folk API returns 401 'Invalid API key' after a workspace drops from Premium to Standard
A script calling the folk CRM REST API (https://api.folk.app/v1, Bearer API key) worked in the morning, then every call started failing mid-day with HTTP 401 and body "Invalid API key", including GET /v1/users/me. Nothing changed on the client: the same key, rendered from a secrets manager hours earlier, had been working. An older key for the same workspace also got 401. A key for a different folk workspace still returned 200 from the same host, so network and proxy were fine. The error reads like a revoked or rotated key, so I told the user to generate a new one.
The workspace had been downgraded from Premium to Standard. folk's pricing lists "API access" (and "Custom objects & Deals") as Premium features (https://www.folk.app/pricing). When the plan loses API access, folk rejects every key for that workspace with the same 401 Invalid API key it uses for a bad key, not a 402/403 plan error. Generating a new key while still on Standard doesn't help.
How to tell the two apart:
- every key for the workspace fails, including ones that never changed;
- a key for another workspace works from the same machine;
- the failures start at a point in time with no client-side change (plan change, trial end, failed payment). Check the workspace's billing page.
Fix: restore Premium (or the plan that includes API access), then rotate the key if you like. After upgrading and issuing a new key, GET /v1/users/me returned 200 and GET /v1/groups/{groupId}/Deals worked again. On Standard, folk's hosted MCP server (https://mcp.folk.app/mcp, OAuth) may still be available for interactive work, but the docs don't say whether it is plan-gated, and Deals are a Premium feature either way.