From 2bcb3ead24ab09081aa1559bb20372b6e00458b3 Mon Sep 17 00:00:00 2001
From: Milo Hansen <hello@milo.codes>
Date: Tue, 8 Apr 2025 11:56:27 -0700
Subject: [PATCH 1/5] use routePath

Replace indexing into the matchedRoutes with a direct reference to routePath
---
 packages/otel/src/index.ts | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/packages/otel/src/index.ts b/packages/otel/src/index.ts
index 55bfe7a8..03252913 100644
--- a/packages/otel/src/index.ts
+++ b/packages/otel/src/index.ts
@@ -30,9 +30,9 @@ export const otel = <E extends Env = any, P extends string = any, I extends Inpu
       const result = await next()
       const span = trace.getActiveSpan()
       if (span != null) {
-        const route = c.req.matchedRoutes[c.req.matchedRoutes.length - 1]
-        span.setAttribute(ATTR_HTTP_ROUTE, route.path)
-        span.updateName(`${c.req.method} ${route.path}`)
+        const routePath = c.req.routePath
+        span.setAttribute(ATTR_HTTP_ROUTE, routePath)
+        span.updateName(`${c.req.method} ${routePath}`)
       }
       return result
     })
@@ -40,15 +40,15 @@ export const otel = <E extends Env = any, P extends string = any, I extends Inpu
   const tracerProvider = options.tracerProvider ?? trace.getTracerProvider()
   const tracer = tracerProvider.getTracer(PACKAGE_NAME, PACKAGE_VERSION)
   return createMiddleware<E, P, I>(async (c, next) => {
-    const route = c.req.matchedRoutes[c.req.matchedRoutes.length - 1]
+    const routePath = c.req.routePath
     await tracer.startActiveSpan(
-      `${c.req.method} ${route.path}`,
+      `${c.req.method} ${routePath}`,
       {
         kind: SpanKind.SERVER,
         attributes: {
           [ATTR_HTTP_REQUEST_METHOD]: c.req.method,
           [ATTR_URL_FULL]: c.req.url,
-          [ATTR_HTTP_ROUTE]: route.path,
+          [ATTR_HTTP_ROUTE]: routePath,
         },
       },
       async (span) => {

From 5315ef7e0d1ad654b99a358f3dfab99704031bcb Mon Sep 17 00:00:00 2001
From: Milo Hansen <hello@milo.codes>
Date: Tue, 8 Apr 2025 11:56:47 -0700
Subject: [PATCH 2/5] Update package.json

Bump version
---
 packages/otel/package.json | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/otel/package.json b/packages/otel/package.json
index f19e3291..7ddb548d 100644
--- a/packages/otel/package.json
+++ b/packages/otel/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@hono/otel",
-  "version": "0.1.0",
+  "version": "0.1.1",
   "description": "OpenTelemetry middleware for Hono",
   "type": "module",
   "module": "dist/index.js",

From a638a15346cb2fb907228626468b3b781b402baf Mon Sep 17 00:00:00 2001
From: Milo Hansen <milo.hansen@avanade.com>
Date: Tue, 8 Apr 2025 12:09:41 -0700
Subject: [PATCH 3/5] set span name and attributes after the request is handled

---
 packages/otel/src/index.ts | 24 +++++++++++++++---------
 1 file changed, 15 insertions(+), 9 deletions(-)

diff --git a/packages/otel/src/index.ts b/packages/otel/src/index.ts
index 03252913..06c382d5 100644
--- a/packages/otel/src/index.ts
+++ b/packages/otel/src/index.ts
@@ -1,5 +1,5 @@
 import type { TracerProvider } from '@opentelemetry/api'
-import { SpanKind, SpanStatusCode,  trace } from '@opentelemetry/api'
+import { SpanKind, SpanStatusCode, trace } from '@opentelemetry/api'
 import {
   ATTR_HTTP_REQUEST_HEADER,
   ATTR_HTTP_REQUEST_METHOD,
@@ -10,17 +10,19 @@ import {
 } from '@opentelemetry/semantic-conventions'
 import type { Env, Input } from 'hono'
 import { createMiddleware } from 'hono/factory'
-import metadata from '../package.json' with { type: 'json'}
+import metadata from '../package.json' with { type: 'json' }
 
 const PACKAGE_NAME = metadata.name
 const PACKAGE_VERSION = metadata.version
 
-export type OtelOptions = {
-  augmentSpan?: false;
-  tracerProvider?: TracerProvider
-} | {
-  augmentSpan: true;
-}
+export type OtelOptions =
+  | {
+      augmentSpan?: false
+      tracerProvider?: TracerProvider
+    }
+  | {
+      augmentSpan: true
+    }
 
 export const otel = <E extends Env = any, P extends string = any, I extends Input = {}>(
   options: OtelOptions = {}
@@ -42,7 +44,7 @@ export const otel = <E extends Env = any, P extends string = any, I extends Inpu
   return createMiddleware<E, P, I>(async (c, next) => {
     const routePath = c.req.routePath
     await tracer.startActiveSpan(
-      `${c.req.method} ${routePath}`,
+      `${c.req.method} ${c.req.routePath}`,
       {
         kind: SpanKind.SERVER,
         attributes: {
@@ -57,6 +59,10 @@ export const otel = <E extends Env = any, P extends string = any, I extends Inpu
         }
         try {
           await next()
+          // Update the span name and route path now that we have the response
+          // because the route path may have changed
+          span.updateName(`${c.req.method} ${c.req.routePath}`)
+          span.setAttribute(ATTR_HTTP_ROUTE, c.req.routePath)
           span.setAttribute(ATTR_HTTP_RESPONSE_STATUS_CODE, c.res.status)
           for (const [name, value] of c.res.headers.entries()) {
             span.setAttribute(ATTR_HTTP_RESPONSE_HEADER(name), value)

From 9f37b9755efa6208a1801cc3741f1f94672c30e8 Mon Sep 17 00:00:00 2001
From: Milo Hansen <milo.hansen@avanade.com>
Date: Tue, 8 Apr 2025 12:12:08 -0700
Subject: [PATCH 4/5] revert version bump

---
 packages/otel/package.json | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/otel/package.json b/packages/otel/package.json
index 7ddb548d..f19e3291 100644
--- a/packages/otel/package.json
+++ b/packages/otel/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@hono/otel",
-  "version": "0.1.1",
+  "version": "0.1.0",
   "description": "OpenTelemetry middleware for Hono",
   "type": "module",
   "module": "dist/index.js",

From 3fb6df0f0f1909ef6e0267f740a4f62f1c9aabd8 Mon Sep 17 00:00:00 2001
From: Milo Hansen <milo.hansen@avanade.com>
Date: Tue, 8 Apr 2025 12:13:33 -0700
Subject: [PATCH 5/5] changeset

---
 .changeset/ripe-parents-sing.md | 5 +++++
 1 file changed, 5 insertions(+)
 create mode 100644 .changeset/ripe-parents-sing.md

diff --git a/.changeset/ripe-parents-sing.md b/.changeset/ripe-parents-sing.md
new file mode 100644
index 00000000..3cfc0281
--- /dev/null
+++ b/.changeset/ripe-parents-sing.md
@@ -0,0 +1,5 @@
+---
+'@hono/otel': patch
+---
+
+Use `req.routePath` to augment spans with the path that handled the request.