Gateway API Reference

The gateway JavaScript API is grouped by layer. These exports are intended for local foundation work, tests, and the v4.2.0 mock-only gateway foundation.

Protocol and Contracts

Status: stable foundation.

• Gateway protocol constants.
• Request validation and normalization helpers.
• Normalized error helpers.
• Provider adapter description helpers.
• Routing request and route decision constructors.

These helpers do not start servers, read credentials, or call providers.

Runtime Registry

Status: metadata-only.

• buildGatewayRegistrySnapshot
• Provider, model, local-model, and routing-preset registry helpers.
• Registry loader, normalization, and validation helpers.

Registry snapshots are deterministic and runtime-readable. They do not read credential values, probe local engines, or contact provider URLs.

Routing

Status: dry-run only.

• Candidate creation and filtering.
• Routing policy normalization.
• Deterministic scoring.
• Route resolution and dry-run route planning.
• Fallback-chain planning.

Routing functions return decisions and explanations. They do not execute requests or fallback attempts.

Resilience

Status: simulation-only.

• Failure classification.
• Retry eligibility.
• Backoff planning.
• Timeout budget planning.
• Fallback transition planning.
• Circuit-breaker simulation.
• Rate-limit and quota response planning.
• Full resilience simulation.

Resilience APIs use caller-supplied simulated outcomes. They do not sleep, retry, persist state, or call providers.

Runtime

Status: local mock & governed non-stream (v4.3 Sprint E1).

• createGatewayServer
• createExecutionDispatcher
• validateGovernedRuntimeConfig
• Gateway runtime config validation.
• Mock provider & governed non-stream dispatcher.
• Request body, response, SSE, timeout, auth, and lifecycle helpers.

The runtime supports localhost mock /health, /v1/models, and /v1/chat/completions (both mock non-stream/stream and governed external non-stream execution via injected transport). External streaming is deferred to Sprint E2.

Clients

Status: preview-only.

• Client profile registry.
• Endpoint normalization.
• Compatibility validation.
• Config preview generation.
• Local compatibility harness.
• Redacted diagnostics.

Client APIs generate previews and tests against the mock runtime. They do not write global configuration, install third-party clients, or execute those clients.

Observability

Status: local in-memory.

• createGatewayObservabilityCollector
• Event, trace, usage, cost, metrics, health, redaction, query, and snapshot helpers.

Observability is bounded and redacted. It does not persist logs, upload telemetry, retain prompt/completion content by default, or probe external providers.