The `@boneskull/typedoc-plugin-mermaid` creates both dark and light theme
variants of each diagram, each with identical marker IDs (e.g., `#arrowhead`).
When mermaid renders SVGs at runtime, lines reference `url(#arrowhead)`, but
the browser resolves this to the first match in document order — the hidden
dark-theme SVG — causing arrows to be invisible.
The fix removes dark-theme `<div class="mermaid dark">` elements at build time,
leaving only one SVG per diagram with unique marker IDs. A CSS filter
(`filter: invert(1) hue-rotate(180deg)`) handles dark mode styling instead.
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>
Previously, the script only supported extracting regions from `.ts/.tsx`
files using the `#regionName` syntax. Now it also supports including
entire files without a region specifier, enabling sync of any file type
(JSON, YAML, shell scripts, etc.) into documentation.
Changes:
- Make `#regionName` optional in the `source=""` attribute
- Accept any fence language (not just `ts`/`tsx`)
- Simplify cache to flat map with composite keys
- Add validation error for region extraction on non-TypeScript files
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Rename `startServer` to `startStreamableHTTPServer` and add a new
`startStdioServer` helper to make the transport type explicit. Remove
the `ServerOptions` interface in favor of reading `PORT` directly from
the environment inside the function (defaulting to `3001`).
Also update Python examples to default to port `3001` for consistency.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
- Add importmap entry for main SDK exports (applyDocumentTheme, etc.)
- Import and apply host theme and styles on context changes
- Apply initial host context theme/styles when app connects
- Update CSS to use [data-theme="dark"] selector for host-provided themes
- Keep @media prefers-color-scheme as fallback for standalone mode
- Add color-scheme meta tag for native element theming
* Add appCapabilities.availableDisplayModes documentation to spec
Document the availableDisplayModes field in McpUiAppCapabilities that allows
apps to declare which display modes they support. This enables hosts to
compute the intersection of host and app capabilities and only offer
appropriate display mode controls.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>
* Address PR review feedback
- Change "Guest UI" to "View" terminology
- Add "View" prefix to availableDisplayModes heading for disambiguation
- Remove intersection logic - host only checks its own supported modes
- Remove assumption that apps must support inline mode
- Simplify host behavior to honor/reject based on its own capabilities
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>
* Add appCapabilities.availableDisplayModes to types
- Add `availableDisplayModes` field to `McpUiAppCapabilities` so apps can
declare which display modes they support
- Change `HostContext.availableDisplayModes` type from `string[]` to
`McpUiDisplayMode[]` for type safety
- Regenerate schemas
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>
* Address Olivier's feedback - consolidate display mode docs
- Remove separate "App Capabilities" section for availableDisplayModes
- Add display mode requirements to existing ui/request-display-mode section:
- Host MUST NOT switch View to mode not in appCapabilities.availableDisplayModes
- Host MAY decline requests from Views that didn't declare modes
- View MUST declare supported modes during initialization
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>
* Restore McpUiAppCapabilities docs and fix display mode clause
- Restore McpUiAppCapabilities interface documentation with availableDisplayModes
- Restore "View MUST check if the requested mode is in availableDisplayModes
from host context" clause that was accidentally removed
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>
* Create unified Display Modes section
Consolidate all display mode documentation into a single section:
- Display mode types (inline, fullscreen, pip)
- Declaring support from View (appCapabilities.availableDisplayModes)
- Declaring support from Host (HostContext.availableDisplayModes)
- Requesting changes (ui/request-display-mode)
- Notifying changes (ui/notifications/host-context-changed)
- All MUST/SHOULD requirements for View and Host behavior
The ui/request-display-mode in Requests section now references
the Display Modes section for behavior details.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>
* Remove mode coercion clause from display modes
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>
* Regenerate schemas with correct version
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>
---------
Co-authored-by: Claude <noreply@anthropic.com>
* feat(basic-host): add theme toggle and MCP style variables
Add theme support to basic-host example:
- theme.ts: Global theme manager with light/dark toggle
- host-styles.ts: Full set of MCP CSS variables using light-dark()
- ThemeToggle component with sun/moon icons
- Theme-aware CSS using CSS custom properties
- Pass theme + styles to apps via hostContext
- Notify apps when theme changes via sendHostContextChange
Apps now receive:
- hostContext.theme: 'light' | 'dark'
- hostContext.styles.variables: All 60+ MCP CSS variables
- onhostcontextchanged notifications when theme changes
* test: update e2e goldens for theme changes
* fix(say-server): add --index flag to uv run for PyPI resolution
The pocket-tts dependency wasn't resolving without explicit --index flag
when invoked via npm scripts.
* fix(qr-server): allow Docker bridge IP in transport security
Add 172.17.0.1:* to allowed_hosts to fix 421 Misdirected Request errors
when the server is accessed from Docker containers.
* feat(server): add hasUiSupport/getUiCapability for experimental+extensions
Support double-tagging for MCP Apps capability negotiation:
- Check both experimental and extensions fields in client capabilities
- Add hasUiSupport() to easily check if client supports MCP Apps
- Add getUiCapability() to retrieve the capability settings
- Update spec to document both capability locations
This enables forward compatibility as MCP transitions from experimental
to the extensions field (SEP-1724).
Claude-Generated-By: Claude Code (cli/claude-opus-4-5=100%)
Claude-Steers: 0
Claude-Permission-Prompts: 0
Claude-Escapes: 0
* fix: update @types/node version in package-lock.json
Replace invalid 22.19.5/22.19.6/22.19.7 versions with valid 22.19.3
* docs(spec): clarify hosts SHOULD double-tag, servers SHOULD check both
- Hosts SHOULD advertise capabilities in both experimental and extensions
- Servers SHOULD check both locations, preferring extensions when present
- Updated example to show double-tagging pattern
* chore: remove double-tagging recommendation, keep hasUiSupport helper
Reverts the spec changes that recommended clients double-tag capabilities
in both experimental and extensions fields. The helper functions remain
as they're useful for checking capability in either location.
* refactor(server): simplify to only getUiCapability, remove hasUiSupport
- Remove hasUiSupport function (use getUiCapability directly)
- Remove double-tagging logic (only check extensions field)
- Add ClientCapabilitiesWithExtensions type using SDK's ClientCapabilities
- Update spec to use getUiCapability
- Simplify tests
* fix: update @see link to getUiCapability
* refactor(server): inline ClientCapabilitiesWithExtensions type in getUiCapability
* refactor: move McpUiClientCapabilities to spec.types.ts
* fix(test): update map-server test to expect 'CesiumJS Map Server'
The server name was renamed but the E2E test config was not updated.
* fix: change in another file
---------
Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: Olivier Chafik <ochafik@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>
* Update spec: drop Intents reference, rename Notify to Log
- Remove "intent" from the list of MCP-UI message types in the rationale
section (Intents concept is being dropped)
- Rename "Notify" to "Log" in the lifecycle diagram to better reflect
that notifications/message is for debugging/telemetry logging, not
for sending messages to the chat (which is now ui/message)
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
* spec: remove Intents reference from rationale
Remove 'intent' from the list of MCP-UI message types - Intents concept was dropped in earlier discussions.
---------
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
* feat(examples): add debug-server example
A comprehensive debug/development server for testing MCP Apps SDK features:
- Vanilla TypeScript UI with collapsible panels
- Message visualization (sent, received, errors)
- Server tool calling interface
- Multiple tool endpoints for testing
* refactor(debug-server): convert to React
- Replace vanilla TypeScript with React components
- Add comprehensive Host Styles panel showing all CSS variables grouped by category
- Use React hooks (useApp, useHostStyles, useAutoResize)
- Cleaner state management with useReducer for event log
- Collapsible sections for better organization
- CSS modules for scoped styling
* fix(debug-server): correct server name in main.ts
* Revert "refactor(debug-server): convert to React"
This reverts commit 5d22d2daa9a98ba412892447202ef10fbdb62f5b.
* fix(debug-server): update default values for multipleBlocks and includeMeta
* fix(debug-server): correct serve script and server name
- serve script now runs main.ts instead of server.ts
- Updated server name to 'Debug Server'
- Fixed npx command in comment
* fix: increase maxHeight to 6000px and add tools capability to debug app
- basic-host: Increase maxHeight from 600 to 6000px
- debug-server: Add tools capability to enable oncalltool/onlisttools handlers
* fix(debug-server): use consistent callback names for event tracking
Event types now match callback names (ontoolinput, ontoolresult, etc.)
so the Callback Status panel shows correct counts and payloads.
* feat(debug-server): add Update (Image) button for model context
* feat(debug-server): add expandable event log entries
- Click on any event log row to expand/collapse
- Arrow indicator rotates when expanded
- Full JSON payload shown indented in pre block
- Max height with scroll for large payloads
* style(debug-server): format long line in fullPayload function
* test(debug-server): add to E2E tests and screenshot specs
* chore: regenerate package-lock.json for cross-platform compatibility
* update dep
* fix(map-server): simplify location update message format
* fix(say-server): pass host to streamable_http_app for non-localhost deployments
* refactor(pdf-server): simplify to stateless range-query architecture
- Remove caching/indexing in favor of direct HTTP Range requests
- Use HEAD requests to get file size (no full download)
- Use Range requests to proxy byte chunks (no caching)
- Local files: fs.read with offset/length
- Remote files: HTTP Range header
- Zero memory footprint (no PDF caching)
- Truly stateless (no session management needed)
- Single server.ts (~350 lines) + main.ts CLI entry point
- Instant startup (no preloading)
- Security: whitelist local files, allowed origins
Removed files:
- src/pdf-indexer.ts
- src/pdf-loader.ts
- src/types.ts
* feat(pdf-server): add dark mode support
- Add CSS variables with light-dark() function for automatic theme switching
- Sync theme with host via applyDocumentTheme()
- Apply host CSS variables via applyHostStyleVariables()
* feat(pdf-server): add list_pdfs tool back
Lists local files and allowed remote origins.
Also moves CHUNK_SIZE to module level constant.
* feat(pdf-server): improve tool descriptions and increase context limit
- display_pdf: list all allowed domains in description
- Increase MAX_MODEL_CONTEXT_LENGTH to 15000
- Move CHUNK_SIZE to module level constant
* chore(say-server): remove deployment docs from repo
Keep server.py fix for non-localhost deployments.
Deployment docs kept locally but not in repo.
* refactor(pdf-server): simplify updateModelContext format
- Add widget ID for multi-widget disambiguation
- Use concise header: 'PDF viewer (id) | title | Current Page: X/Y'
- Add 'Page content:' prefix before text
- Keep selection markers (<pdf-selection>...</pdf-selection>)
* refactor: rename widgetUUID to viewUUID for consistency
Aligns with main's standardization on 'view' terminology (PR #325).
Also dynamically generate allowed domains in display_pdf description.
* viewUUID
* fix(map-server): fix syntax error in location update message
* fix(pdf-server): restore package.json, improve server docs
- Restore --external pdfjs-dist in build
- Rewrite server.ts header for newcomers (list tools, not implementation details)
- Minimize main.ts diff
* chore(pdf-server): remove unused addAllowedOrigin/addAllowedLocalFile
* docs(pdf-server): update README for new architecture
* docs(pdf-server): restore full README, add theming section, remove get_pdf_info
* rm
* fix(pdf-server): restore createMcpExpressApp and error handling
- Use createMcpExpressApp for DNS rebinding protection
- Restore error callback in app.listen()
* fix(say-server): pass host to streamable_http_app for non-localhost deployments
* chore(say-server): remove deployment docs from repo
* widgetId->tool id
* fix(map-server): add null check for center in location update
chore(pdf-server): dedupe and sort allowed origins
* fix(map-server): use transparent background for rounded corners
* prettier
* 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>
Configure TypeDoc to use the GitHub-styled theme for better visual
consistency with the project's GitHub presence. Also reorganize the
config options and enable group navigation for improved documentation
structure.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
* feat(qr-server): embed widget HTML for self-contained usage
Embed the widget HTML directly in server.py following the same pattern
as the say-server. This allows the QR server to be run without any
local file dependencies using `uv run <url>`.
The get_widget_html() function prefers the built version from dist/
for local development but falls back to the embedded HTML for unbundled
usage.
* refactor(qr-server): remove widget.html and simplify embedded HTML
Address PR review feedback:
- Remove separate widget.html file (no longer needed)
- Remove get_widget_html() function and dist/mcp-app.html reference
- Inline EMBEDDED_WIDGET_HTML directly in widget() resource
- Remove unused Path import
The server is now fully self-contained in a single file.
---------
Co-authored-by: Claude <noreply@anthropic.com>
Update the spec to clarify that:
- ui.domain format and validation rules are host-dependent
- Servers must consult host-specific documentation for expected format
- Common patterns: hash-based subdomains, URL-derived subdomains
- Updated examples to reflect realistic host-controlled domains
This addresses the gap between the spec's previous implied flexibility
(arbitrary domains like weather-widget.example.com) and real-world
constraints where hosts must control sandbox domains for security.
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>
