The circuit breaker for AI agents.
Set a budget. FuseGuard kills the call before it breaks it — not a $47,000 bill later.
Open-source · your API key never leaves your infrastructure.
An AI agent looped for 11 days and ran up a $47,000 bill. The team had a dashboard. Slack alerts at 50/80/95%. A provider spend cap. None of them stopped it.
Alerts fire after the money's gone. Provider caps reconcile too late. FuseGuard refuses the next call, synchronously, before it's sent.
They watch. We stop.
| Feature | LangSmith / Helicone / Langfuse | FuseGuard |
|---|---|---|
| Shows you spend | ||
| Stops the spend | ||
| Blocks before the call | ||
| Kills runaway loops | ||
| One-line integration |
One line. No SDK rewrite.
from anthropic import Anthropic
client = Anthropic(
api_key="fg_live_...", # your FuseGuard key
base_url="https://fuseguard.app/v1", # point at FuseGuard
)
# Over budget? You get a 402 — not a $47k bill.1
Point your base_url at FuseGuard.
2
Set a budget — per key or session, $ or tokens.
3
FuseGuard hard-blocks before a breach. Loops killed.
Pricing
Free / Self-host
$0
- 1 key, budget enforcement, hard kill
- Self-host the full engine (MIT)
- Community support
Popular
Pro — $15/mo
$15
- Unlimited keys + sessions
- Loop detection, team, alerts
- Managed dashboard, no infra