feat(remix): Server Timing Headers Trace Propagation - #18653

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feat(remix): Server Timing Headers Trace Propagation#18653
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Adds automatic trace propagation from server to client via the Server-Timing HTTP header for Remix applications. The client-side reading of Server-Timing headers via the Performance API was added in #18673.

Adds:

  • generateSentryServerTimingHeader(span) public utility that generates a Server-Timing header value containing Sentry trace context
  • Automatic injection in the document request handler for normal page responses
  • Automatic injection on redirect responses from loaders and actions, which bypass the document request handler entirely. This is an advantage over meta tag injection, which cannot work on redirect responses since they have no HTML body
  • For Cloudflare/Hydrogen apps: call generateSentryServerTimingHeader() manually and append the value to the response's Server-Timing header in entry.server.tsx (see remix-hydrogen e2e test for example)

Works on both Node.js and Cloudflare Workers environments.

Closes#18696

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Pull request overview

This PR implements a proof-of-concept for propagating Sentry trace context from server to client using the Server-Timing HTTP header and the browser Performance API. This provides an alternative to meta tag-based trace propagation, particularly useful for streaming SSR responses and edge runtimes.

Key changes:

  • Added utilities for generating and injecting Server-Timing headers with Sentry trace data
  • Implemented client-side parsing of Server-Timing headers via the Performance API
  • Updated server instrumentation to capture and propagate trace context via Server-Timing headers
  • Added comprehensive E2E test coverage for both Node.js and Cloudflare environments

Reviewed changes

Copilot reviewed 25 out of 27 changed files in this pull request and generated 16 comments.

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FileDescription
packages/remix/src/server/serverTimingTracePropagation.tsNew utility module for generating Server-Timing headers with trace context
packages/remix/src/client/serverTimingTracePropagation.tsNew client-side utilities for parsing trace data from Server-Timing headers
packages/remix/src/server/instrumentServer.tsUpdated server instrumentation to inject Server-Timing headers and refactored trace propagation logic
packages/remix/src/client/performance.tsxUpdated pageload span initialization to use Server-Timing trace propagation
packages/remix/src/server/index.tsExported new Server-Timing utilities for public API
packages/remix/src/client/index.tsExported new client-side Server-Timing utilities
packages/remix/src/cloudflare/index.tsExported Server-Timing utilities for Cloudflare runtime
dev-packages/e2e-tests/test-applications/remix-server-timing/*New E2E test application validating Server-Timing trace propagation
dev-packages/e2e-tests/test-applications/remix-hydrogen/*Updated Hydrogen test app to demonstrate Cloudflare support

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Comment threadpackages/remix/src/server/serverTimingTracePropagation.ts Outdated
Comment threadpackages/remix/src/server/instrumentServer.ts Outdated
Comment threadpackages/remix/src/client/serverTimingTracePropagation.ts Outdated
Comment threadpackages/remix/src/server/instrumentServer.ts Outdated
Comment threadpackages/remix/src/server/instrumentServer.ts Outdated
Comment threadpackages/remix/src/server/instrumentServer.ts Outdated
Comment threadpackages/remix/src/server/instrumentServer.ts Outdated
Comment thread...2e-tests/test-applications/remix-server-timing/tests/server-timing-trace-propagation.test.ts Outdated
Comment threadpackages/remix/src/server/serverTimingTracePropagation.ts Outdated
Comment threadpackages/remix/src/server/instrumentServer.ts Outdated
@onurtemizkan
onurtemizkanforce-pushed the onur/remix-server-timing-headers branch 4 times, most recently from 1f07bc8 to 67ec468CompareJanuary 2, 2026 15:42
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node-overhead report 🧳

Note: This is a synthetic benchmark with a minimal express app and does not necessarily reflect the real-world performance impact in an application.

ScenarioRequests/s% of BaselinePrev. Requests/sChange %
GET Baseline8,958-9,206-3%
GET With Sentry1,71919%1,710+1%
GET With Sentry (error only)6,08168%6,099-0%
POST Baseline1,200-1,202-0%
POST With Sentry59049%579+2%
POST With Sentry (error only)1,03987%1,059-2%
MYSQL Baseline3,248-3,346-3%
MYSQL With Sentry42713%457-7%
MYSQL With Sentry (error only)2,59180%2,668-3%

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Comment threadpackages/remix/src/server/instrumentServer.ts
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Comment threadpackages/remix/src/server/serverTimingTracePropagation.ts Outdated
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@onurtemizkan sorry for the delay on this! I merged in #18673 to get support for server-timing trace continuation on the client side in the general browser SDK. Could you update the PR to use this instead of the remix-specific approach? The server side looks fine to me, though I'll give this a more proper look once the PR is updated.

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Codecov Results 📊

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Comment threaddev-packages/e2e-tests/test-applications/remix-hydrogen/app/entry.server.tsx Outdated
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size-limit report 📦

⚠️Warning: Base artifact is not the latest one, because the latest workflow run is not done yet. This may lead to incorrect results. Try to re-run all tests to get up to date results.

PathSize% ChangeChange
@sentry/browser25.64 kB--
@sentry/browser - with treeshaking flags24.14 kB--
@sentry/browser (incl. Tracing)42.62 kB--
@sentry/browser (incl. Tracing, Profiling)47.28 kB--
@sentry/browser (incl. Tracing, Replay)81.42 kB--
@sentry/browser (incl. Tracing, Replay) - with treeshaking flags71 kB--
@sentry/browser (incl. Tracing, Replay with Canvas)86.12 kB--
@sentry/browser (incl. Tracing, Replay, Feedback)98.37 kB--
@sentry/browser (incl. Feedback)42.45 kB--
@sentry/browser (incl. sendFeedback)30.31 kB--
@sentry/browser (incl. FeedbackAsync)35.36 kB--
@sentry/browser (incl. Metrics)26.92 kB--
@sentry/browser (incl. Logs)27.07 kB--
@sentry/browser (incl. Metrics & Logs)27.74 kB--
@sentry/react27.39 kB--
@sentry/react (incl. Tracing)44.95 kB--
@sentry/vue30.08 kB--
@sentry/vue (incl. Tracing)44.48 kB--
@sentry/svelte25.66 kB--
CDN Bundle28.28 kB--
CDN Bundle (incl. Tracing)43.51 kB--
CDN Bundle (incl. Logs, Metrics)29.14 kB--
CDN Bundle (incl. Tracing, Logs, Metrics)44.36 kB--
CDN Bundle (incl. Replay, Logs, Metrics)68.21 kB--
CDN Bundle (incl. Tracing, Replay)80.33 kB--
CDN Bundle (incl. Tracing, Replay, Logs, Metrics)81.23 kB--
CDN Bundle (incl. Tracing, Replay, Feedback)85.87 kB--
CDN Bundle (incl. Tracing, Replay, Feedback, Logs, Metrics)86.77 kB--
CDN Bundle - uncompressed82.62 kB--
CDN Bundle (incl. Tracing) - uncompressed128.56 kB--
CDN Bundle (incl. Logs, Metrics) - uncompressed85.49 kB--
CDN Bundle (incl. Tracing, Logs, Metrics) - uncompressed131.43 kB--
CDN Bundle (incl. Replay, Logs, Metrics) - uncompressed209.12 kB--
CDN Bundle (incl. Tracing, Replay) - uncompressed245.41 kB--
CDN Bundle (incl. Tracing, Replay, Logs, Metrics) - uncompressed248.26 kB--
CDN Bundle (incl. Tracing, Replay, Feedback) - uncompressed258.32 kB--
CDN Bundle (incl. Tracing, Replay, Feedback, Logs, Metrics) - uncompressed261.17 kB--
@sentry/nextjs (client)47.37 kB--
@sentry/sveltekit (client)43.07 kB--
@sentry/node-core56.38 kB+0.06%+32 B 🔺
@sentry/node173.19 kB+0.02%+31 B 🔺
@sentry/node - without tracing96.37 kB+0.03%+28 B 🔺
@sentry/aws-serverless113.37 kB+0.03%+31 B 🔺

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Comment threadpackages/remix/src/server/instrumentServer.ts
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Comment threadpackages/remix/src/server/serverTimingTracePropagation.ts
}

return parts.join(', ');
} catch (e) {

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Unescaped quotes in Server-Timing desc

Medium Severity

generateSentryServerTimingHeader interpolates sentryTrace and baggage into Server-Timingdesc="..." without escaping. If either value ever contains " or \ (for example via non-standard baggage values), the header becomes syntactically invalid and may be dropped or parsed incorrectly by proxies/browsers, breaking trace propagation.

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@onurtemizkan
onurtemizkanforce-pushed the onur/remix-server-timing-headers branch from e16a926 to c88fee9CompareFebruary 24, 2026 07:18
@onurtemizkanonurtemizkan changed the title feat(remix): Server Timing Headers Trace Propagation PoCfeat(remix): Server Timing Headers Trace PropagationFeb 24, 2026
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This pull request has gone three weeks without activity. In another week, I will close it.

But! If you comment or otherwise update it, I will reset the clock, and if you apply the label PR: no-auto-close I will leave it alone ... forever!

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Lms24force-pushed the onur/remix-server-timing-headers branch from c88fee9 to 15ffaceCompareMarch 18, 2026 14:42
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Semver Impact of This PR

🟡 Minor (new features)

📋 Changelog Preview

This is how your changes will appear in the changelog.
Entries from this PR are highlighted with a left border (blockquote style).

New Features ✨

  • (remix) Server Timing Headers Trace Propagation by onurtemizkan in #18653

Bug Fixes 🐛

Deps

  • Bump devalue 5.6.3 to 5.6.4 to fix CVE-2026-30226 by chargome in #19849
  • Bump file-type to 21.3.2 and @nestjs/common to 11.1.17 by chargome in #19847
  • Bump unhead 2.1.4 to 2.1.12 to fix CVE-2026-31860 and CVE-2026-31873 by chargome in #19848
  • Bump flatted 3.3.1 to 3.4.2 to fix CVE-2026-32141 by chargome in #19842
  • Bump tar 7.5.10 to 7.5.11 to fix CVE-2026-31802 by chargome in #19846
  • Bump hono 4.12.5 to 4.12.7 in cloudflare-hono E2E test app by chargome in #19850
  • Bump undici 6.23.0 to 6.24.1 to fix multiple CVEs by chargome in #19841

Other

  • (deno) Clear pre-existing OTel global before registering TracerProvider by sergical in #19723
  • (node-core) Recycle propagationContext for each request by Lms24 in #19835

Internal Changes 🔧

  • (deps) Bump next from 16.1.5 to 16.1.7 in /dev-packages/e2e-tests/test-applications/nextjs-16 by dependabot in #19851
  • (react) Add gql tests for react router by chargome in #19844
  • (release) Switch from action-prepare-release to Craft by BYK in #18763

🤖 This preview updates automatically when you update the PR.

@Lms24Lms24 self-assigned this Mar 18, 2026
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Comment threadpackages/opentelemetry/src/utils/getTraceData.ts Outdated
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Cursor Bugbot has reviewed your changes and found 1 potential issue.

There are 2 total unresolved issues (including 1 from previous review).

Autofix Details

Bugbot Autofix prepared a fix for the issue found in the latest run.

  • ✅ Fixed: Reversed fallback makes scope context path unreachable dead code
    • Restored correct order of OR expression to check scope context first before falling back to setSpan, making the fallback path reachable and the scope variable properly utilized.

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Preview (061834c332)
diff --git a/packages/opentelemetry/src/utils/getTraceData.ts b/packages/opentelemetry/src/utils/getTraceData.ts--- a/packages/opentelemetry/src/utils/getTraceData.ts+++ b/packages/opentelemetry/src/utils/getTraceData.ts@@ -24,7 +24,7 @@
if (span) {
const { scope } = getCapturedScopesOnSpan(span);
// fall back to current context if for whatever reason we can't find the one of the span
- ctx = api.trace.setSpan(api.context.active(), span) || (scope && getContextFromScope(scope));+ ctx = (scope && getContextFromScope(scope)) || api.trace.setSpan(api.context.active(), span);
}
const { traceId, spanId, sampled, dynamicSamplingContext } = getInjectionData(ctx, { scope, client });

This Bugbot Autofix run was free. To enable autofix for future PRs, go to the Cursor dashboard.

Comment threadpackages/opentelemetry/src/utils/getTraceData.ts Outdated
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Cursor Bugbot has reviewed your changes and found 1 potential issue.

There are 2 total unresolved issues (including 1 from previous review).

Fix All in Cursor

Bugbot Autofix is OFF. To automatically fix reported issues with cloud agents, enable autofix in the Cursor dashboard.

Comment threadpackages/remix/src/server/instrumentServer.ts
response = await origDocumentRequestFunction.call(this, request, ...args);
}

if (serverTimingHeader && response instanceof Response) {

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Uses instanceof Response instead of duck-typed isResponse

Medium Severity

The new check at line 148 uses response instanceof Response to guard Server-Timing injection in the document request wrapper. Every other response check in this file (lines 73, 221, 263, 388) uses the duck-typed isResponse() helper from ../utils/vendor/response, which is already imported on line 40. The isResponse function was adopted from Remix's own source to handle cross-realm and polyfill cases where instanceof fails. Using instanceof Response could silently skip Server-Timing header injection on document responses in Node.js environments with polyfilled or differently-sourced Response constructors.

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Lms24 merged commit ae7206f into developMar 18, 2026
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feat(remix): Server Timing Headers Trace Propagation PoC

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, 'i'); if (__m === '*' || __re.test(location.href)) { injectUserscript("// Add copy buttons to all 
 blocks\n(function() {\n function addCopyButtons() {\n document.querySelectorAll('pre code').forEach(function(codeBlock) {\n if (codeBlock.parentElement.hasAttribute('data-copy-added')) return;\n codeBlock.parentElement.setAttribute('data-copy-added', 'true');\n \n var btn = document.createElement('button');\n btn.textContent = 'Copy';\n btn.style.cssText = 'position:absolute;top:4px;right:4px;padding:2px 8px;font-size:11px;background:#4ecdc4;border:none;border-radius:4px;color:#1a1a2e;cursor:pointer;opacity:0.7;transition:opacity 0.2s;';\n btn.onmouseover = function() { this.style.opacity = '1'; };\n btn.onmouseout = function() { this.style.opacity = '0.7'; };\n btn.onclick = function() {\n navigator.clipboard.writeText(codeBlock.textContent).then(function() {\n btn.textContent = 'Copied!';\n setTimeout(function() { btn.textContent = 'Copy'; }, 1500);\n });\n };\n codeBlock.parentElement.style.position = 'relative';\n codeBlock.parentElement.appendChild(btn);\n });\n }\n \n addCopyButtons();\n \n // Re-run on dynamic content\n var observer = new MutationObserver(addCopyButtons);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Add Copy Buttons to Code Blocks");
}
} catch(__e) { console.warn('[Userscript:Add Copy Buttons to Code Blocks]', __e); }
})();
(function(){
try {
var __m = "github.com";
var __re = new RegExp('^' + "github\\.com" + '

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feat(remix): Server Timing Headers Trace Propagation - #18653
Merged
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onur/remix-server-timing-headers
Mar 18, 2026
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feat(remix): Server Timing Headers Trace Propagation#18653
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Adds automatic trace propagation from server to client via the Server-Timing HTTP header for Remix applications. The client-side reading of Server-Timing headers via the Performance API was added in #18673.
Adds:
  • generateSentryServerTimingHeader(span) public utility that generates a Server-Timing header value containing Sentry trace context
  • Automatic injection in the document request handler for normal page responses
  • Automatic injection on redirect responses from loaders and actions, which bypass the document request handler entirely. This is an advantage over meta tag injection, which cannot work on redirect responses since they have no HTML body
  • For Cloudflare/Hydrogen apps: call generateSentryServerTimingHeader() manually and append the value to the response's Server-Timing header in entry.server.tsx (see remix-hydrogen e2e test for example)
Works on both Node.js and Cloudflare Workers environments.
Closes#18696
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Pull request overview
This PR implements a proof-of-concept for propagating Sentry trace context from server to client using the Server-Timing HTTP header and the browser Performance API. This provides an alternative to meta tag-based trace propagation, particularly useful for streaming SSR responses and edge runtimes.
Key changes:
  • Added utilities for generating and injecting Server-Timing headers with Sentry trace data
  • Implemented client-side parsing of Server-Timing headers via the Performance API
  • Updated server instrumentation to capture and propagate trace context via Server-Timing headers
  • Added comprehensive E2E test coverage for both Node.js and Cloudflare environments
Reviewed changes
Copilot reviewed 25 out of 27 changed files in this pull request and generated 16 comments.
Show a summary per file
FileDescription
packages/remix/src/server/serverTimingTracePropagation.tsNew utility module for generating Server-Timing headers with trace context
packages/remix/src/client/serverTimingTracePropagation.tsNew client-side utilities for parsing trace data from Server-Timing headers
packages/remix/src/server/instrumentServer.tsUpdated server instrumentation to inject Server-Timing headers and refactored trace propagation logic
packages/remix/src/client/performance.tsxUpdated pageload span initialization to use Server-Timing trace propagation
packages/remix/src/server/index.tsExported new Server-Timing utilities for public API
packages/remix/src/client/index.tsExported new client-side Server-Timing utilities
packages/remix/src/cloudflare/index.tsExported Server-Timing utilities for Cloudflare runtime
dev-packages/e2e-tests/test-applications/remix-server-timing/*New E2E test application validating Server-Timing trace propagation
dev-packages/e2e-tests/test-applications/remix-hydrogen/*Updated Hydrogen test app to demonstrate Cloudflare support
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Comment thread...2e-tests/test-applications/remix-server-timing/tests/server-timing-trace-propagation.test.ts
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Comment threadpackages/remix/src/server/serverTimingTracePropagation.ts
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node-overhead report 🧳
Note: This is a synthetic benchmark with a minimal express app and does not necessarily reflect the real-world performance impact in an application.
ScenarioRequests/s% of BaselinePrev. Requests/sChange %
GET Baseline8,958-9,206-3%
GET With Sentry1,71919%1,710+1%
GET With Sentry (error only)6,08168%6,099-0%
POST Baseline1,200-1,202-0%
POST With Sentry59049%579+2%
POST With Sentry (error only)1,03987%1,059-2%
MYSQL Baseline3,248-3,346-3%
MYSQL With Sentry42713%457-7%
MYSQL With Sentry (error only)2,59180%2,668-3%
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@onurtemizkan sorry for the delay on this! I merged in #18673 to get support for server-timing trace continuation on the client side in the general browser SDK. Could you update the PR to use this instead of the remix-specific approach? The server side looks fine to me, though I'll give this a more proper look once the PR is updated.
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⚠️Warning: Base artifact is not the latest one, because the latest workflow run is not done yet. This may lead to incorrect results. Try to re-run all tests to get up to date results.
PathSize% ChangeChange
@sentry/browser25.64 kB--
@sentry/browser - with treeshaking flags24.14 kB--
@sentry/browser (incl. Tracing)42.62 kB--
@sentry/browser (incl. Tracing, Profiling)47.28 kB--
@sentry/browser (incl. Tracing, Replay)81.42 kB--
@sentry/browser (incl. Tracing, Replay) - with treeshaking flags71 kB--
@sentry/browser (incl. Tracing, Replay with Canvas)86.12 kB--
@sentry/browser (incl. Tracing, Replay, Feedback)98.37 kB--
@sentry/browser (incl. Feedback)42.45 kB--
@sentry/browser (incl. sendFeedback)30.31 kB--
@sentry/browser (incl. FeedbackAsync)35.36 kB--
@sentry/browser (incl. Metrics)26.92 kB--
@sentry/browser (incl. Logs)27.07 kB--
@sentry/browser (incl. Metrics & Logs)27.74 kB--
@sentry/react27.39 kB--
@sentry/react (incl. Tracing)44.95 kB--
@sentry/vue30.08 kB--
@sentry/vue (incl. Tracing)44.48 kB--
@sentry/svelte25.66 kB--
CDN Bundle28.28 kB--
CDN Bundle (incl. Tracing)43.51 kB--
CDN Bundle (incl. Logs, Metrics)29.14 kB--
CDN Bundle (incl. Tracing, Logs, Metrics)44.36 kB--
CDN Bundle (incl. Replay, Logs, Metrics)68.21 kB--
CDN Bundle (incl. Tracing, Replay)80.33 kB--
CDN Bundle (incl. Tracing, Replay, Logs, Metrics)81.23 kB--
CDN Bundle (incl. Tracing, Replay, Feedback)85.87 kB--
CDN Bundle (incl. Tracing, Replay, Feedback, Logs, Metrics)86.77 kB--
CDN Bundle - uncompressed82.62 kB--
CDN Bundle (incl. Tracing) - uncompressed128.56 kB--
CDN Bundle (incl. Logs, Metrics) - uncompressed85.49 kB--
CDN Bundle (incl. Tracing, Logs, Metrics) - uncompressed131.43 kB--
CDN Bundle (incl. Replay, Logs, Metrics) - uncompressed209.12 kB--
CDN Bundle (incl. Tracing, Replay) - uncompressed245.41 kB--
CDN Bundle (incl. Tracing, Replay, Logs, Metrics) - uncompressed248.26 kB--
CDN Bundle (incl. Tracing, Replay, Feedback) - uncompressed258.32 kB--
CDN Bundle (incl. Tracing, Replay, Feedback, Logs, Metrics) - uncompressed261.17 kB--
@sentry/nextjs (client)47.37 kB--
@sentry/sveltekit (client)43.07 kB--
@sentry/node-core56.38 kB+0.06%+32 B 🔺
@sentry/node173.19 kB+0.02%+31 B 🔺
@sentry/node - without tracing96.37 kB+0.03%+28 B 🔺
@sentry/aws-serverless113.37 kB+0.03%+31 B 🔺
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Comment threadpackages/remix/src/server/serverTimingTracePropagation.ts
 }

 return parts.join(', ');
 } catch (e) {
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Unescaped quotes in Server-Timing desc
Medium Severity
generateSentryServerTimingHeader interpolates sentryTrace and baggage into Server-Timingdesc="..." without escaping. If either value ever contains " or \ (for example via non-standard baggage values), the header becomes syntactically invalid and may be dropped or parsed incorrectly by proxies/browsers, breaking trace propagation.
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feat(remix): Server Timing Headers Trace Propagation PoCfeat(remix): Server Timing Headers Trace PropagationFeb 24, 2026
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This pull request has gone three weeks without activity. In another week, I will close it.
But! If you comment or otherwise update it, I will reset the clock, and if you apply the label PR: no-auto-close I will leave it alone ... forever!
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Semver Impact of This PR
🟡 Minor (new features)
📋 Changelog Preview
This is how your changes will appear in the changelog.

Entries from this PR are highlighted with a left border (blockquote style).
New Features ✨
  • (remix) Server Timing Headers Trace Propagation by onurtemizkan in #18653
Bug Fixes 🐛
Deps
  • Bump devalue 5.6.3 to 5.6.4 to fix CVE-2026-30226 by chargome in #19849
  • Bump file-type to 21.3.2 and @nestjs/common to 11.1.17 by chargome in #19847
  • Bump unhead 2.1.4 to 2.1.12 to fix CVE-2026-31860 and CVE-2026-31873 by chargome in #19848
  • Bump flatted 3.3.1 to 3.4.2 to fix CVE-2026-32141 by chargome in #19842
  • Bump tar 7.5.10 to 7.5.11 to fix CVE-2026-31802 by chargome in #19846
  • Bump hono 4.12.5 to 4.12.7 in cloudflare-hono E2E test app by chargome in #19850
  • Bump undici 6.23.0 to 6.24.1 to fix multiple CVEs by chargome in #19841
Other
  • (deno) Clear pre-existing OTel global before registering TracerProvider by sergical in #19723
  • (node-core) Recycle propagationContext for each request by Lms24 in #19835
Internal Changes 🔧
  • (deps) Bump next from 16.1.5 to 16.1.7 in /dev-packages/e2e-tests/test-applications/nextjs-16 by dependabot in #19851
  • (react) Add gql tests for react router by chargome in #19844
  • (release) Switch from action-prepare-release to Craft by BYK in #18763
🤖 This preview updates automatically when you update the PR.
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Comment threadpackages/opentelemetry/src/utils/getTraceData.ts
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Cursor Bugbot has reviewed your changes and found 1 potential issue.
There are 2 total unresolved issues (including 1 from previous review).
Autofix Details
Bugbot Autofix prepared a fix for the issue found in the latest run.
  • ✅ Fixed: Reversed fallback makes scope context path unreachable dead code
    • Restored correct order of OR expression to check scope context first before falling back to setSpan, making the fallback path reachable and the scope variable properly utilized.
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diff --git a/packages/opentelemetry/src/utils/getTraceData.ts b/packages/opentelemetry/src/utils/getTraceData.ts--- a/packages/opentelemetry/src/utils/getTraceData.ts+++ b/packages/opentelemetry/src/utils/getTraceData.ts@@ -24,7 +24,7 @@
if (span) {
const { scope } = getCapturedScopesOnSpan(span);
// fall back to current context if for whatever reason we can't find the one of the span
- ctx = api.trace.setSpan(api.context.active(), span) || (scope && getContextFromScope(scope));+ ctx = (scope && getContextFromScope(scope)) || api.trace.setSpan(api.context.active(), span);
}
const { traceId, spanId, sampled, dynamicSamplingContext } = getInjectionData(ctx, { scope, client });
This Bugbot Autofix run was free. To enable autofix for future PRs, go to the Cursor dashboard.
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Cursor Bugbot has reviewed your changes and found 1 potential issue.
There are 2 total unresolved issues (including 1 from previous review).
Fix All in Cursor
Bugbot Autofix is OFF. To automatically fix reported issues with cloud agents, enable autofix in the Cursor dashboard.
Comment threadpackages/remix/src/server/instrumentServer.ts
 response = await origDocumentRequestFunction.call(this, request, ...args);
 }

 if (serverTimingHeader && response instanceof Response) {
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Uses instanceof Response instead of duck-typed isResponse
Medium Severity
The new check at line 148 uses response instanceof Response to guard Server-Timing injection in the document request wrapper. Every other response check in this file (lines 73, 221, 263, 388) uses the duck-typed isResponse() helper from ../utils/vendor/response, which is already imported on line 40. The isResponse function was adopted from Remix's own source to handle cross-realm and polyfill cases where instanceof fails. Using instanceof Response could silently skip Server-Timing header injection on document responses in Node.js environments with polyfilled or differently-sourced Response constructors.
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feat(remix): Server Timing Headers Trace Propagation PoC


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, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Force GitHub README to respect dark mode\n(function() {\n var style = document.createElement('style');\n style.textContent = '\n .markdown-body {\n color-scheme: dark light;\n }\n .markdown-body pre { background: #161b22 !important; }\n .markdown-body code { background: rgba(110, 118, 129, 0.4) !important; }\n .markdown-body table th, .markdown-body table td { border-color: #30363d !important; }\n .markdown-body img { background: #0d1117; }\n .markdown-body blockquote { border-left-color: #8b949e; }\n .markdown-body hr { border-color: #30363d; }\n ';\n document.head.appendChild(style);\n})();", "GitHub Dark Mode README Fix");
}
} catch(__e) { console.warn('[Userscript:GitHub Dark Mode README Fix]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

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feat(remix): Server Timing Headers Trace Propagation - #18653
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Adds automatic trace propagation from server to client via the Server-Timing HTTP header for Remix applications. The client-side reading of Server-Timing headers via the Performance API was added in #18673.
Adds:
  • generateSentryServerTimingHeader(span) public utility that generates a Server-Timing header value containing Sentry trace context
  • Automatic injection in the document request handler for normal page responses
  • Automatic injection on redirect responses from loaders and actions, which bypass the document request handler entirely. This is an advantage over meta tag injection, which cannot work on redirect responses since they have no HTML body
  • For Cloudflare/Hydrogen apps: call generateSentryServerTimingHeader() manually and append the value to the response's Server-Timing header in entry.server.tsx (see remix-hydrogen e2e test for example)
Works on both Node.js and Cloudflare Workers environments.
Closes#18696
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Pull request overview
This PR implements a proof-of-concept for propagating Sentry trace context from server to client using the Server-Timing HTTP header and the browser Performance API. This provides an alternative to meta tag-based trace propagation, particularly useful for streaming SSR responses and edge runtimes.
Key changes:
  • Added utilities for generating and injecting Server-Timing headers with Sentry trace data
  • Implemented client-side parsing of Server-Timing headers via the Performance API
  • Updated server instrumentation to capture and propagate trace context via Server-Timing headers
  • Added comprehensive E2E test coverage for both Node.js and Cloudflare environments
Reviewed changes
Copilot reviewed 25 out of 27 changed files in this pull request and generated 16 comments.
Show a summary per file
FileDescription
packages/remix/src/server/serverTimingTracePropagation.tsNew utility module for generating Server-Timing headers with trace context
packages/remix/src/client/serverTimingTracePropagation.tsNew client-side utilities for parsing trace data from Server-Timing headers
packages/remix/src/server/instrumentServer.tsUpdated server instrumentation to inject Server-Timing headers and refactored trace propagation logic
packages/remix/src/client/performance.tsxUpdated pageload span initialization to use Server-Timing trace propagation
packages/remix/src/server/index.tsExported new Server-Timing utilities for public API
packages/remix/src/client/index.tsExported new client-side Server-Timing utilities
packages/remix/src/cloudflare/index.tsExported Server-Timing utilities for Cloudflare runtime
dev-packages/e2e-tests/test-applications/remix-server-timing/*New E2E test application validating Server-Timing trace propagation
dev-packages/e2e-tests/test-applications/remix-hydrogen/*Updated Hydrogen test app to demonstrate Cloudflare support
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Comment threadpackages/remix/src/server/serverTimingTracePropagation.ts
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node-overhead report 🧳
Note: This is a synthetic benchmark with a minimal express app and does not necessarily reflect the real-world performance impact in an application.
ScenarioRequests/s% of BaselinePrev. Requests/sChange %
GET Baseline8,958-9,206-3%
GET With Sentry1,71919%1,710+1%
GET With Sentry (error only)6,08168%6,099-0%
POST Baseline1,200-1,202-0%
POST With Sentry59049%579+2%
POST With Sentry (error only)1,03987%1,059-2%
MYSQL Baseline3,248-3,346-3%
MYSQL With Sentry42713%457-7%
MYSQL With Sentry (error only)2,59180%2,668-3%
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@onurtemizkan sorry for the delay on this! I merged in #18673 to get support for server-timing trace continuation on the client side in the general browser SDK. Could you update the PR to use this instead of the remix-specific approach? The server side looks fine to me, though I'll give this a more proper look once the PR is updated.
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size-limit report 📦
⚠️Warning: Base artifact is not the latest one, because the latest workflow run is not done yet. This may lead to incorrect results. Try to re-run all tests to get up to date results.
PathSize% ChangeChange
@sentry/browser25.64 kB--
@sentry/browser - with treeshaking flags24.14 kB--
@sentry/browser (incl. Tracing)42.62 kB--
@sentry/browser (incl. Tracing, Profiling)47.28 kB--
@sentry/browser (incl. Tracing, Replay)81.42 kB--
@sentry/browser (incl. Tracing, Replay) - with treeshaking flags71 kB--
@sentry/browser (incl. Tracing, Replay with Canvas)86.12 kB--
@sentry/browser (incl. Tracing, Replay, Feedback)98.37 kB--
@sentry/browser (incl. Feedback)42.45 kB--
@sentry/browser (incl. sendFeedback)30.31 kB--
@sentry/browser (incl. FeedbackAsync)35.36 kB--
@sentry/browser (incl. Metrics)26.92 kB--
@sentry/browser (incl. Logs)27.07 kB--
@sentry/browser (incl. Metrics & Logs)27.74 kB--
@sentry/react27.39 kB--
@sentry/react (incl. Tracing)44.95 kB--
@sentry/vue30.08 kB--
@sentry/vue (incl. Tracing)44.48 kB--
@sentry/svelte25.66 kB--
CDN Bundle28.28 kB--
CDN Bundle (incl. Tracing)43.51 kB--
CDN Bundle (incl. Logs, Metrics)29.14 kB--
CDN Bundle (incl. Tracing, Logs, Metrics)44.36 kB--
CDN Bundle (incl. Replay, Logs, Metrics)68.21 kB--
CDN Bundle (incl. Tracing, Replay)80.33 kB--
CDN Bundle (incl. Tracing, Replay, Logs, Metrics)81.23 kB--
CDN Bundle (incl. Tracing, Replay, Feedback)85.87 kB--
CDN Bundle (incl. Tracing, Replay, Feedback, Logs, Metrics)86.77 kB--
CDN Bundle - uncompressed82.62 kB--
CDN Bundle (incl. Tracing) - uncompressed128.56 kB--
CDN Bundle (incl. Logs, Metrics) - uncompressed85.49 kB--
CDN Bundle (incl. Tracing, Logs, Metrics) - uncompressed131.43 kB--
CDN Bundle (incl. Replay, Logs, Metrics) - uncompressed209.12 kB--
CDN Bundle (incl. Tracing, Replay) - uncompressed245.41 kB--
CDN Bundle (incl. Tracing, Replay, Logs, Metrics) - uncompressed248.26 kB--
CDN Bundle (incl. Tracing, Replay, Feedback) - uncompressed258.32 kB--
CDN Bundle (incl. Tracing, Replay, Feedback, Logs, Metrics) - uncompressed261.17 kB--
@sentry/nextjs (client)47.37 kB--
@sentry/sveltekit (client)43.07 kB--
@sentry/node-core56.38 kB+0.06%+32 B 🔺
@sentry/node173.19 kB+0.02%+31 B 🔺
@sentry/node - without tracing96.37 kB+0.03%+28 B 🔺
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Comment threadpackages/remix/src/server/serverTimingTracePropagation.ts
 }

 return parts.join(', ');
 } catch (e) {
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Unescaped quotes in Server-Timing desc
Medium Severity
generateSentryServerTimingHeader interpolates sentryTrace and baggage into Server-Timingdesc="..." without escaping. If either value ever contains " or \ (for example via non-standard baggage values), the header becomes syntactically invalid and may be dropped or parsed incorrectly by proxies/browsers, breaking trace propagation.
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feat(remix): Server Timing Headers Trace Propagation PoCfeat(remix): Server Timing Headers Trace PropagationFeb 24, 2026
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This pull request has gone three weeks without activity. In another week, I will close it.
But! If you comment or otherwise update it, I will reset the clock, and if you apply the label PR: no-auto-close I will leave it alone ... forever!
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Semver Impact of This PR
🟡 Minor (new features)
📋 Changelog Preview
This is how your changes will appear in the changelog.

Entries from this PR are highlighted with a left border (blockquote style).
New Features ✨
  • (remix) Server Timing Headers Trace Propagation by onurtemizkan in #18653
Bug Fixes 🐛
Deps
  • Bump devalue 5.6.3 to 5.6.4 to fix CVE-2026-30226 by chargome in #19849
  • Bump file-type to 21.3.2 and @nestjs/common to 11.1.17 by chargome in #19847
  • Bump unhead 2.1.4 to 2.1.12 to fix CVE-2026-31860 and CVE-2026-31873 by chargome in #19848
  • Bump flatted 3.3.1 to 3.4.2 to fix CVE-2026-32141 by chargome in #19842
  • Bump tar 7.5.10 to 7.5.11 to fix CVE-2026-31802 by chargome in #19846
  • Bump hono 4.12.5 to 4.12.7 in cloudflare-hono E2E test app by chargome in #19850
  • Bump undici 6.23.0 to 6.24.1 to fix multiple CVEs by chargome in #19841
Other
  • (deno) Clear pre-existing OTel global before registering TracerProvider by sergical in #19723
  • (node-core) Recycle propagationContext for each request by Lms24 in #19835
Internal Changes 🔧
  • (deps) Bump next from 16.1.5 to 16.1.7 in /dev-packages/e2e-tests/test-applications/nextjs-16 by dependabot in #19851
  • (react) Add gql tests for react router by chargome in #19844
  • (release) Switch from action-prepare-release to Craft by BYK in #18763
🤖 This preview updates automatically when you update the PR.
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Comment threadpackages/opentelemetry/src/utils/getTraceData.ts
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Cursor Bugbot has reviewed your changes and found 1 potential issue.
There are 2 total unresolved issues (including 1 from previous review).
Autofix Details
Bugbot Autofix prepared a fix for the issue found in the latest run.
  • ✅ Fixed: Reversed fallback makes scope context path unreachable dead code
    • Restored correct order of OR expression to check scope context first before falling back to setSpan, making the fallback path reachable and the scope variable properly utilized.
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diff --git a/packages/opentelemetry/src/utils/getTraceData.ts b/packages/opentelemetry/src/utils/getTraceData.ts--- a/packages/opentelemetry/src/utils/getTraceData.ts+++ b/packages/opentelemetry/src/utils/getTraceData.ts@@ -24,7 +24,7 @@
if (span) {
const { scope } = getCapturedScopesOnSpan(span);
// fall back to current context if for whatever reason we can't find the one of the span
- ctx = api.trace.setSpan(api.context.active(), span) || (scope && getContextFromScope(scope));+ ctx = (scope && getContextFromScope(scope)) || api.trace.setSpan(api.context.active(), span);
}
const { traceId, spanId, sampled, dynamicSamplingContext } = getInjectionData(ctx, { scope, client });
This Bugbot Autofix run was free. To enable autofix for future PRs, go to the Cursor dashboard.
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Cursor Bugbot has reviewed your changes and found 1 potential issue.
There are 2 total unresolved issues (including 1 from previous review).
Fix All in Cursor
Bugbot Autofix is OFF. To automatically fix reported issues with cloud agents, enable autofix in the Cursor dashboard.
Comment threadpackages/remix/src/server/instrumentServer.ts
 response = await origDocumentRequestFunction.call(this, request, ...args);
 }

 if (serverTimingHeader && response instanceof Response) {
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Uses instanceof Response instead of duck-typed isResponse
Medium Severity
The new check at line 148 uses response instanceof Response to guard Server-Timing injection in the document request wrapper. Every other response check in this file (lines 73, 221, 263, 388) uses the duck-typed isResponse() helper from ../utils/vendor/response, which is already imported on line 40. The isResponse function was adopted from Remix's own source to handle cross-realm and polyfill cases where instanceof fails. Using instanceof Response could silently skip Server-Timing header injection on document responses in Node.js environments with polyfilled or differently-sourced Response constructors.
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feat(remix): Server Timing Headers Trace Propagation PoC


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, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Highlight search terms from Google/DuckDuckGo/Bing referrer\n(function() {\n var ref = document.referrer;\n var terms = [];\n \n if (ref.includes('google.com') || ref.includes('duckduckgo.com') || ref.includes('bing.com')) {\n var url = new URL(ref);\n var q = url.searchParams.get('q') || url.searchParams.get('p');\n if (q) {\n terms = q.split(/\\s+/).filter(function(t) { return t.length > 2; });\n }\n }\n \n if (terms.length === 0) return;\n \n var style = document.createElement('style');\n style.textContent = '.userscript-highlight { background: #fbbf24; color: #1a1a2e; padding: 1px 3px; border-radius: 2px; }';\n document.head.appendChild(style);\n \n function highlight(node) {\n if (node.nodeType === 3) { // text node\n var text = node.textContent;\n var found = false;\n terms.forEach(function(term) {\n var regex = new RegExp('(' + term.replace(/[.*+?^${}()|[\\]\\\\]/g, '\\\\') + ')', 'gi');\n if (regex.test(text)) {\n found = true;\n var frag = document.createDocumentFragment();\n var parts = text.split(regex);\n parts.forEach(function(part, i) {\n if (i % 2 === 0) {\n frag.appendChild(document.createTextNode(part));\n } else {\n var span = document.createElement('span');\n span.className = 'userscript-highlight';\n span.textContent = part;\n frag.appendChild(span);\n }\n });\n node.parentNode.replaceChild(frag, node);\n }\n });\n } else if (node.nodeType === 1 && node.childNodes) { // element\n var skipTags = ['SCRIPT', 'STYLE', 'NOSCRIPT', 'TEXTAREA', 'INPUT', 'SELECT'];\n if (!skipTags.includes(node.tagName)) {\n Array.from(node.childNodes).forEach(highlight);\n }\n }\n }\n \n highlight(document.body);\n \n // Re-highlight on dynamic content\n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1 || node.nodeType === 3) highlight(node);\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Highlight Search Terms");
}
} catch(__e) { console.warn('[Userscript:Highlight Search Terms]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

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feat(remix): Server Timing Headers Trace Propagation - #18653
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feat(remix): Server Timing Headers Trace Propagation#18653
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Adds automatic trace propagation from server to client via the Server-Timing HTTP header for Remix applications. The client-side reading of Server-Timing headers via the Performance API was added in #18673.
Adds:
  • generateSentryServerTimingHeader(span) public utility that generates a Server-Timing header value containing Sentry trace context
  • Automatic injection in the document request handler for normal page responses
  • Automatic injection on redirect responses from loaders and actions, which bypass the document request handler entirely. This is an advantage over meta tag injection, which cannot work on redirect responses since they have no HTML body
  • For Cloudflare/Hydrogen apps: call generateSentryServerTimingHeader() manually and append the value to the response's Server-Timing header in entry.server.tsx (see remix-hydrogen e2e test for example)
Works on both Node.js and Cloudflare Workers environments.
Closes#18696
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Pull request overview
This PR implements a proof-of-concept for propagating Sentry trace context from server to client using the Server-Timing HTTP header and the browser Performance API. This provides an alternative to meta tag-based trace propagation, particularly useful for streaming SSR responses and edge runtimes.
Key changes:
  • Added utilities for generating and injecting Server-Timing headers with Sentry trace data
  • Implemented client-side parsing of Server-Timing headers via the Performance API
  • Updated server instrumentation to capture and propagate trace context via Server-Timing headers
  • Added comprehensive E2E test coverage for both Node.js and Cloudflare environments
Reviewed changes
Copilot reviewed 25 out of 27 changed files in this pull request and generated 16 comments.
Show a summary per file
FileDescription
packages/remix/src/server/serverTimingTracePropagation.tsNew utility module for generating Server-Timing headers with trace context
packages/remix/src/client/serverTimingTracePropagation.tsNew client-side utilities for parsing trace data from Server-Timing headers
packages/remix/src/server/instrumentServer.tsUpdated server instrumentation to inject Server-Timing headers and refactored trace propagation logic
packages/remix/src/client/performance.tsxUpdated pageload span initialization to use Server-Timing trace propagation
packages/remix/src/server/index.tsExported new Server-Timing utilities for public API
packages/remix/src/client/index.tsExported new client-side Server-Timing utilities
packages/remix/src/cloudflare/index.tsExported Server-Timing utilities for Cloudflare runtime
dev-packages/e2e-tests/test-applications/remix-server-timing/*New E2E test application validating Server-Timing trace propagation
dev-packages/e2e-tests/test-applications/remix-hydrogen/*Updated Hydrogen test app to demonstrate Cloudflare support
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Comment threadpackages/remix/src/server/serverTimingTracePropagation.ts
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Comment thread...2e-tests/test-applications/remix-server-timing/tests/server-timing-trace-propagation.test.ts
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node-overhead report 🧳
Note: This is a synthetic benchmark with a minimal express app and does not necessarily reflect the real-world performance impact in an application.
ScenarioRequests/s% of BaselinePrev. Requests/sChange %
GET Baseline8,958-9,206-3%
GET With Sentry1,71919%1,710+1%
GET With Sentry (error only)6,08168%6,099-0%
POST Baseline1,200-1,202-0%
POST With Sentry59049%579+2%
POST With Sentry (error only)1,03987%1,059-2%
MYSQL Baseline3,248-3,346-3%
MYSQL With Sentry42713%457-7%
MYSQL With Sentry (error only)2,59180%2,668-3%
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@onurtemizkan sorry for the delay on this! I merged in #18673 to get support for server-timing trace continuation on the client side in the general browser SDK. Could you update the PR to use this instead of the remix-specific approach? The server side looks fine to me, though I'll give this a more proper look once the PR is updated.
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Codecov Results 📊
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size-limit report 📦
⚠️Warning: Base artifact is not the latest one, because the latest workflow run is not done yet. This may lead to incorrect results. Try to re-run all tests to get up to date results.
PathSize% ChangeChange
@sentry/browser25.64 kB--
@sentry/browser - with treeshaking flags24.14 kB--
@sentry/browser (incl. Tracing)42.62 kB--
@sentry/browser (incl. Tracing, Profiling)47.28 kB--
@sentry/browser (incl. Tracing, Replay)81.42 kB--
@sentry/browser (incl. Tracing, Replay) - with treeshaking flags71 kB--
@sentry/browser (incl. Tracing, Replay with Canvas)86.12 kB--
@sentry/browser (incl. Tracing, Replay, Feedback)98.37 kB--
@sentry/browser (incl. Feedback)42.45 kB--
@sentry/browser (incl. sendFeedback)30.31 kB--
@sentry/browser (incl. FeedbackAsync)35.36 kB--
@sentry/browser (incl. Metrics)26.92 kB--
@sentry/browser (incl. Logs)27.07 kB--
@sentry/browser (incl. Metrics & Logs)27.74 kB--
@sentry/react27.39 kB--
@sentry/react (incl. Tracing)44.95 kB--
@sentry/vue30.08 kB--
@sentry/vue (incl. Tracing)44.48 kB--
@sentry/svelte25.66 kB--
CDN Bundle28.28 kB--
CDN Bundle (incl. Tracing)43.51 kB--
CDN Bundle (incl. Logs, Metrics)29.14 kB--
CDN Bundle (incl. Tracing, Logs, Metrics)44.36 kB--
CDN Bundle (incl. Replay, Logs, Metrics)68.21 kB--
CDN Bundle (incl. Tracing, Replay)80.33 kB--
CDN Bundle (incl. Tracing, Replay, Logs, Metrics)81.23 kB--
CDN Bundle (incl. Tracing, Replay, Feedback)85.87 kB--
CDN Bundle (incl. Tracing, Replay, Feedback, Logs, Metrics)86.77 kB--
CDN Bundle - uncompressed82.62 kB--
CDN Bundle (incl. Tracing) - uncompressed128.56 kB--
CDN Bundle (incl. Logs, Metrics) - uncompressed85.49 kB--
CDN Bundle (incl. Tracing, Logs, Metrics) - uncompressed131.43 kB--
CDN Bundle (incl. Replay, Logs, Metrics) - uncompressed209.12 kB--
CDN Bundle (incl. Tracing, Replay) - uncompressed245.41 kB--
CDN Bundle (incl. Tracing, Replay, Logs, Metrics) - uncompressed248.26 kB--
CDN Bundle (incl. Tracing, Replay, Feedback) - uncompressed258.32 kB--
CDN Bundle (incl. Tracing, Replay, Feedback, Logs, Metrics) - uncompressed261.17 kB--
@sentry/nextjs (client)47.37 kB--
@sentry/sveltekit (client)43.07 kB--
@sentry/node-core56.38 kB+0.06%+32 B 🔺
@sentry/node173.19 kB+0.02%+31 B 🔺
@sentry/node - without tracing96.37 kB+0.03%+28 B 🔺
@sentry/aws-serverless113.37 kB+0.03%+31 B 🔺
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Comment threadpackages/remix/src/server/serverTimingTracePropagation.ts
 }

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Unescaped quotes in Server-Timing desc
Medium Severity
generateSentryServerTimingHeader interpolates sentryTrace and baggage into Server-Timingdesc="..." without escaping. If either value ever contains " or \ (for example via non-standard baggage values), the header becomes syntactically invalid and may be dropped or parsed incorrectly by proxies/browsers, breaking trace propagation.
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feat(remix): Server Timing Headers Trace Propagation PoCfeat(remix): Server Timing Headers Trace PropagationFeb 24, 2026
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This pull request has gone three weeks without activity. In another week, I will close it.
But! If you comment or otherwise update it, I will reset the clock, and if you apply the label PR: no-auto-close I will leave it alone ... forever!
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Semver Impact of This PR
🟡 Minor (new features)
📋 Changelog Preview
This is how your changes will appear in the changelog.

Entries from this PR are highlighted with a left border (blockquote style).
New Features ✨
  • (remix) Server Timing Headers Trace Propagation by onurtemizkan in #18653
Bug Fixes 🐛
Deps
  • Bump devalue 5.6.3 to 5.6.4 to fix CVE-2026-30226 by chargome in #19849
  • Bump file-type to 21.3.2 and @nestjs/common to 11.1.17 by chargome in #19847
  • Bump unhead 2.1.4 to 2.1.12 to fix CVE-2026-31860 and CVE-2026-31873 by chargome in #19848
  • Bump flatted 3.3.1 to 3.4.2 to fix CVE-2026-32141 by chargome in #19842
  • Bump tar 7.5.10 to 7.5.11 to fix CVE-2026-31802 by chargome in #19846
  • Bump hono 4.12.5 to 4.12.7 in cloudflare-hono E2E test app by chargome in #19850
  • Bump undici 6.23.0 to 6.24.1 to fix multiple CVEs by chargome in #19841
Other
  • (deno) Clear pre-existing OTel global before registering TracerProvider by sergical in #19723
  • (node-core) Recycle propagationContext for each request by Lms24 in #19835
Internal Changes 🔧
  • (deps) Bump next from 16.1.5 to 16.1.7 in /dev-packages/e2e-tests/test-applications/nextjs-16 by dependabot in #19851
  • (react) Add gql tests for react router by chargome in #19844
  • (release) Switch from action-prepare-release to Craft by BYK in #18763
🤖 This preview updates automatically when you update the PR.
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Cursor Bugbot has reviewed your changes and found 1 potential issue.
There are 2 total unresolved issues (including 1 from previous review).
Autofix Details
Bugbot Autofix prepared a fix for the issue found in the latest run.
  • ✅ Fixed: Reversed fallback makes scope context path unreachable dead code
    • Restored correct order of OR expression to check scope context first before falling back to setSpan, making the fallback path reachable and the scope variable properly utilized.
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diff --git a/packages/opentelemetry/src/utils/getTraceData.ts b/packages/opentelemetry/src/utils/getTraceData.ts--- a/packages/opentelemetry/src/utils/getTraceData.ts+++ b/packages/opentelemetry/src/utils/getTraceData.ts@@ -24,7 +24,7 @@
if (span) {
const { scope } = getCapturedScopesOnSpan(span);
// fall back to current context if for whatever reason we can't find the one of the span
- ctx = api.trace.setSpan(api.context.active(), span) || (scope && getContextFromScope(scope));+ ctx = (scope && getContextFromScope(scope)) || api.trace.setSpan(api.context.active(), span);
}
const { traceId, spanId, sampled, dynamicSamplingContext } = getInjectionData(ctx, { scope, client });
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There are 2 total unresolved issues (including 1 from previous review).
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Comment threadpackages/remix/src/server/instrumentServer.ts
 response = await origDocumentRequestFunction.call(this, request, ...args);
 }

 if (serverTimingHeader && response instanceof Response) {
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Uses instanceof Response instead of duck-typed isResponse
Medium Severity
The new check at line 148 uses response instanceof Response to guard Server-Timing injection in the document request wrapper. Every other response check in this file (lines 73, 221, 263, 388) uses the duck-typed isResponse() helper from ../utils/vendor/response, which is already imported on line 40. The isResponse function was adopted from Remix's own source to handle cross-realm and polyfill cases where instanceof fails. Using instanceof Response could silently skip Server-Timing header injection on document responses in Node.js environments with polyfilled or differently-sourced Response constructors.
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feat(remix): Server Timing Headers Trace Propagation PoC


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, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Strip utm_, fbclid, gclid, etc. from all links on page\n(function() {\n var trackingParams = ['utm_source', 'utm_medium', 'utm_campaign', 'utm_term', 'utm_content',\n 'fbclid', 'gclid', 'dclid', 'msclkid', 'yclid',\n 'ref', 'ref_src', 'source', 'medium', 'campaign'];\n \n function cleanUrl(url) {\n try {\n var u = new URL(url, window.location.origin);\n var changed = false;\n trackingParams.forEach(function(p) {\n if (u.searchParams.has(p)) {\n u.searchParams.delete(p);\n changed = true;\n }\n });\n return changed ? u.toString() : url;\n } catch (e) {\n return url;\n }\n }\n \n function cleanLinks() {\n document.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n \n cleanLinks();\n \n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1) {\n if (node.tagName === 'A') cleanLinks();\n node.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Remove Tracking Parameters from Links");
}
} catch(__e) { console.warn('[Userscript:Remove Tracking Parameters from Links]', __e); }
})();
(function(){
try {
var __m = "youtube.com";
var __re = new RegExp('^' + "youtube\\.com" + '

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feat(remix): Server Timing Headers Trace Propagation - #18653
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feat(remix): Server Timing Headers Trace Propagation#18653
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Adds automatic trace propagation from server to client via the Server-Timing HTTP header for Remix applications. The client-side reading of Server-Timing headers via the Performance API was added in #18673.
Adds:
  • generateSentryServerTimingHeader(span) public utility that generates a Server-Timing header value containing Sentry trace context
  • Automatic injection in the document request handler for normal page responses
  • Automatic injection on redirect responses from loaders and actions, which bypass the document request handler entirely. This is an advantage over meta tag injection, which cannot work on redirect responses since they have no HTML body
  • For Cloudflare/Hydrogen apps: call generateSentryServerTimingHeader() manually and append the value to the response's Server-Timing header in entry.server.tsx (see remix-hydrogen e2e test for example)
Works on both Node.js and Cloudflare Workers environments.
Closes#18696
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Pull request overview
This PR implements a proof-of-concept for propagating Sentry trace context from server to client using the Server-Timing HTTP header and the browser Performance API. This provides an alternative to meta tag-based trace propagation, particularly useful for streaming SSR responses and edge runtimes.
Key changes:
  • Added utilities for generating and injecting Server-Timing headers with Sentry trace data
  • Implemented client-side parsing of Server-Timing headers via the Performance API
  • Updated server instrumentation to capture and propagate trace context via Server-Timing headers
  • Added comprehensive E2E test coverage for both Node.js and Cloudflare environments
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FileDescription
packages/remix/src/server/serverTimingTracePropagation.tsNew utility module for generating Server-Timing headers with trace context
packages/remix/src/client/serverTimingTracePropagation.tsNew client-side utilities for parsing trace data from Server-Timing headers
packages/remix/src/server/instrumentServer.tsUpdated server instrumentation to inject Server-Timing headers and refactored trace propagation logic
packages/remix/src/client/performance.tsxUpdated pageload span initialization to use Server-Timing trace propagation
packages/remix/src/server/index.tsExported new Server-Timing utilities for public API
packages/remix/src/client/index.tsExported new client-side Server-Timing utilities
packages/remix/src/cloudflare/index.tsExported Server-Timing utilities for Cloudflare runtime
dev-packages/e2e-tests/test-applications/remix-server-timing/*New E2E test application validating Server-Timing trace propagation
dev-packages/e2e-tests/test-applications/remix-hydrogen/*Updated Hydrogen test app to demonstrate Cloudflare support
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Comment threadpackages/remix/src/server/serverTimingTracePropagation.ts
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Comment thread...2e-tests/test-applications/remix-server-timing/tests/server-timing-trace-propagation.test.ts
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Comment threadpackages/remix/src/client/performance.tsx
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node-overhead report 🧳
Note: This is a synthetic benchmark with a minimal express app and does not necessarily reflect the real-world performance impact in an application.
ScenarioRequests/s% of BaselinePrev. Requests/sChange %
GET Baseline8,958-9,206-3%
GET With Sentry1,71919%1,710+1%
GET With Sentry (error only)6,08168%6,099-0%
POST Baseline1,200-1,202-0%
POST With Sentry59049%579+2%
POST With Sentry (error only)1,03987%1,059-2%
MYSQL Baseline3,248-3,346-3%
MYSQL With Sentry42713%457-7%
MYSQL With Sentry (error only)2,59180%2,668-3%
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@onurtemizkan sorry for the delay on this! I merged in #18673 to get support for server-timing trace continuation on the client side in the general browser SDK. Could you update the PR to use this instead of the remix-specific approach? The server side looks fine to me, though I'll give this a more proper look once the PR is updated.
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Codecov Results 📊
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Comment threaddev-packages/e2e-tests/test-applications/remix-hydrogen/app/entry.server.tsx
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size-limit report 📦
⚠️Warning: Base artifact is not the latest one, because the latest workflow run is not done yet. This may lead to incorrect results. Try to re-run all tests to get up to date results.
PathSize% ChangeChange
@sentry/browser25.64 kB--
@sentry/browser - with treeshaking flags24.14 kB--
@sentry/browser (incl. Tracing)42.62 kB--
@sentry/browser (incl. Tracing, Profiling)47.28 kB--
@sentry/browser (incl. Tracing, Replay)81.42 kB--
@sentry/browser (incl. Tracing, Replay) - with treeshaking flags71 kB--
@sentry/browser (incl. Tracing, Replay with Canvas)86.12 kB--
@sentry/browser (incl. Tracing, Replay, Feedback)98.37 kB--
@sentry/browser (incl. Feedback)42.45 kB--
@sentry/browser (incl. sendFeedback)30.31 kB--
@sentry/browser (incl. FeedbackAsync)35.36 kB--
@sentry/browser (incl. Metrics)26.92 kB--
@sentry/browser (incl. Logs)27.07 kB--
@sentry/browser (incl. Metrics & Logs)27.74 kB--
@sentry/react27.39 kB--
@sentry/react (incl. Tracing)44.95 kB--
@sentry/vue30.08 kB--
@sentry/vue (incl. Tracing)44.48 kB--
@sentry/svelte25.66 kB--
CDN Bundle28.28 kB--
CDN Bundle (incl. Tracing)43.51 kB--
CDN Bundle (incl. Logs, Metrics)29.14 kB--
CDN Bundle (incl. Tracing, Logs, Metrics)44.36 kB--
CDN Bundle (incl. Replay, Logs, Metrics)68.21 kB--
CDN Bundle (incl. Tracing, Replay)80.33 kB--
CDN Bundle (incl. Tracing, Replay, Logs, Metrics)81.23 kB--
CDN Bundle (incl. Tracing, Replay, Feedback)85.87 kB--
CDN Bundle (incl. Tracing, Replay, Feedback, Logs, Metrics)86.77 kB--
CDN Bundle - uncompressed82.62 kB--
CDN Bundle (incl. Tracing) - uncompressed128.56 kB--
CDN Bundle (incl. Logs, Metrics) - uncompressed85.49 kB--
CDN Bundle (incl. Tracing, Logs, Metrics) - uncompressed131.43 kB--
CDN Bundle (incl. Replay, Logs, Metrics) - uncompressed209.12 kB--
CDN Bundle (incl. Tracing, Replay) - uncompressed245.41 kB--
CDN Bundle (incl. Tracing, Replay, Logs, Metrics) - uncompressed248.26 kB--
CDN Bundle (incl. Tracing, Replay, Feedback) - uncompressed258.32 kB--
CDN Bundle (incl. Tracing, Replay, Feedback, Logs, Metrics) - uncompressed261.17 kB--
@sentry/nextjs (client)47.37 kB--
@sentry/sveltekit (client)43.07 kB--
@sentry/node-core56.38 kB+0.06%+32 B 🔺
@sentry/node173.19 kB+0.02%+31 B 🔺
@sentry/node - without tracing96.37 kB+0.03%+28 B 🔺
@sentry/aws-serverless113.37 kB+0.03%+31 B 🔺
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Comment threadpackages/remix/src/server/serverTimingTracePropagation.ts
 }

 return parts.join(', ');
 } catch (e) {
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Unescaped quotes in Server-Timing desc
Medium Severity
generateSentryServerTimingHeader interpolates sentryTrace and baggage into Server-Timingdesc="..." without escaping. If either value ever contains " or \ (for example via non-standard baggage values), the header becomes syntactically invalid and may be dropped or parsed incorrectly by proxies/browsers, breaking trace propagation.
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feat(remix): Server Timing Headers Trace Propagation PoCfeat(remix): Server Timing Headers Trace PropagationFeb 24, 2026
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This pull request has gone three weeks without activity. In another week, I will close it.
But! If you comment or otherwise update it, I will reset the clock, and if you apply the label PR: no-auto-close I will leave it alone ... forever!
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Semver Impact of This PR
🟡 Minor (new features)
📋 Changelog Preview
This is how your changes will appear in the changelog.

Entries from this PR are highlighted with a left border (blockquote style).
New Features ✨
  • (remix) Server Timing Headers Trace Propagation by onurtemizkan in #18653
Bug Fixes 🐛
Deps
  • Bump devalue 5.6.3 to 5.6.4 to fix CVE-2026-30226 by chargome in #19849
  • Bump file-type to 21.3.2 and @nestjs/common to 11.1.17 by chargome in #19847
  • Bump unhead 2.1.4 to 2.1.12 to fix CVE-2026-31860 and CVE-2026-31873 by chargome in #19848
  • Bump flatted 3.3.1 to 3.4.2 to fix CVE-2026-32141 by chargome in #19842
  • Bump tar 7.5.10 to 7.5.11 to fix CVE-2026-31802 by chargome in #19846
  • Bump hono 4.12.5 to 4.12.7 in cloudflare-hono E2E test app by chargome in #19850
  • Bump undici 6.23.0 to 6.24.1 to fix multiple CVEs by chargome in #19841
Other
  • (deno) Clear pre-existing OTel global before registering TracerProvider by sergical in #19723
  • (node-core) Recycle propagationContext for each request by Lms24 in #19835
Internal Changes 🔧
  • (deps) Bump next from 16.1.5 to 16.1.7 in /dev-packages/e2e-tests/test-applications/nextjs-16 by dependabot in #19851
  • (react) Add gql tests for react router by chargome in #19844
  • (release) Switch from action-prepare-release to Craft by BYK in #18763
🤖 This preview updates automatically when you update the PR.
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Cursor Bugbot has reviewed your changes and found 1 potential issue.
There are 2 total unresolved issues (including 1 from previous review).
Autofix Details
Bugbot Autofix prepared a fix for the issue found in the latest run.
  • ✅ Fixed: Reversed fallback makes scope context path unreachable dead code
    • Restored correct order of OR expression to check scope context first before falling back to setSpan, making the fallback path reachable and the scope variable properly utilized.
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diff --git a/packages/opentelemetry/src/utils/getTraceData.ts b/packages/opentelemetry/src/utils/getTraceData.ts--- a/packages/opentelemetry/src/utils/getTraceData.ts+++ b/packages/opentelemetry/src/utils/getTraceData.ts@@ -24,7 +24,7 @@
if (span) {
const { scope } = getCapturedScopesOnSpan(span);
// fall back to current context if for whatever reason we can't find the one of the span
- ctx = api.trace.setSpan(api.context.active(), span) || (scope && getContextFromScope(scope));+ ctx = (scope && getContextFromScope(scope)) || api.trace.setSpan(api.context.active(), span);
}
const { traceId, spanId, sampled, dynamicSamplingContext } = getInjectionData(ctx, { scope, client });
This Bugbot Autofix run was free. To enable autofix for future PRs, go to the Cursor dashboard.
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Cursor Bugbot has reviewed your changes and found 1 potential issue.
There are 2 total unresolved issues (including 1 from previous review).
Fix All in Cursor
Bugbot Autofix is OFF. To automatically fix reported issues with cloud agents, enable autofix in the Cursor dashboard.
Comment threadpackages/remix/src/server/instrumentServer.ts
 response = await origDocumentRequestFunction.call(this, request, ...args);
 }

 if (serverTimingHeader && response instanceof Response) {
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Uses instanceof Response instead of duck-typed isResponse
Medium Severity
The new check at line 148 uses response instanceof Response to guard Server-Timing injection in the document request wrapper. Every other response check in this file (lines 73, 221, 263, 388) uses the duck-typed isResponse() helper from ../utils/vendor/response, which is already imported on line 40. The isResponse function was adopted from Remix's own source to handle cross-realm and polyfill cases where instanceof fails. Using instanceof Response could silently skip Server-Timing header injection on document responses in Node.js environments with polyfilled or differently-sourced Response constructors.
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feat(remix): Server Timing Headers Trace Propagation PoC


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, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Auto-enable theater mode on YouTube\n(function() {\n function tryTheater() {\n var btn = document.querySelector('button[aria-label=\"Theater mode\"], ytd-player #player button[title=\"Theater mode\"]');\n if (btn && !btn.classList.contains('activated')) {\n btn.click();\n }\n }\n \n // Try immediately\n tryTheater();\n \n // Try after navigation (SPA)\n var lastUrl = location.href;\n setInterval(function() {\n if (location.href !== lastUrl) {\n lastUrl = location.href;\n setTimeout(tryTheater, 500);\n }\n }, 1000);\n \n // Also try on player load\n var observer = new MutationObserver(tryTheater);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "YouTube Theater Mode Default");
}
} catch(__e) { console.warn('[Userscript:YouTube Theater Mode Default]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

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feat(remix): Server Timing Headers Trace Propagation - #18653
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feat(remix): Server Timing Headers Trace Propagation#18653
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Adds automatic trace propagation from server to client via the Server-Timing HTTP header for Remix applications. The client-side reading of Server-Timing headers via the Performance API was added in #18673.
Adds:
  • generateSentryServerTimingHeader(span) public utility that generates a Server-Timing header value containing Sentry trace context
  • Automatic injection in the document request handler for normal page responses
  • Automatic injection on redirect responses from loaders and actions, which bypass the document request handler entirely. This is an advantage over meta tag injection, which cannot work on redirect responses since they have no HTML body
  • For Cloudflare/Hydrogen apps: call generateSentryServerTimingHeader() manually and append the value to the response's Server-Timing header in entry.server.tsx (see remix-hydrogen e2e test for example)
Works on both Node.js and Cloudflare Workers environments.
Closes#18696
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Pull request overview
This PR implements a proof-of-concept for propagating Sentry trace context from server to client using the Server-Timing HTTP header and the browser Performance API. This provides an alternative to meta tag-based trace propagation, particularly useful for streaming SSR responses and edge runtimes.
Key changes:
  • Added utilities for generating and injecting Server-Timing headers with Sentry trace data
  • Implemented client-side parsing of Server-Timing headers via the Performance API
  • Updated server instrumentation to capture and propagate trace context via Server-Timing headers
  • Added comprehensive E2E test coverage for both Node.js and Cloudflare environments
Reviewed changes
Copilot reviewed 25 out of 27 changed files in this pull request and generated 16 comments.
Show a summary per file
FileDescription
packages/remix/src/server/serverTimingTracePropagation.tsNew utility module for generating Server-Timing headers with trace context
packages/remix/src/client/serverTimingTracePropagation.tsNew client-side utilities for parsing trace data from Server-Timing headers
packages/remix/src/server/instrumentServer.tsUpdated server instrumentation to inject Server-Timing headers and refactored trace propagation logic
packages/remix/src/client/performance.tsxUpdated pageload span initialization to use Server-Timing trace propagation
packages/remix/src/server/index.tsExported new Server-Timing utilities for public API
packages/remix/src/client/index.tsExported new client-side Server-Timing utilities
packages/remix/src/cloudflare/index.tsExported Server-Timing utilities for Cloudflare runtime
dev-packages/e2e-tests/test-applications/remix-server-timing/*New E2E test application validating Server-Timing trace propagation
dev-packages/e2e-tests/test-applications/remix-hydrogen/*Updated Hydrogen test app to demonstrate Cloudflare support
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Comment threadpackages/remix/src/server/serverTimingTracePropagation.ts
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Comment thread...2e-tests/test-applications/remix-server-timing/tests/server-timing-trace-propagation.test.ts
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node-overhead report 🧳
Note: This is a synthetic benchmark with a minimal express app and does not necessarily reflect the real-world performance impact in an application.
ScenarioRequests/s% of BaselinePrev. Requests/sChange %
GET Baseline8,958-9,206-3%
GET With Sentry1,71919%1,710+1%
GET With Sentry (error only)6,08168%6,099-0%
POST Baseline1,200-1,202-0%
POST With Sentry59049%579+2%
POST With Sentry (error only)1,03987%1,059-2%
MYSQL Baseline3,248-3,346-3%
MYSQL With Sentry42713%457-7%
MYSQL With Sentry (error only)2,59180%2,668-3%
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@onurtemizkan sorry for the delay on this! I merged in #18673 to get support for server-timing trace continuation on the client side in the general browser SDK. Could you update the PR to use this instead of the remix-specific approach? The server side looks fine to me, though I'll give this a more proper look once the PR is updated.
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Codecov Results 📊
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size-limit report 📦
⚠️Warning: Base artifact is not the latest one, because the latest workflow run is not done yet. This may lead to incorrect results. Try to re-run all tests to get up to date results.
PathSize% ChangeChange
@sentry/browser25.64 kB--
@sentry/browser - with treeshaking flags24.14 kB--
@sentry/browser (incl. Tracing)42.62 kB--
@sentry/browser (incl. Tracing, Profiling)47.28 kB--
@sentry/browser (incl. Tracing, Replay)81.42 kB--
@sentry/browser (incl. Tracing, Replay) - with treeshaking flags71 kB--
@sentry/browser (incl. Tracing, Replay with Canvas)86.12 kB--
@sentry/browser (incl. Tracing, Replay, Feedback)98.37 kB--
@sentry/browser (incl. Feedback)42.45 kB--
@sentry/browser (incl. sendFeedback)30.31 kB--
@sentry/browser (incl. FeedbackAsync)35.36 kB--
@sentry/browser (incl. Metrics)26.92 kB--
@sentry/browser (incl. Logs)27.07 kB--
@sentry/browser (incl. Metrics & Logs)27.74 kB--
@sentry/react27.39 kB--
@sentry/react (incl. Tracing)44.95 kB--
@sentry/vue30.08 kB--
@sentry/vue (incl. Tracing)44.48 kB--
@sentry/svelte25.66 kB--
CDN Bundle28.28 kB--
CDN Bundle (incl. Tracing)43.51 kB--
CDN Bundle (incl. Logs, Metrics)29.14 kB--
CDN Bundle (incl. Tracing, Logs, Metrics)44.36 kB--
CDN Bundle (incl. Replay, Logs, Metrics)68.21 kB--
CDN Bundle (incl. Tracing, Replay)80.33 kB--
CDN Bundle (incl. Tracing, Replay, Logs, Metrics)81.23 kB--
CDN Bundle (incl. Tracing, Replay, Feedback)85.87 kB--
CDN Bundle (incl. Tracing, Replay, Feedback, Logs, Metrics)86.77 kB--
CDN Bundle - uncompressed82.62 kB--
CDN Bundle (incl. Tracing) - uncompressed128.56 kB--
CDN Bundle (incl. Logs, Metrics) - uncompressed85.49 kB--
CDN Bundle (incl. Tracing, Logs, Metrics) - uncompressed131.43 kB--
CDN Bundle (incl. Replay, Logs, Metrics) - uncompressed209.12 kB--
CDN Bundle (incl. Tracing, Replay) - uncompressed245.41 kB--
CDN Bundle (incl. Tracing, Replay, Logs, Metrics) - uncompressed248.26 kB--
CDN Bundle (incl. Tracing, Replay, Feedback) - uncompressed258.32 kB--
CDN Bundle (incl. Tracing, Replay, Feedback, Logs, Metrics) - uncompressed261.17 kB--
@sentry/nextjs (client)47.37 kB--
@sentry/sveltekit (client)43.07 kB--
@sentry/node-core56.38 kB+0.06%+32 B 🔺
@sentry/node173.19 kB+0.02%+31 B 🔺
@sentry/node - without tracing96.37 kB+0.03%+28 B 🔺
@sentry/aws-serverless113.37 kB+0.03%+31 B 🔺
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Comment threadpackages/remix/src/server/serverTimingTracePropagation.ts
 }

 return parts.join(', ');
 } catch (e) {
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Unescaped quotes in Server-Timing desc
Medium Severity
generateSentryServerTimingHeader interpolates sentryTrace and baggage into Server-Timingdesc="..." without escaping. If either value ever contains " or \ (for example via non-standard baggage values), the header becomes syntactically invalid and may be dropped or parsed incorrectly by proxies/browsers, breaking trace propagation.
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feat(remix): Server Timing Headers Trace Propagation PoCfeat(remix): Server Timing Headers Trace PropagationFeb 24, 2026
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This pull request has gone three weeks without activity. In another week, I will close it.
But! If you comment or otherwise update it, I will reset the clock, and if you apply the label PR: no-auto-close I will leave it alone ... forever!
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Semver Impact of This PR
🟡 Minor (new features)
📋 Changelog Preview
This is how your changes will appear in the changelog.

Entries from this PR are highlighted with a left border (blockquote style).
New Features ✨
  • (remix) Server Timing Headers Trace Propagation by onurtemizkan in #18653
Bug Fixes 🐛
Deps
  • Bump devalue 5.6.3 to 5.6.4 to fix CVE-2026-30226 by chargome in #19849
  • Bump file-type to 21.3.2 and @nestjs/common to 11.1.17 by chargome in #19847
  • Bump unhead 2.1.4 to 2.1.12 to fix CVE-2026-31860 and CVE-2026-31873 by chargome in #19848
  • Bump flatted 3.3.1 to 3.4.2 to fix CVE-2026-32141 by chargome in #19842
  • Bump tar 7.5.10 to 7.5.11 to fix CVE-2026-31802 by chargome in #19846
  • Bump hono 4.12.5 to 4.12.7 in cloudflare-hono E2E test app by chargome in #19850
  • Bump undici 6.23.0 to 6.24.1 to fix multiple CVEs by chargome in #19841
Other
  • (deno) Clear pre-existing OTel global before registering TracerProvider by sergical in #19723
  • (node-core) Recycle propagationContext for each request by Lms24 in #19835
Internal Changes 🔧
  • (deps) Bump next from 16.1.5 to 16.1.7 in /dev-packages/e2e-tests/test-applications/nextjs-16 by dependabot in #19851
  • (react) Add gql tests for react router by chargome in #19844
  • (release) Switch from action-prepare-release to Craft by BYK in #18763
🤖 This preview updates automatically when you update the PR.
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Comment threadpackages/opentelemetry/src/utils/getTraceData.ts
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Cursor Bugbot has reviewed your changes and found 1 potential issue.
There are 2 total unresolved issues (including 1 from previous review).
Autofix Details
Bugbot Autofix prepared a fix for the issue found in the latest run.
  • ✅ Fixed: Reversed fallback makes scope context path unreachable dead code
    • Restored correct order of OR expression to check scope context first before falling back to setSpan, making the fallback path reachable and the scope variable properly utilized.
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diff --git a/packages/opentelemetry/src/utils/getTraceData.ts b/packages/opentelemetry/src/utils/getTraceData.ts--- a/packages/opentelemetry/src/utils/getTraceData.ts+++ b/packages/opentelemetry/src/utils/getTraceData.ts@@ -24,7 +24,7 @@
if (span) {
const { scope } = getCapturedScopesOnSpan(span);
// fall back to current context if for whatever reason we can't find the one of the span
- ctx = api.trace.setSpan(api.context.active(), span) || (scope && getContextFromScope(scope));+ ctx = (scope && getContextFromScope(scope)) || api.trace.setSpan(api.context.active(), span);
}
const { traceId, spanId, sampled, dynamicSamplingContext } = getInjectionData(ctx, { scope, client });
This Bugbot Autofix run was free. To enable autofix for future PRs, go to the Cursor dashboard.
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Cursor Bugbot has reviewed your changes and found 1 potential issue.
There are 2 total unresolved issues (including 1 from previous review).
Fix All in Cursor
Bugbot Autofix is OFF. To automatically fix reported issues with cloud agents, enable autofix in the Cursor dashboard.
Comment threadpackages/remix/src/server/instrumentServer.ts
 response = await origDocumentRequestFunction.call(this, request, ...args);
 }

 if (serverTimingHeader && response instanceof Response) {
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Uses instanceof Response instead of duck-typed isResponse
Medium Severity
The new check at line 148 uses response instanceof Response to guard Server-Timing injection in the document request wrapper. Every other response check in this file (lines 73, 221, 263, 388) uses the duck-typed isResponse() helper from ../utils/vendor/response, which is already imported on line 40. The isResponse function was adopted from Remix's own source to handle cross-realm and polyfill cases where instanceof fails. Using instanceof Response could silently skip Server-Timing header injection on document responses in Node.js environments with polyfilled or differently-sourced Response constructors.
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feat(remix): Server Timing Headers Trace Propagation PoC


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, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Remove or un-stick sticky/fixed headers that block content\n(function() {\n function unstick() {\n document.querySelectorAll('header, nav, [role=\"banner\"], .header, .navbar, .sticky, .fixed-top, [style*=\"position: fixed\"], [style*=\"position:sticky\"]').forEach(function(el) {\n if (el.style.position === 'fixed' || el.style.position === 'sticky' || \n getComputedStyle(el).position === 'fixed' || getComputedStyle(el).position === 'sticky') {\n el.style.position = 'static';\n el.style.top = 'auto';\n el.style.zIndex = 'auto';\n }\n });\n }\n \n unstick();\n \n var observer = new MutationObserver(unstick);\n observer.observe(document.body, { childList: true, subtree: true, attributes: true, attributeFilter: ['style', 'class'] });\n})();", "Kill Sticky Headers");
}
} catch(__e) { console.warn('[Userscript:Kill Sticky Headers]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

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feat(remix): Server Timing Headers Trace Propagation - #18653
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feat(remix): Server Timing Headers Trace Propagation#18653
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Adds automatic trace propagation from server to client via the Server-Timing HTTP header for Remix applications. The client-side reading of Server-Timing headers via the Performance API was added in #18673.
Adds:
  • generateSentryServerTimingHeader(span) public utility that generates a Server-Timing header value containing Sentry trace context
  • Automatic injection in the document request handler for normal page responses
  • Automatic injection on redirect responses from loaders and actions, which bypass the document request handler entirely. This is an advantage over meta tag injection, which cannot work on redirect responses since they have no HTML body
  • For Cloudflare/Hydrogen apps: call generateSentryServerTimingHeader() manually and append the value to the response's Server-Timing header in entry.server.tsx (see remix-hydrogen e2e test for example)
Works on both Node.js and Cloudflare Workers environments.
Closes#18696
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Pull request overview
This PR implements a proof-of-concept for propagating Sentry trace context from server to client using the Server-Timing HTTP header and the browser Performance API. This provides an alternative to meta tag-based trace propagation, particularly useful for streaming SSR responses and edge runtimes.
Key changes:
  • Added utilities for generating and injecting Server-Timing headers with Sentry trace data
  • Implemented client-side parsing of Server-Timing headers via the Performance API
  • Updated server instrumentation to capture and propagate trace context via Server-Timing headers
  • Added comprehensive E2E test coverage for both Node.js and Cloudflare environments
Reviewed changes
Copilot reviewed 25 out of 27 changed files in this pull request and generated 16 comments.
Show a summary per file
FileDescription
packages/remix/src/server/serverTimingTracePropagation.tsNew utility module for generating Server-Timing headers with trace context
packages/remix/src/client/serverTimingTracePropagation.tsNew client-side utilities for parsing trace data from Server-Timing headers
packages/remix/src/server/instrumentServer.tsUpdated server instrumentation to inject Server-Timing headers and refactored trace propagation logic
packages/remix/src/client/performance.tsxUpdated pageload span initialization to use Server-Timing trace propagation
packages/remix/src/server/index.tsExported new Server-Timing utilities for public API
packages/remix/src/client/index.tsExported new client-side Server-Timing utilities
packages/remix/src/cloudflare/index.tsExported Server-Timing utilities for Cloudflare runtime
dev-packages/e2e-tests/test-applications/remix-server-timing/*New E2E test application validating Server-Timing trace propagation
dev-packages/e2e-tests/test-applications/remix-hydrogen/*Updated Hydrogen test app to demonstrate Cloudflare support
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node-overhead report 🧳
Note: This is a synthetic benchmark with a minimal express app and does not necessarily reflect the real-world performance impact in an application.
ScenarioRequests/s% of BaselinePrev. Requests/sChange %
GET Baseline8,958-9,206-3%
GET With Sentry1,71919%1,710+1%
GET With Sentry (error only)6,08168%6,099-0%
POST Baseline1,200-1,202-0%
POST With Sentry59049%579+2%
POST With Sentry (error only)1,03987%1,059-2%
MYSQL Baseline3,248-3,346-3%
MYSQL With Sentry42713%457-7%
MYSQL With Sentry (error only)2,59180%2,668-3%
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@onurtemizkan sorry for the delay on this! I merged in #18673 to get support for server-timing trace continuation on the client side in the general browser SDK. Could you update the PR to use this instead of the remix-specific approach? The server side looks fine to me, though I'll give this a more proper look once the PR is updated.
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size-limit report 📦
⚠️Warning: Base artifact is not the latest one, because the latest workflow run is not done yet. This may lead to incorrect results. Try to re-run all tests to get up to date results.
PathSize% ChangeChange
@sentry/browser25.64 kB--
@sentry/browser - with treeshaking flags24.14 kB--
@sentry/browser (incl. Tracing)42.62 kB--
@sentry/browser (incl. Tracing, Profiling)47.28 kB--
@sentry/browser (incl. Tracing, Replay)81.42 kB--
@sentry/browser (incl. Tracing, Replay) - with treeshaking flags71 kB--
@sentry/browser (incl. Tracing, Replay with Canvas)86.12 kB--
@sentry/browser (incl. Tracing, Replay, Feedback)98.37 kB--
@sentry/browser (incl. Feedback)42.45 kB--
@sentry/browser (incl. sendFeedback)30.31 kB--
@sentry/browser (incl. FeedbackAsync)35.36 kB--
@sentry/browser (incl. Metrics)26.92 kB--
@sentry/browser (incl. Logs)27.07 kB--
@sentry/browser (incl. Metrics & Logs)27.74 kB--
@sentry/react27.39 kB--
@sentry/react (incl. Tracing)44.95 kB--
@sentry/vue30.08 kB--
@sentry/vue (incl. Tracing)44.48 kB--
@sentry/svelte25.66 kB--
CDN Bundle28.28 kB--
CDN Bundle (incl. Tracing)43.51 kB--
CDN Bundle (incl. Logs, Metrics)29.14 kB--
CDN Bundle (incl. Tracing, Logs, Metrics)44.36 kB--
CDN Bundle (incl. Replay, Logs, Metrics)68.21 kB--
CDN Bundle (incl. Tracing, Replay)80.33 kB--
CDN Bundle (incl. Tracing, Replay, Logs, Metrics)81.23 kB--
CDN Bundle (incl. Tracing, Replay, Feedback)85.87 kB--
CDN Bundle (incl. Tracing, Replay, Feedback, Logs, Metrics)86.77 kB--
CDN Bundle - uncompressed82.62 kB--
CDN Bundle (incl. Tracing) - uncompressed128.56 kB--
CDN Bundle (incl. Logs, Metrics) - uncompressed85.49 kB--
CDN Bundle (incl. Tracing, Logs, Metrics) - uncompressed131.43 kB--
CDN Bundle (incl. Replay, Logs, Metrics) - uncompressed209.12 kB--
CDN Bundle (incl. Tracing, Replay) - uncompressed245.41 kB--
CDN Bundle (incl. Tracing, Replay, Logs, Metrics) - uncompressed248.26 kB--
CDN Bundle (incl. Tracing, Replay, Feedback) - uncompressed258.32 kB--
CDN Bundle (incl. Tracing, Replay, Feedback, Logs, Metrics) - uncompressed261.17 kB--
@sentry/nextjs (client)47.37 kB--
@sentry/sveltekit (client)43.07 kB--
@sentry/node-core56.38 kB+0.06%+32 B 🔺
@sentry/node173.19 kB+0.02%+31 B 🔺
@sentry/node - without tracing96.37 kB+0.03%+28 B 🔺
@sentry/aws-serverless113.37 kB+0.03%+31 B 🔺
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Comment threadpackages/remix/src/server/serverTimingTracePropagation.ts
 }

 return parts.join(', ');
 } catch (e) {
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Unescaped quotes in Server-Timing desc
Medium Severity
generateSentryServerTimingHeader interpolates sentryTrace and baggage into Server-Timingdesc="..." without escaping. If either value ever contains " or \ (for example via non-standard baggage values), the header becomes syntactically invalid and may be dropped or parsed incorrectly by proxies/browsers, breaking trace propagation.
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feat(remix): Server Timing Headers Trace Propagation PoCfeat(remix): Server Timing Headers Trace PropagationFeb 24, 2026
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This pull request has gone three weeks without activity. In another week, I will close it.
But! If you comment or otherwise update it, I will reset the clock, and if you apply the label PR: no-auto-close I will leave it alone ... forever!
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Semver Impact of This PR
🟡 Minor (new features)
📋 Changelog Preview
This is how your changes will appear in the changelog.

Entries from this PR are highlighted with a left border (blockquote style).
New Features ✨
  • (remix) Server Timing Headers Trace Propagation by onurtemizkan in #18653
Bug Fixes 🐛
Deps
  • Bump devalue 5.6.3 to 5.6.4 to fix CVE-2026-30226 by chargome in #19849
  • Bump file-type to 21.3.2 and @nestjs/common to 11.1.17 by chargome in #19847
  • Bump unhead 2.1.4 to 2.1.12 to fix CVE-2026-31860 and CVE-2026-31873 by chargome in #19848
  • Bump flatted 3.3.1 to 3.4.2 to fix CVE-2026-32141 by chargome in #19842
  • Bump tar 7.5.10 to 7.5.11 to fix CVE-2026-31802 by chargome in #19846
  • Bump hono 4.12.5 to 4.12.7 in cloudflare-hono E2E test app by chargome in #19850
  • Bump undici 6.23.0 to 6.24.1 to fix multiple CVEs by chargome in #19841
Other
  • (deno) Clear pre-existing OTel global before registering TracerProvider by sergical in #19723
  • (node-core) Recycle propagationContext for each request by Lms24 in #19835
Internal Changes 🔧
  • (deps) Bump next from 16.1.5 to 16.1.7 in /dev-packages/e2e-tests/test-applications/nextjs-16 by dependabot in #19851
  • (react) Add gql tests for react router by chargome in #19844
  • (release) Switch from action-prepare-release to Craft by BYK in #18763
🤖 This preview updates automatically when you update the PR.
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Comment threadpackages/opentelemetry/src/utils/getTraceData.ts
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Cursor Bugbot has reviewed your changes and found 1 potential issue.
There are 2 total unresolved issues (including 1 from previous review).
Autofix Details
Bugbot Autofix prepared a fix for the issue found in the latest run.
  • ✅ Fixed: Reversed fallback makes scope context path unreachable dead code
    • Restored correct order of OR expression to check scope context first before falling back to setSpan, making the fallback path reachable and the scope variable properly utilized.
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diff --git a/packages/opentelemetry/src/utils/getTraceData.ts b/packages/opentelemetry/src/utils/getTraceData.ts--- a/packages/opentelemetry/src/utils/getTraceData.ts+++ b/packages/opentelemetry/src/utils/getTraceData.ts@@ -24,7 +24,7 @@
if (span) {
const { scope } = getCapturedScopesOnSpan(span);
// fall back to current context if for whatever reason we can't find the one of the span
- ctx = api.trace.setSpan(api.context.active(), span) || (scope && getContextFromScope(scope));+ ctx = (scope && getContextFromScope(scope)) || api.trace.setSpan(api.context.active(), span);
}
const { traceId, spanId, sampled, dynamicSamplingContext } = getInjectionData(ctx, { scope, client });
This Bugbot Autofix run was free. To enable autofix for future PRs, go to the Cursor dashboard.
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Cursor Bugbot has reviewed your changes and found 1 potential issue.
There are 2 total unresolved issues (including 1 from previous review).
Fix All in Cursor
Bugbot Autofix is OFF. To automatically fix reported issues with cloud agents, enable autofix in the Cursor dashboard.
Comment threadpackages/remix/src/server/instrumentServer.ts
 response = await origDocumentRequestFunction.call(this, request, ...args);
 }

 if (serverTimingHeader && response instanceof Response) {
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Uses instanceof Response instead of duck-typed isResponse
Medium Severity
The new check at line 148 uses response instanceof Response to guard Server-Timing injection in the document request wrapper. Every other response check in this file (lines 73, 221, 263, 388) uses the duck-typed isResponse() helper from ../utils/vendor/response, which is already imported on line 40. The isResponse function was adopted from Remix's own source to handle cross-realm and polyfill cases where instanceof fails. Using instanceof Response could silently skip Server-Timing header injection on document responses in Node.js environments with polyfilled or differently-sourced Response constructors.
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feat(remix): Server Timing Headers Trace Propagation PoC


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, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Universal Dark Mode - works on any site\n(function() {\n var enabled = true;\n \n function applyDarkMode() {\n if (!enabled) return;\n \n // Create style element if it doesn't exist\n var style = document.getElementById('universal-dark-mode-style');\n if (!style) {\n style = document.createElement('style');\n style.id = 'universal-dark-mode-style';\n document.head.appendChild(style);\n }\n \n // Dark mode CSS - inverts colors but preserves images/video\n style.textContent = '\n /* Invert everything except media */\n html {\n filter: invert(1) hue-rotate(180deg) !important;\n background: #1a1a2e !important;\n }\n \n /* Restore images, videos, iframes, canvas */\n img, video, iframe, canvas, svg, picture, [style*=\"background-image\"] {\n filter: invert(1) hue-rotate(180deg) !important;\n }\n \n /* Preserve specific elements that should not be inverted */\n .no-dark-mode, .no-dark-mode *,\n [data-theme=\"light\"], [data-theme=\"light\"],\n .ace_editor, .ace_editor *,\n .CodeMirror, .CodeMirror *,\n .monaco-editor, .monaco-editor *,\n .markdown-body pre, .markdown-body pre *,\n .highlight, .highlight *,\n pre code, pre code * {\n filter: none !important;\n }\n \n /* Fix common UI elements */\n .modal, .popup, .dropdown-menu, .tooltip, .popover {\n filter: invert(1) hue-rotate(180deg) !important;\n background: #2d2d44 !important;\n border-color: #444 !important;\n }\n \n /* Scrollbars */\n ::-webkit-scrollbar { background: #1a1a2e !important; }\n ::-webkit-scrollbar-thumb { background: #444 !important; }\n ::-webkit-scrollbar-thumb:hover { background: #555 !important; }\n \n /* Selection */\n ::selection { background: #4ecdc4 !important; color: #1a1a2e !important; }\n ::-moz-selection { background: #4ecdc4 !important; color: #1a1a2e !important; }\n ';\n }\n \n function removeDarkMode() {\n var style = document.getElementById('universal-dark-mode-style');\n if (style) style.remove();\n }\n \n // Toggle with Alt+Shift+D\n document.addEventListener('keydown', function(e) {\n if (e.altKey && e.shiftKey && e.key === 'D') {\n e.preventDefault();\n enabled = !enabled;\n if (enabled) {\n applyDarkMode();\n console.log('[Universal Dark Mode] Enabled');\n } else {\n removeDarkMode();\n console.log('[Universal Dark Mode] Disabled');\n }\n }\n });\n \n // Apply on load\n applyDarkMode();\n \n // Re-apply on dynamic content\n var observer = new MutationObserver(function(mutations) {\n if (enabled && !document.getElementById('universal-dark-mode-style')) {\n applyDarkMode();\n }\n });\n observer.observe(document.head, { childList: true });\n \n console.log('[Universal Dark Mode] Loaded - Press Alt+Shift+D to toggle');\n})();", "Universal Dark Mode");
}
} catch(__e) { console.warn('[Userscript:Universal Dark Mode]', __e); }
})();
})();

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feat(remix): Server Timing Headers Trace Propagation - #18653
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Adds automatic trace propagation from server to client via the Server-Timing HTTP header for Remix applications. The client-side reading of Server-Timing headers via the Performance API was added in #18673.
Adds:
  • generateSentryServerTimingHeader(span) public utility that generates a Server-Timing header value containing Sentry trace context
  • Automatic injection in the document request handler for normal page responses
  • Automatic injection on redirect responses from loaders and actions, which bypass the document request handler entirely. This is an advantage over meta tag injection, which cannot work on redirect responses since they have no HTML body
  • For Cloudflare/Hydrogen apps: call generateSentryServerTimingHeader() manually and append the value to the response's Server-Timing header in entry.server.tsx (see remix-hydrogen e2e test for example)
Works on both Node.js and Cloudflare Workers environments.
Closes#18696
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Pull request overview
This PR implements a proof-of-concept for propagating Sentry trace context from server to client using the Server-Timing HTTP header and the browser Performance API. This provides an alternative to meta tag-based trace propagation, particularly useful for streaming SSR responses and edge runtimes.
Key changes:
  • Added utilities for generating and injecting Server-Timing headers with Sentry trace data
  • Implemented client-side parsing of Server-Timing headers via the Performance API
  • Updated server instrumentation to capture and propagate trace context via Server-Timing headers
  • Added comprehensive E2E test coverage for both Node.js and Cloudflare environments
Reviewed changes
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Show a summary per file
FileDescription
packages/remix/src/server/serverTimingTracePropagation.tsNew utility module for generating Server-Timing headers with trace context
packages/remix/src/client/serverTimingTracePropagation.tsNew client-side utilities for parsing trace data from Server-Timing headers
packages/remix/src/server/instrumentServer.tsUpdated server instrumentation to inject Server-Timing headers and refactored trace propagation logic
packages/remix/src/client/performance.tsxUpdated pageload span initialization to use Server-Timing trace propagation
packages/remix/src/server/index.tsExported new Server-Timing utilities for public API
packages/remix/src/client/index.tsExported new client-side Server-Timing utilities
packages/remix/src/cloudflare/index.tsExported Server-Timing utilities for Cloudflare runtime
dev-packages/e2e-tests/test-applications/remix-server-timing/*New E2E test application validating Server-Timing trace propagation
dev-packages/e2e-tests/test-applications/remix-hydrogen/*Updated Hydrogen test app to demonstrate Cloudflare support
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Comment threadpackages/remix/src/server/serverTimingTracePropagation.ts
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Comment thread...2e-tests/test-applications/remix-server-timing/tests/server-timing-trace-propagation.test.ts
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node-overhead report 🧳
Note: This is a synthetic benchmark with a minimal express app and does not necessarily reflect the real-world performance impact in an application.
ScenarioRequests/s% of BaselinePrev. Requests/sChange %
GET Baseline8,958-9,206-3%
GET With Sentry1,71919%1,710+1%
GET With Sentry (error only)6,08168%6,099-0%
POST Baseline1,200-1,202-0%
POST With Sentry59049%579+2%
POST With Sentry (error only)1,03987%1,059-2%
MYSQL Baseline3,248-3,346-3%
MYSQL With Sentry42713%457-7%
MYSQL With Sentry (error only)2,59180%2,668-3%
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@onurtemizkan sorry for the delay on this! I merged in #18673 to get support for server-timing trace continuation on the client side in the general browser SDK. Could you update the PR to use this instead of the remix-specific approach? The server side looks fine to me, though I'll give this a more proper look once the PR is updated.
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Comment threaddev-packages/e2e-tests/test-applications/remix-hydrogen/app/entry.server.tsx
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size-limit report 📦
⚠️Warning: Base artifact is not the latest one, because the latest workflow run is not done yet. This may lead to incorrect results. Try to re-run all tests to get up to date results.
PathSize% ChangeChange
@sentry/browser25.64 kB--
@sentry/browser - with treeshaking flags24.14 kB--
@sentry/browser (incl. Tracing)42.62 kB--
@sentry/browser (incl. Tracing, Profiling)47.28 kB--
@sentry/browser (incl. Tracing, Replay)81.42 kB--
@sentry/browser (incl. Tracing, Replay) - with treeshaking flags71 kB--
@sentry/browser (incl. Tracing, Replay with Canvas)86.12 kB--
@sentry/browser (incl. Tracing, Replay, Feedback)98.37 kB--
@sentry/browser (incl. Feedback)42.45 kB--
@sentry/browser (incl. sendFeedback)30.31 kB--
@sentry/browser (incl. FeedbackAsync)35.36 kB--
@sentry/browser (incl. Metrics)26.92 kB--
@sentry/browser (incl. Logs)27.07 kB--
@sentry/browser (incl. Metrics & Logs)27.74 kB--
@sentry/react27.39 kB--
@sentry/react (incl. Tracing)44.95 kB--
@sentry/vue30.08 kB--
@sentry/vue (incl. Tracing)44.48 kB--
@sentry/svelte25.66 kB--
CDN Bundle28.28 kB--
CDN Bundle (incl. Tracing)43.51 kB--
CDN Bundle (incl. Logs, Metrics)29.14 kB--
CDN Bundle (incl. Tracing, Logs, Metrics)44.36 kB--
CDN Bundle (incl. Replay, Logs, Metrics)68.21 kB--
CDN Bundle (incl. Tracing, Replay)80.33 kB--
CDN Bundle (incl. Tracing, Replay, Logs, Metrics)81.23 kB--
CDN Bundle (incl. Tracing, Replay, Feedback)85.87 kB--
CDN Bundle (incl. Tracing, Replay, Feedback, Logs, Metrics)86.77 kB--
CDN Bundle - uncompressed82.62 kB--
CDN Bundle (incl. Tracing) - uncompressed128.56 kB--
CDN Bundle (incl. Logs, Metrics) - uncompressed85.49 kB--
CDN Bundle (incl. Tracing, Logs, Metrics) - uncompressed131.43 kB--
CDN Bundle (incl. Replay, Logs, Metrics) - uncompressed209.12 kB--
CDN Bundle (incl. Tracing, Replay) - uncompressed245.41 kB--
CDN Bundle (incl. Tracing, Replay, Logs, Metrics) - uncompressed248.26 kB--
CDN Bundle (incl. Tracing, Replay, Feedback) - uncompressed258.32 kB--
CDN Bundle (incl. Tracing, Replay, Feedback, Logs, Metrics) - uncompressed261.17 kB--
@sentry/nextjs (client)47.37 kB--
@sentry/sveltekit (client)43.07 kB--
@sentry/node-core56.38 kB+0.06%+32 B 🔺
@sentry/node173.19 kB+0.02%+31 B 🔺
@sentry/node - without tracing96.37 kB+0.03%+28 B 🔺
@sentry/aws-serverless113.37 kB+0.03%+31 B 🔺
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Comment threadpackages/remix/src/server/serverTimingTracePropagation.ts
 }

 return parts.join(', ');
 } catch (e) {
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Unescaped quotes in Server-Timing desc
Medium Severity
generateSentryServerTimingHeader interpolates sentryTrace and baggage into Server-Timingdesc="..." without escaping. If either value ever contains " or \ (for example via non-standard baggage values), the header becomes syntactically invalid and may be dropped or parsed incorrectly by proxies/browsers, breaking trace propagation.
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feat(remix): Server Timing Headers Trace Propagation PoCfeat(remix): Server Timing Headers Trace PropagationFeb 24, 2026
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This pull request has gone three weeks without activity. In another week, I will close it.
But! If you comment or otherwise update it, I will reset the clock, and if you apply the label PR: no-auto-close I will leave it alone ... forever!
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Semver Impact of This PR
🟡 Minor (new features)
📋 Changelog Preview
This is how your changes will appear in the changelog.

Entries from this PR are highlighted with a left border (blockquote style).
New Features ✨
  • (remix) Server Timing Headers Trace Propagation by onurtemizkan in #18653
Bug Fixes 🐛
Deps
  • Bump devalue 5.6.3 to 5.6.4 to fix CVE-2026-30226 by chargome in #19849
  • Bump file-type to 21.3.2 and @nestjs/common to 11.1.17 by chargome in #19847
  • Bump unhead 2.1.4 to 2.1.12 to fix CVE-2026-31860 and CVE-2026-31873 by chargome in #19848
  • Bump flatted 3.3.1 to 3.4.2 to fix CVE-2026-32141 by chargome in #19842
  • Bump tar 7.5.10 to 7.5.11 to fix CVE-2026-31802 by chargome in #19846
  • Bump hono 4.12.5 to 4.12.7 in cloudflare-hono E2E test app by chargome in #19850
  • Bump undici 6.23.0 to 6.24.1 to fix multiple CVEs by chargome in #19841
Other
  • (deno) Clear pre-existing OTel global before registering TracerProvider by sergical in #19723
  • (node-core) Recycle propagationContext for each request by Lms24 in #19835
Internal Changes 🔧
  • (deps) Bump next from 16.1.5 to 16.1.7 in /dev-packages/e2e-tests/test-applications/nextjs-16 by dependabot in #19851
  • (react) Add gql tests for react router by chargome in #19844
  • (release) Switch from action-prepare-release to Craft by BYK in #18763
🤖 This preview updates automatically when you update the PR.
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Comment threadpackages/opentelemetry/src/utils/getTraceData.ts
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Cursor Bugbot has reviewed your changes and found 1 potential issue.
There are 2 total unresolved issues (including 1 from previous review).
Autofix Details
Bugbot Autofix prepared a fix for the issue found in the latest run.
  • ✅ Fixed: Reversed fallback makes scope context path unreachable dead code
    • Restored correct order of OR expression to check scope context first before falling back to setSpan, making the fallback path reachable and the scope variable properly utilized.
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Preview (061834c332)
diff --git a/packages/opentelemetry/src/utils/getTraceData.ts b/packages/opentelemetry/src/utils/getTraceData.ts--- a/packages/opentelemetry/src/utils/getTraceData.ts+++ b/packages/opentelemetry/src/utils/getTraceData.ts@@ -24,7 +24,7 @@
if (span) {
const { scope } = getCapturedScopesOnSpan(span);
// fall back to current context if for whatever reason we can't find the one of the span
- ctx = api.trace.setSpan(api.context.active(), span) || (scope && getContextFromScope(scope));+ ctx = (scope && getContextFromScope(scope)) || api.trace.setSpan(api.context.active(), span);
}
const { traceId, spanId, sampled, dynamicSamplingContext } = getInjectionData(ctx, { scope, client });
This Bugbot Autofix run was free. To enable autofix for future PRs, go to the Cursor dashboard.
Comment threadpackages/opentelemetry/src/utils/getTraceData.ts
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Cursor Bugbot has reviewed your changes and found 1 potential issue.
There are 2 total unresolved issues (including 1 from previous review).
Fix All in Cursor
Bugbot Autofix is OFF. To automatically fix reported issues with cloud agents, enable autofix in the Cursor dashboard.
Comment threadpackages/remix/src/server/instrumentServer.ts
 response = await origDocumentRequestFunction.call(this, request, ...args);
 }

 if (serverTimingHeader && response instanceof Response) {
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Uses instanceof Response instead of duck-typed isResponse
Medium Severity
The new check at line 148 uses response instanceof Response to guard Server-Timing injection in the document request wrapper. Every other response check in this file (lines 73, 221, 263, 388) uses the duck-typed isResponse() helper from ../utils/vendor/response, which is already imported on line 40. The isResponse function was adopted from Remix's own source to handle cross-realm and polyfill cases where instanceof fails. Using instanceof Response could silently skip Server-Timing header injection on document responses in Node.js environments with polyfilled or differently-sourced Response constructors.
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feat(remix): Server Timing Headers Trace Propagation PoC


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