0.0
- Update all example package versions to 1.0.0
- Regenerate package-lock.json
* prettier
* chore: align protocol version with spec release 2026-01-26
- Add 'Protocol Version: 2026-01-26' to spec header
- Update LATEST_PROTOCOL_VERSION from '2025-11-21' to '2026-01-26'
- Update spec examples to use '2026-01-26' protocol version
- Add '2025-11-21' to SUPPORTED_PROTOCOL_VERSIONS for backwards compatibility
* chore: update spec references to stable 2026-01-26
- Update typedoc.config.mjs navigation link
- Update docs/overview.md spec links (10 occurrences)
- Update plugins/mcp-apps/skills/create-mcp-app/SKILL.md spec link
- Update src/spec.types.ts @see links
- Update AGENTS.md spec path
- Regenerate src/generated/schema.ts with updated links
* chore: simplify versioning - first stable release
- Remove backwards compatibility version (2025-11-21) - this is the first stable release
- Remove redundant 'Protocol Version' header - spec version IS the protocol version
* chore: add history reference comment to stable spec
Update links from `claude.ai/docs/` to `claude.com/docs/` for the
remote and local MCP server configuration documentation.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Add Codex to the list of agents supporting skills in `agent-skills.md`.
Add Goose to the list of supported clients in `testing-mcp-apps.md` and
rename "VS Code Copilot" to "VS Code (Insiders)" for accuracy.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Add intro explaining what Agent Skills are and link to the two skill
files (`create-mcp-app`, `migrate-oai-app`). Reorganize headings and add
"Invoke a Skill" and "Test Your App" sections. Update `README.md` link
text and add tip to quickstart suggesting agent skills as an alternative.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Document how to test MCP Apps using `basic-host` and MCP Apps-compatible
hosts like Claude.ai and VS Code Copilot. Cover debugging features for
`basic-host`, and using `cloudflared` to expose local servers for remote
hosts.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Add framing prose to the migration guide to improve navigation:
- Expanded intro describing document purpose and how to use it
- Added note about features marked "Not yet implemented"
- Added brief transition sentences before Server-Side and Client-Side sections
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Add `docs/agent-skills.md` with installation instructions for multiple AI
coding agents including Claude Code, VS Code/Copilot, Gemini CLI, Cline,
and Goose. The guide provides three installation methods: Claude Code
plugin, Vercel Skills CLI (`npx skills add`), and manual installation.
Update `README.md` to link to the new guide and reframe the plugin
section around the broader "Agent Skills" concept.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Adds `docs/overview.md` covering the core concepts: architecture,
lifecycle, UI resources, bidirectional communication, theming, display
modes, and security. Includes mermaid flowchart and sequence diagrams.
Also adds the `@boneskull/typedoc-plugin-mermaid` TypeDoc plugin for
mermaid diagram support. However, the plugin handles HTML entities from
TypeDoc incorrectly, so `scripts/typedoc-plugin-fix-mermaid-entities.mjs`
decodes HTML entities before the plugin processes them.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Rewrites the Quickstart tutorial to provide a more focused, step-by-step
introduction to building MCP Apps. The guide now uses synced code fences
that pull from `examples/quickstart/`, ensuring all code shown in the
documentation is type-checked and tested.
Key improvements:
- Clearer project setup instructions with explicit commands
- Streamlined explanations of the tool + resource registration pattern
- Added screenshot showing the completed app
- E2E test coverage validates the example works end-to-end
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Migrate JSDoc and markdown documentation from `{@includeCode ./file#region}`
tags to inline code fences with `source="./file#region"` attributes.
Code examples are now visible directly in source files while remaining
type-checked via their `.examples.ts` source files.
Add `scripts/sync-snippets.ts` to extract code from `//#region` blocks
and sync it into labeled fences. Run with `npm run sync:snippets`.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
* docs: standardize UI terminology to use "view" consistently
Replaces "widget" and "Guest UI" terminology with "view" across
the codebase as decided in the community survey.
This change updates:
- Specification document
- SDK source code and JSDoc comments
- Example servers and documentation
- Plugin documentation and skills
Closes#71
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Add explicit backtick-wrapped display text to all `{@link}` tags for
monospace rendering in TypeDoc output. This improves readability by:
- Using monospace font for code references (types, methods, functions)
- Stripping module prefixes from display text (e.g., `app!App.connect`
displays as `App.connect`)
Updated files across the SDK including `App`, `AppBridge`,
`PostMessageTransport`, React hooks, server helpers, types, and
documentation.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Each pattern section now includes a "See examples/..." link pointing
to a working implementation in the repository. This helps readers
quickly find real code demonstrating each pattern.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Add new pattern showing how to combine `updateModelContext()` with
`sendMessage()` when data exceeds message size limits. The example
demonstrates offloading a large transcript to model context first,
then sending a brief trigger message.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Documents `updateModelContext` for keeping the model informed about user
interactions. The example shows a shopping cart use case with YAML frontmatter
for structured, parseable context.
Also refines the `updateModelContext` JSDoc to clarify the difference from
`sendMessage` and removes the `structuredContent` example.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Add `IntersectionObserver` pattern for pausing expensive operations
(animations, WebGL, polling) when widgets scroll out of view.
- Add `visibilityBasedPause` example to `patterns.tsx` with play/pause
callbacks and `onteardown` cleanup
- Document pattern in `patterns.md` with link to MDN docs
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Replaces the TODO stub with complete server-side and client-side examples
based on the `pdf-server` implementation pattern:
- Server: shows returning `widgetUUID` via `CallToolResult._meta`
- Client: shows receiving UUID via `ontoolresult`, using it as localStorage
key with generic `saveState<T>()` / `loadState<T>()` helpers
Also clarifies the distinction between widget state persistence (UI state
surviving page reloads) and `updateModelContext()` (model-visible state).
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Adds JSDoc example `App_updateModelContext_reportError` showing how to
report runtime errors (e.g., microphone permission denied) back to the
model using `updateModelContext`.
Updates patterns.md with clearer framing:
- Server-side (tool handler): return `{ isError: true, ... }`
- Client-side (app): use `updateModelContext` for runtime errors
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
- Expand `App_ontoolinputpartial_progressiveRendering` example in
`app.examples.ts` to show full state management pattern with
`toolInputs` and `toolInputsPartial` variables
- Add healed JSON caveat to `ontoolinputpartial` JSDoc in `app.ts`
- Update `patterns.md` to reference the expanded example and document
the streaming preview pattern
- Remove empty `lowerPerceivedLatency` placeholder from `patterns.tsx`
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Add `App_onhostcontextchanged_respondToDisplayMode` example showing how to
listen for display mode changes and update UI with `classList.toggle()`.
Update `App_requestDisplayMode_fullscreen` to `App_requestDisplayMode_toggle`
to show the common toggle pattern checking `availableDisplayModes` first.
Refactor full examples (pdf-server, shadertoy-server) to use
`classList.toggle(class, condition)` instead of add/remove branches.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Merge the separate "Support native host styling using CSS variables" and
"Reacting to light/dark theme changes" sections into a single "Matching
host styling (CSS variables, theme, and fonts)" pattern. This provides
clearer guidance by covering all three concerns together.
- Rename `docs/patterns.ts` to `docs/patterns.tsx` for JSX support
- Add `hostStylingVanillaJs` and `hostStylingReact` consolidated examples
- Enhance `applyHostFonts_fromHostContext` to apply initial fonts after
`connect()`, not just on context change
- Add CSS usage examples to `applyHostStyleVariables()` JSDoc
- Update font example to use `var(--font-sans, system-ui, sans-serif)`
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Reference existing JSDoc examples instead of maintaining a separate one in
`docs/patterns.ts`:
- Vanilla JS: `applyDocumentTheme_fromHostContext` from `styles.examples.ts`
- React: `useDocumentTheme_conditionalRender` for reactive theme reading
Expand `applyDocumentTheme_fromHostContext` example to show both the
`onhostcontextchanged` handler and initial theme application after `connect()`.
Note in the docs that `useHostStyles()` applies theme automatically, so React
apps don't need additional setup unless they want to read the theme reactively
for conditional rendering.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
References existing type-checked examples instead of a stub:
- Vanilla JS: `applyHostStyleVariables_fromHostContext` from `src/styles.examples.ts`
- React: `useHostStyles_basicUsage` from `src/react/useHostStyles.examples.tsx`
Expanded `applyHostStyleVariables_fromHostContext` to show the full pattern:
using CSS variables in styles, applying on `onhostcontextchanged`, and
applying initial styles after `connect()`.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Document the `_meta.ui.visibility: ["app"]` feature in `docs/patterns.md`
by referencing the existing type-checked example from
`src/server/index.examples.ts#registerAppTool_toolVisibility`.
- Fix typo: `["apps"]` → `["app"]` (singular)
- Remove placeholder function from `docs/patterns.ts`
- Expand description to explain use cases
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Introduces a patterns documentation page for common MCP Apps recipes.
The skeleton includes TODO sections for: perceived latency, iframe/MCP Apps
coexistence, authenticated calls, private tools, theme changes, fullscreen,
host styling, data persistence, OpenAI migration, and error handling.
- Add `docs/patterns.md` to `projectDocuments` in `typedoc.config.mjs`
- Add `docs/patterns.ts` companion file with region-delimited code stubs
- Include `docs/**/*.ts` in `tsconfig.json` for type-checking
- Document the standalone docs pattern in `CLAUDE.md`
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Adds a new skill (`plugins/mcp-apps/skills/migrate-oai-app/SKILL.md`)
that guides developers through migrating OpenAI Apps SDK applications
to the MCP Apps SDK. Includes API mapping tables, CSP configuration
guidance, and a "Before Finishing" checklist.
Also fixes the `registerAppResource()` JSDoc example in `src/server/index.ts`
to show CSP configuration in the correct location (on the content item,
not the resource config).
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
- Reorganize prerequisites to emphasize MCP concepts first
- Add tip linking to official MCP quickstart for newcomers
- Update install command to use published npm package
- Remove zod dependency and `structuredContent` usage
- Use `RESOURCE_MIME_TYPE` constant for consistency
- Add clearer comments explaining tool/resource registration
- Simplify UI to extract time from text content
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Remove 'server.ts' argument from 'npx tsc --noEmit' command.
When a file is specified directly, TypeScript ignores tsconfig.json,
causing skipLibCheck and other options to not apply. This results in
errors from node_modules (especially zod v4 locale files).
The correct command lets tsc use the project's tsconfig.json settings.
* docs: add tool visibility and restructure _meta.ui
- Restructure tool metadata: `_meta["ui/resourceUri"]` → `_meta.ui.resourceUri`
- Add `visibility` array field: ["model"], ["apps"], or ["model", "apps"]
- Default ["model"] preserves standard MCP behavior
- ["apps"] enables widget-only tools hidden from agent
- Add McpUiToolMeta interface for type safety
- Add Design Decision #4 explaining approach vs OpenAI's two-field model
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>
* address PR review comments
- Change default visibility to ["model", "apps"]
- Add deprecation notice for flat ui/resourceUri format
- Add McpUiToolMeta and McpUiToolVisibility to spec.types.ts
- Improve tools/list and tools/call behavior wording
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>
* chore: regenerate schemas for McpUiToolMeta types
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>
* feat: tool visibility and nested _meta.ui format
- Rename visibility "apps" → "app" in McpUiToolVisibility type
- Add _meta.ui.resourceUri nested format (deprecate flat format)
- Add getToolUiResourceUri() utility with backward compatibility
- Add visibility demo to system-monitor-server:
- get-system-stats: visibility ["model"] with resourceUri
- refresh-stats: visibility ["app"] (app-only polling)
- Update all example servers to use new _meta.ui format
- Add 11 unit tests for getToolUiResourceUri()
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>
* chore: regenerate schemas with updated dependencies
* feat: export McpUiToolMeta type and add type annotations
- Export McpUiToolMeta and McpUiToolVisibility types from types.ts
- Export corresponding Zod schemas (McpUiToolMetaSchema, McpUiToolVisibilitySchema)
- Add `as McpUiToolMeta` type annotations to all example servers
- Update docs/quickstart.md with proper typing
Ensures type safety for `_meta.ui` tool metadata across the codebase.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>
* feat: add server helpers and optional connect() transport
Add `src/server/` with convenience functions for registering MCP App tools
and resources:
- `registerAppTool(server, name, config, handler)`
- `registerAppResource(server, name, uri, config, callback)`
The `transport` parameter in `App.connect()` is now optional, defaulting to
`PostMessageTransport(window.parent)`.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>
* Update src/server/index.ts
Co-authored-by: Jonathan Hefner <jonathan@hefner.pro>
* feat: update McpUiAppToolConfig to support both _meta.ui and flat formats
* refactor: simplify server helper imports
* docs: add deprecation notice and improve resourceUri documentation
* feat: add backward compat normalization in registerAppTool
- If _meta.ui.resourceUri is set, also set legacy flat key
- If legacy flat key is set, also set _meta.ui.resourceUri
- Preserves existing visibility when merging
- Does not overwrite if both formats already set
* refactor: avoid mutating config arg in registerAppTool
* style: format with prettier
---------
Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: Olivier Chafik <ochafik@anthropic.com>
Co-authored-by: Jonathan Hefner <jonathan@hefner.pro>
