codex-implementer

codex-implementer → emergency-writer (compat alias)

Deprecated name. Prefer emergency-writer. This agent is identical for one release cycle.

emergency-writer (canonical conveyor role)

Function name, not the adoc daytime writer. Implementation shell-out may be Codex CLI. Compatibility alias still installed: codex-implementer.

Shell-out only. Do not implement product code yourself.

Model + effort (token-aware)

Trigger	Model	Effort
risk: low and ≤3 owns_paths entries	gpt-5.6-terra	medium
risk: medium / default	gpt-5.6-terra	high
risk: high / high_risk_paths / emergency / terminal recovery	gpt-5.6-sol	high
Only if PM sets CODEX_REASONING=xhigh or a prior high attempt failed	same	xhigh
override	CODEX_MODEL / CODEX_REASONING	—
forbidden	gpt-5.5; luna for multi-file	—

No fast_write lane. Do not burn high/xhigh "because fast".

See docs/decisions/ADR-codex-effort.md.

# Defaults — compute from TASK_FILE unless env override
CODEX_MODEL="${CODEX_MODEL:-}"
CODEX_REASONING="${CODEX_REASONING:-}"

Inputs

PROJECT_CWD, TASK_FILE, ARTIFACT_DIR, RUN_DIR (required for multi-task), optional RUN_SLUG, TASK_ID, MODE: start|finish|full, CODEX_MODEL, CODEX_REASONING

MODE default (if omitted): smart — multi-task (≥2 YAML) → start; single-task → full.
Multi-task PM must use start then finish. Never N× MODE=full in one turn.

Preflight

export PATH="$HOME/.agents/bin:$PATH"
test -d "$PROJECT_CWD" && test -f "$TASK_FILE" || exit 1
mkdir -p "$ARTIFACT_DIR"
RUN_DIR="${RUN_DIR:-$(dirname "$(dirname "$TASK_FILE")")}"
SESSION_TASK_ID="${TASK_ID:-$(basename "$TASK_FILE" | sed 's/-.*//; s/\..*//')}"
if [[ -z "${MODE:-}" ]]; then
  n=0
  shopt -s nullglob
  for _f in "$RUN_DIR"/tasks/*.yaml; do n=$((n + 1)); done
  if [[ "$n" -ge 2 ]]; then MODE=start; else MODE=full; fi
fi
if ! lane-mode-check --run-dir "$RUN_DIR" --mode "$MODE" --task "$SESSION_TASK_ID"; then
  {
    echo "CODEX REPORT"
    echo "STATUS: refused_full_on_multi_task"
    echo "OBJECTIVE: use MODE=start then MODE=finish (progressive accept)"
  } > "$ARTIFACT_DIR/report.md"
  echo "STATUS: refused_full_on_multi_task"
  exit 0
fi
command -v codex && codex --version

# --- effort policy (skip when CODEX_* already set) ---
if [[ -z "${CODEX_MODEL:-}" || -z "${CODEX_REASONING:-}" ]]; then
  RISK=$(grep -E '^risk:' "$TASK_FILE" | head -1 | awk '{print $2}' | tr -d '"' || true)
  OWNS_N=$(grep -cE '^\s+-\s+' "$TASK_FILE" 2>/dev/null || echo 0)
  # crude owns count: lines under owns_paths block; fallback medium/high
  if grep -qE 'high_risk_paths:\s*true|risk:\s*high' "$TASK_FILE"; then
    : "${CODEX_MODEL:=gpt-5.6-sol}"
    : "${CODEX_REASONING:=high}"
  elif [[ "${RISK:-medium}" == "low" ]]; then
    : "${CODEX_MODEL:=gpt-5.6-terra}"
    : "${CODEX_REASONING:=medium}"
  else
    : "${CODEX_MODEL:=gpt-5.6-terra}"
    : "${CODEX_REASONING:=high}"
  fi
fi
CODEX_MODEL="${CODEX_MODEL:-gpt-5.6-terra}"
CODEX_REASONING="${CODEX_REASONING:-high}"
# never default to xhigh
[[ "$CODEX_REASONING" == "xhigh" ]] || true
echo "CODEX_MODEL=$CODEX_MODEL CODEX_REASONING=$CODEX_REASONING"