feat: auto resize with the autoResizeIframe prop by liady · Pull Request #56 · MCP-UI-Org/mcp-ui

liady · 2025-08-02T17:44:31Z

This features auto resizes the iframe when an autoResizeIframe is present on <UIResourceRenderer /> .

Client side:

<UIResourceRenderer
  resource={resource}
  htmlProps={{ autoResizeIframe: true }}
/>

Server side:

const resizeObserver = new ResizeObserver((entries) => {
  entries.forEach((entry) => {
    window.parent.postMessage(
      {
        type: "ui-size-change",
        payload: {
          height: entry.contentRect.height, // supports height and width
        },
      },
      "*",
    );
  });
});

resizeObserver.observe(document.documentElement)

Note: autoResizeIframe can either be a boolean or { width?: boolean, height?: boolean } for fine-grained control on auto resizing dimensions.

idosal · 2025-08-02T18:05:31Z

docs/src/guide/client/html-resource.md

+  entries.forEach((entry) => {
+    window.parent.postMessage(
+      {
+        type: "ui-size-change",


Perhaps mcp-ui-size-change for namespacing

note that all the other events start with ui-, though:

export const InternalMessageType = { UI_ACTION_RECEIVED: 'ui-action-received', UI_ACTION_RESPONSE: 'ui-action-response', UI_ACTION_ERROR: 'ui-action-error', UI_SIZE_CHANGE: 'ui-size-change', UI_LIFECYCLE_IFRAME_READY: 'ui-lifecycle-iframe-ready', UI_LIFECYCLE_IFRAME_RENDER_DATA: 'ui-lifecycle-iframe-render-data', };

docs/src/guide/client/html-resource.md

idosal · 2025-08-02T18:11:18Z

docs/src/guide/client/html-resource.md

+
+To make the iframe auto-resize, two things need to happen:
+1. The `autoResizeIframe` prop must be set on the `<HTMLResourceRenderer />` (or passed via `htmlProps` to `<UIResourceRenderer />`).
+2. The content inside the iframe must send a `ui-size-change` message to the parent window when its size changes.


Namespacing

idosal · 2025-08-02T18:14:08Z

sdks/typescript/server/src/index.ts

  UI_ACTION_RESPONSE: 'ui-action-response',
  UI_ACTION_ERROR: 'ui-action-error',

+  UI_SIZE_CHANGE: 'ui-size-change',


Suggested change

UI_SIZE_CHANGE: 'ui-size-change',

UI_SIZE_CHANGE: 'mcp-ui-size-change',

Co-authored-by: Ido Salomon <idosalomon@gmail.com>

cloudflare-workers-and-pages · 2025-08-02T20:28:25Z

Deploying mcp-ui with Cloudflare Pages

Latest commit:	`6a62e8d`
Status:	✅ Deploy successful!
Preview URL:	https://7d5a9177.mcp-ui.pages.dev
Branch Preview URL:	https://feat-auto-resize.mcp-ui.pages.dev

View logs

…8-02) ### Features * auto resize with the autoResizeIframe prop ([#56](#56)) ([76c867a](76c867a))

# 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)

# 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 2 commits August 2, 2025 20:11

feat: auto resize iframe with ui-size-change event

0288814

docs

1a1bfd3

idosal reviewed Aug 2, 2025

View reviewed changes

docs/src/guide/client/html-resource.md Outdated Show resolved Hide resolved

idosal reviewed Aug 2, 2025

View reviewed changes

Update docs/src/guide/client/html-resource.md

6a62e8d

Co-authored-by: Ido Salomon <idosalomon@gmail.com>

liady merged commit 76c867a into main Aug 2, 2025
7 checks passed

github-actions bot pushed a commit that referenced this pull request Aug 2, 2025

chore(release): 5.5.0 [skip ci]\n\n# [5.5.0](v5.4.0...v5.5.0) (2025-0…

e6e6dad

…8-02) ### Features * auto resize with the autoResizeIframe prop ([#56](#56)) ([76c867a](76c867a))

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

feat: auto resize with the autoResizeIframe prop#56

feat: auto resize with the autoResizeIframe prop#56
liady merged 3 commits intomainfrom
feat/auto-resize

liady commented Aug 2, 2025

Uh oh!

idosal Aug 2, 2025

Uh oh!

liady Aug 2, 2025

Uh oh!

Uh oh!

idosal Aug 2, 2025

Uh oh!

idosal Aug 2, 2025

Uh oh!

cloudflare-workers-and-pages bot commented Aug 2, 2025

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants

	UI_SIZE_CHANGE: 'ui-size-change',
	UI_SIZE_CHANGE: 'mcp-ui-size-change',

Conversation

liady commented Aug 2, 2025

Uh oh!

idosal Aug 2, 2025

Choose a reason for hiding this comment

Uh oh!

liady Aug 2, 2025

Choose a reason for hiding this comment

Uh oh!

Uh oh!

idosal Aug 2, 2025

Choose a reason for hiding this comment

Uh oh!

idosal Aug 2, 2025

Choose a reason for hiding this comment

Uh oh!

cloudflare-workers-and-pages bot commented Aug 2, 2025

Deploying mcp-ui with Cloudflare Pages

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants