# Cron > Create and manage Codex app automations stored in the local SQLite database (~/.codex/sqlite/codex-dev.db). Use when you need to add, list, update, enable/disable, delete, or run-now automations; edit automation names, prompts, RRULE schedules, or cwd scopes; or inspect automation records while troubleshooting app automation behavior. Use when this capability is needed. - Skill: `tomevault-io/cron` (Agent Skill, multi-file: 2 files) - Install (CLI): `npx skillmds@latest add tomevault-io/cron` - Raw SKILL.md: https://api.skillmd.com/api/skills/tomevault-io/cron/raw - Safety review: pending (external: skill-scanner PASS, skillspector PASS) - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Coding & Dev Tools - Author: tomevault-io (https://skillmd.com/u/tomevault-io) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/tomevault-io/cron --- # Cron ## Overview Use this skill to manage Codex automations through the native Zig `cron` CLI. Runtime paths are Zig-only (no Python fallback, no shell launchd wrappers). ## Zig CLI Iteration Repos When iterating on `cron`, use these two repos: - `skills-zig` (`/Users/tk/workspace/tk/skills-zig`): source for the `cron` binary, build/test wiring, release tags. - `homebrew-tap` (`/Users/tk/workspace/tk/homebrew-tap`): formula/checksum updates for released binaries. ## Quick Start ```bash run_cron_tool() { install_cron_direct() { local repo="${SKILLS_ZIG_REPO:-$HOME/workspace/tk/skills-zig}" if ! command -v zig >/dev/null 2>&1; then echo "zig not found. Install Zig from https://ziglang.org/download/ and retry." >&2 return 1 fi if [ ! -d "$repo" ]; then echo "skills-zig repo not found at $repo." >&2 echo "clone it with: git clone https://github.com/tkersey/skills-zig \"$repo\"" >&2 return 1 fi if ! (cd "$repo" && zig build build-cron -Doptimize=ReleaseFast); then echo "direct Zig build failed in $repo." >&2 return 1 fi if [ ! -x "$repo/zig-out/bin/cron" ]; then echo "direct Zig build did not produce $repo/zig-out/bin/cron." >&2 return 1 fi mkdir -p "$HOME/.local/bin" install -m 0755 "$repo/zig-out/bin/cron" "$HOME/.local/bin/cron" } local os="$(uname -s)" if command -v cron >/dev/null 2>&1 && cron --help 2>&1 | grep -q "cron.zig"; then cron "$@" return fi if [ "$os" = "Darwin" ]; then if ! command -v brew >/dev/null 2>&1; then echo "homebrew is required on macOS: https://brew.sh/" >&2 return 1 fi if ! brew install tkersey/tap/cron; then echo "brew install tkersey/tap/cron failed." >&2 return 1 fi elif ! (command -v cron >/dev/null 2>&1 && cron --help 2>&1 | grep -q "cron.zig"); then if ! install_cron_direct; then return 1 fi fi if command -v cron >/dev/null 2>&1 && cron --help 2>&1 | grep -q "cron.zig"; then cron "$@" return fi echo "cron binary missing or incompatible after install attempt." >&2 if [ "$os" = "Darwin" ]; then echo "expected install path: brew install tkersey/tap/cron" >&2 else echo "expected direct path: SKILLS_ZIG_REPO= zig build build-cron -Doptimize=ReleaseFast" >&2 fi return 1 } ``` - List automations: `run_cron_tool list` - Show one automation: `run_cron_tool show --id ` - Create an automation: `run_cron_tool create --name "Weekly release notes" --prompt-file /path/to/prompt.md --rrule "RRULE:FREQ=WEEKLY;BYDAY=FR;BYHOUR=9;BYMINUTE=0"` - Update an automation: `run_cron_tool update --id --rrule "RRULE:FREQ=DAILY;BYHOUR=9;BYMINUTE=0"` - Enable or disable: `run_cron_tool enable --id ` or `run_cron_tool disable --id ` - Run immediately: `run_cron_tool run-now --id ` - Delete: `run_cron_tool delete --id ` - Run due automations once: `run_cron_tool run-due` - Run due automations dry-run: `run_cron_tool run-due --dry-run` - Install/start launchd scheduler (macOS): `run_cron_tool scheduler install` - Stop/remove launchd scheduler (macOS): `run_cron_tool scheduler uninstall` - Show scheduler status (macOS): `run_cron_tool scheduler status` Runtime bootstrap policy mirrors `seq`/`cas`/`lift`: require the Zig binary, default to Homebrew install on macOS, and fallback to direct Zig install from `skills-zig` on non-macOS. Subcommand `--help` prints top-level usage. For detailed options, use the matrix below. ## Workflow 1. Choose working directories (`cwds`). Default is current repo if omitted on `create`. 2. Write the automation prompt (use `--prompt-file` for multi-line prompts). 3. Provide an RFC5545 RRULE string. 4. Create or update with `cron`. 5. For unattended execution, install scheduler via `cron scheduler install`. ## Headless Runner - `cron run-due` executes due automations by calling `codex exec` and updates: - `automations.last_run_at` - `automations.next_run_at` - `automation_runs` rows - `cron run-due --dry-run` is read-only: - no `automation_runs` rows are inserted/updated - no `automations.last_run_at`/`next_run_at` updates - no automation files or `memory.md` writes - `--codex-bin` accepts executable name or absolute path (default resolves `$CODEX_BIN` or `codex` in `PATH`). - Locking is label-scoped and fail-closed (`--lock-label`, or env `CRON_LAUNCHD_LABEL`). - `--lock-label` uses strict label validation: only `[A-Za-z0-9._-]` (no slashes/spaces). - `run-due` default batch limit is `10` automations per invocation (`--limit` overrides). - Scheduler commands are macOS-only and manage `~/Library/LaunchAgents/