# Bytesms

> Bytesms is a Resend-compatible email API for developers: send transactional and marketing email over REST, SMTP or MCP, verify your own domains (DKIM + return path), and track delivery with signed webhooks. REST base URL: https://api.bytesms.com/api (public resources under /api/v1). Auth: `Authorization: Bearer tp_live_…`.

Key facts: max 50 recipients per email (to+cc+bcc), batch up to 100 emails, 10 requests/second per workspace by default, `Idempotency-Key` on sends (24h), attachments not supported, errors are `{ statusCode, message, name }`.

## Getting started

- [Introduction](https://bytesms.com/docs): base URL, concepts, test addresses (delivered@/bounced@/complained@/suppressed@test.bytesms.com)
- [Quickstart](https://bytesms.com/docs/quickstart): API key → verify a domain → send the first email
- [Authentication](https://bytesms.com/docs/authentication): full_access vs sending_access keys, domain-scoped keys
- [Errors](https://bytesms.com/docs/errors): error envelope and every error name
- [Rate limits & quotas](https://bytesms.com/docs/rate-limits): request rate, daily/monthly quotas, pay-as-you-go limits
- [Idempotency](https://bytesms.com/docs/idempotency): safe retries with Idempotency-Key

## API reference

- [Emails](https://bytesms.com/docs/emails): POST /v1/emails, POST /v1/emails/batch, GET /v1/emails, GET/PATCH /v1/emails/{id}, GET /v1/emails/{id}/events, POST /v1/emails/{id}/cancel
- [Domains](https://bytesms.com/docs/domains): POST/GET /v1/domains, GET/DELETE /v1/domains/{id}, POST /v1/domains/{id}/verify, DNS records
- [API keys](https://bytesms.com/docs/api-keys): POST/GET /v1/api-keys, DELETE /v1/api-keys/{id}
- [Templates](https://bytesms.com/docs/templates): /v1/templates CRUD, publish, duplicate, {{{variable|fallback}}} syntax
- [Audiences & contacts](https://bytesms.com/docs/audiences): /v1/audiences, /v1/audiences/{id}/contacts
- [Broadcasts](https://bytesms.com/docs/broadcasts): /v1/broadcasts CRUD, send, cancel

## Integrations

- [Webhooks](https://bytesms.com/docs/webhooks): event types, payloads, bytesms-signature and Svix signature verification, retries
- [SMTP](https://bytesms.com/docs/smtp): smtp.bytesms.com, ports 465/2465 (TLS) and 587/2587 (STARTTLS), user `bytesms`, password = API key
- [MCP server](https://bytesms.com/docs/mcp): https://api.bytesms.com/api/mcp, OAuth 2.1 or API key, tool list
- [Regions & deliverability](https://bytesms.com/docs/regions): ap-southeast-7 / ap-southeast-1 / eu-central-1, DKIM, SPF, DMARC, what "delivered" means

## Machine-readable

- [OpenAPI 3.1 spec](https://bytesms.com/openapi.json): the public /v1 API and webhook payload schemas