feat: record opencode resume metadata

examples/agent_challenges/opencode_resume.py

@@ -0,0 +1,92 @@
+from __future__ import annotations
+
+import json
+import subprocess
+from pathlib import Path
+from typing import Any
+
+FINAL_REPORT_PROMPT = (
+    "Your workflow attempt is over. Do not continue coding. Return only the "
+    "final challenge report using the required challenge_report YAML schema. "
+    "Include run_id, evidence, failed attempts, read flags, missed requirements, "
+    "and whether the run succeeded."
+)
+
+CONTINUE_PROMPT = (
+    "Continue this same trial from the current session. Do not restart in a new "
+    "workspace. If the workflow is already complete, stop and return only the "
+    "final challenge_report YAML using the required schema."
+)
+
+
+def _event_session_id(event: dict[str, Any]) -> str | None:
+    session_id = event.get("sessionID")
+    if isinstance(session_id, str) and session_id:
+        return session_id
+    part = event.get("part")
+    if isinstance(part, dict):
+        nested = part.get("sessionID")
+        if isinstance(nested, str) and nested:
+            return nested
+    return None
+
+
+def extract_session_id(stdout: str) -> str | None:
+    """Return the first OpenCode session id found in JSONL stdout."""
+    for line in stdout.splitlines():
+        if not line.strip():
+            continue
+        try:
+            event = json.loads(line)
+        except json.JSONDecodeError:
+            continue
+        if not isinstance(event, dict):
+            continue
+        session_id = _event_session_id(event)
+        if session_id is not None:
+            return session_id
+    return None
+
+
+def resume_prompt_for_result(result: dict[str, object]) -> str:
+    """Choose a continuation prompt from the result failure shape."""
+    task_outcome = result.get("task_outcome")
+    assertion_failures = result.get("assertion_failures")
+    failures = assertion_failures if isinstance(assertion_failures, list) else []
+    if task_outcome == "timeout":
+        return CONTINUE_PROMPT
+    if any("could not extract challenge report" in str(item) for item in failures):
+        return FINAL_REPORT_PROMPT
+    if result.get("parsed") is None and result.get("stdout"):
+        return FINAL_REPORT_PROMPT
+    return CONTINUE_PROMPT
+
+
+def build_resume_command(
+    *,
+    session_id: str,
+    attach_url: str | None,
+    model: str,
+    variant: str,
+    prompt: str,
+) -> list[str]:
+    command = ["opencode", "run", "--session", session_id]
+    if attach_url is not None:
+        command.extend(["--attach", attach_url])
+    command.extend(["--format", "json", "--model", model, "--variant", variant, prompt])
+    return command
+
+
+def display_resume_command(command: list[str]) -> str:
+    """Render an argv list for copy-paste display without changing execution."""
+    return subprocess.list2cmdline(command)
+
+
+def resume_result_path(result_path: Path) -> Path:
+    stem = result_path.with_suffix("")
+    index = 1
+    while True:
+        candidate = stem.with_name(f"{stem.name}.resume-{index:03d}.json")
+        if not candidate.exists():
+            return candidate
+        index += 1