# Couryo

> Couryo is a transactional and product email API by Wunka, built for developers and AI agents. Send over the REST API (https://api.couryo.com/v1) or the remote MCP server (https://mcp.couryo.com), with SMTP coming soon. Automatic DNS, every bounce explained in plain words, public trust levels and pauses that are always explained.

- Authentication: `Authorization: Bearer ck_live_...` (live) or `ck_test_...` (test: never delivers, status `captured`).
- Always send the `Idempotency-Key` header on POST: same key and same body within 24 h returns the same response; a different body returns 409.
- Sending: `POST /v1/emails` returns 202 with `{ id, status }` only once the email is queued. Batch: `POST /v1/emails/batch`, up to 100.
- Errors: `{ error: { type, code, message, param, doc_url, request_id } }`, with a stable `code`.
- Webhooks follow Standard Webhooks (HMAC-SHA256, webhook-id, webhook-timestamp and webhook-signature headers).
- Domains: DKIM by CNAME on couryo1._domainkey and couryo2._domainkey, return path by CNAME on bounces.<domain> to rp.couryo.com, and DMARC; no SPF on the root domain.
- Remote MCP at https://mcp.couryo.com with your API key (`Authorization: Bearer ck_...`): send_email, get_email, domain_health and why_bounced. OAuth coming soon.
- Every docs page is available as Markdown: add `.md` to the URL.
- Pricing: Free: 3,000 emails per month (up to 100 per day) and 1 domain, no card. Pro: US$ 19 per month with 50,000 emails and US$ 0.35 per extra 1,000. Scale: US$ 59 per month with 200,000 emails and US$ 0.28 per extra 1,000. Enterprise: custom. Companies in Brazil pay in reais: Pro R$ 99 (R$ 1,80 per extra 1,000) and Scale R$ 299 (R$ 1,40 per extra 1,000).

## Docs

- [Developer guide](https://couryo.com/en/docs.md): Everything you need to send transactional email with Couryo, over the REST API or from your AI agent (MCP).
- [Quickstart](https://couryo.com/en/docs/quickstart.md): Send your first email with Couryo in 5 minutes, from sign-up to the message timeline.
- [Authentication and keys](https://couryo.com/en/docs/authentication.md): How to authenticate with the Couryo API using ck_live_ and ck_test_ keys, scopes, allowed IPs and good practices.
- [Test mode](https://couryo.com/en/docs/test-mode.md): ck_test_ keys capture emails without delivering them and simulate delivery, bounces, complaints and deferrals by recipient address, with real events and webhooks.
- [Sending email](https://couryo.com/en/docs/sending.md): POST /v1/emails in detail. Fields, recipients as a string or a list, idempotency, batch sending, scheduling, tags, metadata, attachments and the pre-send check.
- [SMTP](https://couryo.com/en/docs/smtp.md): Coming soon. Couryo's SMTP relay, to send without changing code. Host, ports, username, password and examples for Laravel, Node and Supabase.
- [Domains and DNS](https://couryo.com/en/docs/domains.md): How to verify a domain on Couryo. The DKIM (couryo1 and couryo2), return path and DMARC records the API generates, why there is no SPF on your root domain, and how DMARC moves up to p=reject.
- [Webhooks](https://couryo.com/en/docs/webhooks.md): Get your email events by webhook, signed with Standard Webhooks and retried for up to 3 days. Verification examples in Node, PHP and Python.
- [Events and timeline](https://couryo.com/en/docs/events.md): Every step of an email on Couryo, with time, receiving server, SMTP code, the original response and a plain-language explanation.
- [Suppression](https://couryo.com/en/docs/suppressions.md): Couryo's suppression list protects your reputation. Reasons, streams, and how to list, add and remove addresses through the API.
- [Errors](https://couryo.com/en/docs/errors.md): Couryo API error format, types, HTTP statuses and every code with cause and fix.
- [Limits and trust levels](https://couryo.com/en/docs/limits.md): Couryo trust levels, daily and monthly limits, each plan's limits (emails and domains), the spending limit, rate limit headers, pauses and how to request a review.
- [MCP and AI agents](https://couryo.com/en/docs/mcp.md): Couryo's remote MCP server at mcp.couryo.com, the send_email, get_email, domain_health and why_bounced tools, and how to connect from Claude, Cursor and ChatGPT.

## Pricing

- [Pricing](https://couryo.com/pricing.md): Plans, overage, pricing commitments and payment methods, as Markdown.

## Legal (drafts)

- [Terms of use](https://couryo.com/en/terms.md): Draft of Couryo's terms of use. The service, your account, plans and payment, trust levels, cancellation and responsibilities.
- [Privacy policy](https://couryo.com/en/privacy.md): Draft of Couryo's privacy policy. What data we process, why, who we share it with, how long we keep it and your rights.
- [Acceptable use and suspension policy](https://couryo.com/en/acceptable-use.md): Draft of Couryo's sending rules. What is forbidden, how trust levels work, gradual pauses, immediate suspension and how to request a review.

## Optional

- [Portuguese version of this file](https://couryo.com/llms.txt)
- [llms-full.txt](https://couryo.com/en/llms-full.txt)
- [Sign up (dashboard)](https://app.couryo.com)