Aster Spot API Errors (v3 — Testnet)

Payload: { "code": -1121, "msg": "..." }. Handle by code (stable); messages may vary.

Rate limits: From GET /api/v3/exchangeInfo → rateLimits. REQUEST_WEIGHT: per IP; header X-MBX-USED-WEIGHT-*. ORDERS: per account; header X-MBX-ORDER-COUNT-*. 429: back off. 418: IP banned (2 min–3 days). Prefer WebSocket to reduce REST load.

Security: Invalid nonce/timestamp or signature → check EIP-712 and clock; use GET /api/v3/time.

HTTP: 4XX = client (403 WAF, 429, 418); 5XX = server. 503 = may have been processed—do not assume failure.

Payload shapes: reference.md.