Changelog¶

All notable changes to relay are documented in this file.

[0.3.0] - Phase G: Protocol Extensions¶

WebSocket support (websocket.go) - full-duplex connections with typed message handlers, ping/pong keepalive, and automatic reconnection
Dynamic TLS watcher (tls_watcher.go) - hot-reload TLS certificates from disk without restarting the client; watches for file changes and rotates credentials transparently
Transport adapters (transport_adapters.go) - plug in custom http.RoundTripper implementations; includes built-in adapters for Unix socket, in-memory, and custom dial functions
HTTP/3 QUIC extension (ext/http3/) - QUIC transport via quic-go; automatic fallback to HTTP/2 when QUIC is unavailable

Bulkhead isolation - per-endpoint concurrency limits using semaphores to prevent one slow upstream from consuming all goroutines
Request hedging (hedging.go) - send a duplicate request after a configurable delay; the fastest response wins, improving tail latency
Content negotiation - automatic Accept and Content-Type header management with codec registration (JSON, CBOR, MessagePack, XML)
Timeout tiers (config.go) - separate dial, TLS handshake, response header, and total request timeouts
Typed pagination (pagination.go) - generic Paginator[T] that follows Link, cursor, offset, or custom next-page strategies
Circuit breaker - token-bucket state machine that opens after N failures and probes recovery after a configurable timeout
DNS cache - in-process DNS resolution cache with configurable TTL to reduce DNS lookup latency

Semantic hooks - typed lifecycle hooks: OnRequest, OnResponse, OnError, OnRetry
Idempotency keys (idempotency.go) - automatic Idempotency-Key header injection with configurable generators
Response classification (classification.go) - categorise responses into success, client error, server error, redirect with structured error types
Generic decode helpers (generics.go) - relay.Decode[T]() and relay.DecodeSlice[T]() for zero-boilerplate typed response parsing
Redirect chain (response.go) - Response.RedirectChain() exposes the full list of intermediate URLs followed during a redirect

Declarative request builder with method chaining
Automatic JSON marshal/unmarshal for request bodies and responses
Configurable retry with exponential backoff, jitter, and per-status-code policies
BaseURL + path composition
Context propagation and cancellation support
Structured error types with status code and body access
Default headers and query parameters
Basic authentication and Bearer token helpers
http.RoundTripper transport slot for full customisation