[adamsilverstein]

@jgraham asked for a web-features ID for Document-Isolation-Policy on the Interop proposal, so here is a first take: web-platform-tests/interop#1332 (comment)

I had Claude work through the contribution guide and precedents, this is the result:

Adds a document-isolation-policy feature for the Document-Isolation-Policy HTTP header, which makes a single document cross-origin isolated without needing COOP/COEP across the whole frame tree.

BCD has no data for the header yet, so this follows the intersection-observer-v2 pattern: a hand-set status with a TODO pointing at the BCD PR (mdn/browser-compat-data#30939) and a chromestatus link for the versions. Once that data is released, the override can be replaced with compat_features: [http.headers.Document-Isolation-Policy]. If it is preferred to wait for BCD and land this with compat_features from the start, that works too.

A few choices worth a look:

• ID and name: document-isolation-policy / "Document isolation policy", matching the header name, which is what developers search for.
• Group: security, alongside iframe-credentialless, which is the closest existing feature (another way to embed content while cross-origin isolated).
• Spec: the WICG draft, which is listed in browser-specs (npm run test:specs passes).
• Support: Chrome 137, Chrome Android 146, Edge 137, per https://chromestatus.com/feature/5141940204208128. The Edge version comes from Chromium and hasn't been checked against Edge release notes.

npm run dist, test:specs, test:schematypes, test:index, test:dist, Prettier and ESLint all pass locally.

AI Use

Written with 🤖 Claude Code, which drafted the feature file and this description. I will review and test.