feat: support generic messages response #35

liady · 2025-07-17T13:49:20Z

This supports returning responses for every message that contains a messageId, given the onUIAction was provided:

An immediate "ack" response of type ui-action-received - so that the calling frame will know that the rendering environment is using mcp-ui
A respose message of type ui-action-response with the result of onUIAction

packages/client/src/components/HTMLResourceRenderer.tsx

lemonmade

General approach makes sense to me, just had a couple small questions/ suggestions

packages/client/src/components/HTMLResourceRenderer.tsx

cloudflare-workers-and-pages · 2025-07-18T14:26:00Z

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Pull Request Overview

This PR adds support for asynchronous message handling in UI actions by introducing an optional messageId field to all UI action types. When a messageId is provided and an onUIAction callback exists, the system automatically sends acknowledgment and response messages back to the iframe for better asynchronous communication patterns.

Adds optional messageId field to all UI action result types
Implements automatic response messaging with acknowledgment, success, and error states
Updates documentation with comprehensive examples of asynchronous communication patterns

Reviewed Changes

Copilot reviewed 11 out of 11 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
packages/server/src/types.ts	Adds GenericActionMessage type with messageId field to all UI action result types
packages/client/src/types.ts	Mirrors server-side type changes for client package
packages/server/src/index.ts	Exports InternalMessageType constants for response message types
packages/client/src/components/HTMLResourceRenderer.tsx	Implements async message handling with automatic response posting
Multiple documentation files	Updates API documentation and adds comprehensive async communication examples

packages/client/src/components/HTMLResourceRenderer.tsx

# [5.2.0](v5.1.2...v5.2.0) (2025-07-18) ### Features * support generic messages response ([#35](#35)) ([10b407b](10b407b))

# 1.0.0 (2025-07-19) ### Bug Fixes * add a bridge to pass messages in and out of the proxy ([#38](#38)) ([30ccac0](30ccac0)) * **client:** specify iframe ([fd0b70a](fd0b70a)) * **client:** styling ([6ff9b68](6ff9b68)) * dependencies ([887f61f](887f61f)) * export RemoteDomResource ([2b86f2d](2b86f2d)) * export ResourceRenderer and HtmlResource ([2b841a5](2b841a5)) * exports ([3a93a16](3a93a16)) * iframe handle ([#15](#15)) ([66bd4fd](66bd4fd)) * lint ([4487820](4487820)) * lint ([d0a91f9](d0a91f9)) * package config ([8dc1e53](8dc1e53)) * packaging ([9e6babd](9e6babd)) * pass ref explicitly using iframeProps ([#33](#33)) ([d01b5d1](d01b5d1)) * publish ([0943e7a](0943e7a)) * ref passing to UIResourceRenderer ([#32](#32)) ([d28c23f](d28c23f)) * remove shared dependency ([e66e8f4](e66e8f4)) * rename components and methods to fit new scope ([#22](#22)) ([6bab1fe](6bab1fe)) * rename delivery -> encoding and flavor -> framework ([#36](#36)) ([9a509ed](9a509ed)) * support react-router ([21ffb95](21ffb95)) * text and blob support in RemoteDOM resources ([ec68eb9](ec68eb9)) * trigger release ([aaca831](aaca831)) * typescript types to be compatible with MCP SDK ([#10](#10)) ([74365d7](74365d7)) * update deps ([4091ef4](4091ef4)) * use targetOrigin in the proxy message relay ([#40](#40)) ([b3fb54e](b3fb54e)) * validate URL ([b7c994d](b7c994d)) ### Documentation * bump ([#4](#4)) ([ad4d163](ad4d163)) ### Features * add proxy option to externalUrl ([#37](#37)) ([7b95cd0](7b95cd0)) * add remote-dom content type ([#18](#18)) ([5dacf37](5dacf37)) * add Ruby server SDK ([#31](#31)) ([5ffcde4](5ffcde4)) * change onGenericMcpAction to optional onUiAction ([1913b59](1913b59)) * **client:** allow setting supportedContentTypes for HtmlResource ([#17](#17)) ([e009ef1](e009ef1)) * consolidate ui:// and ui-app:// ([#8](#8)) ([2e08035](2e08035)) * pass iframe props down ([#14](#14)) ([112539d](112539d)) * separate html and remote-dom props ([#24](#24)) ([a7f0529](a7f0529)) * support generic messages response ([#35](#35)) ([10b407b](10b407b)) * support ui action result types ([#6](#6)) ([899d152](899d152)) * switch to ResourceRenderer ([#21](#21)) ([6fe3166](6fe3166)) ### BREAKING CHANGES * The existing naming is ambiguous. Renaming delivery to encoding and flavor to framework should clarify the intent. * exported names have changed * removed deprecated client API * (previous one didn't take due to semantic-release misalignment)

# 1.0.0-alpha.1 (2025-10-10) ### Bug Fixes * adapter version ([259c842](259c842)) * add a bridge to pass messages in and out of the proxy ([#38](#38)) ([30ccac0](30ccac0)) * bump client version ([75c9236](75c9236)) * **client:** specify iframe ([fd0b70a](fd0b70a)) * **client:** styling ([6ff9b68](6ff9b68)) * dependencies ([887f61f](887f61f)) * export RemoteDomResource ([2b86f2d](2b86f2d)) * export ResourceRenderer and HtmlResource ([2b841a5](2b841a5)) * exports ([3a93a16](3a93a16)) * iframe handle ([#15](#15)) ([66bd4fd](66bd4fd)) * lint ([4487820](4487820)) * lint ([d0a91f9](d0a91f9)) * minor typo ([a0bee9c](a0bee9c)) * move react dependencies to be peer dependencies ([#91](#91)) ([f672f3e](f672f3e)), closes [#90](#90) * package config ([8dc1e53](8dc1e53)) * packaging ([9e6babd](9e6babd)) * pass ref explicitly using iframeProps ([#33](#33)) ([d01b5d1](d01b5d1)) * publish ([0943e7a](0943e7a)) * ref passing to UIResourceRenderer ([#32](#32)) ([d28c23f](d28c23f)) * release ([420efc0](420efc0)) * remove shared dependency ([e66e8f4](e66e8f4)) * rename components and methods to fit new scope ([#22](#22)) ([6bab1fe](6bab1fe)) * rename delivery -> encoding and flavor -> framework ([#36](#36)) ([9a509ed](9a509ed)) * Ruby comment ([b22dc2e](b22dc2e)) * support react-router ([21ffb95](21ffb95)) * text and blob support in RemoteDOM resources ([ec68eb9](ec68eb9)) * trigger release ([aaca831](aaca831)) * typescript ci publish ([e7c0ebf](e7c0ebf)) * typescript types to be compatible with MCP SDK ([#10](#10)) ([74365d7](74365d7)) * update deps ([4091ef4](4091ef4)) * update isUIResource to use EmbeddedResource type ([#122](#122)) ([5a65a0b](5a65a0b)), closes [#117](#117) * use targetOrigin in the proxy message relay ([#40](#40)) ([b3fb54e](b3fb54e)) * validate URL ([b7c994d](b7c994d)) * wc dist overwrite ([#63](#63)) ([9e46c56](9e46c56)) ### Documentation * bump ([#4](#4)) ([ad4d163](ad4d163)) ### Features * add adapters infra (appssdk) ([#125](#125)) ([2e016cd](2e016cd)) * add convenience function isUIResource to client SDK ([#86](#86)) ([607c6ad](607c6ad)) * add embeddedResourceProps for annotations ([#99](#99)) ([b96ec44](b96ec44)) * add proxy option to externalUrl ([#37](#37)) ([7b95cd0](7b95cd0)) * add remote-dom content type ([#18](#18)) ([5dacf37](5dacf37)) * add Ruby server SDK ([#31](#31)) ([5ffcde4](5ffcde4)) * add sandbox permissions instead of an override ([#83](#83)) ([b1068e9](b1068e9)) * add ui-request-render-data message type ([#111](#111)) ([26135ce](26135ce)) * add UIResourceRenderer Web Component ([#58](#58)) ([ec8f299](ec8f299)) * auto resize with the autoResizeIframe prop ([#56](#56)) ([76c867a](76c867a)) * change onGenericMcpAction to optional onUiAction ([1913b59](1913b59)) * **client:** allow setting supportedContentTypes for HtmlResource ([#17](#17)) ([e009ef1](e009ef1)) * consolidate ui:// and ui-app:// ([#8](#8)) ([2e08035](2e08035)) * pass iframe props down ([#14](#14)) ([112539d](112539d)) * refactor UTFtoB64 (bump server version) ([#95](#95)) ([2d5e16b](2d5e16b)) * send render data to the iframe ([#51](#51)) ([d38cfc7](d38cfc7)) * separate html and remote-dom props ([#24](#24)) ([a7f0529](a7f0529)) * support generic messages response ([#35](#35)) ([10b407b](10b407b)) * support passing resource metadata ([#87](#87)) ([f1c1c9b](f1c1c9b)) * support ui action result types ([#6](#6)) ([899d152](899d152)) * switch to ResourceRenderer ([#21](#21)) ([6fe3166](6fe3166)) ### BREAKING CHANGES * The existing naming is ambiguous. Renaming delivery to encoding and flavor to framework should clarify the intent. * exported names have changed * removed deprecated client API * (previous one didn't take due to semantic-release misalignment)

# 1.0.0-alpha.1 (2025-10-10) ### Bug Fixes * adapter version ([259c842](259c842)) * add a bridge to pass messages in and out of the proxy ([#38](#38)) ([30ccac0](30ccac0)) * bump client version ([75c9236](75c9236)) * **client:** specify iframe ([fd0b70a](fd0b70a)) * **client:** styling ([6ff9b68](6ff9b68)) * dependencies ([887f61f](887f61f)) * export RemoteDomResource ([2b86f2d](2b86f2d)) * export ResourceRenderer and HtmlResource ([2b841a5](2b841a5)) * exports ([3a93a16](3a93a16)) * iframe handle ([#15](#15)) ([66bd4fd](66bd4fd)) * lint ([4487820](4487820)) * lint ([d0a91f9](d0a91f9)) * minor typo ([a0bee9c](a0bee9c)) * move react dependencies to be peer dependencies ([#91](#91)) ([f672f3e](f672f3e)), closes [#90](#90) * package config ([8dc1e53](8dc1e53)) * packaging ([9e6babd](9e6babd)) * pass ref explicitly using iframeProps ([#33](#33)) ([d01b5d1](d01b5d1)) * publish ([0943e7a](0943e7a)) * ref passing to UIResourceRenderer ([#32](#32)) ([d28c23f](d28c23f)) * release ([420efc0](420efc0)) * remove shared dependency ([e66e8f4](e66e8f4)) * rename components and methods to fit new scope ([#22](#22)) ([6bab1fe](6bab1fe)) * rename delivery -> encoding and flavor -> framework ([#36](#36)) ([9a509ed](9a509ed)) * Ruby comment ([b22dc2e](b22dc2e)) * server versioning ([2324371](2324371)) * support react-router ([21ffb95](21ffb95)) * text and blob support in RemoteDOM resources ([ec68eb9](ec68eb9)) * trigger release ([aaca831](aaca831)) * typescript ci publish ([e7c0ebf](e7c0ebf)) * typescript types to be compatible with MCP SDK ([#10](#10)) ([74365d7](74365d7)) * update deps ([4091ef4](4091ef4)) * update isUIResource to use EmbeddedResource type ([#122](#122)) ([5a65a0b](5a65a0b)), closes [#117](#117) * use targetOrigin in the proxy message relay ([#40](#40)) ([b3fb54e](b3fb54e)) * validate URL ([b7c994d](b7c994d)) * wc dist overwrite ([#63](#63)) ([9e46c56](9e46c56)) ### Documentation * bump ([#4](#4)) ([ad4d163](ad4d163)) ### Features * add adapters infra (appssdk) ([#125](#125)) ([2e016cd](2e016cd)) * add convenience function isUIResource to client SDK ([#86](#86)) ([607c6ad](607c6ad)) * add embeddedResourceProps for annotations ([#99](#99)) ([b96ec44](b96ec44)) * add proxy option to externalUrl ([#37](#37)) ([7b95cd0](7b95cd0)) * add remote-dom content type ([#18](#18)) ([5dacf37](5dacf37)) * add Ruby server SDK ([#31](#31)) ([5ffcde4](5ffcde4)) * add sandbox permissions instead of an override ([#83](#83)) ([b1068e9](b1068e9)) * add ui-request-render-data message type ([#111](#111)) ([26135ce](26135ce)) * add UIResourceRenderer Web Component ([#58](#58)) ([ec8f299](ec8f299)) * auto resize with the autoResizeIframe prop ([#56](#56)) ([76c867a](76c867a)) * change onGenericMcpAction to optional onUiAction ([1913b59](1913b59)) * **client:** allow setting supportedContentTypes for HtmlResource ([#17](#17)) ([e009ef1](e009ef1)) * consolidate ui:// and ui-app:// ([#8](#8)) ([2e08035](2e08035)) * pass iframe props down ([#14](#14)) ([112539d](112539d)) * refactor UTFtoB64 (bump server version) ([#95](#95)) ([2d5e16b](2d5e16b)) * send render data to the iframe ([#51](#51)) ([d38cfc7](d38cfc7)) * separate html and remote-dom props ([#24](#24)) ([a7f0529](a7f0529)) * support generic messages response ([#35](#35)) ([10b407b](10b407b)) * support passing resource metadata ([#87](#87)) ([f1c1c9b](f1c1c9b)) * support ui action result types ([#6](#6)) ([899d152](899d152)) * switch to ResourceRenderer ([#21](#21)) ([6fe3166](6fe3166)) ### BREAKING CHANGES * The existing naming is ambiguous. Renaming delivery to encoding and flavor to framework should clarify the intent. * exported names have changed * removed deprecated client API * (previous one didn't take due to semantic-release misalignment)

jonathanhefner · 2025-11-01T18:37:07Z

An immediate "ack" response of type ui-action-received - so that the calling frame will know that the rendering environment is using mcp-ui

I realize this predates ui-lifecycle-iframe-render-data, but now that we have ui-lifecycle-iframe-render-data could it serve this purpose (thus obsoleting ui-message-received)?

idosal · 2025-11-03T19:50:47Z

An immediate "ack" response of type ui-action-received - so that the calling frame will know that the rendering environment is using mcp-ui

I realize this predates ui-lifecycle-iframe-render-data, but now that we have ui-lifecycle-iframe-render-data could it serve this purpose (thus obsoleting ui-message-received)?

@jonathanhefner Great question. I think that "knowing the environment supports mcp-ui" doesn't quite capture the reasoning. It signals support for the specific action and message. For example, some hosts may choose not to handle some action types but neglect to respond with an error, or there may be a bug with the host's event handling.

# 1.0.0 (2025-11-04) ### Bug Fixes * add a bridge to pass messages in and out of the proxy ([#38](#38)) ([30ccac0](30ccac0)) * bump client version ([75c9236](75c9236)) * **client:** specify iframe ([fd0b70a](fd0b70a)) * **client:** styling ([6ff9b68](6ff9b68)) * dependencies ([887f61f](887f61f)) * Enable bidirectional message relay in rawhtml proxy mode ([#138](#138)) ([f0bdefb](f0bdefb)) * ensure Apps SDK adapter is bundled properly and initialized wth config ([#137](#137)) ([4f7c25c](4f7c25c)) * export RemoteDomResource ([2b86f2d](2b86f2d)) * export ResourceRenderer and HtmlResource ([2b841a5](2b841a5)) * exports ([3a93a16](3a93a16)) * fix file extension reference in package.json ([927989c](927989c)) * iframe handle ([#15](#15)) ([66bd4fd](66bd4fd)) * lint ([4487820](4487820)) * lint ([d0a91f9](d0a91f9)) * minor typo ([a0bee9c](a0bee9c)) * move react dependencies to be peer dependencies ([#91](#91)) ([f672f3e](f672f3e)), closes [#90](#90) * package config ([8dc1e53](8dc1e53)) * packaging ([9e6babd](9e6babd)) * pass ref explicitly using iframeProps ([#33](#33)) ([d01b5d1](d01b5d1)) * publish ([0943e7a](0943e7a)) * ref passing to UIResourceRenderer ([#32](#32)) ([d28c23f](d28c23f)) * remove shared dependency ([e66e8f4](e66e8f4)) * rename components and methods to fit new scope ([#22](#22)) ([6bab1fe](6bab1fe)) * rename delivery -> encoding and flavor -> framework ([#36](#36)) ([9a509ed](9a509ed)) * Ruby comment ([b22dc2e](b22dc2e)) * support react-router ([21ffb95](21ffb95)) * text and blob support in RemoteDOM resources ([ec68eb9](ec68eb9)) * trigger release ([aaca831](aaca831)) * typescript ci publish ([e7c0ebf](e7c0ebf)) * typescript types to be compatible with MCP SDK ([#10](#10)) ([74365d7](74365d7)) * update deps ([4091ef4](4091ef4)) * update isUIResource to use EmbeddedResource type ([#122](#122)) ([5a65a0b](5a65a0b)), closes [#117](#117) * use targetOrigin in the proxy message relay ([#40](#40)) ([b3fb54e](b3fb54e)) * validate URL ([b7c994d](b7c994d)) * wc dist overwrite ([#63](#63)) ([9e46c56](9e46c56)) ### Documentation * bump ([#4](#4)) ([ad4d163](ad4d163)) ### Features * add convenience function isUIResource to client SDK ([#86](#86)) ([607c6ad](607c6ad)) * add embeddedResourceProps for annotations ([#99](#99)) ([b96ec44](b96ec44)) * add proxy option to externalUrl ([#37](#37)) ([7b95cd0](7b95cd0)) * add remote-dom content type ([#18](#18)) ([5dacf37](5dacf37)) * add Ruby server SDK ([#31](#31)) ([5ffcde4](5ffcde4)) * add sandbox permissions instead of an override ([#83](#83)) ([b1068e9](b1068e9)) * add ui-request-render-data message type ([#111](#111)) ([26135ce](26135ce)) * add UIResourceRenderer Web Component ([#58](#58)) ([ec8f299](ec8f299)) * auto resize with the autoResizeIframe prop ([#56](#56)) ([76c867a](76c867a)) * change onGenericMcpAction to optional onUiAction ([1913b59](1913b59)) * **client:** allow setting supportedContentTypes for HtmlResource ([#17](#17)) ([e009ef1](e009ef1)) * consolidate ui:// and ui-app:// ([#8](#8)) ([2e08035](2e08035)) * pass iframe props down ([#14](#14)) ([112539d](112539d)) * refactor UTFtoB64 (bump server version) ([#95](#95)) ([2d5e16b](2d5e16b)) * send render data to the iframe ([#51](#51)) ([d38cfc7](d38cfc7)) * separate html and remote-dom props ([#24](#24)) ([a7f0529](a7f0529)) * support adapters ([#127](#127)) ([d4bd152](d4bd152)) * support generic messages response ([#35](#35)) ([10b407b](10b407b)) * support metadata in Python SDK ([#134](#134)) ([9bc3c64](9bc3c64)) * support passing resource metadata ([#87](#87)) ([f1c1c9b](f1c1c9b)) * support proxy for rawHtml ([#132](#132)) ([1bbeb09](1bbeb09)) * support ui action result types ([#6](#6)) ([899d152](899d152)) * switch to ResourceRenderer ([#21](#21)) ([6fe3166](6fe3166)) ### BREAKING CHANGES * The existing naming is ambiguous. Renaming delivery to encoding and flavor to framework should clarify the intent. * exported names have changed * removed deprecated client API * (previous one didn't take due to semantic-release misalignment)

liady added 3 commits July 17, 2025 16:43

feat: support generic messages response

23a4662

change requestId to messageId

0c63ac7

return the response only if onUIAction was provided

874322a

idosal requested a review from Copilot July 17, 2025 14:39

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send error

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lemonmade reviewed Jul 17, 2025

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liady added 5 commits July 17, 2025 22:48

lighter payload

86898b1

move messageId up

a5f54aa

rename

a6f2305

Merge branch 'main' into feat/generic-messages-response

050b6e0

add event origin to responses

237e055

liady added 4 commits July 18, 2025 17:37

better event origin

882067d

add docs

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Merge branch 'main' into feat/generic-messages-response

970fea7

fix in case the iframe is srcdoc

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idosal requested a review from Copilot July 18, 2025 21:07

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remove binding

c9d563d

liady merged commit 10b407b into main Jul 18, 2025
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github-actions bot pushed a commit that referenced this pull request Jul 18, 2025

chore(release): 5.2.0 [skip ci]

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# [5.2.0](v5.1.2...v5.2.0) (2025-07-18) ### Features * support generic messages response ([#35](#35)) ([10b407b](10b407b))

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