Cleanup and remove old preview format using /url/preview

[taranvohra]

It is no longer needed

[changeset-bot]

⚠️ No Changeset found

Latest commit: bf66f05

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[github-actions]

Summary of the deployments:

Version	URL	Status
Vercel		❌
Cloudflare	https://ae61e133-gitbook-open-v2-preview.gitbook.workers.dev	✅

Test content

Site	2v	2c
GitBook	/url/gitbook.com/docs	https://ae61e133-gitbook-open-v2-preview.gitbook.workers.dev/url/gitbook.com/docs
E2E	/url/gitbook.gitbook.io/test-gitbook-open	https://ae61e133-gitbook-open-v2-preview.gitbook.workers.dev/url/gitbook.gitbook.io/test-gitbook-open

[argos-ci]

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Build	Status	Details	Updated (UTC)
customers-v2-cloudflare (Inspect)	⚠️ Changes detected (Review)	19 changed	Mar 17, 2026, 4:48 PM
v2-cloudflare (Inspect)	⚠️ Changes detected (Review)	21 changed	Mar 17, 2026, 4:54 PM

[Copilot]

Pull request overview

This PR removes support for the legacy preview URL format (notably the https://preview/... host and /url/preview/... routes) and standardizes preview handling around GITBOOK_PREVIEW_BASE_URL (defaulting to https://sites.gitbook.com/preview/).

Changes:

• Remove legacy “preview host” support and update preview detection/identifier extraction to rely on GITBOOK_PREVIEW_BASE_URL.
• Update unit tests to use the new preview URL format and ensure the old format is treated as non-preview.
• Remove obsolete E2E coverage for the deprecated /url/preview/... route format.

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
packages/gitbook/src/middleware.ts	Removes legacy preview-host mention in route handling comments.
packages/gitbook/src/lib/preview.ts	Updates preview URL detection/identifier parsing and preview cookie URL scoping.
packages/gitbook/src/lib/preview.test.ts	Updates preview URL fixtures and assertions for new vs legacy formats.
packages/gitbook/src/lib/links.test.ts	Adjusts preview linker test fixture to reflect new preview URL structure.
packages/gitbook/src/lib/images/getImageResizingContextId.test.ts	Updates preview URL fixture used for context-id extraction.
packages/gitbook/e2e/internal.spec.ts	Drops E2E cases for the deprecated /url/preview/... format (new “Site Previews” suite remains).

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