@openstatus/health-fly

Fly.io server metadata for @openstatus/health. Renders the region, machine and deployment that produced the response under a server key.

deno add jsr:@openstatus/health jsr:@openstatus/health-fly
npm install @openstatus/health @openstatus/health-fly

import { Hono } from "hono";
import { healthRoute } from "@openstatus/health-hono";
import { flyExtend } from "@openstatus/health-fly";
import { tursoProbe } from "@openstatus/health-turso";

const app = new Hono();

app.route("/", healthRoute({
  probes: [tursoProbe({ client })],
  extend: flyExtend(),
}));

{
  "status": "ok",
  "checkedAt": "2026-09-11T12:00:00.000Z",
  "latencyMs": 41,
  "checks": [{ "name": "database", "status": "ok", "critical": true, "latencyMs": 3 }],
  "server": {
    "platform": "fly",
    "region": "ams",
    "instanceId": "148e21ebd47089",
    "service": "openstatus-api",
    "version": "registry.fly.io/openstatus-api:deployment-01H9RK9EYO9PGNBYAKGXSHV0PH",
    "primaryRegion": "cdg",
    "processGroup": "app",
    "machineVersion": "01H9RKA2WPYNA",
    "memoryMb": 256
  }
}

With more than one machine behind one hostname, a health body without an instance identity answers "is something up", not "is this replica up". region against primaryRegion is the pair worth watching: a replica serving from ams while PRIMARY_REGION is cdg is a fact you want in the response, not in a dashboard.

Fields

| Field | Environment variable | | ----- | -------------------- | | region | FLY_REGION | | instanceId | FLY_MACHINE_ID, falling back to FLY_ALLOC_ID | | service | FLY_APP_NAME | | version | FLY_IMAGE_REF — the deployment, not the git sha | | primaryRegion | PRIMARY_REGION | | processGroup | FLY_PROCESS_GROUP | | machineVersion | FLY_MACHINE_VERSION | | memoryMb | FLY_VM_MEMORY_MB, as a number |

Values are passed through exactly as Fly sets them. Fields Fly does not set are absent rather than empty, and FLY_PUBLIC_IP / FLY_PRIVATE_IP are left out on purpose — they are topology, not health.

Off Fly

flyServer() returns undefined when FLY_MACHINE_ID and FLY_APP_NAME are both missing, and flyExtend() then renders no server key at all. The same code runs unchanged on your laptop, in CI and on Fly, with no branching — and nothing pretends to be a machine that does not exist.

Deploying the same build to more than one platform? Chain them; only the packages you import are bundled:

import { flyServer } from "@openstatus/health-fly";
import { vercelServer } from "@openstatus/health-vercel";

extend: () => ({ server: flyServer() ?? vercelServer() }),

Composing

flyExtend() is sugar for the common case. flyServer() returns the object, so your own fields sit beside it:

extend: (_report, c) => ({
  server: flyServer(),
  requestId: c.get("requestId"),
}),

Both accept { env } to read from a record you supply instead of the process environment, which is how the tests avoid touching the real one.

Public endpoints

extend output follows exposeChecks: when checks are hidden, server is hidden too, so a public /health never leaks the machine id. To serve both audiences from one route, gate on the request; to serve two routes, share one check so the probes run once:

app.route("/", healthRoute({
  probes,
  exposeChecks: (c) => c.req.header("x-health-token") === env.HEALTH_TOKEN,
  extend: flyExtend(),
}));

To publish part of server but not all of it, both functions take a typed omit list and drop those keys before anything is rendered:

extend: flyExtend({ omit: ["instanceId", "version"] }),

The keys are checked against FlyServerInfo, so "machineId" is a compile error, and platform may be omitted too when you would rather not advertise the host.

About openstatus

openstatus is the open-source uptime monitoring and status page platform. This package is part of @openstatus/health, the /health endpoints behind openstatus's own services, extracted so any JavaScript server can expose one. Point an openstatus monitor at the endpoint and assert on status in the body to be alerted on degraded before it becomes unhealthy.

Source: github.com/openstatusHQ/health. Issues and PRs welcome.

License

MIT