Invariant Labs

Agent Reliability Infrastructure

Ship Agents That Hold

Maulfind Holdsmeasure Vigilprevent

01 · find failures

Maul

How does the agent behave under failure?

An adversarial OpenAI-compatible proxy. Point the agent's base_url at Maul to inject controlled failures and record how the workflow responds.

Artifact reliability_report.json

terminal · maul
$ maul test --config maul.yaml \
  --agent "python agent.py"

scenario        force_429
faults_injected 3
recovered       2
report written  artifacts/reliability_report.json

02 · measure quality

Holds

Did the agent actually solve the job?

A suite-first evaluation harness. Run representative tasks repeatedly, grade real outcomes, and stop regressions before they reach production.

Artifacts holds.yaml · baseline.json

terminal · holds
$ holds run --suite holds.yaml

tasks        12
pass_rate    96%
consistency  92%
threshold    passed

$ holds compare --baseline baseline.json

03 · prevent incidents

Vigil

Are unsafe or expensive behaviors stopped?

A runtime policy SDK for explicit operational controls. Define budgets, allowlists, circuit breakers, routing, and redacted audit behavior.

Artifacts vigil.yaml · audit.jsonl

vigil.yaml
budgets:
  max_llm_calls_per_workflow: 12
  max_cost_usd_per_workflow: 0.75

controls:
  - type: circuit_breaker
    condition: repeated_equivalent_request
    max_occurrences: 3

Use cases

Same agent. One run fails. One holds.

Fixtures shaped like Maul action-smoke, the Holds refund suite, and Vigil support-agent audit events.

01 · Maul

Retry under force_500

Same retry_agent.py. Left never recovers, so --fail-on resilience is red. Right recovers on the next same-session call.

maul test · unrecovered

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maul test · recovered

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03 · Vigil

Retry loop · circuit breaker

Same retry loop, fingerprint samefp. Left has no policy, so the agent keeps spending. Right trips the breaker and writes the audit line.

audit.jsonl · ungoverned

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audit.jsonl · vigil

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