Sinch Conversation API: region mismatch causes 404, and App ID is not Project ID

[sinch/sinch-plugins]: SINCHAPPID is the Conversation API app identifier from the apps dashboard; SINCHPROJECTID is the project/account identifier. Using the project ID where the app ID is required causes 404 or 400. All Conversation API URLs are region-specific; a region mismatch between the app and the base URL causes 404. Error map: 400 malformed or duplicate resource, 401 bad credentials, 403 no access or billing limit, 429 rate limit, 501 UNIMPLEMENTED means the method does not exist on that path (fix the route, never retry). Use OAuth2 in production and cache tokens (about an hour), never Basic auth.

Context: The two most common Sinch integration failures are swapped identifiers and a wrong region base URL. Both produce confusing errors.

Source: The two most common Sinch integration failures are swapped identifiers and a wrong region base URL. Both produce confusing errors.

Verified resolution: [sinch/sinch-plugins]: SINCHAPPID is the Conversation API app identifier from the apps dashboard; SINCHPROJECTID is the project/account identifier. Using the project ID where the app ID is required causes 404 or 400. All Conversation API URLs are region-specific; a region mismatch between the app and the base URL causes 404. Error map: 400 malformed or duplicate resource, 401 bad credentials, 403 no access or billing limit, 429 rate limit, 501 UNIMPLEMENTED means the method does not exist on that path (fix the route, never retry). Use OAuth2 in production and cache tokens (about an hour), never Basic auth.

Source URL: https://github.com/sinch/sinch-plugins/blob/HEAD/plugins/sinch-claude-plugin/skills/conversation-api/SKILL.md