API & Developer Documentation
The thanks.io REST API and full developer documentation — including authentication, API tokens, webhooks, rate limits, code examples, and endpoint references — is hosted at:
What you'll find at docs.thanks.io
- Authentication — generating API keys and API tokens, authorization headers
- Sending mail via API — orders API, sending postcards, letters, and handwritten cards programmatically
- Campaigns API — creating and managing campaigns via API
- Mailing lists API — managing contact lists, adding and removing contacts
- Templates API — retrieving template IDs, handwriting style IDs, image template and message template IDs
- Webhooks — setting up webhook delivery, easy add-to-list webhooks, webhook error troubleshooting
- Rate limits — API rate limiting and best practices
- Error codes — full list of API error codes and how to resolve them
- Code examples — sample code in multiple languages (Node.js, Python, PHP, Ruby, etc.)
- MCP server — thanks.io MCP server setup and configuration for AI integrations
- Test mode — using API test mode (orders auto-cancel in test mode)
- First API request — getting started walkthrough for developers
Head to docs.thanks.io to get started.