Reliability
MCP rate limit errors and 429 responses
Debug 429 rate limit responses from hosted MCP endpoints, generated tools, and edge abuse protections.
Symptom
The endpoint returns 429, too_many_requests, billing_required, or intermittent failures during agent retries.
First check
Check whether the 429 came from Astrail edge limits, workspace billing limits, or the upstream provider API.
Quick fix
Slow the client retry loop, reduce concurrent tool calls, and confirm production uses a distributed limiter for public MCP traffic.
Identify which layer rejected the request
Astrail can rate-limit the MCP edge, enforce workspace billing limits, and surface upstream provider limits. The response code, error_code, and trace details should tell you whether the request reached the generated tool runtime.
Control agent retry behavior
Agents can turn a single missing parameter into many fast retries. Add backoff, cap retries, and ask the agent to inspect schema detail before retrying a failed tools/call.
Use distributed limits for production
Per-instance memory buckets are acceptable for protected previews. Public production endpoints should use shared Redis-backed limits plus provider edge protection so traffic is enforced across all instances.
Tune limits by endpoint risk
Read-only metadata can usually tolerate higher rates than expensive or state-changing tools. Keep stricter caps for auth failures, tool calls, large request bodies, and anonymous public traffic.
FAQ
Is every 429 an Astrail limit?
No. Some 429 responses come from the upstream API. Check the trace and execution mode before raising Astrail MCP limits.
Can I disable rate limits during launch?
Do not disable them for public endpoints. Use temporary higher limits only with monitoring and provider-level protection in place.