Worker setup

Minimum configuration

{
  "name": "clawdwatch",
  "main": "src/index.ts",
  "compatibility_date": "2026-07-01",
  "compatibility_flags": ["nodejs_compat"],

  "d1_databases": [
    {
      "binding": "MONITORING_DB",
      "database_name": "clawdwatch",
      "database_id": "<from wrangler d1 create>",
      "migrations_dir": "node_modules/clawdwatch/migrations"
    }
  ],

  "triggers": { "crons": ["*/5 * * * *"] },

  "vars": { "BASE_URL": "https://clawdwatch.example.workers.dev" }
}

D1 is the only binding required. There is no R2 bucket and no analytics dataset — v2 had both, and neither earned its place.

Migrations

wrangler d1 migrations apply clawdwatch --local    # development
wrangler d1 migrations apply clawdwatch --remote   # production

Migrations ship inside the package, so migrations_dir points at node_modules/clawdwatch/migrations. The reference worker uses a relative path because it lives in this repository.

Secrets

Never in wrangler.jsonc — vars are visible in the dashboard and in your repository.

wrangler secret put SLACK_WEBHOOK_URL      # alerts reach Slack
wrangler secret put ALERT_SIGNING_SECRET   # signs webhooks and capability links
wrangler secret put CF_ACCESS_TEAM_DOMAIN
wrangler secret put CF_ACCESS_AUD

Plus one for each credential your checks need, wired through the secrets option. See Secrets.

Cron

The cron sets the floor for how often anything runs. */5 * * * * suits most deployments; go to * * * * * if you need minute-resolution checks, and expect proportionally more invocations.

Each run only executes checks whose interval has elapsed, so a one-minute cron with mostly hourly checks is cheap.

Concurrency and limits

Checks run several at a time (six by default). A serial loop would be a liability: ten checks at a ten-second timeout with a retry each could exceed the invocation's wall clock and lose the entire tick.

If you monitor many slow endpoints, raise concurrency rather than the timeout.

defaults: { concurrency: 12 }

Custom domain

Alert links use BASE_URL, so set it to the address you actually browse:

"routes": [{ "pattern": "status.example.com", "custom_domain": true }],
"vars": { "BASE_URL": "https://status.example.com" }

Costs

The Worker itself is a cron invocation every five minutes plus whatever dashboard traffic you generate. D1 holds check definitions and a rolling 48 hours of results — kilobytes for a typical deployment. Both sit inside the free tier for most people; the paid plan is only needed for higher volume.