Trace Replay
Deterministic replay of a workflow run from its stored trace — the debugging primitive that makes 'why did the agent do that' a question with an answer.
Non-deterministic systems are debuggable when their inputs are captured and their behavior is replayable. Trace replay is the discipline of capturing enough inputs to make the run reproducible.
What it solves
Removes the 'cannot reproduce' verdict on agent bugs. Lets a developer step through last Thursday's bad output with the same model inputs, retrieval results, and tool outputs.
How we build it
Traces capture every input that could change behavior: event payload, retrieved chunks, tool inputs and outputs, model parameters, and the model response. Replay runs the same workflow against captured inputs; differences from production are themselves a tracked signal.
- Captured inputs at every step
- Re-run from any trace ID
- Diff vs production behavior
- Replay-friendly tool stubs in dev
What changes when it is in place
Agent debugging becomes an engineering discipline instead of a guessing game.