# Send Cron Worker Guardrails to your agent
Hand the extracted package to your coding agent with a concrete install brief instead of figuring it out manually.
## Fast path
- Download the package from Yavira.
- Extract it into a folder your agent can access.
- Paste one of the prompts below and point your agent at the extracted folder.
## Suggested prompts
### New install

```text
I downloaded a skill package from Yavira. Read SKILL.md from the extracted folder and install it by following the included instructions. Tell me what you changed and call out any manual steps you could not complete.
```
### Upgrade existing

```text
I downloaded an updated skill package from Yavira. Read SKILL.md from the extracted folder, compare it with my current installation, and upgrade it while preserving any custom configuration unless the package docs explicitly say otherwise. Summarize what changed and any follow-up checks I should run.
```
## Machine-readable fields
```json
{
  "schemaVersion": "1.0",
  "item": {
    "slug": "cron-worker-guardrails",
    "name": "Cron Worker Guardrails",
    "source": "tencent",
    "type": "skill",
    "category": "安全合规",
    "sourceUrl": "https://clawhub.ai/phenomenoner/cron-worker-guardrails",
    "canonicalUrl": "https://clawhub.ai/phenomenoner/cron-worker-guardrails",
    "targetPlatform": "OpenClaw"
  },
  "install": {
    "downloadUrl": "/downloads/cron-worker-guardrails",
    "sourceDownloadUrl": "https://wry-manatee-359.convex.site/api/v1/download?slug=cron-worker-guardrails",
    "sourcePlatform": "tencent",
    "targetPlatform": "OpenClaw",
    "packageFormat": "ZIP package",
    "primaryDoc": "SKILL.md",
    "includedAssets": [
      "SKILL.md",
      "references/cron-agent-contract.md",
      "references/pitfalls.md"
    ],
    "downloadMode": "redirect",
    "sourceHealth": {
      "source": "tencent",
      "status": "healthy",
      "reason": "direct_download_ok",
      "recommendedAction": "download",
      "checkedAt": "2026-04-23T16:43:11.935Z",
      "expiresAt": "2026-04-30T16:43:11.935Z",
      "httpStatus": 200,
      "finalUrl": "https://wry-manatee-359.convex.site/api/v1/download?slug=4claw-imageboard",
      "contentType": "application/zip",
      "probeMethod": "head",
      "details": {
        "probeUrl": "https://wry-manatee-359.convex.site/api/v1/download?slug=4claw-imageboard",
        "contentDisposition": "attachment; filename=\"4claw-imageboard-1.0.1.zip\"",
        "redirectLocation": null,
        "bodySnippet": null
      },
      "scope": "source",
      "summary": "Source download looks usable.",
      "detail": "Yavira can redirect you to the upstream package for this source.",
      "primaryActionLabel": "Download for OpenClaw",
      "primaryActionHref": "/downloads/cron-worker-guardrails"
    },
    "validation": {
      "installChecklist": [
        "Use the Yavira download entry.",
        "Review SKILL.md after the package is downloaded.",
        "Confirm the extracted package contains the expected setup assets."
      ],
      "postInstallChecks": [
        "Confirm the extracted package includes the expected docs or setup files.",
        "Validate the skill or prompts are available in your target agent workspace.",
        "Capture any manual follow-up steps the agent could not complete."
      ]
    }
  },
  "links": {
    "detailUrl": "https://openagent3.xyz/skills/cron-worker-guardrails",
    "downloadUrl": "https://openagent3.xyz/downloads/cron-worker-guardrails",
    "agentUrl": "https://openagent3.xyz/skills/cron-worker-guardrails/agent",
    "manifestUrl": "https://openagent3.xyz/skills/cron-worker-guardrails/agent.json",
    "briefUrl": "https://openagent3.xyz/skills/cron-worker-guardrails/agent.md"
  }
}
```
## Documentation

### Cron Worker Guardrails (POSIX)

A reliability-first checklist for OpenClaw cron workers and any unattended automation.

### Scope (important)

This skill is POSIX-focused (bash/sh examples).
The principles are portable, but if you're on Windows/PowerShell you'll need equivalent patterns.

### The NO_REPLY convention

Many OpenClaw setups treat emitting exactly NO_REPLY as "silent success" (no human notification).

If your runtime does not support NO_REPLY, interpret it as: print nothing on success.

### Quick Start

Scripts-first: move logic into a repo script (recommended: tools/<job>.py or tools/<job>.sh).
One command in cron: cron should run one short command (no multi-line bash -lc '...').
Deterministic cwd/env: cd to the repo (or have the script do it), and document required env vars.
Silent on success: print nothing (or exactly NO_REPLY) when OK; only emit a short alert when broken.

Also see:

references/cron-agent-contract.md
references/pitfalls.md

### Why this skill exists

Cron failures are rarely "logic bugs". In practice they're often:

brittle shell quoting (bash -lc '...' nested quotes)
command substitution surprises ($(...))
one-liners that hide escaping bugs (python -c "...")
cwd/env drift ("works locally, fails in cron")
pipelines that fail for the wrong reason (pipefail + head / SIGPIPE)

The fix is boring but effective: scripts-first + deterministic execution + silent-on-success.

### Portability rules (still apply)

Even on POSIX, do not hardcode deployment-specific absolute paths tied to one machine.

Prefer:

repo-relative paths
environment variables you document
minimal wrappers that cd into the repo

### 1) unexpected EOF while looking for matching ')'

Likely causes:

unclosed $(...) from command substitution
broken nested quotes in bash -lc ' ... '

Fix pattern:

Replace the whole multi-line shell block with a script.
Cron calls exactly one short command, for example:

python3 tools/<job>.py

### 2) False failure from pipefail + head (SIGPIPE)

Symptom:

command exits non-zero even though the output you wanted is fine

Fix pattern:

avoid pipefail when piping into head
or better: do the filtering in a script (read only what you need)

### 3) "Works locally, fails in cron"

Common causes:

wrong working directory
missing env vars
different PATH

Fix pattern:

cd into the repo (or have the script do it)
keep dependencies explicit and documented

### Git footgun: git push rejected (non-fast-forward)

Symptom:

! [rejected] ... (non-fast-forward) when automation pushes to a long-lived PR/feature branch.

Conservative fix (no force-push):

On rejection, fetch the remote branch, transplant your new local commits onto it (cherry-pick), then retry push once.

### Copy/paste hardening header (portable)

Use this near the top of a cron prompt (2 lines, low-noise):

Hardening (MUST): follow references/cron-agent-contract.md (scripts-first, deterministic cwd, silent-on-success).
Also apply the cron-worker-guardrails skill. If parsing/multi-step logic is needed, write/run a small tools/*.py script.
## Trust
- Source: tencent
- Verification: Indexed source record
- Publisher: phenomenoner
- Version: 1.0.5
## Source health
- Status: healthy
- Source download looks usable.
- Yavira can redirect you to the upstream package for this source.
- Health scope: source
- Reason: direct_download_ok
- Checked at: 2026-04-23T16:43:11.935Z
- Expires at: 2026-04-30T16:43:11.935Z
- Recommended action: Download for OpenClaw
## Links
- [Detail page](https://openagent3.xyz/skills/cron-worker-guardrails)
- [Send to Agent page](https://openagent3.xyz/skills/cron-worker-guardrails/agent)
- [JSON manifest](https://openagent3.xyz/skills/cron-worker-guardrails/agent.json)
- [Markdown brief](https://openagent3.xyz/skills/cron-worker-guardrails/agent.md)
- [Download page](https://openagent3.xyz/downloads/cron-worker-guardrails)