Turn on error tracking

Send unhandled errors from the api, the web server and the browser to Sentry. With no DSN set, the Sentry SDK never starts and nothing is sent; setting the DSN is the only switch. About 15 minutes; both services redeploy.

What gets reported: unhandled errors in the api's raw routes (/cron/*, /hooks/*, /chat/stream), genuine server failures from tRPC procedures (not client errors such as unauthorized or not found), web server render and route errors, and browser errors. Browser events go through the app's own /monitoring route, so the Content-Security-Policy allows them and ad blockers don't drop them. Personal data is never attached (sendDefaultPii is off) and session replay is off; turn either on only with a scrubbing policy.

Before you start

A Sentry project (one for both services, or one each) and its DSN
Access to the api's and web app's environment variables

Steps

On the api, set:
```
SENTRY_DSN=<api-dsn>
```
On Render, SENTRY_ENVIRONMENT is already production on monark-api and staging on monark-api-staging. Elsewhere it falls back to NODE_ENV.
On the web app, set:
```
NEXT_PUBLIC_SENTRY_DSN=<web-dsn>
NEXT_PUBLIC_SENTRY_ENVIRONMENT=production
```
On Vercel, give the Preview environment NEXT_PUBLIC_SENTRY_ENVIRONMENT=staging.
Optional, for readable browser stack traces: set SENTRY_ORG, SENTRY_PROJECT and SENTRY_AUTH_TOKEN on the web app's build. A build without the token still succeeds; it only skips the source-map upload.
Optional, for performance tracing: raise SENTRY_TRACES_SAMPLE_RATE (api and web server) and NEXT_PUBLIC_SENTRY_TRACES_SAMPLE_RATE (browser) above 0, for example 0.1. Tracing is off by default so turning on errors doesn't add trace volume.
Redeploy both services.

Verify

Open the web app, then run this in the browser console:

setTimeout(() => {
  throw new Error("Sentry test");
});

The network panel shows a request to /monitoring, and the error appears in Sentry within a minute, tagged with the environment you set.

If something goes wrong

Symptom	Cause	Fix
No browser events	`NEXT_PUBLIC_SENTRY_DSN` set without a redeploy	Redeploy; `NEXT_PUBLIC_*` values are build-time.
Browser stack traces are minified	source-map upload skipped	Set the three build variables in step 3.
Staging errors show up as production	environment tag not set on Preview	Set `NEXT_PUBLIC_SENTRY_ENVIRONMENT` per Vercel environment.
Expected 404s or permission errors missing	client errors are deliberately not reported	None; only server failures are sent.

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