## Summary
Fixes#18524
Fixes the MCP response contract for non-`initialize` methods.
Previously, `/mcp` returned initialize-style metadata for methods like
`tools/list`, which caused strict MCP clients to reject the response
shape. The endpoint also returned `201 Created` for RPC calls even
though no resource was being created.
## Changes
- return only method-specific payloads for MCP list methods
- `tools/list` -> `{ tools: [...] }`
- `prompts/list` -> `{ prompts: [] }`
- `resources/list` -> `{ resources: [] }`
- keep MCP server metadata only on `initialize`
- make `/mcp` return `200 OK` instead of `201 Created`
- add regression tests for:
- `tools/list` response shape
- `prompts/list` response shape
- `resources/list` response shape
## Why
Strict MCP clients expect:
- standard RPC transport semantics over HTTP
- method-specific JSON-RPC result payloads
Returning initialize metadata for non-`initialize` methods breaks that
expectation and can cause client deserialization or protocol validation
failures.
## Verification
- reproduced the issue locally against `/mcp`
- verified `tools/list` was previously returning initialize-style fields
- verified `tools/list` now returns only `result.tools`
- verified `/mcp` now returns `200 OK`
- ran targeted Jest tests:
```bash
cd /Users/apple/MyProjects/OpenSource/twenty/packages/twenty-server
npx jest --runInBand src/engine/api/mcp/services/__tests__/mcp-protocol.service.spec.ts src/engine/api/mcp/services/__tests__/mcp-tool-executor.service.spec.ts
---------
Co-authored-by: Félix Malfait <felix@twenty.com>
…PC validation
- Introduced full integration test suite for MCP controller, testing
`POST /mcp` with valid and invalid payloads.
- Added `@IsDefined` validation to ensure the `method` field is required
in JSON-RPC requests.
- Applied `RestApiExceptionFilter` to MCP controller for consistent
error handling.
- Enhanced validation pipe in MCP controller to whitelist and reject
non-whitelisted properties.
- Consolidated exception filters in SSOAuthController.
Sri Hari Haran Sharma