Rehearsal — Development skill for Claude Code

Rehearsal

Find out whether changing your coding agent's instructions actually helps.

Rehearsal runs a fixed task through the real Claude Code CLI, records the instructions and evidence, and grades the result. You can replay a workflow stage after editing a skill, or repeat a session to see how much its results vary. The goal is a debugger and regression suite for an engineer's instruction corpus: project guidance, skills, output styles, and agent definitions.

For example, a shorter instruction might produce a better reply once. Rehearsal helps you inspect that attempt, repeat the task, and compare quality with cost before deciding the instruction earned its place.

**Early development.** The CLI is usable, and a local browser UI reads recorded evidence. Some workflows still depend on the maintainer's environment. Session confirmation groups work; multi-case comparisons of those groups do not yet. See [current state and priorities](docs/status.md) before planning an experiment.

How it works

Choose a case + instructions + model
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          Run the real agent
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       Grade and retain evidence
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       Inspect → edit → run again
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     Confirm with repeated trials

• Session cases run one prompt in a temporary directory, optionally with fixture files or a captured conversation prefix. Deterministic checks grade the reply and tool transcript.
• Pipeline cases run a declared sequence of skills against a target Git repository. A Product Owner answers questions, independent Judges grade each stage, and checkpoints let you replay a stage without rerunning its predecessors.
• Confirmation runs repeat frozen inputs and report reliability and resource usage. A single attempt is debugging evidence, not proof of improvement.

The current provider is Claude Code. This is a local tool using your credentials and agent environment, with records under `.benchmark-runs/`