Install policy

Install policy is a dedicated resource, not project PATCH JSON. It marks multi-file paths as Keep if exists (KEEP_IF_EXISTS).

When to use

Use with multi-file package_type when local user files should be kept. Single-file lines have no Manifest path policy.

Configuration entry

Settings → Install policy templates or channel Install policy. Steps: Install policy.

Rules and error codes

On the same (os, arch), channel rules overlay project rules by path. Only later new Manifests are stamped. Ignore _keep.json / keep_if_exists.txt. Reference Manifest uses in-channel CompareVersions, not versions?latest=true. Unknown matrix pair → 400 INVALID_REQUESTIllegal body/fields (including non-.mmdb, caps, unknown matrix pair, duplicate listing). Illegal path → INVALID_PATHIllegal path.

KEEP_IF_EXISTS is metadata; integrity still uses Manifest SHA. Official SDKs may omit that path from needed_paths when the file already exists.

Related: Incremental updates, Platform matrix.