CodeTracer records a program run once, then lets you step forwards and backwards through everything that happened — every value, every call, every branch.
Built for engineers working in
Stop re-running to reproduce. Record the run once and investigate it as a fixed, explorable recording.
Capture a full program run — every value, branch and call — into a portable trace, then replay it deterministically as often as you like.
Move the cursor forwards and backwards. Jump straight to where a value last changed instead of re-running to guess.
One debugging model over many recorders — native, Ruby, Python, the EVM and more — so the same time-travel workflow follows you everywhere.
Run your program once under a CodeTracer recorder to capture a complete, portable trace of the execution.
Open the trace in CodeTracer and move forwards, backwards, or straight to the moment a value changed.
Free for open-source languages, with paid tiers for teams that need all languages, cloud replay and collaboration.
For individuals getting started.
For professionals and teams.
For collaborative use at scale.
Python and Ruby (Linux & macOS, with full web replay), plus C/C++, Rust and others (Linux desktop replay). New languages are added frequently.
The execution trace of your program captures every program state over time, so you can replay and inspect the whole run deterministically.
Yes. You can call agents from within CodeTracer or use external agents.
Yes — you can attach an arbitrary number of replays as links. They open directly in the CodeTracer web IDE.
No. Reviewers can open shared replays in the CodeTracer web IDE, straight from a pull request link.
Free and open source. Download a build and record your first trace in minutes — or join the community on Discord.