The claude runner takes the model its harness's init event reports unbounded and unshaped into the answer (internal/core/runner/claude.go parseClaude), and the loop writes it into state.json through the route record; a model string over 4 MiB pushes state.json past its read bound, so every later read refuses and the run is bricked, and control bytes travel into the record verbatim.

The claude runner takes the model its harness's init event reports unbounded and unshaped into the answer (internal/core/runner/claude.go parseClaude), and the loop writes it into state.json through the route record; a model string over 4 MiB pushes state.json past its read bound, so every later read refuses and the run is bricked, and control bytes travel into the record verbatim.

Grounds

• pursued: a harness reporting a 5 MiB model or one carrying control bytes falls back with an unparsable reason and the run's state stays readable with no receipt carrying it; a real id such as claude-opus-4-6[1m] refused, or a state.json holding the odd model, would show it wrong