jules-cronjob

name	jules-cronjob
description	Schedule Jules API sessions via cron-job.org. Use when the user asks to create a Jules session in the future, schedule a Jules task, automate a Jules coding job, or trigger Jules via cron. Handles cron-job.org API auth, correct payload format, timing, and Jules session body.

Jules Session via cron-job.org

Schedule a POST https://jules.googleapis.com/v1alpha/sessions request using the cron-job.org HTTP cron service.

Credentials

Jules API Key

Read from environment or config (in priority order):

# 1. Environment variable
echo $JULES_API_KEY

# 2. Stored config (after `verne auth login`)
cat ~/.config/verne/config.json

cron-job.org API Key

Available as the environment variable CRONJOB_API_KEY:

echo $CRONJOB_API_KEY

cron-job.org API Reference

Base URL: https://api.cron-job.org Auth header: Authorization: Bearer <key>

Operation	Method	Path
List jobs	GET	/jobs
Create job	PUT	/jobs
Get job	GET	/jobs/{jobId}
Update job	PATCH	/jobs/{jobId}
Delete job	DELETE	/jobs/{jobId}
Get job history	GET	/jobs/{jobId}/history
Get execution detail	GET	/jobs/{jobId}/history/{identifier}

IMPORTANT: Headers format

extendedData.headers must be a dict/object, NOT an array:

"headers": {
  "x-goog-api-key": "<jules-key>",
  "Content-Type": "application/json"
}

requestMethod values

0=GET, 1=POST, 2=OPTIONS, 3=HEAD, 4=PUT, 5=DELETE, 8=PATCH

Schedule format

All arrays. Use [-1] for "every":

"schedule": {
  "timezone": "UTC",
  "minutes": [51],     // specific minute, or [-1] for every minute
  "hours":   [17],     // specific hour, or [-1] for every hour
  "mdays":   [11],     // day of month 1-31, or [-1] for every day
  "months":  [4],      // month 1-12, or [-1] for every month
  "wdays":   [-1]      // 0-6 (Sun-Sat), or [-1] for every weekday
}

Full Create-Job Payload

{
  "job": {
    "url": "https://jules.googleapis.com/v1alpha/sessions",
    "enabled": true,
    "title": "<descriptive name>",
    "saveResponses": true,
    "requestMethod": 1,
    "extendedData": {
      "headers": {
        "x-goog-api-key": "<JULES_API_KEY>",
        "Content-Type": "application/json"
      },
      "body": "{\"title\": \"<session title>\", \"prompt\": \"<prompt text>\"}"
    },
    "schedule": {
      "timezone": "UTC",
      "minutes": [<minute>],
      "hours": [<hour>],
      "mdays": [<day>],
      "months": [<month>],
      "wdays": [-1]
    }
  }
}

Note: body must be a JSON-encoded string (the inner JSON serialized as a string value).

Workflow

Step 1 — Get credentials

JULES_KEY=$(python3 -c "
import os, json
from pathlib import Path
env = os.getenv('JULES_API_KEY')
if env:
    print(env)
else:
    cfg = Path.home() / '.config/verne/config.json'
    print(json.loads(cfg.read_text())['api_key'])
")
CRONJOB_KEY="$CRONJOB_API_KEY"

Step 2 — Get current UTC time, calculate target minute

date -u +"%H %M %d %m"
# Add 1-2 minutes to current minute for the schedule

Step 3 — Build and send the request

import json, os, subprocess, datetime

jules_key = "<from step 1>"
cronjob_key = os.environ["CRONJOB_API_KEY"]

now = datetime.datetime.utcnow()
target = now + datetime.timedelta(minutes=2)

request_body = json.dumps({
    "title": "<session title>",
    "prompt": "<detailed prompt>"
})

payload = {
    "job": {
        "url": "https://jules.googleapis.com/v1alpha/sessions",
        "enabled": True,
        "title": "<cron job label>",
        "saveResponses": True,
        "requestMethod": 1,
        "extendedData": {
            "headers": {
                "x-goog-api-key": jules_key,
                "Content-Type": "application/json"
            },
            "body": request_body
        },
        "schedule": {
            "timezone": "UTC",
            "minutes": [target.minute],
            "hours": [target.hour],
            "mdays": [target.day],
            "months": [target.month],
            "wdays": [-1]
        }
    }
}

result = subprocess.run(
    ["curl", "-s", "-w", "\nHTTP:%{http_code}", "-X", "PUT",
     "https://api.cron-job.org/jobs",
     "-H", f"Authorization: Bearer {cronjob_key}",
     "-H", "Content-Type: application/json",
     "-d", json.dumps(payload)],
    capture_output=True, text=True
)

lines = result.stdout.strip().split("\n")
print("HTTP:", lines[-1])
print("Response:", json.loads("\n".join(lines[:-1])))

Step 4 — Confirm and report to user

After a successful response ({"jobId": 12345}), report:

• Job ID
• Scheduled time (UTC)
• Target URL
• Jules session title and prompt summary

Step 5 — Optionally check execution result

After the scheduled time has passed:

# List history for the job
curl -s "https://api.cron-job.org/jobs/<jobId>/history" \
  -H "Authorization: Bearer $CRONJOB_API_KEY" | python3 -m json.tool

# Get detail of a specific execution
curl -s "https://api.cron-job.org/jobs/<jobId>/history/<identifier>" \
  -H "Authorization: Bearer $CRONJOB_API_KEY" | python3 -m json.tool

Jules Session Body Fields

Field	Type	Notes
title	string	Required. Human-readable session name.
prompt	string	The coding task description.
sourceContext.source	string	Optional. e.g. "sources/github.com/owner/repo"
sourceContext.githubRepoContext.startingBranch	string	Optional branch.
automationMode	string	Optional.
requirePlanApproval	bool	Optional.

Common Mistakes to Avoid

• DO NOT hardcode API keys in skill docs or scripts — always read from $CRONJOB_API_KEY.
• DO NOT use an array for extendedData.headers — must be a plain object/dict.
• DO NOT use POST /jobs — the create endpoint is PUT /jobs.
• DO NOT forget to JSON-serialize extendedData.body as a string (double-encode).
• DO NOT forget that schedule.months is 1-indexed (January = 1).
• Always use saveResponses: true so you can inspect the Jules API response later.