Step inside the agent loop.

See when hooks fire, inspect their JSON, and watch allow, block, context, crash, and timeout change the run.

Safe simulation. No pasted code executes, no files are accessed, and payloads contain only fictional values.

Recipe

Failure injection

Hook timeout

Agent lifecycle

Synchronous hooks may block; observers never change control flow

Ready

Hook stack

JSON on stdin

Redacted, versioned, simulated context

Harness decision

ALLOW

Allow tool call

Policy hook approved the sanitized request.

Coverage84%

Latency42ms

False blocks1.2%

Payload1.8KB

Failure scenarios

Practical recipes

Audit trace

Security checklist

Least privilege · explicit matchers · environment allowlist · path normalization · bounded runtime · idempotency · schema validation · secret redaction · fail closed for destructive actions · fail open only for telemetry.