OFFICIAL DOCUMENTATION · v0.4.17

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API contracts, practical integration guides, security boundaries, and release operations in one place.

START HERE

A safe first request

Create a server-side API key in Mail settings with only the scope your integration needs. Copy it once to a secret manager, then call the documented versioned endpoint over HTTPS.

Learn about API keys →

curl --fail-with-body -H 'Authorization: Bearer ${LUCION_MAIL_API_KEY}' -H 'Accept: application/json' 'https://lucionmail.com/api/v1/mail/messages?limit=25'

API referenceRoutes, headers, fields, response shape, and OpenAPI.Security modelCredential protection, account isolation, and content handling.Errors & recoveryUnderstand failures and retry only when it is safe.

GET STARTED

3 guides

Get started

Set up an integration and understand the Mail API boundary.

Quickstart

Make your first authenticated read or idempotent send.

Core concepts

Accounts, addresses, messages, scopes, and ownership.

AUTHENTICATION

3 guides

API keys

Create, scope, store, rotate, and revoke API credentials.

Authentication

Identity sessions for the app and bearer keys for integrations.

Security model

Credential handling, tenant boundaries, email content, and operations.

API REFERENCE

6 guides

API reference

Version 1 endpoints, parameters, request fields, and response shapes.

Read messages

Folders, bounded pagination, response fields, and content privacy.

Send messages

Plain-text sends, recipients, sender ownership, and provider outcomes.

Errors and recovery

HTTP statuses and safe caller recovery behavior.

Rate limits and pagination

Per-key and per-account limits, bounds, and Retry-After handling.

Idempotent sending

Retry safely after timeouts or uncertain provider acceptance.

PLATFORM

5 guides

Mailbox and data model

Personal mailbox ownership, address routing, message fields, and attachments.

Delivery and webhooks

What send acceptance means, inbound delivery, and provider event handling.

Versioning and compatibility

API version headers, compatibility boundaries, and deprecation policy.

Health and operations

Readiness, release state, production checks, and support diagnostics.

Documentation changelog

Dated product and contract changes for each release.

Release and service status

The application release manifest is separate from the stable v1 API contract. Check the live health endpoint, release manifest, and dated release notes before diagnosing an integration.

Health endpoint Release manifest Documentation changelog Status page

Organization API keys are available to administrators and bind to one shared mailbox. Each key remains limited to its assigned mailbox and scopes.