Send Lumberjack metrics to Grafana

Chart Lumberjack's requests, errors, latency, queues and hosts in Grafana, and alert on them there. Grafana reads Lumberjack's read-only metrics API.

1. Get a credential

Pick one:

• A team token. A team owner or admin creates one under Team > API and MCP tokens, with the projects Grafana may read and the read scope. It starts with lj_mcp_ and is shown once. See Let an AI agent read your errors for the form.
• Public stats, for one project and without a token. An owner or admin turns on Public stats under Keys in the project's Settings. This gives an unguessable URL ending in /api/v1/public/ps_.../ that serves aggregates only: no error messages, stack traces or host names.

2. Add the data source

1. In Grafana, install the Infinity data source plugin and add a data source of that type.
2. Under Authentication, pick Bearer token and paste the token. For public stats, leave authentication off.
3. Add your Lumberjack's address to Allowed hosts.

3. Import the dashboard

Lumberjack ships a ready-made dashboard: docs/grafana/lumberjack.json.

1. In Grafana, go to Dashboards, New, Import, and upload the file.
2. Pick the Infinity data source you added.
3. At the top of the dashboard, set Lumberjack URL to your Lumberjack's address and Project slug to the project, such as shop.

When it works: the dashboard shows Requests, Error rate, p95 per route for the five busiest routes, and a Routes table, refreshed every 30 seconds.

4. Build your own panels

In a new panel, pick the Infinity data source, type JSON, source URL, format Time series, and a URL such as:

https://your-lumberjack/api/v1/projects/shop/series/p95?from=${__from}&to=${__to}&interval=${__interval}

Set Rows / root to points, and add the columns t (timestamp), value (number) and series (string).

• Swap p95 for another metric: requests, errors, error_rate, apdex, occurrences, queue_size, queue_wait, job_failures, cpu_load, lcp_p75 and more.
• Add &group_by=route (or queue, host, release, ...) for one line per value.
• Add filters such as &environment=production or &route=/api/*.

For a table, use format Table, a URL such as https://your-lumberjack/api/v1/projects/shop/routes?period=24h, and Rows / rootrows. Other tables are issues, jobs, queues, hosts and releases.

With public stats, replace https://your-lumberjack/api/v1 with the public stats URL.

5. Alert on the numbers

Lumberjack serves its current numbers in the Prometheus text format at /api/v1/metrics:

scrape_configs:
    - job_name: lumberjack
      scheme: https
      metrics_path: /api/v1/metrics
      scrape_interval: 60s
      authorization:
          type: Bearer
          credentials: lj_mcp_...
      static_configs:
          - targets: ['your-lumberjack']

Add that Prometheus as a data source in Grafana and alert on gauges such as lumberjack_error_rate, lumberjack_request_duration_p95_seconds or lumberjack_queue_size. These cover what Lumberjack's own alert rules do not, such as a project's error rate or p95 crossing a limit.

Limits

What	Limit
Requests per token or public key	120 a minute
Time range of a series	90 days, at most 2,000 points

Reference

• Metrics API: every endpoint, metric, filter and gauge.
• MCP: creating and revoking tokens.