A CLI tool that runs real GitHub Actions workflows locally with step-level debugging and high runner fidelity
GitHub Actions forces a push-and-pray debug cycle: every workflow change requires a commit, a push, and a 3-5 minute wait to see if it fails. The dominant workaround, nektos/act, fails on most real workflows because it cannot match the hosted runner environment. This CLI runs actual .github/workflows YAML locally inside a high-fidelity synthetic runner, with step-level breakpoints, secret injection, and service containers, so engineers debug in seconds instead of minutes per iteration.
Demand Breakdown
Social Proof 6 sources
Gap Assessment
4 tools exist (nektos/act, Dagger, Earthly, Buildkite) but gaps remain: Fails on most production workflows: runner image divergence from real GitHub runners causes step failures that do not exist in CI, service containers (postgres, redis) are unreliable, matrix builds are incomplete, secrets handling is manual and error-prone. No step-level debugger, no breakpoints, no variable inspection.; Requires completely rewriting existing GitHub Actions YAML workflows into Dagger modules. Not a drop-in debugger for .github/workflows files. Teams must adopt Dagger's mental model from scratch, which is a multi-week migration, not a debugging tool..
Features8 agent-ready prompts
Competitive LandscapeFREE
| Product | Does | Missing |
|---|---|---|
| nektos/act | Runs GitHub Actions locally by pulling GitHub-hosted runner images and executing workflow YAML. The closest existing solution with 72k GitHub stars. | Fails on most production workflows: runner image divergence from real GitHub runners causes step failures that do not exist in CI, service containers (postgres, redis) are unreliable, matrix builds are incomplete, secrets handling is manual and error-prone. No step-level debugger, no breakpoints, no variable inspection. |
| Dagger | Pipelines as typed code (Go, Python, TypeScript) running in containers that execute identically locally and in CI. Solves the local/CI parity problem. | Requires completely rewriting existing GitHub Actions YAML workflows into Dagger modules. Not a drop-in debugger for .github/workflows files. Teams must adopt Dagger's mental model from scratch, which is a multi-week migration, not a debugging tool. |
| Earthly | Makefile-like build system that runs identically locally and in CI. Eliminates the local/CI environment gap for build steps. | Also requires rewriting pipelines into Earthfile syntax. Does not debug existing GitHub Actions YAML. No step-level breakpoints or variable inspection. $8.6M raised but limited traction vs. Dagger. |
| Buildkite | Self-hosted CI/CD with a managed control plane. Eliminates GitHub-hosted runner unreliability by running on your own machines. | Full CI platform replacement, not a local debugging tool. Requires migrating away from GitHub Actions entirely. No local workflow execution. $41.3M raised, enterprise pricing. |
Notable VoicesFREE
"The Pain That Is GitHub Actions — the push-and-pray loop means every YAML fix costs 3-5 minutes of CI time before you know if it worked."
"GitHub Actions is slowly killing engineering teams — the absence of any local execution or debug mode turns trivial CI changes into hour-long time sinks."
Leads743BUILDER
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