Runtime capabilities

Package: @cavi-ai/api-client Verified by: declaration + fixture + conformance test Contract: capabilities Version: 0.11.0 Stability: stable Source of truth: upstream-compatible-mirror Capability: supported

Capability declarations mirrored for compatible runtime clients.

Purpose and lifecycle

Lets callers gate optional operations without inferring runtime support from type presence.

Fetched from a runtime client and evaluated before each optional operation.

Packed declaration signatures

RuntimeCapabilities

/** Provider-declared capability profile. Returned by RuntimeClient. */
export type RuntimeCapabilities = {
    providerKind: string;
    protocolVersion?: string | null;
    auth?: {
        type?: string;
        required?: boolean;
    };
    supports: Partial<Record<RuntimeSurface, boolean>>;
};

Field constraints

• capability value: Documentation support states are supported, unsupported, conditional, or unknown.

Behavior

Errors: Capability discovery failures leave support unknown. Retry: Discovery may be retried under the provider transport policy. Cancellation: A cancellation capability does not guarantee a particular upstream termination latency. Streaming: Stream must be reported and implemented before use.

Dependencies

Capabilities: capability discovery Transports: provider-defined upstream transport

Valid example

{
  "stream": true
}

The caller also checks streamRun before streaming.

Invalid example

{
  "stream": "always"
}

Expected failure: The value does not match the packed capability field type.

Compatibility notes

Capabilities are observations of an upstream implementation, not protocol ownership claims.

Public symbols

• ./core/runtime:RuntimeCapabilities

Verification evidence

• declaration: docs/api-client/source/releases/0.11.0-manifest.json
• fixture: docs/examples/contracts/capabilities.ts
• conformance-test: src/__tests__/core/runtime/capabilities.test.ts