Documentation

API reference

A REST API over HTTPS that speaks JSON. Every SDK is a thin wrapper over these same endpoints, and every page has a live "Try it" console.

Base URL

https://api.mailcraft.host/v1

Authentication

Send your API key as a bearer token on every request. Keys are scoped — create one per use case (for example, a send-only key for a server process) under Settings → API keys.

terminal

curl https://api.mailcraft.host/v1/emails \
  -H "Authorization: Bearer $MAILCRAFT_API_KEY"

Errors

Non-2xx responses return JSON. Validation failures are 422 with a per-field errors map; other errors carry a message, and billing limits add a machine-readable error.type.

422 Unprocessable Content

{
  "message": "The subject field is required.",
  "errors": {
    "subject": ["The subject field is required."]
  }
}

Rate limits

Limits apply per workspace: 20 requests an hour on the Free plan, 120 a minute on paid plans. Responses include X-RateLimit-Limit and X-RateLimit-Remaining; going over returns 429 Too Many Requests.

Resources

Emails Send transactional email and look up delivery status for previously sent messages.5 endpoints Contacts Upsert and manage contacts, including custom properties and list membership.8 endpoints Lists Static lists (managed by explicit membership) and dynamic lists (membership computed from a segment).7 endpoints Properties Custom contact fields. Each property is a schema definition — values live in the JSON `properties` object on the contact itself.3 endpoints Domains Sending domains, verified through SPF, DKIM, and DMARC DNS records.5 endpoints Senders From-addresses on a verified domain. A sender must be verified before it can send.4 endpoints Templates Reusable, versioned email bodies rendered with Mustache syntax (`{{ name }}`). Organize them into folders. Campaigns and emails pin a specific version, so editing a template never changes past sends.8 endpoints Campaigns One-time broadcast sends to a list or segment, rendered from a template.5 endpoints Automations Multi-step sequences — send an email, wait, update the contact — started by a trigger or by enrolling contacts directly.11 endpoints Segments Dynamic contact filters, expressed as a condition tree over contact fields and properties.4 endpoints Suppression list Addresses that are blocked from receiving mail — populated automatically on hard bounce or spam complaint, or added manually.3 endpoints Webhooks Subscribe an HTTPS endpoint to email and contact lifecycle events. Payloads are signed with HMAC-SHA256.3 endpoints Metrics & reputation Time-series send metrics and a rolling sending-reputation score based on bounce and complaint rate.2 endpoints Webhook events Every event type, its payload, and how to verify signatures.