Developer platform · API v1

Build with the FastMail API.

Read the live demo database through a typed, versioned API. Selected integration writes are implemented behind bearer-token authentication.

Open Swagger UIOpen ReDocDownload swagger.jsonView on GitHub
Public preview access. GET endpoints require no authentication. Writes return 503 until FASTSME_API_TOKEN is configured; enabled clients send Authorization: Bearer <token>.

Resources

Messages

Mailbox messages and conversation metadata.

GET /api/v1/messagesGET /api/v1/messages/{id}

Contacts

Mail contacts and company details.

GET /api/v1/contactsGET /api/v1/contacts/{id}

Labels

User-defined mailbox labels.

GET /api/v1/labelsGET /api/v1/labels/{id}

Calendar events

Calendar events associated with the mailbox.

GET /api/v1/eventsGET /api/v1/events/{id}

Quick start

curl "https://mail.fastsme.com/api/v1/messages?limit=20"

python - <<'PY'
import requests
rows = requests.get("https://mail.fastsme.com/api/v1/messages", timeout=20).json()
print(rows["data"])
PY

Runtime OpenAPI: /api/openapi.json · Stable compatibility schema: /swagger.json · Interactive docs: /api/docs