Support MCP UI

[Matvey-Kuk]

Dear community, let's build some cool stuff 🚀🚀🚀

Please refrain from publishing the PR before you are assigned to this issue!

1. Bring the support of MCP UI (https://github.com/MCP-UI-Org/mcp-ui) in Archestra Chat UI.
2. Make sure it works in 3'rd third-party UI via our MCP Gateway.
3. Make sure it works in 3'rd third-party UI via our LLM Gateway.
4. Test at least two real-life vendors' MCPs with MCP UI and bring them to our catalog.

The acceptance criteria is a demo showing all four steps working besides the PR itself 🏆

[Matvey-Kuk]

/bounty 900

[algora-pbc]

💎 $900 bounty • Archestra

Steps to solve:

1. Comment /attempt #1301 with your implementation plan
2. Make sure you're assigned to the issue by the core team member.
3. Start working: Read contribution guideline: https://www.archestra.ai/docs/contributing
4. Submit work: Create a pull request including /claim #1301 in the PR body to claim the bounty
5. Receive payment: 100% of the bounty is received 2-5 days post-reward. Make sure you are eligible for payouts

Thank you for contributing to archestra-ai/archestra!

Attempt	Started (UTC)	Solution	Actions
🟢 @Geetk172	Dec 01, 2025, 08:44:34 AM	#1366	Reward
🟢 @developerfred	Dec 01, 2025, 03:40:47 PM	#1441	Reward
🟢 @SaikiranSurapalli17	Dec 02, 2025, 05:22:06 AM	WIP
🟢 @Grayking1905	Feb 02, 2026, 08:07:05 AM	WIP
🟢 @ernestofosu05	Feb 02, 2026, 08:51:05 AM	#2558	Reward
🟢 @gs03-dev	Dec 02, 2025, 09:25:38 AM	WIP
🟢 @gechdejenb	Feb 03, 2026, 09:13:35 AM	WIP
🟢 @Ido-Levi	Feb 03, 2026, 08:08:09 PM	#2589	Reward
🟢 @kajal1322705	Dec 04, 2025, 01:37:57 PM	#1433	Reward
🟢 @Excellencedev	Jan 09, 2026, 05:45:11 AM	WIP
🟢 @SandyUndefined	Dec 11, 2025, 06:52:47 AM	WIP
🟢 @GhostDragonAlpha	Jan 14, 2026, 10:58:33 PM	#2139	Reward
🟢 @abhinav-m22	Jan 15, 2026, 10:20:15 AM	WIP
🟢 @nicefacer	Dec 19, 2025, 10:49:22 PM	WIP
🟢 @MichaelWalker-git	Jan 20, 2026, 05:59:49 AM	#2248	Reward
🟢 @barran33	Dec 20, 2025, 01:07:12 PM	WIP
🟢 @KishoreGhost	Jan 22, 2026, 05:51:31 AM	WIP
🟢 @it-baron	Jan 22, 2026, 10:10:47 AM	WIP
🟢 @itisaasim	Jan 22, 2026, 12:20:19 PM	#2447	Reward
🟢 @gineakhil-alt	Dec 24, 2025, 10:53:08 AM	WIP
🟢 @Pranjal6955	Nov 28, 2025, 05:30:16 PM	WIP
🟢 @devroy10	Nov 28, 2025, 06:07:42 PM	WIP
🟢 @guptapratykshh	Nov 29, 2025, 06:51:01 PM	WIP
🟢 @JohnSuperIndividual	Jan 30, 2026, 04:59:34 AM	#2529	Reward
🟢 @ethanwater	Nov 30, 2025, 09:22:37 PM	WIP

[Pranjal6955]

/attempt #1301

[devroy10]

/attempt #1301

[Matvey-Kuk]

Hi @Pranjal6955 and @devroy10! Do you have an implementation plan in mind?

[Pranjal6955]

Hi @Matvey-Kuk
Here is the implementation Plan :

1. Research the MCP UI library, understand its structure and API, set up the development environment, and design where MCP UI will integrate inside Archestra Chat UI.

2. Install the MCP UI package, replace existing tool display components with MCP UI components, improve how tools are rendered inside chat messages, and add resource or prompt UI if needed.

3. Extend the MCP Gateway to support MCP UI, add discovery and metadata endpoints, create a test third-party UI for validation, and document the integration process.

4. Extend the LLM Gateway to support MCP UI, add an MCP UI configuration endpoint, test the flow using a third-party UI, and document this integration as well.

5. Choose at least two MCP servers, test them across all environments (Archestra Chat UI, MCP Gateway, and LLM Gateway), and add both MCPs to the catalog with proper documentation.

[guptapratykshh]

/attempt 1301

[ethanwater]

/attempt #1301

Looks fun, love adding new features. Here's my plan:

1. Add MCP-UI rendering inside Chat UI

first we want the chat UI to treat MCP-UI resources as VIP. The UI already handles generic MCP resources, so the logic becomes:

• detect UIResources carrying the mcpui.dev/ui-* metadata
• spin up an iframe with the MCP-UI client instead of treating the resource as static text/html
• hook the iframe into our existing event bus so UI actions → Archestra actions

this means implementing the full postMessage contract (intent, notify, tool, prompt, link, data requests, render-data, and size updates). Chat UI basically becomes the “host” described in the MCP-UI spec.

2. Ensure the MCP Gateway passes UIResources cleanly

archestra’s MCP Gateway is the single ingress point, so we absolutely cannot mutate any UIResource payloads.
i'll validate that:

• _meta, uiMetadata, blob encodings, and embedded resource fields survive the RPC boundary
• UI actions coming from the iframe route back through the gateway the same way normal tool calls do
• the gateway does not collapse/flatten/strip any fields that MCP-UI relies on

so we want here 3rd-party UI → MCP Gateway → MCP server → back → UI, with interactive UI intact.

3. Same thing for LLM Gateway

the LLM Gateway needs to behave identically from the UI’s point of view. That means:

• if an LLM produces a UIResource, we normalize it so that Chat UI sees the same shape as if it came from a real MCP.
• when the user interacts with an MCP-UI iframe, those actions must route back through the LLM Gateway without any branching logic.

If both gateways end up looking identical upstream, Chat UI stays simple and predictable.

4. Test with two real MCPs and add em to the catalog

i’ll use two very different MCPs so the whole protocol surface is exercised:

• MCP A: simple HTML/uri-list style UI
• MCP B: remote-dom / more interactive UI using the full MCP-UI event model (intents, data requests, etc....)

validate the whole loop: render → user clicks → action hits gateway → MCP responds → iframe updates.

5. Demo Time!

speaks for itself! showcase the awesome chat enhancement.

feel free to share any recs/changes. dope project and would love to be assigned to this. thanks! @Matvey-Kuk

[ethanwater]

And just to be a bit more specific on step 1, I would spin up an MCPUIWrapper iframe that fully implements the MCP-UI postMessage contract, then hook it into chatSession.sendMessage / addToolResult so all UI actions flow seamlessly back to the MCP or LLM. Since /platform/frontend/src/app/chat/page.tsx already tracks conversation state, prompts, etc., we can manage the iframe lifecycle here—including dialog popups for MCP-UI-triggered tool calls. This way, we leverage existing gateways, preserve all current chat states, and keep the integration predictable 😎. MCP UI provides some helpful documentation on their embedding process: https://mcpui.dev/guide/embeddable-ui and in-depth app integration: https://mcpui.dev/guide/mcp-apps

[Geetk172]

/attempt #1301

Implementation Plan

I've created a comprehensive technical plan after analyzing the Archestra codebase. Here's my approach:

Architecture Overview

• Frontend: Integrate MCP UI client with iframe-based rendering in Chat UI
• MCP Gateway: Preserve UIResource metadata and add UI action routing
• LLM Gateway: Generate normalized UIResources from LLM responses
• Catalog: Add 2 test MCPs with UI capabilities

Key Implementation Details

Phase 1 - Chat UI Integration:

• Create MCPUIRenderer component with full postMessage protocol
• Detect mcpui.dev/ui-* metadata in resources
• Handle all MCP UI events: intent, notify, tool, prompt, link, data
• Integrate into existing mcp-tools-display.tsx

Phase 2 - MCP Gateway:

• Ensure _meta, uiMetadata, blob fields pass through unchanged
• Add POST /mcp-gateway/ui-action endpoint for UI interactions
• Add GET /mcp-gateway/servers/:id/ui-capabilities for discovery
• Support all UI resource ty

[developerfred]

/attempt #1301

My implementation plan is to use the following TypeScript libraries: @mcp-ui/server and @mcp-ui/client. I'll use the library guide https://mcpui.dev/guide/introduction to create a clean integration, respecting the entire project architecture.

• Code using project best practices
• Unit tests
• Once everything is ready, I'll make screen record.

My environment is macOS. Is it necessary to test in other environments?

[iskhakov]

@Pranjal6955 @ethanwater @Geetk172 @developerfred thank you for the plan, may I ask a few questions.

1. Could you please confirm that it will work well with MCP Apps announced here and here https://github.com/modelcontextprotocol/ext-apps? As I see on https://mcpui.dev, it's already beginning to migrate to MCP Apps.

2. Please specify which MCP servers you plan to use for testing.

3. Also we need more comprehensive plan around:

Make sure it works in 3'rd third-party UI via our MCP Gateway.
Make sure it works in 3'rd third-party UI via our LLM Gateway.

Because that's where the biggest complexity lies, since we need to process the MCPUI requests on LLM (https://archestra.ai/docs/platform-llm-proxy) and MCP proxies (https://archestra.ai/docs/platform-mcp-gateway)

[developerfred]

@developerfred thank you for the plan, may I ask a few questions.

1. Could you please confirm that it will work well with MCP Apps announced here and here https://github.com/modelcontextprotocol/ext-apps? As I see on https://mcpui.dev, it's already beginning to migrate to MCP Apps.
2. Please specify which MCP servers you plan to use for testing.
3. Also we need more comprehensive plan around:

Make sure it works in 3'rd third-party UI via our MCP Gateway.
Make sure it works in 3'rd third-party UI via our LLM Gateway.

Because that's where the biggest complexity lies, since we need to process the MCPUI requests on LLM (https://archestra.ai/docs/platform-llm-proxy) and MCP proxies (https://archestra.ai/docs/platform-mcp-gateway)

Hey @iskhakov, thanks for questions, let's go!

1 - Yes, the MCP UI already supports the patterns of MCP Apps.

2 - I thought about using the MCP-UI Demo Server (https://remote-mcp-server-authless.idosalomon.workers.dev/mcp) itself

3 - MCP Gateway is a JSON-RPC pass-through proxy, so it only receives JSON-RPC requests from the client and forwards them to the MCP Server. Since UIResource is just another type of JSON-RPC, it will have full compatibility with the existing implementation.

This also applies to the LLM Gateway, where UIResource comes within the JSON tool_result string. I believe we won't need to address this here.