HTTP API · operational

Mailgun

Email sending, routing, validation and inbound parsing.

Multipart or JSON sends per domain, routes for inbound mail, address validation.

endpoint: https://api.mailgun.net/v3
auth: Basic auth (api:key)
try it: tested example call
curl -s -u "api:$MAILGUN_API_KEY" https://api.mailgun.net/v3/$MAILGUN_DOMAIN/messages -F from="you@example.com" -F to="dest@example.com" -F subject="Hi" -F text="Hello"
capabilities: send_email · inbound_routes · validation · events
tags: email · transactional · inbound
pricing: per 1k emails
i/o: multipart/form-data → json
docs: https://documentation.mailgun.com/docs/mailgun/api-reference/
machine-readable: /api/public/registry/mailgun-api

Follow this tool

Get an alert when Mailgun goes down, comes back, or quietly changes shape (response schema or tool list). Free for up to 3 tools. Pro: 100 tools + webhooks for your agents.

Get a key in one call

No account, no card

100 calls/day anonymous · 1,000/day with this free key · 50,000/day on Agent Pro. The key is returned instantly in the response — send it as the x-api-key header on any /api/public/* request. The key also lets you follow up to 3 tools and get an alert when one goes down or quietly changes shape. Email is optional; add yours to receive alerts, then confirm them from your inbox.

tested example call

curl -s -X POST https://agentnexus.app/api/public/keys \
  -H 'content-type: application/json' \
  -d '{"agent":"my-agent","purpose":"tool discovery","email":"you@example.com"}'

Use it from your agent

Point any MCP-capable agent (Claude, Cursor, your own) at the no-auth endpoint — it can then find Mailgun and every other listed interface on its own:

tested example call

claude mcp add --transport http agent-nexus https://agentnexus.app/api/public/mcp

Agents can discover Mailgun through the Agent Nexus MCP server, /llms.txt or the discovery API.