The routes that make the typed storage reachable. Until now the manifest,
the resolver and the migration all existed with nothing able to call them.
GET /settings/contract serves the public manifest behind an ETag — clients
vendor a pinned copy and generate bindings from it, so the common request
asks "still the same contract?" rather than transferring it. Its
capabilities sibling reports revision and supported scopes for feature
detection instead of version sniffing.
/settings/values/{key} reads, writes and clears an explicit value at one
named scope, which is what a reset affordance needs: "did I set this here"
is a different question from "what applies", and the old endpoint could
only answer a blurred version of both. Scope comes from the query while
profile and device come from session headers, so one profile cannot address
another's settings by naming it.
/settings/values/effective resolves any number of keys in one request, with
the resolution ladder and the source of each answer reported so a client can
offer "reset this device's override" against the exact row holding it.
Asking for no keys returns every remote setting, which is what a settings
screen wants.
Writes are idempotent when a client sends X-Silo-Mutation-Id: a retry after
a dropped response replays the receipt, and reusing an id with different
content is a conflict rather than a silent overwrite of the wrong thing.
Three things the string-only endpoint could not do, each pinned by a test:
an unknown key is refused rather than stored in the extension bag, values
are checked against their declared type and range, and a write to a scope
the definition does not allow is rejected.
Registered before the catch-all /{key} routes, which would otherwise
swallow "contract" and "values" as setting names. The legacy endpoints stay
live for now; deleting them is the next commit, once their consumers move.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>