Account MCP Server

Overview

The Account MCP server lets an AI agent take actions in your CallMissed account through the Model Context Protocol. Point any MCP client at one URL, authenticate with an API key, and the agent can send a WhatsApp message, look through conversations and contacts, or place a call with one of your voice agents.

It is hosted, so there is nothing to install and nothing to run locally.

Endpoint

https://api.callmissed.com/api/v1/mcp

The transport is Streamable HTTP: every call is a single POST that returns one JSON response. There is no session to open or close, so the server works behind any load balancer and needs no sticky routing. GET and DELETE return 405 by design — this server does not offer a server-initiated event stream.

Authentication

Authenticate with an API key from your dashboard, exactly as you would for any other CallMissed endpoint:

Authorization: Bearer cm_your_api_key

API keys only. A dashboard login token is refused with 401, even though it works elsewhere in the API. Scope checks are what keep an agent inside its lane, and those only apply to API keys — so this endpoint accepts nothing else.

Everything attached to the key still applies: its scopes, its spend budget, its rate limit, and its domain allowlist. A key that runs out of budget gets 402; one over its rate limit gets 429.

Scopes

Give each key only the scopes the agent needs. A tool whose scope is missing returns a readable refusal naming the scope to add, so the agent can tell you what to fix.

Tools

send_whatsapp_message

Send a free-form WhatsApp text from one of your connected business numbers.

Free-form text only reaches someone inside the 24-hour customer service window. Outside it, send an approved template from the messages API.

list_whatsapp_campaigns

List your broadcast campaigns, newest first, with status and recipient counts.

list_conversations

List conversations across channels, newest first, each with a preview of the latest message and an unread count.

list_contacts

List contacts in your address book, newest first, with their per-channel opt-in state.

place_call

Place an outbound call from one of your numbers, answered by one of your voice agents.

Connect a client

Most MCP clients accept a remote server as a URL plus a header. In Claude Code:

claude mcp add --transport http callmissed \
  https://api.callmissed.com/api/v1/mcp \
  --header "Authorization: Bearer cm_your_api_key"

For clients configured by file, the shape is usually:

{
  "mcpServers": {
    "callmissed": {
      "type": "http",
      "url": "https://api.callmissed.com/api/v1/mcp",
      "headers": {
        "Authorization": "Bearer cm_your_api_key"
      }
    }
  }
}

Keep the key out of version control — reference an environment variable if your client supports it.

Call it directly

The endpoint is plain JSON-RPC, so you can drive it with curl. List the tools your key can reach:

curl https://api.callmissed.com/api/v1/mcp \
  -H "Authorization: Bearer cm_your_api_key" \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "id": 1,
    "method": "tools/list"
  }'

Call one:

curl https://api.callmissed.com/api/v1/mcp \
  -H "Authorization: Bearer cm_your_api_key" \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "id": 2,
    "method": "tools/call",
    "params": {
      "name": "list_contacts",
      "arguments": { "q": "jane", "limit": 10 }
    }
  }'

A successful call returns the data twice — once as structuredContent and once serialized into a text block — so clients that only read one shape still work:

{
  "jsonrpc": "2.0",
  "id": 2,
  "result": {
    "content": [{ "type": "text", "text": "[{\"id\":\"...\",\"name\":\"Jane\"}]" }],
    "structuredContent": { "result": [{ "id": "...", "name": "Jane" }] },
    "isError": false
  }
}

Errors

Two different shapes, matching the protocol:

A malformed request — an unknown tool, a missing argument, a bad method — comes back as a JSON-RPC error:

{
  "jsonrpc": "2.0",
  "id": 3,
  "error": { "code": -32602, "message": "Unknown tool: send_sms" }
}

A refused action — a missing scope, no credits, a closed messaging window — is a successful result carrying isError, so the agent can read the reason and adapt instead of treating it as a crash:

{
  "jsonrpc": "2.0",
  "id": 4,
  "result": {
    "content": [{ "type": "text", "text": "API key missing required scope: whatsapp:send." }],
    "isError": true
  }
}

Authentication failures happen before any tool runs and use normal HTTP status codes: 401 for a missing, malformed, or non-API-key credential, 402 when the key is out of budget, 429 when it is over its rate limit.

Protocol version

The server implements MCP revision 2025-06-18 and also accepts 2025-03-26. Send the version you speak on every call after initializing:

MCP-Protocol-Version: 2025-06-18

Omit the header and the server assumes 2025-03-26, per the specification. Send a version it does not support and the call returns 400. Batched requests are not accepted — the 2025-06-18 revision removed them, so send one request object per POST.