rewind

Record-replay debugger for AI agent runs.

An agent only touches the outside world through a narrow boundary: model calls in, tool calls out. rewind captures everything crossing that boundary, then replays it exactly — or branches from any step to explore alternate trajectories.

Installation

pip install rewind-llm

Quickstart

CLI proxy

# Record a session
rewind record -- claude "fix the bug"

# Replay it
rewind replay traces/anthropic_20260101_120000.jsonl -- claude "fix the bug"

CLI commands

rewind ls                                           # List traces
rewind show <trace.jsonl>                           # Pretty-print
rewind diff <a.jsonl> <b.jsonl> [--html out.html]   # Diff traces
rewind branch <trace> --at N --edit|--inject|--live  # Branch
rewind record -- <cmd>                              # Record via proxy
rewind replay <trace> -- <cmd>                      # Replay via proxy

Development

pip install -e ".[dev]"
python -m pytest tests/ -v

License

MIT