[thelastbackspace]

From running traceperf run on a Fastify 4 + Drizzle + pg RealWorld app: every article slug and username was its own label.

• traceperf/auto: when the app depends on fastify, its module export is replaced (in the module cache, before the app loads it; require and import both read it) with a factory that adds an onRequest hook writing request.routeOptions.url (routerPath before 4.10) onto the raw request
• the server instrumentation labels by that route; Express's req.route is still used when it is absent
• ROUTE symbol exported so other frameworks can do the same; wrapFastifyFactory for manual use
• tested against real Fastify 5 (prefixes, unmatched URLs) and by hand on the Fastify 4 app through tsx