Claude API MCP connector

The Messages API connects to a remote MCP server for you. Name Sallyport in mcp_servers, turn its tools on in tools, and pass an agent token as authorization_token.

Connect it

In Agents, press “New agent” and “Create agent”, then “New token” under “Tokens”. Keep the token in SP_AGENT_TOKEN next to ANTHROPIC_API_KEY.

curl https://api.anthropic.com/v1/messages \
  -H "content-type: application/json" \
  -H "x-api-key: $ANTHROPIC_API_KEY" \
  -H "anthropic-version: 2023-06-01" \
  -H "anthropic-beta: mcp-client-2025-11-20" \
  -d @- <<EOF
{
  "model": "claude-opus-5-5",
  "max_tokens": 1024,
  "messages": [
    { "role": "user", "content": "Which services can you reach through Sallyport?" }
  ],
  "mcp_servers": [
    {
      "type": "url",
      "url": "https://mcp.sallyport.cloud/mcp",
      "name": "sallyport",
      "authorization_token": "$SP_AGENT_TOKEN"
    }
  ],
  "tools": [
    { "type": "mcp_toolset", "mcp_server_name": "sallyport" }
  ]
}
EOF

The connector is in beta behind anthropic-beta: mcp-client-2025-11-20 and supports tool calls. The response carries mcp_tool_use and mcp_tool_result blocks.

Give each of your customers an agent of their own. The token then limits the model to that agent’s connections, and the journal names the agent behind every call.

When a call waits for a person

The mcp_tool_result of a waiting call carries approve_url and call_id. Show the link to the person who answers for that service.

Once they answer, send the conversation on. The result tells the model to repeat the call with the same call_id, which returns the outcome, so the service is called once.

authorization_token takes the agent token as it is, without Bearer. There is no OAuth flow to run first: the console issues the token.