Commit graph ext-apps/src/app.ts
Author SHA1 Message Date
Olivier Chafik
0266171b92
Add addEventListener/removeEventListener with DOM-model on* semantics (#573)
* feat(events): DOM-model on* semantics with addEventListener/removeEventListener

Fixes #551 (useHostStyles broken: fonts clobber theme/CSS variables)
Fixes #225 (user onhostcontextchanged and SDK hooks mutually exclusive)

The on* setters now follow the DOM event model:
- Replace semantics (like el.onclick) with getters
- Coexist with addEventListener/removeEventListener listeners
- Both channels fire on dispatch: on* handler then listeners

Introduces ProtocolWithEvents base class between Protocol and
App/AppBridge. Each notification event gets a slot with two independent
channels (singular on* handler + addEventListener listener array).

useHostStyles hooks now use addEventListener with proper cleanup,
so they compose correctly with user on* handlers.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* Fix typedoc validation warnings

- Export AppEventMap, AppBridgeEventMap, ProtocolWithEvents so they
  appear in generated docs (they're part of public addEventListener
  signatures)
- Move AppBridgeEventMap above the AppBridge class JSDoc — it had been
  inserted between the doc block and the class, orphaning the AppBridge
  docs onto the wrong type
- Drop @param callback tags from on* getter/setter pairs — typedoc
  attaches the doc block to the getter signature which has no params
- Add MethodSchema to intentionallyNotExported (internal zod helper
  referenced by the now-documented eventSchemas field)

---------

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-03-30 18:48:33 +01:00
Mel Ludowise
fd1186cc2d
Revert fullscreen size-changed skip (#570)
Reverts the fullscreen displayMode guard added in #567. Skipping
size-changed measurement during fullscreen caused apps to not receive
an initial size report after the transition, breaking layout for some
apps.
2026-03-26 16:46:48 +00:00
Mel Ludowise
a7273bbf42
Fix auto-resize destroying horizontal scroll positions (#567)
* Fix auto-resize destroying horizontal scroll positions

The setupSizeChangedNotifications method temporarily sets
html.style.width to 'fit-content' to measure intrinsic content width.
For responsive apps that derive width from their container (width: 100%,
flex: 1, etc.), fit-content resolves to 0px. The synchronous reflow at
0px causes browsers to clamp scrollLeft on all horizontal scroll
containers to 0, permanently destroying their scroll positions.

Replace the fit-content width measurement with window.innerWidth. The
height measurement (max-content) is preserved since hosts rely on it.
Neither the iOS nor web host uses the width value from size-changed
notifications, so this change has no functional impact on hosts while
fixing scroll position clamping for all MCP apps with horizontal scroll
views.

* Skip size-changed measurement during fullscreen

Hosts determine the container size in fullscreen mode, so size-changed
notifications are not needed. The temporary max-content height override
used for measurement causes visible vertical jitter during animated
fullscreen transitions by briefly reflowing the document on every frame.
2026-03-26 10:08:18 +00:00
Frédéric Barthelet
c026b398a1
Add ui/notifications/request-teardown notification for view-initiated termination (#215)
* Add ui/close-resource request for UI to initiate termination

* Add missing METHOD export

* Fix typo in remaining ui/request-close

* Align spec terminology to teardown/termination instead of close/clearnup

* Implement final comments

* Removing view behavior on initiation of request termination
2026-03-19 22:01:59 +02:00
Hryhorii (Greg) Avcharov
19fe73a08a
Replace deprecated RESOURCE_URI_META_KEY usage with modern format (#457) 2026-03-06 14:32:04 +00:00
Olivier Chafik
ef8fc6e2f0
fix: make listServerResources() params optional (#528)
Follow-up to #470. Matches MCP SDK Client.listResources(params?) signature
so callers can omit the empty {} for the common case.

Also reflows a line in app-bridge.test.ts that prettier flagged.
2026-03-06 14:30:36 +00:00
Hryhorii (Greg) Avcharov
4f9a7ebc74
feat: add readServerResource() and listServerResources() api to App (#470)
* feat: add readServerResource() and listServerResources() api to App class

* test: add listServerResources and readServerResource integration tests
2026-03-06 14:20:45 +00:00
Mel Ludowise
26928b8622
Fix autoResize reporting viewport height when content is taller (#525)
fit-content clamps to the containing block's available size. For <html>,
that's the iframe viewport, so when content exceeds the viewport height
the SDK reported the viewport height instead of the true content height,
causing internal scrolling instead of iframe growth.

max-content has no available-space constraint and correctly reports the
intrinsic content height in both directions (shrink and grow). Width
stays fit-content to preserve responsive wrapping.
2026-03-06 13:30:13 +00:00
Anton Pidkuiko MacBook
3757271641
refactor: use MCP resource types for ui/download-file params
Replace custom {filename, content, mimeType, encoding} params with
standard MCP resource types: EmbeddedResource for inline content and
ResourceLink for host-resolved references.

New params shape:
  params: { contents: (EmbeddedResource | ResourceLink)[] }

This reuses existing MCP primitives instead of inventing new ones,
and enables hosts to show resource 'bubbles' or resolve ResourceLink
URIs via resources/read on the MCP server.
2026-02-20 12:00:35 +00:00
Anton Pidkuiko MacBook
494c73e7ca
feat: add ui/download-file method for host-mediated file downloads
Add a new ui/download-file JSON-RPC request that allows MCP App views to
request file downloads through the host. Since MCP Apps run in sandboxed
iframes where direct downloads are blocked (allow-downloads not set),
this provides a host-mediated mechanism for file exports.

Spec changes (draft):
- Add ui/download-file request to Requests (View → Host) section
- Add downloadFile capability to HostCapabilities
- Document host behavior requirements (confirmation dialog, filename
  sanitization, base64 decoding, size limits)

SDK changes:
- Add McpUiDownloadFileRequest/Result interfaces to spec.types.ts
- Add downloadFile() method to App class
- Add ondownloadfile setter to AppBridge class
- Add DOWNLOAD_FILE_METHOD constant
- Generate Zod schemas

Example:
- Add download demo to integration-server (exports JSON with server time)
- Capability check: only shows download button when host advertises
  downloadFile capability

Based on developer feedback requesting file export capabilities for
visualization tools, document editors, and data analysis apps.
2026-02-19 21:25:48 +00:00
Olivier Chafik
f615123711
Add double-connect guard to prevent protocol message handling errors (#450)
* fix: guard against double-connect in App and AppBridge (#429)

Calling connect() twice on the same transport instance caused the MCP
SDK's Protocol class to chain onmessage handlers, so each incoming
message was processed twice. This made incoming responses get consumed
by the first processing (resolving the handler) and then trigger a
spurious "Received a response for an unknown message ID" error on the
second processing pass, since the handler was already removed from the
response map.

Add an explicit guard in both App.connect() and AppBridge.connect() that
throws if the instance is already connected. This converts the silent
message-corruption into a clear, actionable error and prevents
downstream confusion.

Adds three regression tests:
- AppBridge.connect() throws when already connected
- App.connect() throws when already connected
- Demonstrates the double-processing root cause and verifies it is fixed

Fixes #429

https://claude.ai/code/session_01XU3FW1TpjBkyRbkBUH5gqR

* test: replace redundant regression test with cleaner same-transport guard check

The previous third test in "double-connect guard" never actually attempted
a double-connect — it created fresh instances and verified normal operation,
which every other test already covers. The stray bridge.onupdatemodelcontext
and bridgeTransport.close() at the top were leftover noise.

Replace it with a focused test that verifies the guard fires even when
the caller passes the *same* transport object (not just a different one),
which is the exact scenario described in #429.

https://claude.ai/code/session_01XU3FW1TpjBkyRbkBUH5gqR

---------

Co-authored-by: Claude <noreply@anthropic.com>
2026-02-17 18:15:24 +00:00
Olivier Chafik
666952980f
feat(app): throw helpful error when callServerTool is called with a string (#449)
Users frequently call callServerTool("tool_name", args) instead of the
correct callServerTool({ name: "tool_name", arguments: args }), resulting
in a silent/confusing failure. Detect this and throw immediately with
a message that shows the correct call shape.

Also fixes the incorrect example in examples/pdf-server/README.md that
demonstrated this same wrong usage pattern.

Fixes #386

https://claude.ai/code/session_01GqAyN4Ux7svWoU2HqsSLZF

Co-authored-by: Claude <noreply@anthropic.com>
2026-02-13 21:05:21 +00:00
Jonathan Hefner
c6c2428e0b
Improve patterns guide with concrete examples and safe area insets
- 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>
2026-01-27 17:32:41 -06:00
Jonathan Hefner
58019a48ce
Replace {@includeCode} with synced code fences
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>
2026-01-23 07:34:56 -06:00
Liad Yosef
4fc71656a3
docs: standardize UI terminology to use "view" consistently (#325)
* 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>
2026-01-23 04:36:52 +02:00
Jonathan Hefner
9dd995562a
Format {@link} tags with monospace display text
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>
2026-01-22 14:37:04 -06:00
Jonathan Hefner
e626b84d44 Complete "Sending large follow-up messages" pattern documentation
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>
2026-01-20 13:31:11 -06:00
Jonathan Hefner
89653cbb7a Complete "Passing contextual information" pattern documentation
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>
2026-01-20 13:31:11 -06:00
Jonathan Hefner
a0265f92d2 Complete "Giving errors back to model" pattern documentation
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>
2026-01-20 13:31:11 -06:00
Jonathan Hefner
a1ae100ef0 Complete "Lowering perceived latency" pattern documentation
- 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>
2026-01-20 13:31:11 -06:00
Jonathan Hefner
dce143e92e Complete "Entering / exiting fullscreen" pattern documentation
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>
2026-01-20 13:31:11 -06:00
Jonathan Hefner
f0c7cc1b14 Refine JSDoc examples for consistency and type safety
Follow-up to the examples extraction: pass dependencies as function
parameters instead of using global stub declarations, rename region
names to match method names (e.g., `AppBridge_guestCapabilities_*` →
`AppBridge_getAppCapabilities_*`), and simplify examples using optional
chaining.

Also clarifies `RESOURCE_URI_META_KEY` documentation to indicate it's
for tool definition metadata (from `tools/list`), not tool result
metadata, and removes the redundant `setNotificationHandler` example
in favor of the simpler event setter approach.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
2026-01-19 20:43:47 -06:00
Jonathan Hefner
ad04e89745 Move JSDoc examples to type-checked .examples.ts files
Extract inline code examples from JSDoc comments into companion
`.examples.ts`/`.examples.tsx` files. Examples are now:

- Type-checked by wrapping them in functions
- Referenced via `{@includeCode ./file.examples.ts#regionName}` tags
- Organized using `//#region` and `//#endregion` markers

This keeps the main source files cleaner while ensuring examples
compile correctly. Updated TypeDoc config with `exampleTag: false`
to support title text on `@example` tags.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
2026-01-19 20:41:19 -06:00
Jonathan Hefner
d48e35d88a
Improve JSDoc comments with cross-references and clarifications (#254)
Key improvements:
- Add `{@link}` cross-references throughout the codebase to make API
  documentation navigable and help AI models understand relationships
- Use `{@link module!Export}` syntax for cross-module references
- Add backticks for inline code formatting (`ResizeObserver`, `App`, etc)
- Fix `PostMessageTransport` examples to show required two-argument form
- Clarify `onteardown` callback return type requirement
- Document React hooks cleanup behavior and Strict Mode considerations
- Add tool visibility example for `registerAppTool`
- Add CSP example for `registerAppResource`
- Fix notification direction documentation in `spec.types.ts`

TypeDoc config migrated from `typedoc.json` to `typedoc.config.mjs` to:
- Support custom `@description` block tag
- Add `intentionallyNotExported` for internal types
- Include `src/server/index.ts` entry point

Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
2026-01-14 00:41:17 +00:00
Ido Salomon
b273279849
feat: add ui/update-model-context (#125)
---------

Co-authored-by: Olivier Chafik <ochafik@anthropic.com>
2026-01-12 15:21:45 +00:00
Olivier Chafik
c7ef5f009b
fix: Add missing origin parameter to PostMessageTransport default constructor, verify origins in example sandbox proxy (#207)
* fix(app): add source validation to default PostMessageTransport

App.connect() now passes window.parent as both eventTarget and eventSource,
enabling source validation by default. This ensures apps only accept
messages from their parent window, preventing potential cross-app
message spoofing attacks.

Previously, the default transport only specified the target but not the
source for validation, meaning apps would accept messages from ANY window.

* fix(sandbox): add origin validation for host messages

The sandbox proxy now validates that messages from the parent window
come from the expected host origin (derived from document.referrer).
This prevents malicious pages from sending spoofed messages to the sandbox.

Changes:
- Extract EXPECTED_HOST_ORIGIN from document.referrer
- Validate event.origin against expected origin for parent messages
- Use specific origin instead of '*' when sending to parent
- Reject and log messages from unexpected origins

This addresses the TODO comment that was previously in the code.

* validate messages from app come from same origin as sandbox proxy

* fix(basic-host): be resilient to individual server connection failures

Use Promise.allSettled instead of Promise.all when connecting to
servers, so that a single server failure doesn't crash the entire UI.
Failed connections are logged as warnings but the UI continues with
the servers that connected successfully.

Also fixes video-resource-server missing server-utils.ts.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

---------

Co-authored-by: Claude <noreply@anthropic.com>
2026-01-07 14:20:49 +00:00
martinalong
dc226be962
Remove viewport 2025-12-31 21:36:29 -08:00
Anton Pidkuiko
242ec23856
Merge pull request #159 from modelcontextprotocol/martinalong/mcp-apps/custom-fonts
[MCP Apps] Add way to pass custom fonts
2025-12-17 17:45:54 +07:00
Olivier Chafik
2dd223b611
refactor: rename request methods to remove send prefix (#161)
* refactor: rename request methods to remove send prefix

Following the MCP TS SDK convention where request methods don't have
the "send" prefix (reserved for notifications):

- App.sendMessage() → App.message()
- App.sendOpenLink() → App.openLink()
- AppBridge.sendResourceTeardown() → AppBridge.resourceTeardown()

The old method names are kept as deprecated aliases for backwards
compatibility.

Updated all examples to use the new method names.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

* test: add tests for deprecated method aliases

- Update existing tests to use new method names (message, openLink)
- Add tests verifying deprecated aliases are same reference as new methods
- Add tests verifying deprecated aliases still work functionally

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

* refactor: rename message→sendMessage, resourceTeardown→teardownResource

- App.message() → App.sendMessage() (with deprecated message alias)
- AppBridge.resourceTeardown() → AppBridge.teardownResource() (with deprecated aliases)

This better follows the pattern where methods that send data have 'send' or action verb prefix.

* fix: update examples to use sendMessage instead of message

* fix: update basic-host to use teardownResource

* fix: update threejs-server to use sendMessage

* refactor: remove deprecated app.message alias

The app.message alias was removed since sendMessage is the correct name.
sendResourceTeardown already exists in AppBridge.

* refactor: remove resourceTeardown alias, keep only sendResourceTeardown

---------

Co-authored-by: Claude <noreply@anthropic.com>
2025-12-16 22:07:06 +00:00
Olivier Chafik
bea0ae27f5
feat: add server helpers, make connect() to default to parent post transport (#165)
* 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>

* fix: refine server helper types

- Make RESOURCE_URI_META_KEY required in McpUiAppToolConfig (tools need a UI resource)
- Make _meta optional in McpUiAppResourceConfig (not all resources need custom metadata)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

* refactor: simplify RESOURCE_URI_META_KEY re-export

* refactor: consolidate export statements

---------

Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: Jonathan Hefner <jonathan@hefner.pro>
2025-12-16 21:25:26 +00:00
martinalong
6397ec1511
Add way to pass fonts 2025-12-15 22:54:53 -08:00
martinalong
c516cf0894
Merge pull request #152 from modelcontextprotocol/martinalong/mcp-apps/display-mode-updates
[MCP Apps] Have apps request display mode instead
2025-12-15 16:12:45 -08:00
martinalong
8f591b69f2
Update naming of functions to reflect styles.variables nesting 2025-12-15 11:42:22 -08:00
martinalong
a8b3bf0ccd
Add utility to set + read theme 2025-12-15 11:42:17 -08:00
martinalong
aa8968808a
Add utility for using styles 2025-12-15 11:42:17 -08:00
martinalong
83860d7c31
Have apps request display mode instead 2025-12-14 19:00:56 -08:00
Olivier Chafik
54344552b7
api: optional Client in AppBridge (allow custom forwarding), better protocol types (AppRequest, AppNotification, AppResult) (#146)
* Add setter-based handlers for MCP request/notification forwarding

- Add oncalltool, onlistresources, onlistresourcetemplates, onreadresource, onlistprompts setters for Guest UI → Host requests
- Add sendToolListChanged, sendResourceListChanged, sendPromptListChanged methods for Host → Guest UI notifications
- Refactor connect() to use new setters with inlined callbacks
- Update documentation to clarify optional client parameter behavior
- Remove unused forwardRequest/forwardNotification helper methods
- Add comprehensive tests for AppBridge without MCP client (manual handlers)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

* Potential fix for pull request finding 'Unused variable, import, function or class'

Co-authored-by: Copilot Autofix powered by AI <223894421+github-code-quality[bot]@users.noreply.github.com>

* fix: move prettier to dependencies for git-based installs

* fix: add explicit prettierrc to prevent inheriting parent configs during git-based installs

* Apply suggestions from code review

Co-authored-by: Jonathan Hefner <jonathan@hefner.pro>

* refactor(tests): factor out test values and add missing assertions

Address PR review feedback:
- Factor out test value objects (toolCall, resultContent, etc.) for clearer tests
- Add missing assertions on receivedRequests[0] for list handlers
- Improve test readability by defining expected values at the top of each test

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

* docs: improve TypeDoc formatting and use `as const` for notification methods

- Use proper TypeDoc syntax with `@param callback.params` and `@param callback.extra`
- Add {@link ResultType} references for return types
- Replace `as Notification` with `as const` on method literals where possible
  (sendResourceListChanged, sendPromptListChanged)
- Simplify sendHostContextChange cast syntax

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

* refactor(types): use explicit type unions for AppBridge protocol types

- Add AppBridgeRequest, AppBridgeNotification, AppBridgeResult type unions
  that explicitly list all valid types for the protocol
- Replace generic SDK Request/Notification/Result with our specific types
- Remove all type casts by using `as const` on method literals
- Add index signature to McpUiHostContext for forward compatibility

This improves type safety and documents exactly what the AppBridge supports.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

* refactor: move AppRequest/AppNotification/AppResult to types.ts

Move protocol type unions from app-bridge.ts to types.ts where they
belong with other type definitions.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

* chore: regenerate schemas with clean npm install

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

---------

Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: Copilot Autofix powered by AI <223894421+github-code-quality[bot]@users.noreply.github.com>
Co-authored-by: Jonathan Hefner <jonathan@hefner.pro>
2025-12-13 21:07:13 +00:00
Olivier Chafik
eaea3f9e07
feat: store and expose hostContext in App class (#139)
* feat: store and expose hostContext in App class

Fixes #129 - The App class now stores the initial hostContext received
during initialization and exposes it via getHostContext().

Changes:
- Add _hostContext private property to App class
- Store result.hostContext in connect() method
- Add getHostContext() getter method (parallel to getHostCapabilities())
- Update onhostcontextchanged setter to merge partial updates into
  stored context
- Add default notification handler to update context even when
  user hasn't set onhostcontextchanged

This enables apps to:
- Access toolInfo immediately after connection (only in initial context)
- Render with correct theme/locale without waiting for first notification
- Synchronously access viewport, timezone, and other initial state

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

* fix: use sendHostContextChange for partial update accumulation test

Address PR review feedback: The test was using setHostContext with full
context spreads which didn't clearly demonstrate partial update
accumulation. Now uses sendHostContextChange directly to send truly
partial updates (only theme, then only viewport), making it clear
the App correctly merges multiple partial notifications.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

---------

Co-authored-by: Claude <noreply@anthropic.com>
2025-12-12 00:39:58 +01:00
Olivier Chafik
70b393a7e6
feat: implement ui/notifications/tool-cancelled + add missing App.onteardown (#120)
* feat: implement ui/notifications/tool-cancelled throughout SDK

Wire the tool-cancelled notification that hosts MUST send when tool
execution is cancelled (user action, timeout, classifier intervention, etc.):

- Add McpUiToolCancelledNotification type in spec.types.ts
- Generate Zod schema via ts-to-zod
- Add AppBridge.sendToolCancelled() method for hosts
- Add App.ontoolcancelled setter for guest UIs
- Export type and schema from types.ts
- Add tests for notification with/without reason

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Co-Authored-By: Claude <noreply@anthropic.com>

* feat: add App.onteardown handler for graceful shutdown

Wire the guest UI side of ui/resource-teardown request:

- Add onteardown setter in App class for guest UIs to handle teardown
- Allow ui/resource-teardown in assertRequestHandlerCapability
- Import McpUiResourceTeardownRequest/Result types
- Add tests for sync and async cleanup handlers

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Co-Authored-By: Claude <noreply@anthropic.com>

* feat(example): wire tool-cancelled and teardown in basic-host

Update basic-host example to properly use the new notifications:

- Send sendToolCancelled when tool call promise rejects
- Send sendResourceTeardown when React component unmounts
- Store appBridge ref for cleanup access

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Co-Authored-By: Claude <noreply@anthropic.com>

* fix(example): implement graceful teardown per spec recommendation

Address review feedback: the host now waits for guest's teardown
response before unmounting, following the spec: "Host SHOULD wait
for a response before tearing down the resource (to prevent data loss)."

Changes:
- Add close button to tool call panels
- Two-phase unmount: isDestroying state dims panel and disables events
- sendResourceTeardown() completes before component removal
- Non-app tool results close immediately

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Co-Authored-By: Claude <noreply@anthropic.com>

* feat(examples): add onteardown handlers to demo apps

Demonstrate graceful shutdown with simulated 500ms cleanup work.

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Co-Authored-By: Claude <noreply@anthropic.com>

---------

Co-authored-by: Claude <noreply@anthropic.com>
2025-12-11 20:31:17 +01:00
Anton Pidkuiko
6a8f5031be
Fix mimeType, CSP settings and QR code example (#111)
- Fix RESOURCE_MIME_TYPE to match spec: "text/html;profile=mcp-app"
- Add CSP field to McpUiSandboxResourceReadyNotification type and schema
- Update basic-host to extract and pass CSP metadata from resources
- Update sandbox.ts to dynamically inject CSP meta tag into inner iframe
- Remove static CSP from sandbox.html (now dynamic based on resource metadata)
- Update QR server to use custom read_resource handler for _meta injection
- Update requirements.txt to require mcp[cli]>=1.23.3

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Co-authored-by: Claude <noreply@anthropic.com>
2025-12-09 20:26:34 +01:00
Olivier Chafik
3ac7c7935b
Add RESOURCE_MIME_TYPE constant (#108)
* Add RESOURCE_MIME_TYPE constant

* Update app-bridge.ts

* update syntax
2025-12-09 19:10:56 +01:00
Anton Pidkuiko
5ae292106c
Remove temporary JSON-RPC envelope unwrapping hack (#90)
The host implementation has been fixed to return the correct result
format, so this workaround is no longer needed.

Reverts the hack added in #82.

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Co-authored-by: Claude <noreply@anthropic.com>
2025-12-08 16:32:15 +01:00
Olivier Chafik
3aa93db3c3
Add AppBridge.sendHostContextChange + reexport RESOURCE_URI_META_KEY (#87)
* Export  RESOURCE_URI_META_KEY from app-bridge

* add sendHostContextChange

* nit
2025-12-08 15:28:21 +01:00
Liad Yosef
ba1a27e465
fix: change size-changed to be in correct tense (#83)
* fix: change size-changed to be in correct tense

* sdk changes
2025-12-08 12:14:56 +01:00
Jerome
a09354bdf2
Fix compatibility with @modelcontextprotocol/sdk 1.23+ (#84)
* Fix compatibility with @modelcontextprotocol/sdk 1.23+

Implement required abstract methods `assertTaskCapability` and
`assertTaskHandlerCapability` in App and AppBridge classes. These
were added to the Protocol base class in SDK 1.23+.

Also regenerates package-lock.json with valid npm registry versions
(previously had non-existent vite@6.4.1).

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Co-Authored-By: Claude <noreply@anthropic.com>

* Add pkg-pr-new workflow for PR/commit publishing

Enables automatic publishing of any commit or PR to pkg.pr.new,
allowing consumers to install directly from git commits:

npm install https://pkg.pr.new/modelcontextprotocol/ext-apps/@modelcontextprotocol/ext-apps@<commit-or-pr>

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Co-Authored-By: Claude <noreply@anthropic.com>

---------

Co-authored-by: Claude <noreply@anthropic.com>
2025-12-08 12:13:07 +01:00
Anton Pidkuiko MacBook
9743051f06
Fix callServerTool to handle wrapped JSON-RPC responses
Some host implementations incorrectly return the full JSON-RPC envelope
(with result, jsonrpc, id fields) instead of just the unwrapped result.
This causes apps using callServerTool() to fail when accessing result.content.

This fix detects wrapped responses and unwraps them automatically.

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Co-Authored-By: Claude <noreply@anthropic.com>
2025-12-05 23:12:26 +00:00
Jonathan Hefner
1a6f237501
Fix iframe sizing to use actual content dimensions (#57)
The previous approach measured html/body elements which expand to fill
the viewport, causing the iframe to be larger than necessary.

Fix by using CSS fit-content to measure the true minimum content size:
- Temporarily set html to fit-content to shrink it to content
- This automatically includes body margins
- Cache last sent size to prevent feedback loops from style changes
- Simplify scrollbar compensation (already 0 when no scrollbar)

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Co-authored-by: Claude <noreply@anthropic.com>
2025-12-01 23:04:09 +00:00
Jonathan Hefner
1cf95e53e4
Fix iframe size feedback loop on Linux/Windows (#54)
Compensate for viewport scrollbar width in size change notifications.
On Linux/Windows, scrollbars consume space from the content area, causing
a feedback loop where the iframe progressively shrinks to zero.

- Use window.innerWidth - clientWidth to detect scrollbar width
- Use max of getBoundingClientRect (CSS transforms) and scroll dimensions
  (content overflow) to report accurate size

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Co-authored-by: Claude <noreply@anthropic.com>
2025-12-01 20:05:35 +00:00
Jonathan Hefner
16a9e6f034
Add API docs (#29)
* Refactor types.ts to use explicit interfaces with JSDoc

Replace z.infer<typeof Schema> patterns with explicit interface
definitions for all MCP UI types. Add VerifySchemaMatches helper
type to ensure compile-time verification that schemas match their
interfaces.

Add comprehensive JSDoc documentation to all exported types including:
- Clear descriptions of purpose and usage
- @see references to related types and methods
- Code examples where helpful
- @internal markers for implementation details

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Co-Authored-By: Claude <noreply@anthropic.com>

* Add JSDoc documentation and TypeDoc tooling

Add comprehensive JSDoc documentation to:
- AppBridge class and all methods
- App class and all methods
- PostMessageTransport class and callbacks
- React hooks (useApp, useAutoResize)
- React module index

Set up TypeDoc for API documentation generation:
- Add typedoc.json configuration
- Add docs and docs:watch npm scripts
- Add typedoc dev dependency
- Update .gitignore to exclude generated docs

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Co-Authored-By: Claude <noreply@anthropic.com>

* Add JSDoc documentation for callback handler setters

Document all notification and request handler setters in AppBridge
and App classes with comprehensive JSDoc comments including:
- Clear descriptions of when handlers are called
- Parameter documentation and types
- Practical code examples with error handling
- Cross-references to related types and methods
- Security considerations where relevant

Also update types.ts to document optional isError fields in result
types and make McpUiInitializedNotification params optional.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

* Add JSDoc for new App methods and fix result type compatibility

Document new public APIs introduced in merge commit 74a7b1f:
- getHostCapabilities() - getter for host capabilities after connect
- getHostVersion() - getter for host implementation info after connect
- oncalltool setter - convenience handler for tool call requests
- onlisttools setter - convenience handler for tool listing requests
- RESOURCE_URI_META_KEY constant - metadata key for resource URIs

Add index signatures to McpUiMessageResult and McpUiOpenLinkResult
for MCP SDK Protocol class compatibility, matching the existing
pattern in McpUiInitializeResult.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

* Add comprehensive JSDoc documentation across library

- Document App methods with detailed descriptions and examples
- Add JSDoc to AppBridge methods including getters and setters
- Document PostMessageTransport callback properties
- Improve React hook documentation (useApp, useAutoResize)
- Add documentation for types.ts result and notification types
- Add @see cross-references between related methods
- Fix code examples to use correct syntax and patterns
- Clarify error handling behavior in method descriptions

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

* Fix TypeDoc cross-module link resolution warnings

Replace unqualified @link references with module-qualified syntax to fix
"Failed to resolve link" warnings during docs generation. TypeDoc cannot
resolve links like {@link App.sendOpenLink} without imports, so use the
module-qualified format {@link app.App.sendOpenLink} instead.

Changes:
- types.ts: Fix 9 cross-module links to App and AppBridge methods
- app-bridge.ts: Fix 2 references to App.sendSizeChange
- message-transport.ts: Fix 2 references to App.connect and AppBridge.connect

This eliminates all "Failed to resolve link" warnings without requiring
circular imports or removing documentation cross-references.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

* Remove TypeDoc links to undocumented external types

Remove @link references to types that are either:
- Not exported (AppOptions) - internal implementation detail
- From external packages (@modelcontextprotocol/sdk) - not included in docs

This eliminates warnings about resolved but undocumented types. The type
information is still available through TypeScript's type system and parameter
documentation, but without broken links in the generated documentation.

Removed links to:
- AppOptions (internal type)
- Implementation, CallToolRequest, CallToolResult (MCP SDK types)
- ListToolsRequest, LoggingMessageNotification (MCP SDK types)

Reduces warnings from 12 to 4 (remaining are about missing example files).

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Co-Authored-By: Claude <noreply@anthropic.com>

* Bump @modelcontextprotocol/sdk to ^1.23.0

Update SDK dependency to fix CI build failures caused by version
mismatch. CI was installing 1.23.0 (latest compatible with ^1.22.0)
while local builds used 1.22.0.

Note: package-lock.json is gitignored, which prevents reproducible
builds. Consider committing it to ensure CI uses the same versions
as local development.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

* Fix Zod type compatibility with @modelcontextprotocol/sdk

The SDK imports Zod from 'zod/v4' while this package imported from
'zod'. Although both resolve to the same version (3.25.x), TypeScript
sees them as separate modules with incompatible type declarations.

This caused type errors when:
- Extending SDK schemas like RequestSchema.extend()
- Passing SDK schemas to setRequestHandler/setNotificationHandler
- Using ZodObject/ZodLiteral types from different import paths

Changes:
- Import zod from 'zod/v4' to match SDK import path
- Update z.record() calls to use Zod v4 signature (requires both
  key and value schemas)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

* Add GitHub Actions workflow to deploy docs to gh-pages

Adds a workflow with manual trigger (workflow_dispatch) that generates
TypeDoc documentation and publishes it to the gh-pages branch using
peaceiris/actions-gh-pages.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

* Add docs index.html redirect to API documentation

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

* Revise README for clarity and audience focus

- Add API documentation badge linking to GitHub Pages
- Reorganize content around two audiences: App Developers and Host Developers
- Convert relative links to absolute GitHub URLs for better portability
- Simplify installation and examples sections
- Add Resources section with links to docs, spec, and discussion

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Co-Authored-By: Claude <noreply@anthropic.com>

* Update src/app-bridge.ts

---------

Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: Olivier Chafik <ochafik@anthropic.com>
2025-11-27 22:09:22 +00:00
Olivier Chafik
8ac79a9731
lib: add capabilities & version getters (#24)
* add App{,Bridge}.get{App,Host}{Version,Capabilities}()

* Add App.{oncalltool,onlisttools}
2025-11-25 04:05:33 +00:00