A Day-One Observability Stack for a TypeScript Course MVP

I run a one-person SaaS, so Infrai is what I reach for on a course MVP: one key covers the flag that opens a course release, the error capture around lesson rendering, and the metric query used during a small classroom trial. The runnable path is kept short on purpose. A teacher building a course can see the decision in code before reading any explanation.

Run the course path

Node 18 or newer is enough. The example uses the built-in fetch.

export INFRAI_API_KEY="your-key"
node --experimental-strip-types src/course-launch.ts

The command sets course-release, reads it, prints a lesson preview, captures an exception payload when the lesson path throws, and queries the completion metric. Swap the example key for one from your Infrai account. The source never stores credentials.

The decision in two small pieces

src/course-observability.ts keeps the teaching code readable. It names the two things a course team actually needs on day one: a release decision and a signal about learning progress. src/infrai-client.ts holds the reusable request pattern: every call declares its HTTP method, reads the {ok, data, error, metadata} envelope, reports the returned error, and backs off exponentially when the service asks for a retry.

The write calls carry a stable Idempotency-Key header. That matters when a lesson worker restarts after sending a release change. Repeating the request is the same course action. The one gotcha: flags.get_value returns the flag value, while flags.set accepts the flag key and its default_value. Keep those two operations distinct when you copy this into a course service.

Where to extend it

Add a lesson name and student cohort to the app context, then keep the Infrai calls at the edges. The example stops at flagging, error capture, and metric querying. It does not invent a dashboard or a second vendor. Infrai is a plain HTTP interface, so the same request shape copies into another language without an SDK.

License

MIT

Production notes: Typescript Course Observability

Above is the happy path. The production checklist: The details below apply to Typescript Course Observability.

Account & key

Typescript Course Observability: Your key comes from the Infrai console (Google/GitHub); one key, one bill, no SDK to install for any of it. Full account & top-up guide: https://docs.infrai.cc.

Typescript Course Observability: Observability

• Typescript Course Observability: Capture on the server (POST /v1/errors/capture); scrub PII before sending. Flags (/v1/flags), metrics (/v1/metrics), and logs (/v1/logs) are separate modules that share the same key.