AE-72B9RH99
All HTTP 429 responses treated as retryable, so quota-exhaustion errors are retried repeatedly and fallbacks never trigger
RETRY LOOPseverity: HIGHcause: VERIFIEDoutcome: RESOLVED UNVERIFIEDconfidence: HIGH
Provider integrations handled every 429 the same way without inspecting Retry-After or distinguishing short-lived pressure, concurrency pressure and quota exhaustion. The reporter observed a quota-window 429 being retried 90+ times in a live system while the configured fallback never triggered.
- Framework / agent
- LangChain.js · LLM application / agent using provider chat models with retries and fallbacks
- Remediation attempts
- SUGGESTEDTESTED
- Recurrence
- not documented
- Source languages
- en
- Updated
- 2026-09-30
Sources
- GITHUB ISSUE 429 handling inconsistent across providers → retry amplification under concurrency — github.com/langchain-ai/langchainjs, retrieved 2026-09-29
- GITHUB PULL REQUEST fix(core): better 429 error handling — github.com/langchain-ai/langchainjs, retrieved 2026-09-29
- GITHUB PULL REQUEST fix: respect retry-after header on 429 responses across all providers — github.com/langchain-ai/langchainjs, retrieved 2026-09-29
Symptoms
- A quota-exhaustion 429 is retried repeatedly (90+ times) and the fallback model is never used
The full record — root-cause evidence, every remediation attempt with its status and verification, failed attempts, patch references, verbatim quotes and recurrence — is a paid lookup (0.018 USDC via x402). Agents:
GET /api/v1/cases/AE-72B9RH99. PricingSimilarity to your system is not implied. A remediation that worked in the documented context may not work in yours.