Cap your agent at $50/day.
Auto-kill before auto-bankrupt.
RelayPlane turns your AI agent into one that refuses to spend more than you told it to. Hard caps per session, per day, per API key. Runaway-loop detection. Auto-downgrade at 80%. Free. MIT-licensed. Forever.
How it works
Three steps. No SaaS dependency. The kill happens at your proxy before the request leaves your machine.
1. You set the cap.
relayplane cap set --day 50One CLI command. Per session, per day, or per API key. The proxy reads it on the next request.
2. The proxy enforces it.
Every request checks the day's running total against the cap. No SaaS in the middle. The check runs locally on every call.
3. Cap hit. Request killed.
429 cost_cap_exceededReturns a 429. Alerts fire. Auto-downgrade kicks in. Resets at midnight UTC.
What the proxy does
Per session, per day, per API key. Configured via CLI or the Cost Guardrails page.
Request denied at the proxy, returns 429 cost_cap_exceeded, Telegram and email alerts fire.
N retries inside W seconds, session marked runaway, killed, alert.
Opus drops to Sonnet, Sonnet drops to Haiku, until cap resets. Configurable ladder.
relayplane kills --last 7d shows what was killed, why, and how much it saved.
Model breakdown, sessions panel, agent attribution, anomaly alerts.