---
title: "Sign in at an MCP server (discovered authorization server)"
method: POST
path: "/v1/admin/source-connections/oauth/mcp/start"
tags: ["Source Plane"]
---

# Sign in at an MCP server (discovered authorization server)

`POST /v1/admin/source-connections/oauth/mcp/start`

## Request

- Base URL: `https://brain.inite.ai`
- URL: `https://brain.inite.ai/v1/admin/source-connections/oauth/mcp/start`
- Auth: HTTP bearer

The brain as an OAuth client of any MCP server (W4.3): the server’s authorization server is discovered from its 401 (RFC 9728 protected-resource metadata → RFC 8414 / OpenID metadata), a client is registered there dynamically (RFC 7591) unless one the operator registered is passed, and the admin is sent to consent with PKCE and the RFC 8707 `resource`. The callback keeps a `mcp` grant for that resource; a pack’s `auth: oauth` MCP source then runs as it. 404 until `SOURCE_MCP_OAUTH=1`. Connected accounts (docs/source-plane.md § Connected accounts): the brain as an outbound OAuth 2.1 client for the cloud connectors (gdrive, onedrive, dropbox). Answers a bare 404 until `SOURCE_PLANE_ENABLED=1` and `SOURCE_OAUTH_CLIENT=1`; needs `SOURCE_CREDENTIAL_ENCRYPTION_KEY` — tokens are never stored in the clear.

Required scope: `brain:admin`.

## Request body

- SourceOAuthMcpStartRequest
  - `allowPrivate` boolean
  - `client` object
    - `clientId` string, required
    - `clientSecret` string
  - `origin` string, uri
  - `ownerUserId` string
  - `serverUrl` string, uri, required

## Response `201`

The consent URL, the state and the resource.

- SourceOAuthMcpStartResponse
  - `authorizeUrl` string, required
  - `expiresAt` string, required
  - `resource` string, required
  - `state` string, required

## Other responses

- `400`: Validation failed.
- `401`: Missing or unknown bearer key.
- `403`: The key lacks the required scope.
- `404`: No such resource in this tenant.

---

[API](https://skmtc.dev/inite/apis/inite-brain-platform-api.md) · [All operations](https://skmtc.dev/inite/apis/inite-brain-platform-api/llms.txt) · [OpenAPI document](https://skmtc.dev/inite/apis/inite-brain-platform-api/revisions/c7c3eb5e304b?raw)