MCP server

anymail runs a remote Model Context Protocol server. An LLM client can read and update your workspace through tools. After this page your client is connected and you know which tools it can call.


Endpoint	`https://app.anymail.watch/api/mcp`
Transport	MCP Streamable HTTP, stateless, with JSON responses
Methods	`POST` for JSON-RPC, `DELETE` (accepted, no effect). `GET` returns `405`.
Authentication	`Authorization: Bearer sgn_…`, the same API token as the REST API
Server info	name `seegnals`, version `1.0.0`

Every tool calls one endpoint of the REST API on the same origin with the token you connected with. The server can do exactly what the REST API allows. The validation, the workspace isolation and the rate limit are the same.

Connect a client#

Generate a token first. See Authentication.

Claude Code#

claude mcp add --transport http anymail https://app.anymail.watch/api/mcp \
  --header "Authorization: Bearer $ANYMAIL_TOKEN"

Then run /mcp in Claude Code. It lists the server as connected and shows the tools.

Claude Desktop#

The Add custom connector dialog of Claude Desktop supports only OAuth-secured servers, and this server uses a static Bearer token. Bridge it with mcp-remote in claude_desktop_config.json.

{
  "mcpServers": {
    "anymail": {
      "command": "npx",
      "args": [
        "-y", "mcp-remote",
        "https://app.anymail.watch/api/mcp",
        "--header", "Authorization: Bearer sgn_…"
      ]
    }
  }
}

Cursor#

Add the server to .cursor/mcp.json in a project, or to ~/.cursor/mcp.json for all projects.

{
  "mcpServers": {
    "anymail": {
      "url": "https://app.anymail.watch/api/mcp",
      "headers": { "Authorization": "Bearer sgn_…" }
    }
  }
}

Another client#

A client that supports Streamable HTTP with custom headers uses the same shape.

{
  "mcpServers": {
    "anymail": {
      "type": "http",
      "url": "https://app.anymail.watch/api/mcp",
      "headers": { "Authorization": "Bearer sgn_…" }
    }
  }
}

Raw protocol#

To debug, call the server with curl. The transport requires the Accept header.

curl -s "https://app.anymail.watch/api/mcp" \
  -H "Authorization: Bearer $ANYMAIL_TOKEN" \
  -H "Content-Type: application/json" \
  -H "Accept: application/json, text/event-stream" \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/list"}'

Call a tool with tools/call.

curl -s "https://app.anymail.watch/api/mcp" \
  -H "Authorization: Bearer $ANYMAIL_TOKEN" \
  -H "Content-Type: application/json" \
  -H "Accept: application/json, text/event-stream" \
  -d '{"jsonrpc":"2.0","id":2,"method":"tools/call","params":{"name":"add_suppression","arguments":{"target":"example.com"}}}'

The server is stateless. A client does not need to call initialize first, the server issues no Mcp-Session-Id and each HTTP request is complete on its own.

Tools#

The server has 23 tools. Each tool returns the JSON of the REST API as formatted text in content[0].text. When the response is a JSON object, the tool also returns it as structuredContent. The server validates the arguments (required fields, enum values, types) before it makes any HTTP call.

Write tools#

Tool	Calls	Arguments
`create_prospect`	`POST /prospects`	`email` (required), `first_name`, `last_name`, `timezone`, `company_name`, `custom_fields`, `campaign_id`
`update_prospect`	`PATCH /prospects/{id}`	`id` and `email` (required), `first_name`, `last_name`, `timezone`, `company_name`, `custom_fields`
`add_suppression`	`POST /suppressions`	`target` (required)
`create_webhook`	`POST /hooks`	`event` and `target_url` (required)
`delete_webhook`	`DELETE /hooks/{id}`	`id`
`enrol_prospects`	`POST /campaigns/{id}/prospects`	`id`, and one of `prospect_ids` or `emails` (1 to 200 items)
`pause_campaign`	`POST /campaigns/{id}/pause`	`id`
`resume_campaign`	`POST /campaigns/{id}/resume`	`id`
`classify_reply`	`PATCH /replies/{id}`	`id`, `classification` (`interested`, `neutral` or `not_interested`)
`delete_suppression`	`DELETE /suppressions/{id}`	`id`

create_prospect with campaign_id creates the prospect and enrols it in one call. An unknown or unusable campaign returns an error before anything is created. update_prospect follows the rules of PATCH /prospects/{id}: send the full desired state. delete_webhook returns the text Done (HTTP 204, no content). with structuredContent of {"ok": true, "status": 204}.

Read tools#

These tools carry the readOnlyHint: true annotation. They take the same parameters as the endpoints, including limit and cursor.

Tool	Calls	Arguments
`list_prospects`	`GET /prospects`	`email`, `company_id`, `status`, `created_since`, `limit`, `cursor`
`get_prospect`	`GET /prospects/{id}`	`id`
`list_campaigns`	`GET /campaigns`	`status`, `folder_id`, `archived`, `limit`, `cursor`
`get_campaign`	`GET /campaigns/{id}`	`id`
`list_campaign_prospects`	`GET /campaigns/{id}/prospects`	`id`, `status`, `limit`, `cursor`
`list_companies`	`GET /companies`	`search`, `temperature`, `limit`, `cursor`
`get_company`	`GET /companies/{id}`	`id`
`list_replies`	`GET /replies`	`classification`, `since`, `campaign_id`, `prospect_id`, `limit`, `cursor`
`list_offers`	`GET /offers`	`status`, `prospect_id`, `campaign_id`, `limit`, `cursor`
`get_offer`	`GET /offers/{id}`	`id`
`list_suppressions`	`GET /suppressions`	`kind`, `limit`, `cursor`
`list_webhooks`	`GET /hooks`	`limit`, `cursor`
`list_mailboxes`	`GET /mailboxes`	None

Errors#

Situation	What the client sees
No header, or a malformed or revoked token	HTTP `401` with JSON `{"error":"…"}` and `WWW-Authenticate: Bearer realm="anymail API"`.
Rate limit exceeded	HTTP `429` with `Retry-After` in seconds.
Token check impossible because of a database outage	HTTP `500` with `{"error":"Authentication is temporarily unavailable."}`.
`GET /api/mcp`	HTTP `405` with `Allow: POST, DELETE`.
Missing or invalid tool arguments	A tool result with `isError: true` that explains the problem. The server makes no HTTP call.
The REST API answers `4xx` or `5xx`	A tool result with `isError: true` and the text `HTTP <status> from <METHOD> <path>: <API message> (code: <code>)`. A `429` adds `Retry after N seconds.`
The REST API cannot be reached, or it times out	A tool result with `isError: true` that says the API could not be reached.

A tool failure is always a tool result and never a JSON-RPC protocol error, so the model can read the message and correct its input.

Limits#

Rate limit. The REST API allows 60 requests per minute per token. One tool call uses two requests: the MCP request is authenticated with the same limiter, and the proxied REST call is the second. Plan for about 30 tool calls per minute per token. tools/list costs one request.
Request bodies. Prospects up to 64 KiB. Suppressions, hooks and reply classifications up to 4 KiB, as in the REST API.
Timeout. A proxied REST call stops after 20 seconds and returns a tool error.
No sessions. The server has no sessions, no resumability and no server-initiated notifications.
No resources or prompts. The server offers tools only.
Same reach as the REST API. The server cannot create campaigns, edit steps, start a draft or delete prospects.