Authentication - Seamless

The Seamless.AI MCP server supports two authentication methods.

OAuth 2.1 (recommended)
API key

OAuth is the primary method. MCP clients that support the MCP authorization specification handle the flow automatically:

Discovery — Client fetches https://mcp.seamless.ai/.well-known/oauth-authorization-server.
Authorization — Browser login to Seamless.AI and MCP authorization.
Token exchange — Authorization code exchanged with PKCE (S256).
Automatic refresh — Client refreshes expired tokens.

All requests use Authorization: Bearer <token>.

Client identification

Auto-discovery (CIMD / DCR) — Most clients register automatically. Provide only the server URL.
Explicit Client ID — Optional client_id from Settings > Public API Connections > OAuth Connection in the Seamless app.

OAuth endpoints

Parameter	Value
Authorization endpoint	`https://mcp.seamless.ai/mcp/authorize`
Token endpoint	`https://mcp.seamless.ai/mcp/token`
Registration endpoint	`https://mcp.seamless.ai/mcp/register`
Revocation endpoint	`https://mcp.seamless.ai/mcp/revoke`
Grant types	`authorization_code`, `refresh_token`
Code challenge method	`S256` (PKCE required)
Scope	`mcp.all`

Organization setup

Go to Settings > Public API Connections > OAuth Connection in the Seamless app
Click + Create New Connection
Select OAuth Connection
Enter a Connection Name (e.g. “MCP Access”)
Under Scopes, check MCP (and Public API v1 if you also need REST)
Choose the Group with access and Save Connection

Contact your administrator if you see “organization has not enabled MCP access”.

For clients without MCP OAuth, pass an API key in the Token header.

Go to Settings > Public API Connections > API Key in the Seamless app
Click + Create New Connection
Enter a Connection Name and optional Description
Under Scopes, check MCP
Choose the Group and Save Connection
Copy the API key and pass it on every request to https://mcp.seamless.ai/mcp

Client configuration

{
  "mcpServers": {
    "seamless": {
      "url": "https://mcp.seamless.ai/mcp",
      "headers": {
        "Token": "<YOUR_API_KEY>"
      }
    }
  }
}

Test with curl

curl https://mcp.seamless.ai/mcp \
  -H "Content-Type: application/json" \
  -H "Token: <YOUR_API_KEY>" \
  -d '{
    "jsonrpc": "2.0",
    "method": "tools/list",
    "params": {},
    "id": 1
  }'

​Client identification

​OAuth endpoints

​Organization setup

​Client configuration

​Test with curl

Client identification

OAuth endpoints

Organization setup

Client configuration

Test with curl