[s1gr1d]

DESCRIBE YOUR PR

Documents the buildTimeInstrumentation option of sentrySvelteKit. SvelteKit had no entry for it. Users who need to keep a package unbundled (see getsentry/sentry-javascript#25470) also need to know that ssr.external turns off build-time instrumentation for that package.

IS YOUR CHANGE URGENT?

• Urgent deadline (GA date, etc.): YYYY-MM-DD
• Other deadline: YYYY-MM-DD
• No deadline: 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

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Project	Deployment	Actions	Updated
sentry-docs	Ready	Preview	Oct 19, 2026 1:01pm UTC

1 Skipped Deployment

Project	Deployment	Actions	Updated
develop-docs	Ignored	Preview	Oct 19, 2026 1:01pm UTC

[cursor]

The plan checks that the new option text is on the live page. It also checks client errors on that page and not-found counts on the same platform path. An issue escalates when the option text is missing or those client errors rise.

Rollout complete

Services: sentry-docs.

Plan

What changed

Requests to the SvelteKit build-options page now document buildTimeInstrumentation. The page also states that ssr.external skips build-time instrumentation for that package.
This change is live after a sentry-docs production deploy. The path is product docs, not developer docs.

Risk

A bad MDX render can break this static page or throw a client error on hydrate. Readers then lose the current build-options help.
The shared app shell did not change. Other SvelteKit guide pages share that shell. Watch this page first. Then watch other SvelteKit guide errors.

Intended effect

The live page must include the option name buildTimeInstrumentation. Fetch the production URL after deploy. absent means the page still serves and that name is missing.

Signal	Baseline	Window	Rule	Source
Live page text buildTimeInstrumentation	absent	fetch at 2026-10-19T13:10:19Z	must appear after deploy	GET https://docs.sentry.io/platforms/javascript/guides/sveltekit/configuration/build/
docs.page.load for path /platforms/javascript/guides/sveltekit/configuration/build/	4 loads in 7d, 0 in 48h	2026-10-12T13:10:19Z to 2026-10-19T13:10:19Z and 2026-10-17T13:10:19Z to 2026-10-19T13:10:19Z	do not use a rise as proof. Zero over 48h is already normal. Use the live page text as the effect.	Sentry org sentry project docs, environment:production path:"/platforms/javascript/guides/sveltekit/configuration/build/", sum(value, docs.page.load, counter, none)

Regression watch

A failed page shows as a new client error on this URL, or as a not-found on the JavaScript platform path. This page has very little traffic. Treat a new error on this URL as a fault even when volume is low.

Signal	Baseline	Window	Rule	Source
Error events on the build-options URL	0 per 24h, 1 per 7d	2026-10-18T13:10:19Z to 2026-10-19T13:10:19Z and 2026-10-12T13:10:19Z to 2026-10-19T13:10:19Z	hold at 0 per 24h. Pair with 4 page loads per 7d on the same path. A new error is a regression.	Sentry org sentry project docs, environment:production http.url:*platforms/javascript/guides/sveltekit/configuration/build*, count()
Error events on the SvelteKit guide	1 per last 24h. 181 events in the prior 24h were one title: Event Event (type=error) captured as promise rejection	2026-10-18T13:10:19Z to 2026-10-19T13:10:19Z and 2026-10-17T13:10:19Z to 2026-10-19T13:10:19Z	hold near 0-1 per 24h after deploy. Do not use the 181-event burst as the quiet band. If that title returns at that volume, it is likely unrelated noise. New titles or a rise in other errors is a regression.	Sentry org sentry project docs, environment:production http.url:*platforms/javascript/guides/sveltekit*, count() by title
docs.page.not_found for requested_path platforms/javascript	21 per last 24h, 53 per 48h, so 32 in the prior 24h. Band 21-32 per 24h	2026-10-18T13:10:19Z to 2026-10-19T13:10:19Z and 2026-10-17T13:10:19Z to 2026-10-19T13:10:19Z	hold in 21-32 per 24h. This counter keeps only two path segments, so one missing build page can hide here. If it rises, fetch the live build-options URL.	Sentry org sentry project docs, environment:production requested_path:"platforms/javascript", sum(value, docs.page.not_found, counter, none)

Not observable

Pageload duration for this URL is not usable. A 24h pageload trace query returned 0 samples at the 30% trace sample rate.
docs.page.not_found cannot slice to the build-options path. It stores only the first two segments.
Algolia search for the new option name is not in this telemetry set.
Whether readers understand the option is not measurable here.

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[cursor]

Verified in production

• The live build-options page now includes the new option and nearby errors stayed quiet.