Paper: arXiv:2603.09951v1
This paper argues that code models should not only predict program execution, but should also support debugger-like interaction. The core idea is moving from passive execution-trace prediction toward active debugging behaviors such as breakpoints and stepping through code.
The important shift is simple:
- execution traces alone are not enough
- debugging becomes useful when the user can act on the trace
That matters for this repo because agent debugging should not stop at "show me the trace." It should move toward "let me inspect, pause, focus, and reason over the trace at the right boundary."
Right now the repo mostly captures runtime events from the agent. A stronger debugger would also model inspection actions such as:
- set breakpoint
- step into
- step over
- step out
- inspect state
- compare before/after state
These do not need to be neural to be useful. The product benefit comes from representing the actions explicitly.
The paper emphasizes focused execution around relevant code regions. The equivalent here is:
- replay only the critical branch
- replay around an error
- replay from a checkpoint near the failure
- collapse low-value segments
This would make trace review much more practical than scrolling through every event.
An event timeline is necessary but not sufficient. The debugger becomes much better when each interesting event can expose:
- current tool inputs
- outputs
- model response metadata
- decision evidence
- checkpointed state snapshots
- add a "focus from here" replay mode
- add user-defined breakpoints on event type, tool name, or confidence threshold
- add event-to-state inspection panes
- add step controls for walking event-by-event through a session
This paper is about code execution and debugger-like model behavior, not directly about generic agent tracing. The useful lesson is the interaction model, not the assumption that this repo should become a neural interpreter itself.
Implement one selective replay flow:
- choose an error or decision event
- jump to that point
- step forward event by event
- show the nearest checkpointed state beside the trace