Polling Best Practices (J-Claw)
v2.0.0Best practices for automating long-running, asynchronous tasks via cron-style polling. Use when the user wants to monitor a background CLI command or API cal...
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Polling Best Practices
A guidance-style skill for automating long-running, asynchronous tasks using a cron-compatible polling pattern. When a task cannot complete synchronously (e.g., a CLI command that triggers a background job and returns a job ID), this skill guides the agent through: (1) deciding whether polling is appropriate, (2) pre-flight confirmation with the user, (3) setting up a task directory, (4) writing the polling script, (5) launching the background job, and (6) monitoring it to completion or timeout.
Language: All confirmation messages to the user should be written in the user's current session language (check the session language — if the user is writing in Chinese, reply in Chinese; if in English, reply in English).
1. Suitability Checklist
Before proceeding, the agent must answer:
✅ Suitable for Polling — if ALL of the following are true:
- The target command/API returns immediately with a process ID, job ID, artifact ID, or similar handle
- There is a clear, machine-parseable completion condition (e.g., a JSON/TOML field, a status string, an exit code, a file appearing)
- The condition can be checked by re-running the same command or a lightweight query command
- The wait time is predictable (typically 1–15 minutes)
- No real-time user interaction is needed during execution
❌ NOT Suitable — if ANY of the following are true:
- The task requires complex LLM judgment to determine if it's "done" (e.g., "is this output good enough?")
- The task requires streaming or real-time output to be shown to the user
- The task outcome changes during polling based on intermediate results
- The completion condition is ambiguous or subjective
- The user wants to stop or redirect the task mid-execution
If the task is NOT suitable for polling, inform the user and propose an alternative approach (e.g., run synchronously, use a sub-agent with polling only for the final wait, etc.).
2. Post-Poll Actions (轮询后行为)
After polling completes (success, failure, or timeout), one or more actions may be needed. Always define these before writing the poll script.
Category A — Notify (通知)
| Action | Command | When to Use |
|---|---|---|
| Direct notify user | openclaw message send --channel discord --target "$CHAT_ID" -m "msg" | Failure, timeout, simple completion. No agent processing needed. |
| Trigger agent | openclaw agent --channel discord --message "msg" --deliver --timeout 600 | Success requiring next workflow step. Agent receives instructions and executes downstream skill. |
Rules:
- Failure/timeout → always
notify_user(direct). Never trigger agent on failure. - Success, no chaining →
notify_user(direct). Simple "task done" message. - Success, needs chaining →
trigger_agentwith all parameters the next step needs.
Category B — Artifact (产物处理)
| Action | Code Pattern | When to Use |
|---|---|---|
| Download | nlm download audio $ID --id $ART_ID -o $PATH | External service generated a file; bring it local. |
| Verify | [[ -s "$output_path" ]] | Confirm file exists and is non-empty before declaring success. |
| Move/Copy | cp "$temp_path" "$final_path" | User specified a destination; move from temp to final location. |
Category C — Cleanup (清理)
| Action | Code Pattern | When to Use |
|---|---|---|
| Keep temp folder | (default) | For debugging, resume, or manual inspection. |
| Delete temp folder | rm -rf "$TASK_DIR" | Only if user explicitly requested cleanup. Never auto-delete. |
Decision Matrix
| Scenario | Notify | Artifact | Cleanup |
|---|---|---|---|
| Simple task done, no output file | notify_user | — | Keep |
| File generated, user wants it | notify_user | Verify + Move | Keep |
| Chaining to next skill | trigger_agent | — (next skill handles) | Keep |
| Timeout | notify_user with error details | — | Keep (for debug) |
| Failure | notify_user with error details | — | Keep (for debug) |
3. Pre-Flight Confirmation (One-Time, All Parameters)
Before starting any polling task, ask the user to confirm all parameters in a single message. This avoids back-and-forth and sets clear expectations.
Confirm in the user's current session language. Include the post-poll actions in the confirmation.
Example (Chinese):
启动前请确认以下参数:
① 轮询对象
- 任务:[简短描述]
- 状态查询命令:[具体命令]
- 成功判定条件:[例如输出包含 "status": "completed"]
② 轮询频率:每 [X] 分钟一次(默认:5 分钟)
③ 最长持续时间:最多 [Y] 次轮询 = [Z] 分钟(默认:40 分钟 / 8 次)
④ 完成后动作:
- [ ] 通知用户(默认:是)
- [ ] 下载产物 → 保存到 [路径]
- [ ] 触发下一步工作流(说明:...)
- [ ] 清理临时文件夹
⑤ 失败/超时时动作:
- [ ] 通知用户(默认:是)
直接回复修改项,或"确认"以默认参数启动。
Do not begin polling until the user confirms. If triggered by an upstream skill (agent mode), skip confirmation and use the parameters from the trigger message.
4. Temp Folder Structure
Every polling task gets its own temp folder. This makes the task self-contained, resumable, and easy to inspect or clean up later.
/tmp/<category>/ ← category: e.g., notebooklm, deep-research, generic
<YYMMDD-HHmm>_<sanitized-task-name>/ ← timestamped per-task folder
task.json ← task metadata, all parameters, AND post-poll actions
progress.json ← current polling state (poll count, last check time, handles)
poll.log ← log of every poll attempt (timestamp + result)
error.log ← errors encountered
done.flag ← empty file, created on successful completion
<output files> ← any downloaded/generated artifacts
Naming rules:
- Category folder: lowercase, hyphenated, descriptive of the task type (e.g.,
notebooklm-audio,deep-research,generic-async) - Task subfolder:
YYMMDD-HHmm+_+ sanitized task name (spaces→hyphens, max 40 chars, strip special chars)
If a category folder doesn't exist yet, create it. If a task subfolder already exists (e.g., from a previous attempt), ask the user: "Resume the previous task or start fresh?"
task.json schema
Include post-poll actions in the task config so the script knows what to do on completion:
{
"category": "notebooklm-audio",
"task_name": "example-notebook-audio",
"poll_command": "nlm studio status <notebook_id>",
"parse_rule": {
"type": "json",
"path": ".[0].status",
"success_value": "completed",
"failure_value": "failed"
},
"on_complete_command": "nlm download audio <notebook_id> --id <artifact_id> -o <output_path>",
"verify_output": true,
"poll_interval_seconds": 300,
"max_polls": 8,
"output_path": "/path/to/output.m4a",
"temp_dir": "/tmp/notebooklm-audio/260325-1400_example-audio",
"created_at": "2026-03-25T22:00:00Z",
"user_confirmed": true,
"post_poll": {
"on_success": {
"notify_user": true,
"download": false,
"download_path": null,
"trigger_agent": false,
"agent_message": null
},
"on_failure": {
"notify_user": true
},
"on_timeout": {
"notify_user": true
}
}
}
progress.json schema
{
"poll_count": 3,
"last_poll_at": "2026-03-25T22:15:00Z",
"last_poll_result": "in_progress",
"artifact_id": "abc123...",
"current_handle": "..."
}
5. Writing the Polling Script
Write the script to the task's temp folder (<temp_dir>/poll.sh). The script must be self-contained — no external dependencies beyond standard Unix tools and the specific CLI tools for the task.
Required properties:
set -euo pipefailat the top- Check for
done.flagat start — if it exists, exit 0 immediately (already done) - On any error (auth expired, command failed, timeout), log to
error.logand save progress before exiting - Save
progress.jsonafter every poll attempt - Append every poll result to
poll.log(timestamp + truncated output) - Never delete the temp folder — the user decides when to clean up
CHAT_IDmust be injected by the agent at script generation time
Script Template
#!/bin/bash
set -euo pipefail
# ─── Config ────────────────────────────────────────────────────────────────
TASK_DIR="/tmp/category/YYMMDD-HHmm_taskname"
cd "$TASK_DIR"
[[ -f done.flag ]] && echo "Already complete." && exit 0
CHAT_ID="INJECT_CHAT_ID" # ← Agent: replace with Discord channel ID
POLL_COUNT=$(grep '"poll_count"' progress.json 2>/dev/null | sed 's/[^0-9]//g') || POLL_COUNT=0
MAX_POLLS=8
INTERVAL=300
# ─── Helpers ───────────────────────────────────────────────────────────────
log() { echo "[$(date '+%Y-%m-%d %H:%M:%S')] $*" | tee -a poll.log; }
notify_user() {
local message="$1"
openclaw message send --channel discord --target "$CHAT_ID" -m "$message" 2>/dev/null || log "WARNING: notification failed"
}
trigger_agent() {
local message="$1"
openclaw agent --channel discord --message "$message" --deliver --timeout 600 2>/dev/null || {
log "WARNING: agent trigger failed, falling back to direct message"
notify_user "$message"
}
}
# ─── Main Loop ─────────────────────────────────────────────────────────────
while true; do
POLL_COUNT=$((POLL_COUNT + 1))
if [[ $POLL_COUNT -gt $MAX_POLLS ]]; then
echo "[$(date)] TIMEOUT after $MAX_POLLS polls" >> error.log
notify_user "❌ 任务超时(已达最大轮询次数 $MAX_POLLS)。"
exit 1
fi
log "[Poll $POLL_COUNT/$MAX_POLLS] Checking..."
RESULT=$(<your_poll_command> 2>&1) || true
echo "$RESULT" >> poll.log
# Parse status — adapt to your command's output
STATUS=$(echo "$RESULT" | python3 -c "
import sys, json
try:
d = json.loads(sys.stdin.read())
print(d.get('status', 'unknown'))
except: print('parse_error')
" 2>/dev/null)
log "Status: $STATUS"
# ── Success ──────────────────────────────────────────────────────────────
if [[ "$STATUS" == "completed" ]]; then
touch done.flag
# (B1) Download artifact if needed
# <your_download_command> >> poll.log 2>&1 || true
# (B2) Verify output if needed
# [[ -s "$OUTPUT_PATH" ]] || { notify_user "⚠️ 产物文件为空"; exit 1; }
# (A) Notify
notify_user "✅ 任务完成!共 $POLL_COUNT 轮轮询。"
# (A) Trigger agent for chaining (uncomment if needed)
# trigger_agent "✅ 任务完成。产物已就绪。请启动下一步:..."
log "Done."
exit 0
fi
# ── Failure ──────────────────────────────────────────────────────────────
if [[ "$STATUS" == "failed" ]]; then
echo "[$(date)] FAILED" >> error.log
notify_user "❌ 任务失败。"
exit 1
fi
# ── Still in progress ────────────────────────────────────────────────────
sed -i "s/\"poll_count\": [0-9]*/\"poll_count\": $POLL_COUNT/" progress.json
log "Still in_progress. Sleeping ${INTERVAL}s..."
sleep "$INTERVAL"
done
6. Launching and Monitoring
Start the background job
- First, run the trigger command (e.g.,
nlm audio create <notebook_id>) to start the background task and capture its ID/handle. - Save the returned ID to
progress.jsonandtask.json. - Then launch the polling script as a background process.
# In the task's temp dir:
nohup bash poll.sh > /dev/null 2>&1 &
echo "Polling started in background (PID: $!)"
The polling script should outlive the OpenClaw session. The agent should not need to stay alive for polling to continue.
Monitoring strategy
- Do not poll from within the OpenClaw session (sub-agents or exec loops waste resources and complicate recovery).
- If OpenClaw receives a user message asking "is it done yet?", the agent can check
done.flagorpoll.login the temp folder to answer without starting a new poll. - If a new session starts and the user asks to check on a task, read
progress.jsonto determine current status.
7. Timeout and Error Handling
| Situation | Action |
|---|---|
| Max polls reached (timeout) | Log to error.log, notify user with details, do NOT delete temp folder |
| Auth expired | Log to error.log, notify user to re-authenticate, exit |
| Download/generation failed | Log to error.log, notify user, exit |
| Temp folder already exists (duplicate start) | Ask user: resume or restart |
After timeout/failure: Do not auto-retry. Tell the user the task did not complete and present options:
- Re-run with the same parameters
- Adjust parameters and re-run
- Clean up the temp folder
8. Template-Ready Tasks (Frequent Patterns)
If the same type of task is performed frequently (e.g., NotebookLM audio generation, Gemini Deep Research status checks), extract the polling logic into a reusable script template stored in a category-level folder:
/tmp/notebooklm-audio/
poll-template.sh ← reusable template for this category
/260325-1400_task1/ ← individual task folders use the template
/260326-0915_task2/
The per-task poll.sh either copies from the template or is generated from it, keeping the per-task folder minimal.
9. Summary Checklist
Before launching a polling task, confirm ALL of:
- Task is suitable for polling (all suitability ✅)
- User confirmed all parameters in one message (or triggered by upstream skill)
- Post-poll actions defined: notify, download, trigger_agent, cleanup
- Temp folder created with correct
task.jsonandprogress.json - Trigger command run, ID/handle captured
-
CHAT_IDinjected into poll script -
poll.shwritten and tested for syntax (bash -n) - Background process started with
nohup - User informed: task started, how to check status, what happens on completion
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