Figma MCP not working

Figma MCP Endpoint Issue - /mcp endpoint not working, only /sse works

SUMMARY
Despite Figma Desktop indicating that the MCP server is running at the /mcp endpoint, only the /sse endpoint is functional. The /mcp endpoint consistently returns JSON-RPC errors.

ENVIRONMENT DETAILS
- Figma Version: 125.7.5 (latest as of August 12, 2025)
- Operating System: macOS
- MCP Server Port: 3845 (confirmed running)
- Installation: Fresh reinstall to ensure no version conflicts
 

What Works:
- SSE Endpoint (http://127.0.0.1:3845/sse):
  - Returns HTTP 200 OK
  - Content-Type: text/event-stream
  - Proper security headers
  - Establishes connection successfully
  - MCP tools function correctly through this endpoint

What Doesn't Work:
- MCP Endpoint (http://127.0.0.1:3845/mcp):
  - Returns various JSON-RPC errors depending on request format
  - Common errors encountered:
    {"jsonrpc": "2.0", "error": {"code": -32001, "message": "Invalid sessionId"}, "id": null}
    {"jsonrpc": "2.0", "error": {"code": -32000, "message": "Invalid request body for initialize request"}, "id": null}

TECHNICAL INVESTIGATION

Server Status Verification:
I confirmed that Figma is running the MCP server on port 3845 and VS Code can connect to it via the SSE endpoint.

Endpoint Testing Results:
- SSE Endpoint: curl -v http://127.0.0.1:3845/sse returns HTTP 200 OK with proper event-stream content
- MCP Endpoint: curl -X POST http://127.0.0.1:3845/mcp with standard JSON-RPC requests returns error messages

TROUBLESHOOTING STEPS ATTEMPTED

1. Clean Installation:
   - Completely uninstalled and reinstalled Figma Desktop
   - Downloaded latest version (125.7.5) from official website
   - Verified no old MCP installations remained

2. Configuration Cleanup:
   - Removed all third-party MCP installations
   - Cleared MCP-related caches and configurations
   - Ensured no port conflicts

3. Multiple Request Formats Tested:
   - Standard MCP initialize requests
   - Various JSON-RPC parameter combinations
   - Different HTTP headers and content types

4. Process Verification:
   - Confirmed Figma process is running the MCP server
   - Verified port 3845 is correctly bound to Figma
   - Established that VS Code can connect via SSE endpoint

CURRENT WORKAROUND

The SSE endpoint (/sse) works perfectly and provides full MCP functionality. MCP configuration that works:

```json

"Figma Dev Mode MCP": {

"url": "http://127.0.0.1:3845/sse"

}

```

QUESTIONS FOR FIGMA TEAM

1. Is the /mcp endpoint fully implemented in version 125.7.5?
   - The endpoint exists but returns errors for standard MCP requests
   - Are there specific authentication or session requirements?

2. What is the expected request format for the /mcp endpoint?
   - Standard JSON-RPC 2.0 requests fail with "Invalid request body"
   - Is there additional metadata or headers required?

3. Should we continue using the /sse endpoint?
   - It works reliably but may be deprecated
   - What is the migration timeline if any?

4. Are there any known issues with the MCP endpoint in the current version?
   - This could help other developers experiencing similar issues

Please clarify the expected behavior and provide guidance on:
1. Proper usage of the /mcp endpoint
2. Whether /sse will remain supported
3. Any additional configuration required for /mcp endpoint functionality

Thank you for your attention to this matter. The MCP integration is valuable for design-to-code workflows, and clarifying this endpoint behavior would help the developer community.

Of course. But I still need to get work done. The /sse and /mcp endpoints don’t work. I also use motiff.com and their MCP server works perfectly fine.

Until Figma fixes this, I’m actually getting work done using the tool above. If it’s not fixed before I’m done then I’ll just use the tools that actually work.

1. Only http://127.0.0.1:3845/sse can access，and http://127.0.0.1:3845/mcp can’t access

   {"jsonrpc":"2.0","error":{"code":-32001,"message":"Invalid sessionId"},"id":null}

2. Although http://127.0.0.1:3845/sse's OPTIONS, GET responds normally, tools such as get_code report errors，error code：500

            - "OPTIONS /openapi.json HTTP/1.1" 200 OKTom ReemTom Reem

            - "GET /openapi.json HTTP/1.1" 200 OK

            - INFO - Calling endpoint: get_code, with args: {'clientLanguages': 'xml', 'clientFrameworks': 'android'}
            - INFO - Unexpected error calling get_code

            - "POST /get_code HTTP/1.1" 500 Internal Server Error

Please help to check it, thanks~

​@Tom Reem 

1. Only http://127.0.0.1:3845/sse can access, http://127.0.0.1:3845/mcp still can’t access.

   {"jsonrpc":"2.0","error":{"code":-32001,"message":"Invalid sessionId"},"id":null}

2. Although http://127.0.0.1:3845/sse's OPTIONS, GET responds normally, tools such as get_code report errors. error code: 500

           - "OPTIONS /openapi.json HTTP/1.1" 200 OK

            - "GET /openapi.json HTTP/1.1" 200 OK

            - INFO - Calling endpoint: get_code, with args: {'clientLanguages': 'xml', 'clientFrameworks': 'android'}
            - INFO - Unexpected error calling get_code

            - "POST /get_code HTTP/1.1" 500 Internal Server Error

Please help to check it, thanks~

This seems like an expired token or auth. I had Claude Code “Reconnect” and things started working again with /mcp.

Just for your information, guys — in my case, when I try the /mcp endpoints using the get_code tool in VS Code, I encounter a timeout error. Other tools are working fine. Could this be related to a server-side issue?  Anyone finds a solution on this. 

This still seems broken. VSCode 1.103, fresh Figma installation, dev seat, started the MCP, get the toast that it’s running, but then see the following:

VS Code:

2025-08-19 10:31:17.945 [info] Starting server figma
2025-08-19 10:31:17.948 [info] Connection state: Starting
2025-08-19 10:31:17.949 [info] Starting server from Remote extension host
2025-08-19 10:31:17.989 [info] Connection state: Running
2025-08-19 10:31:18.062 [info] Connection state: Error Error sending message to http://127.0.0.1:3845/mcp: TypeError: fetch failed
2025-08-19 10:31:18.062 [error] Server exited before responding to `initialize` request.

Config:

    "figma": {
      // The Figma MCP server requires you to setup the local client.
      //   1. Install the rich client: https://www.figma.com/downloads/
      //   2. Login with a "Dev" account
      //   3. Enable the MCP: Upper left Figma menu -> Preferences -> "Enable Dev Mode MCP Server"
      //   4. Click start above "figma" (above this comment).
      "type": "http",
      "url": "http://127.0.0.1:3845/mcp"
    }

If you nav to the endpoint in a browser, you get:

{"jsonrpc":"2.0","error":{"code":-32001,"message":"Invalid sessionId"},"id":null}

Hey All, thanks for following up! 

As ​@Tom Reem mentioned previously, when you’re testing using CURL or in the browser, you’ll receive the Invalid sessionId, because you’re not passing in a session ID as a parameter. While MCP clients do allow this, it’s not designed to be used directly. Again, this is an issue on the Cursor side of things. Even if it goes red after a few minutes, it should still work.

Again, for direct one on one support with this, we encourage you to reach out to our support team directly and provide screenshots of exactly where in your MCP clients the errors are popping up: https://help.figma.com/hc/en-us/requests/new

👍 This works for me.