Sentry and PostHog activate when configured. Without their variables, neither exports data.
Telemetry export does not depend on either of them: OTEL_EXPORTER_OTLP_ENDPOINT ships traces, metrics, and the canonical log records to any OTLP collector, which remains the supported path for wide-event telemetry. Sentry and PostHog add vendor-native error inboxes and product analytics on top.
Sentry
| Variable | Where it works |
|---|---|
SENTRY_DSN | all three workers (web, api, background) |
Server-side, each worker entry is wrapped with the official @sentry/cloudflare SDK (Sentry.withSentry). Without a DSN the SDK initializes disabled: no transport is configured, so nothing leaves the worker.
Every failed wide event becomes one Sentry exception, tagged with service, event, errorKind, and the error's _tag when it has one, and joined back to the request's OTel trace id. The glue lives in packages/logger/src/providers.ts: the same observability seam that owns OTLP export (see packages/logger/AGENTS.md and ADR 0050 for the invocation-scoping rules).
In the browser, the web app lazily loads @sentry/react only when the root route's loader passes a DSN through (DSNs are public ingest identifiers by design). Client-side errors then report to the same project.
Releases are derived from SERVICE_VERSION / GIT_COMMIT_SHA; source-map upload is an explicit non-goal for now.
PostHog
| Variable | Where it works |
|---|---|
POSTHOG_KEY | web browser analytics + server-side capture |
POSTHOG_HOST | Optional; .env.example defaults to https://us.i.posthog.com |
Server-side follows PostHog's documented Cloudflare Workers pattern: the official posthog-node client with flushAt: 1 / flushInterval: 0, created per invocation and shut down before the invocation ends: the same invocation-scoped I/O rule ADR 0050 applies to OTLP export. One event per wide-event scope is captured, keyed by the trace id, with service, status, and durationMs properties.
In the browser, posthog-js initializes from the same root-route loader data, with history-based page-view capture suited to the SPA router.