A provider-transparent rate limiter keyed by API key + provider can prevent cost blowouts on free-tier API plans without requiring consumer changes
HypothesisA provider-transparent rate limiter keyed by API key + provider can prevent cost blowouts on free-tier API plans without requiring consumer changes
Zero consumer changes needed. Rate limiting invisible inside provider layer. Prevented cost blowouts during early development on Tier 1 plans. Pattern persisted into production.
Changelog
| Date | Summary |
|---|---|
| 2026-04-07 | Created during temporal gap audit |
| 2026-02-27 | Original experiment |
Hypothesis
A transparent sliding-window rate limiter, keyed by API key + provider name, can prevent API cost blowouts on free/Tier 1 plans without any changes to the consuming code.
Method
Built rate-limiter.ts with conservative defaults calibrated to free-tier limits: Google 10 RPM, Anthropic 50 RPM, OpenAI 500 RPM, fallback 20 RPM. On 429 response, automatic retry with exponential backoff. Rate limiting decorates the provider : callers never see it.
Results
Confirmed. Zero consumer changes required. The rate limiter is invisible inside the provider layer. Prevented multiple near-blowouts during the early development phase when running parallel platform workers against all 10 ATS adapters simultaneously.