Bug: Instagram Standalone integration fails in self‑hosted Postiz ("Invalid API key") #1122
Description
📜 Description
instagram Standalone Login cannot be completed on a self‑hosted Postiz installation. The OAuth flow with Instagram completes successfully (code is issued, token exchange works), but Postiz fails at the final step with a 409 Conflict and response:
{"msg":"Invalid API key"}
This appears to be an internal Postiz error (not returned by Instagram) and happens consistently across versions.
Environment
Postiz: v2.10.1 (also tested 2.9.x)
Deployment: Self‑hosted via Coolify (Docker Compose)
Reverse proxy: Cloudflare (also tested with proxy disabled)
Domain: HTTPS, valid cert
Cloudflare R2: Configured and working
Configuration (only relevant env vars)
SERVICE_FQDN_POSTIZ=https://
SERVICE_FQDN_POSTIZ_5000=https://:5000
SERVICE_PASSWORD_JWTSECRET=
SERVICE_URL_POSTIZ=https://.com
SERVICE_URL_POSTIZ_5000=https://:5000
BACKEND_INTERNAL_URL=http://localhost:3000
INSTAGRAM_APP_ID=
INSTAGRAM_APP_SECRET=
NOT_SECURED=false
NEXT_PUBLIC_BACKEND_URL=${SERVICE_URL_POSTIZ}/api
MAIN_URL=${SERVICE_URL_POSTIZ}
FRONTEND_URL=${SERVICE_URL_POSTIZ}
No Facebook Business Login is used. Only Instagram Standalone.
👟 Reproduction steps
- Go to Integrations → Instagram (Standalone)
- Click connect
- Login to Instagram
- Accept permissions
- Instagram redirects back to:
/integrations/social/instagram-standalone?code=...&state=... - Frontend triggers:
POST /api/integrations/social/instagram-standalone/connect - Backend responds with 409 and:
{"msg":"Invalid API key"}
Integration is not created and UI cannot proceed.
👍 Expected behavior
After completing the Instagram Standalone OAuth flow:
User logs in to Instagram and approves requested permissions
Instagram redirects back to Postiz with a valid code and state
Postiz successfully exchanges the code for an Instagram access_token
The Instagram account is persisted as an integration in Postiz
The integration appears in the UI under Integrations / Channels
The user can proceed to publish content without further errors
👎 Actual Behavior with Screenshots
User completes Instagram login and approves permissions
Instagram redirects back to Postiz correctly
Frontend sends:
POST /api/integrations/social/instagram-standalone/connect
Backend responds with HTTP 409 and:
{"msg":"Invalid API key"}
Integration is not created and does not appear in the UI
User cannot proceed past the integration step
💻 Operating system
Linux
🤖 Node Version
v22.21.1
📃 Provide any additional context for the Bug.
What works / what is confirmed
Instagram OAuth code is valid
Manual token exchange works using:
POST https://api.instagram.com/oauth/access_token
Instagram returns access_token, user_id and correct permissions
Redirect URI matches exactly
Same result with Cloudflare proxy ON/OFF
Same result across Postiz versions
This confirms Instagram is correctly configured and the failure happens after OAuth, inside Postiz.
observations
The error message does not come from Instagram
Backend logs show no error output for this request (error seems swallowed)
When calling the endpoint manually later (Postman), it can return 500 instead of 409
Backend responds with x-powered-by: Express, request does reach Nest backend
👀 Have you spent some time to check if this bug has been raised before?
- I checked and didn't find similar issue
Are you willing to submit PR?
None