# haru Mail

> Email sending & receiving API for developers in Japan. REST API + MCP server + CLI, backed by Cloudflare's email infrastructure. Japanese-first docs and support.

Base URL: https://harumail.app
Auth: `Authorization: Bearer hm_...` (API key, per-tenant)

## Docs

- [Full API specification (single file, for AI integration)](https://harumail.app/docs/llms-full.txt): Everything needed to integrate: endpoints, fields, errors, MCP, webhook signature verification.
- [Human docs (Japanese)](https://harumail.app/docs/): クイックスタート・API・MCP・CLI・FAQ
- [Pricing (for AI agents)](https://harumail.app/pricing.md): Plans in JPY; no overage billing (sending stops at the limit); DNS setup done by haru Mail.

## Key facts

- POST /v1/emails sends an email (Resend-like payload: from, to, subject, text/html, reply_to, cc, bcc, headers, attachments).
- Sender domain must be registered to the tenant (strict isolation). Idempotency-Key header prevents double sends.
- MCP endpoint: POST /mcp (Streamable HTTP, same Bearer key). Tools: send_email, list_emails, get_email, list_inbound, get_inbound, list_domains, get_usage.
- CLI: `npx harumail`