Skip to content

Rerunner

Deterministic flight recorder, replay engine, and CI test runner for AI agents.

Record your AI agent once. Replay forever in CI in milliseconds with $0 API tokens, fail-closed @side_effect guards, JSON-safe PII redaction, and SHA-256 tamper-evident hash chains.

1-Line Quickstart

pip install rerunner && rerunner setup --clients claude,cursor,codex

Core Workflows

Workflow Command / API What It Solves
Pytest Deterministic Replay @pytest.mark.rerunner Zero-network, $0 CI tests with per-test auto-named cassettes
AI Coding Agent MCP rerunner mcp / rerunner setup Lets Claude Code, Cursor, and Codex inspect, diff, scrub, and fork cassettes natively
Cross-Language Proxy rerunner serve cassette.jsonl --port 8080 Replay LLM & SSE traffic for TypeScript, Go, Rust, or Docker via OPENAI_BASE_URL
Time-Travel Debugging rerunner fork cassette.jsonl --step 5 Replay steps 1–5 from tape for free, then run step 6 live against your fix
HTML Flight Trace rerunner inspect cassette.jsonl --export-html trace.html Self-contained zero-CDN trace viewer for CI failure artifacts
CI Cost & PR Bot rerunner cost --json / action.yml Model-aware token & USD savings posted directly as sticky PR comments

Next Steps