REQ-NFR-066
Send-text/poll-output fallback channel rate-limited per agent token (60 send-text/min, 600 poll-output/min default)
What
Send-text/poll-output fallback channel SHALL be rate-limited per agent token, with default limits of 60 send-text per minute and 600 poll-output per minute.
Why
Polling agents that spin without backoff burn server capacity unfairly; rate-limit defaults keep the channel viable for many concurrent fallback agents. See arch_decision_nonmcp_fallback memory.
How
Per-token token-bucket counters (same infrastructure as the primary REST surface); 429 response includes Retry-After; long-poll requests do not burn budget while parked.
Done when
Load test: 10 concurrent fallback agents each at burst rates above the limit; aggregate server load stays bounded; 429s match expected pattern; long-poll connections do not contribute to bucket consumption while parked.
Out of scope
Per-IP limits (we trust the bearer token; IP limits are a separate L7 concern).
Category
security/operational
established project management guidelines Mapping
Fallback-channel rate limit protects the comms surface from runaway polling - risk-controlled communications.