atpkt

Modular AT Protocol SDK for Kotlin. Engineered for strict protocol adherence and type-safe integration.

01. Architecture

The atpkt SDK implements a decoupled library-first architecture. This design separates core networking and authentication from high-level service implementations.

• AtpAgent: Centralized interface providing hierarchical namespace access (agent.app.bsky).
• OAuthSessionManager: Automated session lifecycle management with native DPoP compliance.
• Jetstream: High-efficiency JSON-based event streaming via Kotlin Coroutines.
• XrpcClient: Type-safe XRPC communication engine with integrated protocol error decoding.

02. Integration

Dependency specification for Gradle environments:

dependencies {
    implementation("uk.ewancroft:atpkt:1.0.0")
}

03. Core Components

3.1 Authentication

The SDK manages authentication via the OAuthSessionManager. This component handles discovery, PAR, and token exchange.

val manager = OAuthSessionManager(client, sessionStore)
val session = manager.refreshSession(did).getOrThrow()

3.2 API Namespaces

Protocol endpoints are organized into type-safe namespaces generated via KotlinPoet AST.

val agent = AtpAgent(session)
val profile = agent.app.bsky.actor.getProfile(did = session.did)

3.3 Event Streaming

The JetstreamClient provides a reactive interface for network events.

val jetstream = JetstreamClient()
jetstream.subscribe(wantedCollections = listOf("app.bsky.feed.post"))
    .collect { event -> process(event) }

04. Validation

System integrity is maintained through a comprehensive test suite using Kotest and MockK, covering XRPC networking, session serialization, and lexicon adherence.