feat(core): Backfill otel attributes on streamed spans (#20439)

The streaming path skips the `SentrySpanExporter`, which is why we
backfill span data (`sentry.op`, `name`, `sentry.source`) in
`captureSpan` now. Some of the inference logic is duplicated from the
otel package — which we can likely drop once we move away from otel.

closes #20425

Author: chargome

.size-limit.js

@@ -212,7 +212,7 @@ module.exports = [
     name: 'CDN Bundle (incl. Tracing)',
     path: createCDNPath('bundle.tracing.min.js'),
     gzip: true,
-    limit: '46.5 KB',
+    limit: '47 KB',
     disablePlugins: ['@size-limit/esbuild'],
   },
   {
@@ -226,7 +226,7 @@ module.exports = [
     name: 'CDN Bundle (incl. Tracing, Logs, Metrics)',
     path: createCDNPath('bundle.tracing.logs.metrics.min.js'),
     gzip: true,
-    limit: '47.5 KB',
+    limit: '48 KB',
     disablePlugins: ['@size-limit/esbuild'],
   },
   {
@@ -240,14 +240,14 @@ module.exports = [
     name: 'CDN Bundle (incl. Tracing, Replay)',
     path: createCDNPath('bundle.tracing.replay.min.js'),
     gzip: true,
-    limit: '83.5 KB',
+    limit: '84 KB',
     disablePlugins: ['@size-limit/esbuild'],
   },
   {
     name: 'CDN Bundle (incl. Tracing, Replay, Logs, Metrics)',
     path: createCDNPath('bundle.tracing.replay.logs.metrics.min.js'),
     gzip: true,
-    limit: '84.5 KB',
+    limit: '85 KB',
     disablePlugins: ['@size-limit/esbuild'],
   },
   {
@@ -278,7 +278,7 @@ module.exports = [
     path: createCDNPath('bundle.tracing.min.js'),
     gzip: false,
     brotli: false,
-    limit: '139 KB',
+    limit: '140 KB',
     disablePlugins: ['@size-limit/esbuild'],
   },
   {
@@ -294,7 +294,7 @@ module.exports = [
     path: createCDNPath('bundle.tracing.logs.metrics.min.js'),
     gzip: false,
     brotli: false,
-    limit: '142 KB',
+    limit: '143 KB',
     disablePlugins: ['@size-limit/esbuild'],
   },
   {
@@ -310,15 +310,15 @@ module.exports = [
     path: createCDNPath('bundle.tracing.replay.min.js'),
     gzip: false,
     brotli: false,
-    limit: '256 KB',
+    limit: '257 KB',
     disablePlugins: ['@size-limit/esbuild'],
   },
   {
     name: 'CDN Bundle (incl. Tracing, Replay, Logs, Metrics) - uncompressed',
     path: createCDNPath('bundle.tracing.replay.logs.metrics.min.js'),
     gzip: false,
     brotli: false,
-    limit: '260 KB',
+    limit: '260.5 KB',
     disablePlugins: ['@size-limit/esbuild'],
   },
   {

dev-packages/node-integration-tests/suites/tracing/http-client-spans/fetch-basic-streamed/scenario.ts

@@ -0,0 +1,20 @@
+import * as Sentry from '@sentry/node';
+import { loggingTransport } from '@sentry-internal/node-integration-tests';
+
+Sentry.init({
+  dsn: 'https://public@dsn.ingest.sentry.io/1337',
+  release: '1.0',
+  tracesSampleRate: 1.0,
+  traceLifecycle: 'stream',
+  transport: loggingTransport,
+});
+
+async function run(): Promise<void> {
+  await Sentry.startSpan({ name: 'test_transaction' }, async () => {
+    await fetch(`${process.env.SERVER_URL}/api/v0`);
+  });
+
+  await Sentry.flush();
+}
+
+void run();

dev-packages/node-integration-tests/suites/tracing/http-client-spans/fetch-basic-streamed/test.ts

@@ -0,0 +1,29 @@
+import { createTestServer } from '@sentry-internal/test-utils';
+import { expect, test } from 'vitest';
+import { createRunner } from '../../../../utils/runner';
+
+test('infers sentry.op for streamed outgoing fetch spans', async () => {
+  expect.assertions(2);
+
+  const [SERVER_URL, closeTestServer] = await createTestServer()
+    .get('/api/v0', () => {
+      expect(true).toBe(true);
+    })
+    .start();
+
+  await createRunner(__dirname, 'scenario.ts')
+    .withEnv({ SERVER_URL })
+    .expect({
+      span: container => {
+        const httpClientSpan = container.items.find(
+          item =>
+            item.attributes?.['sentry.op']?.type === 'string' && item.attributes['sentry.op'].value === 'http.client',
+        );
+
+        expect(httpClientSpan).toBeDefined();
+      },
+    })
+    .start()
+    .completed();
+  closeTestServer();
+});

dev-packages/node-integration-tests/suites/tracing/httpIntegration-streamed/instrument.mjs

@@ -0,0 +1,10 @@
+import * as Sentry from '@sentry/node';
+import { loggingTransport } from '@sentry-internal/node-integration-tests';
+
+Sentry.init({
+  dsn: 'https://public@dsn.ingest.sentry.io/1337',
+  release: '1.0',
+  tracesSampleRate: 1.0,
+  transport: loggingTransport,
+  traceLifecycle: 'stream',
+});

dev-packages/node-integration-tests/suites/tracing/httpIntegration-streamed/server.mjs

@@ -0,0 +1,16 @@
+import * as Sentry from '@sentry/node';
+import { startExpressServerAndSendPortToRunner } from '@sentry-internal/node-integration-tests';
+import cors from 'cors';
+import express from 'express';
+
+const app = express();
+
+app.use(cors());
+
+app.get('/test', (_req, res) => {
+  res.send({ response: 'ok' });
+});
+
+Sentry.setupExpressErrorHandler(app);
+
+startExpressServerAndSendPortToRunner(app);

dev-packages/node-integration-tests/suites/tracing/httpIntegration-streamed/test.ts

@@ -0,0 +1,34 @@
+import { afterAll, describe, expect } from 'vitest';
+import { cleanupChildProcesses, createEsmAndCjsTests } from '../../../utils/runner';
+
+describe('httpIntegration-streamed', () => {
+  afterAll(() => {
+    cleanupChildProcesses();
+  });
+
+  createEsmAndCjsTests(__dirname, 'server.mjs', 'instrument.mjs', (createRunner, test) => {
+    test('infers sentry.op, name, and source for streamed server spans', async () => {
+      const runner = createRunner()
+        .expect({
+          span: container => {
+            const serverSpan = container.items.find(
+              item =>
+                item.attributes?.['sentry.op']?.type === 'string' &&
+                item.attributes['sentry.op'].value === 'http.server',
+            );
+
+            expect(serverSpan).toBeDefined();
+            expect(serverSpan?.is_segment).toBe(true);
+            expect(serverSpan?.name).toBe('GET /test');
+            expect(serverSpan?.attributes?.['sentry.source']).toEqual({ type: 'string', value: 'route' });
+            expect(serverSpan?.attributes?.['sentry.span.source']).toEqual({ type: 'string', value: 'route' });
+          },
+        })
+        .start();
+
+      await runner.makeRequest('get', '/test');
+
+      await runner.completed();
+    });
+  });
+});

packages/core/src/tracing/spans/captureSpan.ts

@@ -2,7 +2,9 @@ import type { RawAttributes } from '../../attributes';
 import type { Client } from '../../client';
 import type { ScopeData } from '../../scope';
 import {
+  SEMANTIC_ATTRIBUTE_SENTRY_CUSTOM_SPAN_NAME,
   SEMANTIC_ATTRIBUTE_SENTRY_ENVIRONMENT,
+  SEMANTIC_ATTRIBUTE_SENTRY_OP,
   SEMANTIC_ATTRIBUTE_SENTRY_RELEASE,
   SEMANTIC_ATTRIBUTE_SENTRY_SDK_NAME,
   SEMANTIC_ATTRIBUTE_SENTRY_SDK_VERSION,
@@ -51,6 +53,14 @@ export function captureSpan(span: Span, client: Client): SerializedStreamedSpanW
 
   applyCommonSpanAttributes(spanJSON, serializedSegmentSpan, client, finalScopeData);
 
+  // Backfill span data from OTel semantic conventions when not explicitly set.
+  // OTel-originated spans don't have sentry.op, description, etc. — the non-streamed path
+  // infers these in the SentrySpanExporter, but streamed spans skip the exporter entirely.
+  // Access `kind` via duck-typing — OTel span objects have this property but it's not on Sentry's Span type.
+  // This must run before all hooks and beforeSendSpan so that user callbacks can see and override inferred values.
+  const spanKind = (span as { kind?: number }).kind;
+  inferSpanDataFromOtelAttributes(spanJSON, spanKind);
+
   if (spanJSON.is_segment) {
     applyScopeToSegmentSpan(spanJSON, finalScopeData);
     // Allow hook subscribers to mutate the segment span JSON
@@ -150,3 +160,119 @@ export function safeSetSpanJSONAttributes(
     }
   });
 }
+
+// OTel SpanKind values (numeric to avoid importing from @opentelemetry/api)
+const SPAN_KIND_SERVER = 1;
+const SPAN_KIND_CLIENT = 2;
+
+/**
+ * Infer and backfill span data from OTel semantic conventions.
+ * This mirrors what the `SentrySpanExporter` does for non-streamed spans via `getSpanData`/`inferSpanData`.
+ * Streamed spans skip the exporter, so we do the inference here during capture.
+ *
+ * Backfills: `sentry.op`, `sentry.source`, and `name` (description).
+ * Uses `safeSetSpanJSONAttributes` so explicitly set attributes are never overwritten.
+ */
+/** Exported only for tests. */
+export function inferSpanDataFromOtelAttributes(spanJSON: StreamedSpanJSON, spanKind?: number): void {
+  const attributes = spanJSON.attributes;
+  if (!attributes) {
+    return;
+  }
+
+  const httpMethod = attributes['http.request.method'] || attributes['http.method'];
+  if (httpMethod) {
+    inferHttpSpanData(spanJSON, attributes, spanKind, httpMethod);
+    return;
+  }
+
+  const dbSystem = attributes['db.system.name'] || attributes['db.system'];
+  const opIsCache =
+    typeof attributes[SEMANTIC_ATTRIBUTE_SENTRY_OP] === 'string' &&
+    `${attributes[SEMANTIC_ATTRIBUTE_SENTRY_OP]}`.startsWith('cache.');
+  if (dbSystem && !opIsCache) {
+    inferDbSpanData(spanJSON, attributes);
+    return;
+  }
+
+  if (attributes['rpc.service']) {
+    safeSetSpanJSONAttributes(spanJSON, { [SEMANTIC_ATTRIBUTE_SENTRY_OP]: 'rpc' });
+    return;
+  }
+
+  if (attributes['messaging.system']) {
+    safeSetSpanJSONAttributes(spanJSON, { [SEMANTIC_ATTRIBUTE_SENTRY_OP]: 'message' });
+    return;
+  }
+
+  const faasTrigger = attributes['faas.trigger'];
+  if (faasTrigger) {
+    safeSetSpanJSONAttributes(spanJSON, { [SEMANTIC_ATTRIBUTE_SENTRY_OP]: `${faasTrigger}` });
+  }
+}
+
+function inferHttpSpanData(
+  spanJSON: StreamedSpanJSON,
+  attributes: RawAttributes<Record<string, unknown>>,
+  spanKind: number | undefined,
+  httpMethod: unknown,
+): void {
+  // Infer op: http.client, http.server, or just http
+  const opParts = ['http'];
+  if (spanKind === SPAN_KIND_CLIENT) {
+    opParts.push('client');
+  } else if (spanKind === SPAN_KIND_SERVER) {
+    opParts.push('server');
+  }
+  if (attributes['sentry.http.prefetch']) {
+    opParts.push('prefetch');
+  }
+  safeSetSpanJSONAttributes(spanJSON, { [SEMANTIC_ATTRIBUTE_SENTRY_OP]: opParts.join('.') });
+
+  // If the user set a custom span name via updateSpanName(), apply it — OTel instrumentation
+  // may have overwritten span.name after the user set it, so we restore from the attribute.
+  const customName = attributes[SEMANTIC_ATTRIBUTE_SENTRY_CUSTOM_SPAN_NAME];
+  if (typeof customName === 'string') {
+    spanJSON.name = customName;
+    return;
+  }
+
+  if (attributes[SEMANTIC_ATTRIBUTE_SENTRY_SOURCE] === 'custom') {
+    return;
+  }
+
+  // Only overwrite the span name when we have an explicit http.route — it's more specific than
+  // what OTel instrumentation sets as the span name. For all other cases (url.full, http.target),
+  // the OTel-set name is already good enough and we'd risk producing a worse name (e.g. full URL).
+  const httpRoute = attributes['http.route'];
+  if (typeof httpRoute === 'string') {
+    spanJSON.name = `${httpMethod} ${httpRoute}`;
+    safeSetSpanJSONAttributes(spanJSON, { [SEMANTIC_ATTRIBUTE_SENTRY_SOURCE]: 'route' });
+  } else {
+    // Fallback: set source to 'url' for HTTP spans without a route.
+    // The spec requires sentry.span.source on segment spans, and the non-streamed exporter
+    // always sets this — so we need to ensure it's present for streamed spans too.
+    safeSetSpanJSONAttributes(spanJSON, { [SEMANTIC_ATTRIBUTE_SENTRY_SOURCE]: 'url' });
+  }
+}
+
+function inferDbSpanData(spanJSON: StreamedSpanJSON, attributes: RawAttributes<Record<string, unknown>>): void {
+  safeSetSpanJSONAttributes(spanJSON, { [SEMANTIC_ATTRIBUTE_SENTRY_OP]: 'db' });
+
+  // If the user set a custom span name via updateSpanName(), apply it.
+  const customName = attributes[SEMANTIC_ATTRIBUTE_SENTRY_CUSTOM_SPAN_NAME];
+  if (typeof customName === 'string') {
+    spanJSON.name = customName;
+    return;
+  }
+
+  if (attributes[SEMANTIC_ATTRIBUTE_SENTRY_SOURCE] === 'custom') {
+    return;
+  }
+
+  const statement = attributes['db.statement'];
+  if (statement) {
+    spanJSON.name = `${statement}`;
+    safeSetSpanJSONAttributes(spanJSON, { [SEMANTIC_ATTRIBUTE_SENTRY_SOURCE]: 'task' });
+  }
+}