Authentication - GreenTick

Create the key under Developer in the dashboard. The value starts with gt_live_. Send it on every request except GET /health and GET /openapi.json.

curl "https://api.greentick.ai/v1/api-key" \
  --header "Authorization: Bearer gt_live_YOUR_API_KEY"

A valid key returns success: true, the key name, and the account timezone. Use that timezone when you schedule a template without an offset in scheduledAt. The Bearer scheme is required. A bare gt_live_… value, or a Firebase login token, is rejected with 401 and code UNAUTHORIZED.

Errors

Status	Code	Meaning
401	`UNAUTHORIZED`	Missing Bearer token, or the key is invalid or revoked
403	`PLAN_EXPIRED`	The plan is expired, or the Developer API is not on the plan
429		Write rate limit. Wait for the `Retry-After` header

Revoke a key from Developer when it leaks or when someone with Manage developer app leaves the team. Revoked keys fail immediately. Create a new key to replace one. GreenTick cannot show the old secret again.

Do not put the API key in a frontend app, a public spreadsheet cell, or a client-side WhatsApp widget. Google Sheets stores the key in the spreadsheet’s document properties for the add-on. Other tools should keep it on a server.