AI product Open source
OrcaReplay is an open-source replay and debugging tool for AI-agent executions, built by the OrcaRouter.ai team. It records an agent run as a local trace, including model requests and responses, tool calls and results, shell exit codes and timing, filesystem snapshots, MCP traffic, and selected network activity.
It runs as a local proxy and capture layer around an unmodified agent. A proxy records model traffic, while PATH shims, JSON-RPC interception, filesystem snapshots, fetch hooks, and optional TLS interception capture effects that model transcripts cannot show. The resulting timeline can be viewed, exported, queried through JSON or MCP, and analyzed with recorded versus inferred causal edges.
The same recorded stream supports offline replay with the network blocked, forking from a derived checkpoint onto another model, and comparison of several models with an optional verification command. Replay uses the recorded conversation and workspace state; interactive terminal sessions can be approximate because prompts and interactive-only tools may not exist on the wire. The CLI is installed with npm, requires Node 20 or newer, stores runs under `.orca/runs/`, and the code, CLI, viewer, adapters, and trace format implementation are released under Apache-2.0; the trace specification is CC BY 4.0. Traces are local and redacted on write, but the project describes them as sensitive and treats redaction as best-effort.
1 use taken from transcripts — each links to the moment in the video.
A replay system that records agent executions step by step for offline reruns without spending additional tokens. It captures details such as shell exit codes and file permissions and lets users fork a run from a checkpoint onto another model.
1 in the library.