runtime

Hand-written base module for the AT Protocol Kotlin SDK. Kotlin Multiplatform (JVM + iOS) library that every generated model and service depends on.

What's in here

• Typed value classes for every AT Protocol string format: Did, Handle, AtIdentifier, AtUri, Cid, Datetime, Nsid, RecordKey, Language. Use these instead of raw strings — they're zero-overhead and prevent mixing.

• AtField<T> — three-state optionality (Missing / Null / Defined) for mutation payloads where "absent" and "null" are distinct wire states (e.g. putPreferences).

• OpenUnion infrastructure — base types and serializers for sealed-interface unions with a $type discriminator and an Unknown fallback for forward compatibility.

• XrpcClient — Ktor-backed client wrapping a caller-supplied HttpClient. Exposes query() for GETs, procedure() for POSTs. Generated *Service classes wrap this; prefer those for lexicon endpoints.

• AuthProvider — pluggable auth interface. NoAuth for unauthenticated calls; bearer-token and DPoP implementations live in consumer modules (e.g. oauth).

• paginate() / paginatePages() — generic Flow builders for cursor-paginated endpoints. Generated *Flow() / *PageFlow() extensions on service classes call these under the hood.

• Record encode/decode helpers — encodeRecord() injects $type for mutation payloads; decodeRecord<T>() extracts typed records from JsonObject values on the wire.

Typical consumers

• models — declares api(project(":runtime")) so every downstream project transitively picks up the runtime types.

• oauth — builds on AuthProvider and XrpcClient.

• Application code — usually never touches XrpcClient directly; constructs <Namespace>Service(client) from models.