npm normalizes the bare https URL to git+https://….git at publish time
and warns about it on every package. Storing the canonical form removes
the warning and matches what npm's trusted-publisher check compares
against the repository.
The Windows WSL job is the critical path of every CI run (589 to 752 s).
Its checkout sits on the Windows drive, which WSL reaches over 9P, and
writing node_modules there is what makes npm ci take about three minutes
where the Linux job takes 23 s. The step now copies the tree onto the
distro's ext4 filesystem before installing and building, as Microsoft's
WSL guidance recommends for I/O-heavy work.
The e2e job downloaded the full Chromium build (about 165 MB) on every
run, but a headless run with no channel launches chromium-headless-shell
and never opens it. `--only-shell` skips that download.
Every tsconfig now lists the @types packages it uses (node, bun,
vite/client, dom-speech-recognition) instead of relying on TypeScript
auto-including everything under node_modules/@types. On TypeScript 5.9
this is a no-op: identical diagnostics across all 48 projects and
byte-identical emitted .d.ts files. It is a prerequisite for TypeScript 7,
which drops the auto-inclusion; with these lists the Go compiler passes
all 48 projects, so that upgrade becomes a version bump once TypeDoc
supports it.
Two cache-based approaches were evaluated and rejected: an npm cache for
the WSL job (npm ci is slow there because of 9P, not downloads, and a
prefix-restored cache grows without bound) and a Playwright browser cache
(Playwright's docs advise against it; the download is under 10 s).
The client, core and server packages become ^2.0.0 peers and client is
now a required peer (App and AppBridge extend its Protocol class);
server stays optional for View-only consumers. Examples move to
zod ^4.2.0 to match the library peer range.
The root package is not yet published at 2.0.0, so the lockfile now
links the examples' @modelcontextprotocol/ext-apps dependency to the
repository root instead of a registry copy. This drops the stale 1.x
tarball (and its sdk 1.x peer) from the lockfile and makes
scripts/link-self.mjs a no-op.
App and AppBridge extend the public Protocol from @modelcontextprotocol/client; the iframe wire protocol (ui/initialize only) is unchanged. Peers move to the split SDK 2.0 packages with client and server as optional role peers. Fixups (lockfile, peer ranges, restored handler guards, docs, wire-compat tests) follow in a separate PR.
Co-authored-by: Andrew Khadder <andrew@manufact.com>
Co-authored-by: Felix Weinberger <fweinberger@anthropic.com>
Closes#702
No SDK API changes since 1.7.2.
Examples:
- Add lazy-auth-server example (#679)
- Publish lazy-auth-server to npm (added to publish workflows)
Also syncs example dependency ranges to ^1.7.0 (output of npm run bump).
No SDK API changes since 1.7.1.
Examples:
- pdf-server: switch pdf-lib to maintained @cantoo/pdf-lib fork (#651)
- bump example transitives to latest patches (#658)
* feat: Add tool registration and bidirectional tool support
This PR adds comprehensive tool support for MCP Apps, enabling apps
to register their own tools and handle tool calls from the host.
- Add `registerTool()` method for registering tools with input/output schemas
- Add `oncalltool` setter for handling tool call requests from host
- Add `onlisttools` setter for handling tool list requests from host
- Add `sendToolListChanged()` for notifying host of tool updates
- Registered tools support enable/disable/update/remove operations
- Add `sendCallTool()` method for calling tools on the app
- Add `sendListTools()` method for listing available app tools
- Fix: Use correct ListToolsResultSchema (was ListToolsRequestSchema)
- Add comprehensive tests for tool registration lifecycle
- Add tests for input/output schema validation
- Add tests for bidirectional tool call communication
- Add tests for tool list change notifications
- All 27 tests passing
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>
* nits
* Update apps.mdx
* feat: Add automatic request handlers for app tool registration
Implement automatic `oncalltool` and `onlisttools` handlers that are
initialized when apps register tools. This removes the need for manual
handler setup and ensures tools work seamlessly out of the box.
- Add automatic `oncalltool` handler that routes calls to registered tools
- Add automatic `onlisttools` handler that returns full Tool objects with JSON schemas
- Convert Zod schemas to MCP-compliant JSON Schema using `zod-to-json-schema`
- Add 27 comprehensive tests covering automatic handlers and tool lifecycle
- Test coverage includes error handling, schema validation, and multi-app isolation
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>
* type updates
* fix: Ensure tools/list returns valid JSON Schema for all tools
- Always return inputSchema as object (never undefined)
- Keep filter for enabled tools only in list
- Update test to match behavior (only enabled tools in list)
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>
* type updates
* rm zod-to-json-schema
* fix: Update RegisteredTool to use 'handler' instead of 'callback' (SDK API change)
* refactor: Rename sendCallTool/sendListTools to callTool/listTools
Avoid double-verb naming pattern for consistency with existing API.
* feat: Add screenshot and click support to SDK
- Add McpUiScreenshotRequest/Result and McpUiClickRequest/Result types
- Add onscreenshot and onclick handlers to App class
- Add screenshot() and click() methods to AppBridge class
- Generate updated Zod schemas
* feat(map-server): Enable registerTool with navigate-to and get-current-view
- Uncomment and fix the navigate-to tool for animated navigation
- Add get-current-view tool to query camera position and bounding box
- Add flyToBoundingBox function for smooth camera animation
- Add setLabel function for displaying location labels
* feat(pdf-server): Add widget interaction tools
- get-document-info: Get title, current page, total pages, zoom level
- go-to-page: Navigate to a specific page
- get-page-text: Extract text from a page
- search-text: Search for text across the document
- set-zoom: Adjust zoom level
* feat(shadertoy-server): Add widget interaction tools
* feat(examples): Add widget interaction tools to budget-allocator, shadertoy, wiki-explorer, and threejs
budget-allocator:
- get-allocations: Get current budget allocations
- set-allocation: Set allocation for a category
- set-total-budget: Adjust total budget
- set-company-stage: Change stage for benchmarks
- get-benchmark-comparison: Compare against benchmarks
shadertoy:
- set-shader-source: Update shader source code
- get-shader-info: Get shader source and compilation status
- Sends errors via updateModelContext
wiki-explorer:
- search-article: Search for Wikipedia articles
- get-current-article: Get current article info
- highlight-node: Highlight a graph node
- get-visible-nodes: List visible nodes
threejs:
- set-scene-source: Update the Three.js scene source code
- get-scene-info: Get current scene state and any errors
- Sends syntax errors to model via updateModelContext
* feat: Add expand-node tool to wiki-explorer and update tool descriptions
Wiki Explorer:
- Add expand-node tool - the critical missing tool for graph exploration
- Claude can now programmatically expand nodes to discover linked articles
Server descriptions updated to mention widget tools:
- map-server: navigate-to, get-current-view
- pdf-server: go-to-page, get-page-text, search-text, set-zoom, get-document-info
- budget-allocator: get-allocations, set-allocation, set-total-budget, etc.
- shadertoy: set-shader-source, get-shader-info
- wiki-explorer: expand-node, search-article, highlight-node, etc.
All descriptions now mention 'Use list_widget_tools to discover available actions.'
* refactor: Simplify tool descriptions - remove client implementation details
The server tool descriptions now just mention that widgets are interactive
and can be controlled, without teaching the model about list_widget_tools
(which is the client's responsibility to teach).
Before: 'The widget exposes tools: X, Y, Z. Use list_widget_tools to discover...'
After: 'The widget is interactive and exposes tools for X and Y.'
* Remove ui/screenshot and ui/click protocol methods
These will be proposed separately from the app tool registration changes.
* fix(app): auto-register tools capability in registerTool
When registerTool is called before connect() on an App created without
explicit tools capability, setRequestHandler's capability assertion
would throw, breaking app initialization at module load.
Auto-register { tools: { listChanged: true } } on first registerTool
call (pre-connect only), mirroring McpServer.registerTool behavior.
Fixes pdf-annotations e2e failures where the PDF canvas never rendered
because registerTool threw at module scope.
* pdf-server: replace app-tools with 1:1 interact command mapping
Converts the 5 placeholder app-registered tools into 12 tools that map
directly to the server's interact commands (navigate, search, find,
search_navigate, zoom, add_annotations, update_annotations,
remove_annotations, highlight_text, fill_form, get_text, get_screenshot)
plus the existing get-document-info.
Implementation stays DRY by dispatching through the existing
processCommands() handler — each tool callback constructs a PdfCommand
and runs it via a small runCommand() wrapper. For get_text and
get_screenshot, the page-data collection is extracted from
handleGetPages into a shared collectPageData() helper so results can
be returned directly instead of round-tripping through the server.
Tool names and zod schemas mirror the interact command parameter shapes
from server.ts so the model sees the same surface whether it goes
through interact or app-tools. The server-side interact tool is
unchanged and remains available for hosts without app-tool support.
* chore: drop unused test vars and stale Request/Result imports
* docs(spec): address review feedback on app tool registration
- Add outputSchema to Tool struct (matches SDK + core MCP)
- Reword "black box" bullets: drop stale screenshots reference, clarify no DOM access
- Clarify push vs pull contrast with explicit setWidgetState + ui/update-model-context refs
- Add Task-reference future-work bullet for tools outliving render lifecycle
* docs(spec): clarify app DOM is not host-introspectable; frame tools as pull complementing update-model-context push
* fix(app): emit title and omit absent outputSchema in tools/list
* feat(app): accept Standard Schema in registerTool/registerAppTool
App.registerTool and registerAppTool now accept any schema implementing
the Standard Schema spec (Zod ≥3.25, ArkType, Valibot, …) instead of
zod-only. Uses ~standard.validate / ~standard.jsonSchema directly, so
app.ts no longer imports zod at runtime — zod is now an optional peer.
Mirrors the StandardSchemaWithJSON type from
modelcontextprotocol/typescript-sdk#1689 so bumping to SDK v2 is a
drop-in import swap. Adds @standard-schema/spec (types-only) and a
hand-rolled non-zod test.
* docs(spec): reference core MCP Tasks for long-running app tools
App tools/call MAY be task-augmented per the core MCP Tasks utility
(spec 2025-11-25). Adds a Long-Running App Tools subsection: hosts proxy
tasks/* while the app is mounted; apps SHOULD delegate long-lived work
to the server so the task survives iframe teardown. Removes the stale
'future extension' bullet — Tasks is shipped.
* docs(spec): note Schema Validation accepts any Standard Schema library
* chore: clean unused-var and no-op-await diagnostics in app.ts and tests
* refactor(app): fold error prefix into validateStandardSchema; clarify registerAppTool runtime caveat
* chore(typedoc): mark RequestHandlerExtra as intentionally not exported
AppToolCallback (introduced with the Standard Schema migration) references
the local RequestHandlerExtra alias in its parameter type. The alias is a
private Parameters<> derivation and isn't part of the public API surface,
so add it to intentionallyNotExported alongside AppOptions/MethodSchema.
* fix(app): restore zod v3.25 compat via lazy z.toJSONSchema fallback
zod v3.25.x implements ~standard.validate but not ~standard.jsonSchema,
so constraining to StandardSchemaWithJSON broke the ^3.25.0 peer range.
Widen registerTool to StandardSchemaV1 and fall back to a lazy zod/v4
import for serialization when ~standard.jsonSchema is absent and
vendor==='zod'. Non-zod schemas without jsonSchema get a clear error.
* docs(spec): slim Long-Running App Tools to a pointer into core MCP Tasks
* chore: add TODO(sdk-v2) marker in standard-schema.ts
* fix(app): align registerTool runtime with declared types
- Handler reads registeredTool.{input,output}Schema so update() takes effect
- Call cb(extra) when no inputSchema, matching AppToolCallback<undefined>
- Throw on duplicate name; guard list_changed pre-connect; notify on register
- Drop misleading zod optional peer (still required by generated/schema.ts)
- examples: fix pdf search/find stale match count; threejs set-scene-source re-render
- spec: Zod → Standard Schema; clarify tools availability via tools/list after init
* feat(app): type structuredContent from outputSchema in registerTool
AppToolCallback gains an Out param: when outputSchema is provided,
structuredContent is required and typed via StandardSchemaV1.InferOutput,
with an `isError: true` escape hatch. Without outputSchema, return type
is unchanged (CallToolResult). Uses intersection rather than Omit since
CallToolResult's index signature swallows Omit's known keys.
Also drops the `as any` casts on z.object(...) in tests — zod 4 satisfies
StandardSchemaV1 directly.
* fix(app): registerTool edge cases + example tool correctness
App.registerTool:
- Skip outputSchema validation when result.isError (matches AppToolResult type)
- Pin callback arity to original config.inputSchema; only the validation schema is mutable via update()
- Default missing tools/call arguments to {}
- remove() is a no-op if the handle is stale (re-registered or already removed)
- Gate list_changed notifications on the listChanged capability
Examples:
- threejs: propagate executeThreeCode failures to onSceneError/onSceneRendering; catch updateModelContext rejection
- wiki-explorer: search-article preserves graph on no-match
- budget-allocator: fix category/stage values in tool descriptions
* feat(app,app-bridge): guard requests sent before handshake completes (#620)
* feat(app,app-bridge): guard requests sent before handshake completes
Calling host-bound methods before the ui/initialize →
ui/notifications/initialized handshake completes can race the handshake
on strict hosts and leave the iframe permanently hidden.
App (View side):
- All 8 host-bound methods (callServerTool, readServerResource,
listServerResources, sendMessage, updateModelContext, openLink,
downloadFile, requestDisplayMode) now check that connect() has sent
the initialized notification.
- New AppOptions.strict (default false): console.error when false,
throw when true. AppOptions is now exported.
- useApp() forwards strict to the App constructor.
- Flag resets on reconnect.
AppBridge (Host side):
- replaceRequestHandler is overridden to wrap every host-bound handler
with a console.warn if the request arrives before
ui/notifications/initialized. Never throws. ui/initialize and ping
use setRequestHandler directly and are exempt; notifications are
unaffected.
- Catches Views that hand-roll postMessage without the SDK.
- Flag resets on reconnect.
Refs anthropics/claude-ai-mcp#61, anthropics/claude-ai-mcp#149.
* fix(docs): drop AppOptions from intentionallyNotExported now that it is exported
---------
Co-authored-by: Claude <noreply@anthropic.com>
* Fix touch gesture conflicts in WebGL example apps on mobile
* Format with prettier
* fix(examples): improve mobile support for map, pdf, and threejs examples
- map-server: fullscreen button respects safe area insets, hover/opacity
pattern with always-visible on touch devices
- pdf-server: fit-to-width scale for narrow viewports, responsive toolbar
with compact controls on mobile, safe area in fullscreen toolbar via
CSS custom properties
- threejs-server: fullscreen button respects safe area and always visible
on touch, ResizeObserver for responsive width, host containerDimensions
for fullscreen height, no container padding in fullscreen, replace
useHostStyles with inline style application to avoid overwriting
onhostcontextchanged handler
Changes since 1.2.1:
- fix(schemas): import from zod/v4 to match SDK's zod API (#548)
- test(e2e): fix no-op security injection test via frames[] traversal (#540)
* chore: bump ext-apps to 1.1.2
Changes since 1.1.1:
- feat: add ui/download-file method for host-mediated file downloads (#475)
- pdf-server: robust path validation + folder/file root support (#497)
- ci: auto-fix prettier formatting in pre-commit hook and CI (#498)
* fix: sync local SDK build into node_modules for examples
npm workspaces hoists example dependencies to the root node_modules,
but installs the published registry copy of @modelcontextprotocol/ext-apps
instead of linking to the local source. This causes type-check failures
when examples use features not yet published to npm.
Add scripts/link-self.mjs which copies the freshly-built dist/ and
package.json into the hoisted node_modules copy after each SDK build,
ensuring examples always type-check against the latest local types.
See: https://github.com/npm/feedback/discussions/774
* Revert "fix: sync local SDK build into node_modules for examples"
This reverts commit e3387e8434f3def030f5a223a70632092c929119.
Bug fixes / improvements since 1.1.0:
- fix: add audio/video support for basic-host (#460)
- fix(pdf-server): remove page-loading overlay (#493)
- pdf-server: remove domain allowlist, require HTTPS only (#487)
- Set audioSession.type to playback in sheet music app (#489)
- Add MCPB packaging and Claude Code plugin for pdf-server (#491)
* chore: bump ext-apps to 1.1.0
Features:
- registerAppResource now returns the registered resource (#370)
- Accept UIResourceMeta in both resources/list and resources/read (#410)
- callServerTool throws helpful error when called with a string (#449)
- Add double-connect guard to prevent protocol message handling errors (#450)
Bug fixes:
- Only ignore messages that lack jsonrpc 2.0 in message-transport (#448)
- Align basic-host dark mode styles (#438)
Spec:
- Change Host <> Sandbox communication protocol to SHOULD (#435)
- Clarify UIResourceMeta in both list and read responses (#410)
* fix(debug-server): add missing npm package config (main, bin, types, exports)
Align debug-server package.json with all other server examples:
- main: dist/server.js (was server.ts)
- types: dist/server.d.ts
- bin: mcp-server-debug -> dist/index.js
- exports with types
- files: only dist (remove source server.ts)
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>
* fix(examples): use npm reference for ext-apps dependency
Replace local path '../..' with '^1.0.0' npm reference in all example
packages. The local path was accidentally published to npm, causing
npm install to hang when installing server-* packages.
Bump versions to 1.0.1 for all public packages to fix the published
versions.
Fixes npm install hanging issue in dependent projects like
example-remote-server.
Note: npm workspaces automatically resolves the dependency to the
local package during development, so no overrides are needed.
* fix: update zod to 4.x in transcript-server and fix update-lock:docker script
- Update transcript-server to use zod ^4.1.13 for compatibility
- Fix update-lock:docker script to properly clean workspace node_modules
- Regenerate package-lock.json with clean npmjs.org URLs
* 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
* docs: add local development MCP client configuration to READMEs
Add instructions for configuring MCP clients to use locally-cloned
and modified servers. This allows developers to test local changes
with MCP clients like Claude Desktop or VS Code.
- Top-level README: Added 'Local Development' section after npx config
- All TypeScript examples: Added 'Local Development' subsection with
bash one-liner that builds and runs the server
- Python examples (qr-server, say-server): Added local path config
* docs: include all servers in local development config
* docs: use bash wrapper for Python server configs to enable tilde expansion
* Adding a simple (bad) pdf icon for directory (#330)
* chore: bump version to 0.4.2
- Update package version from 0.4.1 to 0.4.2
- Pin @types/node to 22.10.0 for dev compatibility
- Override seroval to ^1.4.1 to fix security vulnerabilities
- Use '*' for workspace SDK dependency (works with unpublished versions)
* fix(e2e): update Map Server display name to CesiumJS Map Server (#324)
* 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>
* feat(server): add getUiCapability helper for capability negotiation (#313)
* 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: update playwright docker image to v1.58.0
* fix: use -i instead of -it for docker commands (no TTY needed)
* fix: Python server dependency resolution and Docker host validation (#333)
* 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(basic-host): Add theme toggle and MCP style variables (#336)
* 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
* [MCP Apps] Add appCapabilities.availableDisplayModes documentation to spec (#331)
* 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(say-server): add light/dark theme support (#338)
- 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
* fix: followup app -> view terminology (#339)
* chore: husky env fix, version pins, update-lock:docker script (#341)
* fix(husky): load Node.js env for GUI apps + add update-lock:docker script
Cherry-picked non-e2e changes from ochafik/fix-e2e-flaky-tests:
- Load nvm/fnm/volta/homebrew paths in pre-commit for GitHub Desktop
- Add update-lock:docker script to regenerate lockfile with public registry
* pin package versions for dev compatibility
- solid-js: 1.9.10
- caniuse-lite: 1.0.30001763
- cheerio: 1.1.2
- electron-to-chromium: 1.5.267
- @playwright/test: 1.57.0
- playwright: 1.57.0
- playwright-core: 1.57.0
* regen
* fix: pin @types/node to existing version and regenerate lockfile
- Fix @types/node 20.19.28 -> 20.19.27 (typo, version didn't exist)
- Regenerate package-lock.json to resolve versions available on both
public npm and Anthropic artifactory registries
* fix(basic-server-solid): bump solid-js 1.9.10 -> 1.9.11 to fix seroval vulnerabilities
* fix: pin seroval to 1.4.1 for dev compatibility
* Refactor server startup functions
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>
* Support full-file inclusion in synced code snippets
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>
* Rewrite Quickstart guide with type-checked code examples
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>
* Add MCP Apps Overview document
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>
* Add Agent Skills installation guide
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>
* Polish OpenAI migration reference for readability
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>
* Fix mermaid diagram arrowheads not rendering
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>
* fix(docs): improve OpenAI migration guide accuracy (#349)
- Add missing setOpenInAppUrl API to 'Not Yet in MCP Apps' section
- Clarify Event Handling table: specify exact OpenAI properties
(toolInput/toolOutput) instead of vague 'window.openai.*'
- Improve notes to distinguish sync property reads vs callbacks
* Add Testing MCP Apps guide
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>
* Fix `onhostcontextchanged` handler invocation in examples
`App.onhostcontextchanged` is a setter-only property with no getter.
TypeScript doesn't prevent reading from setter-only properties, so
`app.onhostcontextchanged?.(ctx)` compiles but silently returns
`undefined` at runtime.
Extract the handler into a named `handleHostContextChanged()` function
and call it directly after `connect()`, matching the pattern used in
`basic-server-vanillajs` and other examples.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
* Expand Agent Skills guide
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>
* fix(e2e): improve test stability and developer experience (#337)
* fix(e2e): add masks for dynamic content and increase timeouts for slow servers
- Add HOST_MASKS for Tool Input/Result panels with dynamic timestamps
- Add say-server to SLOW_SERVERS (10s) for TTS model download
- Add say-server to EXTRA_WAIT_MS (30s) in generate-grid-screenshots
* feat: add update-lock:docker script to regenerate lockfile with public registry
* pin package versions for dev compatibility
* feat(basic-host): add ?theme=hide query param to hide theme toggle in screenshots
- Add hideThemeToggle param to getQueryParams()
- Conditionally render ThemeToggle based on ?theme=hide
- Update e2e tests to use ?theme=hide for consistent screenshots
* update screenshots
* update screenshots
* fix(husky): load Node.js environment for GUI apps like GitHub Desktop
* fix(e2e): increase map-server wait time to 15s for tile loading
* fix(e2e): increase waitForAppLoad timeout to 30s for nested iframe loading
* ci: add workflow to update e2e snapshots
* ci: trigger snapshot update on push to this branch
* chore: update e2e snapshots [skip ci]
* ci: trigger CI after snapshot update
* style: fix prettier formatting in update-snapshots workflow
* fix: pin seroval, seroval-plugins, and solid-js for dev compatibility
---------
Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>
* Improve README structure and clarity
Add "Why MCP Apps?" section to explain the motivation upfront. Reorganize
the "How It Works" section to lead with tool definition. Rename "Overview"
to "Using the SDK" and add "For" prefix to audience headings.
Restructure the Examples section with clearer subsections for running
examples with `basic-host` vs MCP clients using stdio transport. Move the
`qr` server note outside the collapsed details block.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
* Add Codex and Goose to documentation
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>
* chore: regenerate lockfile with public registry, use ^0.4.2 for ext-apps deps
* fix: update quickstart example to use workspace reference
* chore: remove internal registry references from lockfile
* feat(ci): add /update-snapshots comment trigger for PRs
- Comment '/update-snapshots' on any PR to update E2E snapshots
- Adds rocket reaction to acknowledge the command
- Comments back with result (updated or no changes needed)
- Removes hardcoded branch trigger
- Keeps workflow_dispatch for manual runs
* docs: document /update-snapshots PR comment trigger
* fix: pin @hono/node-server to 1.19.7 for dev compatibility
SDK 1.25.3 requires @hono/node-server@^1.19.9 which doesn't exist
on the public npm registry (latest is 1.19.7).
* fix: pin @modelcontextprotocol/sdk to 1.25.2
SDK 1.25.3 has broken dependency on @hono/node-server@^1.19.9
which doesn't exist on public npm registry.
* fix: restore flexible SDK peerDep range (^1.24.0)
devDependencies stays pinned to 1.25.2 for our builds,
but peerDependencies should allow users flexibility.
* fix: pin @types/node to avoid unpublished versions
- Pin quickstart @types/node to 22.19.5 (latest public 22.x)
- Add @types/node override to root package.json
- Regenerate lockfile with public registry only
---------
Co-authored-by: Tobin South <tobin.south@gmail.com>
Co-authored-by: Liad Yosef <liady@users.noreply.github.com>
Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: martinalong <martinalong10@gmail.com>
Co-authored-by: Ido Salomon <idosalomon@gmail.com>
Co-authored-by: Jonathan Hefner <jonathan@hefner.pro>
Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>
* fix(e2e): add masks for dynamic content and increase timeouts for slow servers
- Add HOST_MASKS for Tool Input/Result panels with dynamic timestamps
- Add say-server to SLOW_SERVERS (10s) for TTS model download
- Add say-server to EXTRA_WAIT_MS (30s) in generate-grid-screenshots
* feat: add update-lock:docker script to regenerate lockfile with public registry
* pin package versions for dev compatibility
* feat(basic-host): add ?theme=hide query param to hide theme toggle in screenshots
- Add hideThemeToggle param to getQueryParams()
- Conditionally render ThemeToggle based on ?theme=hide
- Update e2e tests to use ?theme=hide for consistent screenshots
* update screenshots
* update screenshots
* fix(husky): load Node.js environment for GUI apps like GitHub Desktop
* fix(e2e): increase map-server wait time to 15s for tile loading
* fix(e2e): increase waitForAppLoad timeout to 30s for nested iframe loading
* ci: add workflow to update e2e snapshots
* ci: trigger snapshot update on push to this branch
* chore: update e2e snapshots [skip ci]
* ci: trigger CI after snapshot update
* style: fix prettier formatting in update-snapshots workflow
* fix: pin seroval, seroval-plugins, and solid-js for artifactory compatibility
---------
Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.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>
* 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>
After commit 65a62a9f, the server startup code was moved from server.ts
to main.ts, but the serve:http script was not updated accordingly.
This caused 9 example servers to fail to start when running npm start:
- budget-allocator-server
- cohort-heatmap-server
- customer-segmentation-server
- integration-server
- map-server
- scenario-modeler-server
- system-monitor-server
- threejs-server
- wiki-explorer-server
The server.ts file now only exports createServer(), while main.ts
contains the actual server startup logic.
- Add visibility-based animation pause (IntersectionObserver + wrapped rAF)
- Zero CPU usage when widget scrolls out of view
- Apply host style variables via useHostStyles
- Support transparent WebGL background (alpha: true)
- Use light-dark() for theme-aware fallback colors
- Tool no longer echoes code back in result
- Document performance features in README
Add stdio transport configuration snippets near the top of each example
README to help users quickly set up the servers in their MCP clients.
- Node.js examples use npx with the published npm packages
- Python qr-server uses uv with local path
- Removed Claude Desktop-specific references from qr-server
* fix(examples): resolve DIST_DIR path for npm package execution
When servers are compiled to dist/server.js and published to npm,
`import.meta.dirname` already points to dist/, so joining with "dist"
results in dist/dist/ which doesn't exist.
This fix detects whether we're running from TypeScript source or
compiled JavaScript and adjusts the path accordingly:
- From source (server.ts): use dist/ subdirectory
- From compiled (dist/server.js): use current directory
Fixes ENOENT errors like:
"ENOENT: no such file or directory, open '.../dist/dist/mcp-app.html'"
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
* fix(pdf-server): mark pdfjs-dist as external in bundle
The pdf.worker.mjs file wasn't being found when running from npm
because bun bundled pdfjs-dist but didn't include the worker file.
By marking pdfjs-dist as external, it uses the installed package
from node_modules at runtime where the worker is available.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
---------
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
* feat: compile example servers to JavaScript for npm consumption
Add TypeScript compilation for server code so the example packages can be
imported and used by consumers without requiring TypeScript compilation.
Changes:
- Add tsconfig.server.json to each example for compiling server code
- Update package.json exports to point to compiled dist/server/server.js
- Add types field pointing to dist/server/server.d.ts
- Update build scripts to include server compilation step
- Fix .ts import extensions to .js in customer-segmentation-server
This enables importing the createServer function from published packages:
import { createServer } from '@modelcontextprotocol/server-basic-react';
* fix: add type assertion for Nominatim API response
* chore: regenerate schemas
* refactor: split server examples into library and binary entry points
- server.ts: exports createServer() only (library entry point)
- main.ts: entry point with main() that runs the server (binary)
- package.json: adds bin field for npx support, uses inline bun build
- tsconfig.server.json: emitDeclarationOnly, outputs to dist/
This allows:
1. Importing the server as a library: import { createServer } from '@modelcontextprotocol/server-basic-react'
2. Running with npx: npx @modelcontextprotocol/server-basic-react [--stdio]
Added migration script at scripts/migrate-server-examples.ts
* refactor: migrate remaining server examples to library/binary structure
Apply the same refactoring to all 13 remaining server examples:
- scenario-modeler-server, shadertoy-server, map-server
- cohort-heatmap-server, customer-segmentation-server, video-resource-server
- system-monitor-server, budget-allocator-server, sheet-music-server
- threejs-server, integration-server, transcript-server, wiki-explorer-server
Each now has:
- server.ts: exports createServer() (library)
- main.ts: runs the server (binary with shebang)
- bin field in package.json for npx support
* chore: remove unused server-utils.ts from video-resource-server/src
* update
* fix(build): make Windows-compatible by removing chmod and fixing bun externals
- Remove 'chmod +x dist/index.js' which doesn't exist on Windows
- Add '--external ./server.js' to prevent bun from treating the import as a second entry point
* fix(build): use .ts import for bun compatibility
- Change import from './server.js' to './server.ts' in main.ts files
- Remove --external flag since bun should inline everything
- Fixes Windows build where bun couldn't resolve .js to .ts properly
* fix(build): use --external for Windows bun compatibility
Bun on Windows incorrectly treats imported .ts files as entry points.
Use --external './server.js' to work around this, creating a runtime
dependency between index.js and server.js.
* style: fix prettier formatting in pdf-server/main.ts
* fix(build): remove quotes from --external for Windows cmd.exe compatibility
* fix(build): use glob pattern for --external to work on all platforms
The literal path --external ./server.js was not matching the import.
Using glob pattern --external "./server*" correctly externalizes the server module.
* fix(build): use */server.js pattern for --external
The "./server*" pattern was not matching on Windows.
Using "*/server.js" matches any path ending in /server.js which works cross-platform.
* fix(build): use *server.js pattern without slash for Windows compatibility
* update package-lock
* chore: regenerate package-lock.json for cross-platform compatibility
* fix(build): use ./server.js instead of glob pattern for Windows compatibility
* fix(build): use double quotes for banner to fix Windows cmd.exe compatibility
---------
Co-authored-by: Olivier Chafik <ochafik@anthropic.com>
- Add `.gitignore` files to all 19 examples (`node_modules/`, `dist/`)
- Replace custom `log` objects with standard `console` methods
- Add `ontoolcancelled` handler to all `basic-server-*` examples
- Add host styling integration (`applyDocumentTheme`, `applyHostFonts`,
`applyHostStyleVariables`) to non-React `basic-server-*` examples
- Add section headers for better code organization in feature examples
- Update READMEs with Build System section explaining single-file
bundling
These changes make examples more consistent and easier to adapt.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
* feat: add script to generate 300x300 grid-cell.png screenshots for examples
- Add generate-grid-screenshots.spec.ts Playwright test to capture screenshots
- Add npm run generate:screenshots command (Docker-based for Santa compatibility)
- Add sharp dependency for image resizing with centered-fill mode
- Generate grid-cell.png for 14 example servers (only React for basic-server-* series)
The screenshots are 300x300 PNG images cropped with centered fill mode,
suitable for use in a grid layout showcasing the examples.
* docs: add example gallery grid to README
Add a 3-column visual grid showcasing 14 example MCP Apps with:
- Thumbnail screenshots (300x300 grid-cell.png)
- Clickable links to example directories
- Hover tooltips with brief descriptions
Organized by visual impact: 3D/WebGL examples first, then
visualizations, charts, monitoring, and starter templates.
* fix: use aspect-fit instead of crop for screenshots
Change from fit: 'cover' (crops) to fit: 'contain' (letterbox)
so the full app content is visible without cropping.
* feat: improve screenshot generation
- Constrain viewport to 500px width for consistent rendering
- Wait 5 seconds for full app load (tiles, animations, data)
- Screenshot just the inner iframe (no extra whitespace)
- Save both screenshot.png (full-size) and grid-cell.png (300x300 thumbnail)
- Use contain mode to preserve aspect ratio
* fix: use cover mode with top alignment for grid thumbnails
No letterboxing - crops to fill 300x300, aligned to top so headers
and important content are always visible.
* feat: improve screenshot gallery
- Remove integration-server from gallery (it's for E2E testing only)
- Add 30s extra wait for Map and Video servers to load fully
- Improve Three.js default scene: isometric rotation + better lighting
- Update README: Starter Templates row with links to all framework variants
(React, Vue, Svelte, Preact, Solid, Vanilla JS)
- Regenerate all screenshots with updated settings
* fix: improve README gallery layout
- Fix uneven column widths by using minimal separator
- Move Starter Templates to separate 2-cell table with description
- Add screenshot.png to top of each example README (13 examples)
- Shorten tooltips for cleaner table
* revert to document.write again; cesiumjs doesn't like srcdoc, period.
* fix: map-server screenshot now renders properly
- Merged ochafik/post-fixes which reverts sandbox from srcdoc to document.write
(CesiumJS doesn't work with srcdoc iframes)
- Fixed map-server name in screenshot test ('Map Server' not 'CesiumJS Map Server')
- Simplified screenshot generation script (removed complex debugging code)
- Increased map-server wait time to 45s for reliable tile loading
- Regenerated all 13 screenshots
* fix: remove redundant screenshots from READMEs
Remove the simple \ line from READMEs that
already had nicer HTML table screenshots. Keep it only for examples
that didn't have existing screenshots.
* docs: move gallery to Examples section
- Move screenshot gallery from top of README to Examples section
- Remove redundant list of basic examples (now shown visually in gallery)
- Clean up duplicate run instructions
* fix: remove empty header row from starter templates table
* fix: remove empty header rows from both tables
* fix: add prettier-ignore to prevent table header expansion
* feat: use custom screenshot for video-resource-server
- Use better screenshot from PR #253 comment showing actual video playback
- Skip video-resource-server in screenshot generation script
- Add SKIP_SERVERS set for manually maintained screenshots
* fix: revert unrelated map-server name change
* fix: use correct server name 'CesiumJS Map Server' in screenshot test
