docs(langchain): Document TypeSafeClassifier evaluation tracing

[sentry-junior]

DESCRIBE YOUR PR

Document tracing of TypeSafeClassifier runs from @langchain/typesafe, which now show up as gen_ai.evaluate spans. This applies to standalone calls, calls from LangGraph nodes, and the classifiers that the @langchain/typesafe agent middleware creates.

The LangChain page gets a new section with a setup example, the data captured, and privacy controls, plus the supported @langchain/typesafe range. The LangGraph page gets a short section with a StateGraph node example that points to the LangChain section. The TypeSafe page now links to it. This follows the Mastra classifier section from #19878. The new sections are hidden on Cloudflare because the SDK has no test coverage there.

Shipped in Sentry JavaScript SDK 11.6.0 via getsentry/sentry-javascript#25120, with agent and LangGraph coverage in getsentry/sentry-javascript#25132.

IS YOUR CHANGE URGENT?

• Urgent deadline (GA date, etc.):
• Other deadline:
• None: Not urgent, can wait up to 1 week+

PRE-MERGE CHECKLIST

• Checked Vercel preview for correctness, including links
• PR was reviewed and approved by any necessary SMEs (subject matter experts)
• PR was reviewed and approved by a member of the Sentry docs team

via Andrei Borza.

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Project	Deployment	Actions	Updated
sentry-docs	Ready	Preview	Oct 9, 2026 12:32pm UTC

1 Skipped Deployment

Project	Deployment	Actions	Updated
develop-docs	Ignored	Preview	Oct 9, 2026 12:32pm UTC

[cursor]

The change adds classifier evaluation tracing docs to three JavaScript integration pages. The plan checks client errors on those pages, site-wide client errors, and missing-page counts. An issue escalates when those page errors appear or the site error rate rises.

Rollout complete

Services: sentry-docs.

Plan

What changed

Readers of the LangChain, LangGraph, and TypeSafe JavaScript integration pages now see TypeSafeClassifier evaluation tracing. Those pages document gen_ai.evaluate spans, captured data, and privacy controls. The change is live after sentry-docs deploys. The pages live under docs/platforms/javascript/. They do not ship on develop-docs. Deploy config maps the Vercel project sentry-docs to this service.

Risk

Wrong MDX or PlatformSection markup can break render on those three pages. New code samples can throw in the shared code-tab client. New cross-links can 404. The same code-tab and platform-selector code runs on other JavaScript integration pages.

Intended effect

This change is documentation text. Telemetry cannot show that the new sections are on the page. Treat intended effect as not queryable. Do not use a missing-error result as proof the text shipped.

Regression watch

Wrong markup fails first as client errors on the changed integration pages. Shared code-tab and platform-selector failures show as a site-wide error-rate rise. Bad new links show as a missing-page-rate rise.

Existing production errors are mostly TypeError and Event. Hold the measured rates. Do not treat that baseline noise as a new fault.

Signal	Baseline	Window	Source	Comparison
Client errors on langchain, langgraph, or typesafe integration page URLs	0	2026-10-08T10:08:00Z to 2026-10-09T10:08:00Z	Sentry errors, project docs, environment:production and url or transaction contains langchain, langgraph, or typesafe	hold at 0. Detected if the count rises above 0
Production client error rate	0.90%, 167 errors per 18583 page loads	2026-10-08T10:08:00Z to 2026-10-09T10:08:00Z	Sentry errors environment:production count() over docs.page.load sum, project docs	hold at or below 0.90%. Detected if the rate rises above 0.90%
Missing-page rate	2.43%, 452 missing pages per 18583 page loads	2026-10-08T10:08:00Z to 2026-10-09T10:08:00Z	Sentry metrics docs.page.not_found sum over docs.page.load sum, project docs, production	hold at or below 2.43%. Detected if the rate rises above 2.43%
Platforms page loads	9283, 50% of 18583 page loads	2026-10-08T10:08:00Z to 2026-10-09T10:08:00Z	Sentry metrics docs.page.load sum with page_type:platforms, project docs, production	hold near 50% of page loads. Detected if the platforms share falls far below 50%

If the error rate rises, inspect code-tab and platform-selector errors on the changed pages.

Not observable

Whether the new prose is present on the live pages. Whether the documented SDK spans match production SDK behavior. Page-specific web vitals: the baseline window had 37 sampled pageload and navigation spans on those URLs, and p95 was 11.7 s. That sample is too small for a hold band.