The full upstream README, mirrored here for reference. Install config, tool schemas, adoption signals, and an original overview live on the Agent47 listing page.
Stop runaway agents before they burn money.
Zero-dependency Python kill switch for AI agents. Hard budget caps. Loop detection. Local traces. MIT.
When spend crosses the hard limit, BudgetExceeded is raised and the run stops.
Session budget can still have headroom. One goal can still be killed:
Or scaffold a starter file:
| Problem | Guard | Exception |
|---|---|---|
| Spend blowup | BudgetGuard | BudgetExceeded |
| Same tool forever | LoopGuard | LoopDetected |
| Fuzzy / A-B-A-B loops | FuzzyLoopGuard | LoopDetected |
| Retry storms | RetryGuard | RetryLimitExceeded |
| Hung runs | TimeoutGuard | TimeoutExceeded |
| Spam calls | RateLimitGuard | — |
| Wallet drain (x402/USDC) | X402SpendGuard | BudgetExceeded |
Not a dashboard. Not a model router. An in-process exception that kills the bad run mid-flight.
Agents that pay per-call via x402 (USDC micropayments) can drain a wallet in a
silent loop. X402SpendGuard wraps the payment step and refuses before paying:
AgentGuard meters and refuses; it never signs or settles. Amounts come from your x402 client. No crypto dependencies.
BudgetGuard.goal(...) for sub-task caps + warn hookspatch_openai / patch_anthropicHttpSinkThe SDK is the free local proof path. Start local. Add hosted ingest later only if you want retained history, alerts, team visibility, spend trends, hosted decision history, or dashboard-managed remote kill signals. Local guards remain authoritative. HttpSink mirrors trace and decision events; it does not execute remote kill signals by itself.
OpenAI · Anthropic · LangChain · LangGraph · CrewAI · raw agent loops
The base install declares zero runtime dependencies. pip install agentguard47 pulls nothing, so a default install adds no third-party exposure.
Extras pull real dependency trees. The [crewai] extra pulls chromadb, which carries PYSEC-2026-311: a pre-authentication remote code execution advisory with no fixed release available. Nothing in AgentGuard calls the affected endpoint, and installing the extra does not start a ChromaDB server. You are exposed only if you run a ChromaDB server reachable by untrusted callers. A 2026-08-28 pip-audit run also flags CVE-2026-45830, CVE-2026-45831, and CVE-2026-45833 against the same chromadb release, none with a fixed version. The [langchain], [langgraph], and [otel] extras resolve clean under pip-audit. See #702 for the full finding.
npx -y @agentguard47/mcp-serverThe hosted page is an optional next step, not a requirement. The SDK stays free, local, and MIT, and the local guards stay authoritative. Nothing in this package phones home. The only network egress is a sink or exporter you configure yourself, such as HttpSink or an OpenTelemetry exporter.
MIT · Built for people who ship agents and hate surprise bills.