AgentLoop vs Kerno: Features, Pricing & Which Is Better (2026)
A side-by-side comparison of AgentLoop and Kerno — features, pricing, and ideal use cases — to help you decide which AI tool fits your workflow.
AgentLoop
Edward Yi
AgentLoop turns a single ChatGPT plan into unattended Codex worker + independent-critic cycles that build against your local rubric until the work passes.
Key features
- Fresh Worker Per Cycle: Each build cycle spawns a clean Codex worker with fresh context so long-running loops do not accumulate stale state or memory drift.
- Independent Critic Process: A separate fresh process grades every result against your rubric so passing tests never become permission to stop looking.
- Rubric in GUIDELINES.md: Definition-of-done lives as plain Markdown in your repo and is read on every cycle, so standards persist while prompts do not.
- Evidence Carried in Files: Worker output, critic verdicts, and fixes are written to project files so the next cycle inherits the actual state of the work.
- Bounded Goal + Cycle Budget: You cap the loop with a goal.md and cycle budget so unattended runs stop at a predictable ceiling.
- MCP Status Interface: Ask ChatGPT for status through MCP so you can monitor cycles, verdicts, transcripts, and cost without opening the dashboard.
- Local-first Install: git clone the pinned v1.1.0 release and run node src/daemon.js — no npm install, no hosted workspace, MIT licensed.
Best for
- Shipping a bounded feature: Add a CSV export across UI, API, and regression suite while the critic enforces end-to-end behavior and edge cases.
- Migration work: Run an unattended migration where fresh workers apply the change and the critic verifies each step against a rubric.
- Hardening pass: Give AgentLoop a hardening goal so it iterates on defects the existing test suite misses, like malformed input handling.
- Product polish loop: Point AgentLoop at a polish goal with clear acceptance criteria and let it converge to VERDICT: PASS.
- Unattended overnight runs: Kick off a long loop, monitor cycle verdicts, and cancel from the dashboard or via MCP when the receipt looks right.
- Enforcing team standards: Codify team engineering standards in GUIDELINES.md so every worker builds against the same definition of done.
Kerno
Kerno
Autonomously writes, runs, and maintains integration tests in your IDE to cover backend codebases and speed safe shipping.
Key features
- Autonomous Test Generation: Automatically writes integration tests by analyzing backend code paths and service interactions to produce tests that exercise edge cases and typical workflows.
- In-IDE Execution: Runs generated integration tests directly from the developer's IDE, providing immediate feedback and fast iteration without leaving the development environment.
- Test Maintenance and Updating: Detects code changes and intelligently updates or repairs existing integration tests to prevent test rot and reduce manual upkeep.
- Comprehensive Coverage Mapping: Identifies untested areas of the backend and generates tests to fill gaps, helping teams achieve broader and deeper integration coverage.
- CI/CD Integration: Designed to integrate with existing continuous integration pipelines so generated tests can be executed automatically as part of builds and deployments.
- Regression Detection: Continuously runs and compares integration test outcomes to detect regressions early and surface actionable failure context to developers.
- Autonomous generation of integration tests that cover backend code paths
- Execution of integration tests from within the developer IDE
- Automated maintenance and updates of tests as code evolves
- Agent runtime for executing workflows and tests
- Support materials and example repositories in multiple languages (Go, Java/Kotlin, Python, TypeScript)
- Benchmarking methodology (Kerno MCP) for agent workflow evaluation with logs and review
- Integrates with developer workflows and CI/CD pipelines
- Provides developer challenges and code samples for onboarding and evaluation
Best for
- Accelerating backend feature delivery by auto-generating integration tests that validate new endpoints and service interactions before merge.
- Reducing regressions by continuously maintaining and running integration tests that adapt as the codebase changes.
- Onboarding new team members by providing a ready suite of integration tests that demonstrate expected system behavior and interactions.
- Improving test coverage for legacy services by automatically creating integration tests that exercise rarely used or complex code paths.
- Integrating automated integration tests into CI pipelines to block unsafe deployments and ensure consistent safety checks across releases.
- Automatically generate and run integration tests for microservices and backend APIs
- Keep integration tests up to date after refactors or API changes
- Run and debug integration tests directly from the IDE during development
- Integrate test execution into CI/CD pipelines to increase release confidence
- Benchmark agent-driven workflows and collect logs for human and structural review
- Provide coding challenges and test harnesses for technical hiring and candidate evaluation