Trace Artifacts

Top-Level Fields

• task_id (string)
• version (int)
• seed (int)
• success (bool)
• termination_reason (string)
• failure_reason (string | null)
• failure_type (string | null)
• steps_used (int)
• tool_calls_used (int)
• metrics (object)
• action_trace (array)
• run_id (string, UUID hex)
• trace_id (string, UUID hex)
• agent (string, path)
• task_ref (string, <id>@<version>)
• started_at (string, ISO 8601)
• completed_at (string, ISO 8601)
• harness_version (string)

Trace Entry Schema

{
  "step": 1,
  "observation": {
    "step": 1,
    "task": { "id": "filesystem_hidden_config", "description": "..." },
    "last_action": null,
    "last_action_result": null,
    "visible_state": {},
    "budget_remaining": { "steps": 199, "tool_calls": 39 }
  },
  "action": { "type": "list_dir", "args": { "path": "." } },
  "result": { "ok": true, "files": ["config", "readme.txt"] },
  "budget_after_step": { "steps": 199, "tool_calls": 39 }
}

Compatibility Notes

• Additive fields are allowed. Removals or renames require a version bump and changelog entry.
• Consumers should ignore unknown keys to remain forward compatible.
• metrics is reserved for derived values.
• Action/result payloads are task-defined; only the surrounding envelope is standardized.