Reference
API reference documentation for Capa SDK.
This section contains API reference documentation for Capa SDK components.
API Documentation
Capa provides a unified API layer for cloud application development. The following reference documentation is available:
Core APIs
- Service Invocation (RPC) - HTTP/gRPC service-to-service communication
- Configuration - Dynamic configuration management
- Pub/Sub - Publish and subscribe messaging
- State Management - Key-value state storage
- Telemetry - Logging, metrics, and distributed tracing
API Specifications
The Capa API specifications follow community standards and are defined in the cloud-runtimes-jvm repository.
1 - Versions and Compatibility
Published versions and compatibility boundaries across Capa APIs, SDKs, runtimes, and adapters.
Capa API contracts, SDKs, runtimes, and cloud adapters are released independently. Match versions at the integration boundary instead of assuming that every repository shares one version.
Current documented versions
| Component | Version or status | Purpose |
|---|
| cloud-runtimes-jvm | 1.19.RELEASE | JVM API contracts and partial runtime adapters |
| capa-java | 1.11.13.2.RELEASE | Java rich SDK |
| capa-java-aws | 1.11.13.5.RELEASE | AWS SPI modules for Capa Java |
| cloud-runtimes-golang | Interface specification | Go API contracts; no bundled runtime implementation |
| cloud-runtimes-python | Alpha source API | Install from source until a corrected package is published |
| capa | Experimental | Go sidecar/runtime with a separate implementation roadmap |
Compatibility rules
- Use the exact SDK and adapter versions documented by the adapter repository.
- Confirm that the selected adapter implements every operation used by the application.
- Treat API presence as a contract definition, not proof of runtime support.
- Run integration tests against the target middleware or cloud service before production deployment.
- Review release notes and source changes before upgrading across minor or release-suffix versions.
For Java API types, start with the cloud-runtimes-api source. For Java SDK usage, use the capa-java examples.