feat: add proxy option to externalUrl by idosal · Pull Request #37 · MCP-UI-Org/mcp-ui

idosal · 2025-07-17T22:25:26Z

Hosts with strict frame-src CSP can't render arbitrary externalUrls. The proxy prop allows them to whitelist a specific domain (the "proxy"), and have that script render an internal sandboxed iframe with the target URL. For convenience, MCP-UI hosts https://proxy.mcpui.dev free of charge.

packages/client/scripts/proxy.html

cloudflare-workers-and-pages · 2025-07-17T23:18:59Z

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Pull Request Overview

This PR adds proxy functionality to the external URL feature in MCP-UI, allowing external URLs to be rendered through a proxy server to comply with strict Content Security Policies. The key changes include adding a proxy parameter to HTML resource processing, implementing security validation to prevent same-origin proxy usage, and providing a complete demonstration example.

Adds proxy prop to HTMLResourceRenderer and UIResourceRenderer components for external URL proxying
Implements proxy URL validation and security checks to prevent same-origin proxy usage
Creates a comprehensive demo example with proxy functionality and CSP demonstration

Reviewed Changes

Copilot reviewed 20 out of 21 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
packages/client/src/utils/processResource.ts	Adds proxy parameter and implements proxy URL processing logic with security validation
packages/client/src/components/HTMLResourceRenderer.tsx	Adds proxy prop to component interface and passes it to processHTMLResource
packages/client/src/components/UIResourceRenderer.tsx	Handles proxy prop filtering for rawHtml vs externalUrl content types
packages/client/src/utils/tests/processResource.test.ts	Comprehensive test coverage for proxy functionality including edge cases
packages/client/scripts/proxy/index.html	Standalone proxy script for rendering external URLs in nested iframes
examples/external-url-demo/	Complete demo application showcasing proxy functionality with CSP
docs/src/guide/client/	Documentation updates explaining proxy functionality and usage

Files not reviewed (1)

pnpm-lock.yaml: Language not supported

packages/client/src/utils/processResource.ts

packages/client/scripts/proxy/index.html

packages/client/src/components/UIResourceRenderer.tsx

# [5.1.0](v5.0.0...v5.1.0) (2025-07-18) ### Features * add proxy option to externalUrl ([#37](#37)) ([7b95cd0](7b95cd0))

# 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)

# 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)

feat: add proxy option to externalUrl

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idosal requested a review from Copilot July 17, 2025 22:25

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liady reviewed Jul 17, 2025

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idosal added 2 commits July 18, 2025 02:26

rename

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fix sizing

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idosal requested a review from Copilot July 18, 2025 00:00

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add external url

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idosal requested a review from Copilot July 18, 2025 00:01

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idosal added 2 commits July 18, 2025 03:27

fix docs

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security

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idosal requested a review from Copilot July 18, 2025 00:30

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fix docs

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idosal requested a review from Copilot July 18, 2025 00:34

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prettier

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idosal requested a review from Copilot July 18, 2025 00:37

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idosal merged commit 7b95cd0 into main Jul 18, 2025
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chore(release): 5.1.0 [skip ci]

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# [5.1.0](v5.0.0...v5.1.0) (2025-07-18) ### Features * add proxy option to externalUrl ([#37](#37)) ([7b95cd0](7b95cd0))

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feat: add proxy option to externalUrl#37

feat: add proxy option to externalUrl#37
idosal merged 8 commits intomainfrom
feat/proxy

idosal commented Jul 17, 2025 •

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idosal commented Jul 17, 2025 •

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