Recurring (cron) webhooks

A cron in Webhook Relay sends a webhook on a schedule. Each cron has its own bucket; the configured payload/headers/method are injected and delivered to the destination (and to any additional outputs on its bucket) every time the schedule fires. Failed runs are retried and visible in the dashboard.

Manage crons with the relay cron subcommand (create/ls/inspect/update/rm), the REST API via relay api, or the dashboard at https://my.webhookrelay.com/cron.

Requires a relay CLI build that includes the cron command. If relay cron --help is not found, update the CLI or use the relay api path shown further below — both hit the same /v1/crons API.

Prerequisites

1. relay CLI installed and logged in (relay login). Confirm with relay cron ls (or relay api /v1/crons --jq '.').

Cron object fields

Schedule format is standard 5-field cron (minute hour day month weekday):

• */15 * * * * — every 15 minutes
• 0 * * * * — hourly, on the hour
• 0 9 * * * — every day at 09:00 (in the cron's timezone)
• 0 9 * * 1-5 — 09:00 on weekdays
• 0 0 1 * * — 00:00 on the 1st of each month

Create and manage with relay cron

# Create (prints the new cron ID). --schedule and --destination are required.
relay cron create hourly-ping \
  --schedule "0 * * * *" \
  --timezone "Europe/London" \
  --method POST \
  --destination https://example.com/webhook \
  --payload '{"ping":"hourly"}' \
  --header Content-Type=application/json

# List (table shows SCHEDULE, TIMEZONE, METHOD, DESTINATION, ENABLED, NEXT RUN)
relay cron ls

# Inspect full JSON (by name or ID)
relay cron inspect hourly-ping

# Update only the fields you pass (others are preserved)
relay cron update hourly-ping --schedule "*/30 * * * *"
relay cron update hourly-ping --enabled=false      # pause without deleting
relay cron update hourly-ping --function format-payload   # attach a transform

# Remove
relay cron rm hourly-ping

Key create/update flags: --schedule/-s, --timezone, --method/-m (default POST), --destination/-d, --payload/-p, --header (repeatable key=value), --function/-F (name or ID), --enabled, --recurring.

Alternative: the raw REST API (relay api)

Works on any CLI version and is handy for scripting from a JSON file. See examples/cron.json.

# Create
relay api -X POST /v1/crons --input examples/cron.json --jq '.id'

# Create inline (-F = typed bool/number, -f = string)
relay api -X POST /v1/crons \
  -f name="hourly-ping" -F enabled=true -F recurring=true \
  -f schedule="0 * * * *" -f timezone="Europe/London" \
  -f method="POST" -f destination="https://example.com/webhook" \
  -f payload='{"ping":"hourly"}'

# List / get / update / delete
relay api /v1/crons --jq '.'
relay api /v1/crons/<id> --jq '.'
relay api -X PUT /v1/crons/<id> --input examples/cron.json
relay api -X DELETE /v1/crons/<id> -i        # expect: HTTP/1.1 204 No Content

Patterns

Fan-out on a schedule. A cron delivers to its destination; to hit several endpoints, add extra outputs to the cron's bucket (relay output ls / relay output create -b <bucket> --type public -d <url>).

Transform on a timer. Set function_id to a deployed JavaScript function to build/sign the payload at send time (e.g. format a Slack reminder). See the webhook-transformations skill.

Health checks / heartbeats. Point destination at a monitoring endpoint (e.g. a Better Uptime / Healthchecks.io ping URL) on a tight schedule like */5 * * * *.

Verify

After creating, list crons and check next_run. Point destination at https://bin.webhookrelay.com or https://webhook.site first to watch the scheduled requests arrive, then switch to the real target. The dashboard (https://my.webhookrelay.com/cron) shows run history and lets you retry failures.

Notes

• Times are interpreted in the cron's timezone; set it explicitly to avoid UTC surprises.
• payload is a string — JSON-encode objects (e.g. "{\"ping\":\"hourly\"}").
• Set enabled: false to pause without deleting.

References

Webhook Relay docs (these .md URLs render as plain markdown for easy reading):

• Using cron webhooks: https://webhookrelay.com/docs/webhooks/cron/using-cron-webhooks.md
• Recurring webhooks overview: https://webhookrelay.com/cron.md
• Transform the payload at send time with a function: https://webhookrelay.com/docs/webhooks/functions.md
• Install the CLI: https://webhookrelay.com/docs/installation/cli.md