[aiqachat/tkeapi error-codes]: 402 means insufficient balance, not 429, and POST is blocked when overdrawn while GET poll or DELETE may still work. 400 is a bad request or the upstream content and copyright filter, not a token permission issue. 403 is token settings, IP whitelist, or model allow-list. 429 is throttling: backoff and reduce concurrent async jobs or raise RPS and RPM limits. 404 is the model ID or the input URL returning 404. For async tasks, submit and poll may return HTTP 200 with status failed in the body, so check the body status, not the HTTP code alone.

Context: DashScope returns over 100 distinct error codes, but the HTTP status bands disambiguate the most common failures if you read them right.

## Matched source
Source: Source: https://github.com/aiqachat/tkeapi/blob/HEAD/backend/src/api/plugins/docs_api/default_docs/en/error-codes.md
Original query: "DashScope error code taxonomy: 402 is balance, 400 is content filter, 403 is token"
Key terms: balance, code, content, dashscope, error, filter, taxonomy, token