SpamTitan

SpamTitan MCP Server

A Model Context Protocol (MCP) server for SpamTitan email security. Enables AI assistants to manage quarantine, maintain allowlists and blocklists, and view email filtering statistics.

This is a Model Context Protocol (MCP) server that connects Claude (or any MCP-compatible AI) to your SpamTitan environment.

Part of the MSP Claude Plugins ecosystem — a growing suite of AI integrations for the MSP stack. Built by MSPs, for MSPs.

Installation

npm install @wyre-ai/spamtitan-mcp

Configuration

Copy .env.example and set the variables below.

Variable	Required	Description
SPAMTITAN_API_KEY	For stdio and AUTH_MODE=env	SpamTitan API key
SPAMTITAN_BASE_URL	No	SpamTitan instance URL, including any path prefix (e.g. https://mail.example.com/spamtitan/). Defaults to https://api-spamtitan.titanhq.com. In gateway mode the per-request X-SpamTitan-Base-URL header takes precedence.
MCP_TRANSPORT	No	stdio (default) or http
AUTH_MODE	No	gateway (Docker image and Compose) or env. Gateway mode requires X-SpamTitan-API-Key on each /mcp request and does not fall back to SPAMTITAN_API_KEY. env uses that variable only after S2S auth succeeds. Unset means env (stdio and single-tenant HTTP).
CONDUIT_S2S_SECRET	Yes for HTTP	Service-to-service secret. The HTTP server logs an error and exits non-zero when this is empty or a known placeholder (changeme, secret, replace-me, your-s2s-secret, replace-with-a-real-secret, and the other example values). Generate one with openssl rand -hex 32. Compose will not start without it. The value is never logged.
MCP_ALLOW_INSECURE_DEV	No	Set to exactly 1 only for local development to start HTTP without CONDUIT_S2S_SECRET. The process logs a warning, does not enforce X-Gateway-S2S, and binds 127.0.0.1 only. A non-loopback MCP_HTTP_HOST refuses to start. A known placeholder secret still refuses to start.
MCP_HTTP_HOST	No	Bind address when a real CONDUIT_S2S_SECRET is set. Unset keeps 0.0.0.0, the historical container bind. The image and Compose set 0.0.0.0 inside the container.
MCP_HTTP_PORT	No	HTTP port. Defaults to 8080.

/health and /healthz stay unauthenticated and do not read credentials. The stdio transport does not use CONDUIT_S2S_SECRET.

HTTP authentication

With MCP_TRANSPORT=http and CONDUIT_S2S_SECRET set, every /mcp request must include X-Gateway-S2S. The check is verifyS2sHeader in src/s2s-verify.ts: the header value is t=<unix seconds>,v1=<hex>, where the hex is HMAC-SHA256 of the literal string t=<unix seconds> keyed with CONDUIT_S2S_SECRET (64 lowercase hex characters). The timestamp must be within 300 seconds of the server clock. A missing or invalid header is HTTP 401, before vendor credentials are read.

TS=$(date +%s)
SIG=$(printf 't=%s' "$TS" | openssl dgst -sha256 -hmac "$CONDUIT_S2S_SECRET" -hex | awk '{print $NF}')
curl -sS http://127.0.0.1:8080/mcp \
  -H 'Content-Type: application/json' \
  -H 'Accept: application/json, text/event-stream' \
  -H "X-Gateway-S2S: t=${TS},v1=${SIG}" \
  -H "X-SpamTitan-API-Key: $SPAMTITAN_API_KEY" \
  -H "X-SpamTitan-Base-URL: $SPAMTITAN_BASE_URL" \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/list"}'

In AUTH_MODE=gateway, /mcp also requires X-SpamTitan-API-Key. That header is the only API-key source for the request. X-SpamTitan-Base-URL is optional and, when present, selects the tenant instance. AUTH_MODE=env still requires the signed X-Gateway-S2S header, then uses SPAMTITAN_API_KEY and SPAMTITAN_BASE_URL from the environment.

Usage

Running with Claude Desktop

Add to your Claude Desktop claude_desktop_config.json:

{
  "mcpServers": {
    "spamtitan-mcp": {
      "command": "npx",
      "args": ["@wyre-ai/spamtitan-mcp"],
      "env": {
        "SPAMTITAN_API_KEY": "your-spamtitan-api-key"
      }
    }
  }
}

Running with Claude Code (CLI)

claude mcp add spamtitan-mcp \
  -e SPAMTITAN_API_KEY=your-value \
  -- npx -y @wyre-ai/spamtitan-mcp

Docker

The image listens on 0.0.0.0 inside the container (MCP_HTTP_HOST) and defaults to AUTH_MODE=gateway. Publish the port on loopback and pass a real S2S secret. In gateway mode, SpamTitan credentials arrive on each request as headers; the API key is not read from the environment.

docker build -t spamtitan-mcp .
docker run \
  -e CONDUIT_S2S_SECRET="$CONDUIT_S2S_SECRET" \
  -p 127.0.0.1:8080:8080 \
  spamtitan-mcp

Compose refuses to start when CONDUIT_S2S_SECRET is unset or empty. The gateway service sets AUTH_MODE=gateway, does not inject SPAMTITAN_API_KEY or SPAMTITAN_BASE_URL, and publishes 127.0.0.1:8080:8080:

CONDUIT_S2S_SECRET="$CONDUIT_S2S_SECRET" docker compose up

Single-tenant HTTP (AUTH_MODE=env) still requires the S2S secret, then uses SPAMTITAN_API_KEY and SPAMTITAN_BASE_URL. It is separate from the gateway Compose service above.

docker run \
  -e CONDUIT_S2S_SECRET="$CONDUIT_S2S_SECRET" \
  -e AUTH_MODE=env \
  -e SPAMTITAN_API_KEY=your-value \
  -e SPAMTITAN_BASE_URL=https://mail.example.com/spamtitan/ \
  -p 127.0.0.1:8080:8080 \
  spamtitan-mcp

Local HTTP without a secret is development-only. It binds 127.0.0.1 and logs a warning. A non-loopback MCP_HTTP_HOST (including the image default 0.0.0.0) makes startup exit:

MCP_TRANSPORT=http MCP_HTTP_HOST=127.0.0.1 MCP_ALLOW_INSECURE_DEV=1 npm start

Available Domains

Lists

Manage allowlists and blocklists

Quarantine

Email quarantine review and management

Stats

Email filtering statistics and reports

Features

• Interactive quarantined-message card (MCP Apps, SEP-1865) — spamtitan_get_message renders as a read-only interactive card in MCP Apps hosts (Claude Desktop/web); plain-JSON behavior is unchanged in other hosts. The card is neutral by default, brandable via window.__BRAND__ injection or MCP_BRAND_* env vars (MCP_BRAND_NAME, MCP_BRAND_LOGO_URL, MCP_BRAND_PRIMARY_COLOR, MCP_BRAND_ACCENT_COLOR, MCP_BRAND_BG, MCP_BRAND_TEXT) — no rebuild needed. Rebuild the card bundle with npm run build:ui after editing ui/.

Development

# Clone the repository
git clone https://github.com/WYRE-AI/spamtitan-mcp.git
cd spamtitan-mcp

# Install dependencies
npm install

# Build
npm run build

# Run tests
npm test

# HTTP refuses to start until CONDUIT_S2S_SECRET is a real secret
MCP_TRANSPORT=http CONDUIT_S2S_SECRET="$CONDUIT_S2S_SECRET" npm start

# Local HTTP only, without a service-to-service secret (binds 127.0.0.1)
MCP_TRANSPORT=http MCP_HTTP_HOST=127.0.0.1 MCP_ALLOW_INSECURE_DEV=1 npm start

Contributing

Contributions are welcome! Please see CONTRIBUTING.md if present, or open an issue to discuss changes.

License

Licensed under the Apache License, Version 2.0. See LICENSE for details.