API & Developer Documentation
The thanks.io REST API and full developer documentation - including authentication, API keys, webhooks, rate limits, code examples, and endpoint references - is hosted at:
Generate an API Key
API keys live on Settings → API Access. To get there, click your name in the top right of the dashboard to open the account menu, then choose API Access under Developer. API Access is a main-account page, so switch to your main account first if a sub-account is active.
Authorization Headers
When making API calls or setting up webhooks, use the following headers to authorize your connection.
API Test Mode
Use API Test Mode to build an integration safely - orders sent via API or Zapier are cancelled automatically, and a Radius Search bought that way is limited to 5 records per purchase.
Finding Creative & Template IDs
Find the IDs the API, Zapier, n8n, HubSpot workflows and AI assistants need - a creative's ID, its front and message template IDs, and mailing list IDs - and where your API keys are.
Estimating an Order's Cost
Price an API order before you send it - post the same request body to the estimate endpoint to get the total, a cost breakdown, and whether your balance covers it, with nothing charged or mailed.