Transport Selection Guide

Kruda ships with three transports. The default is Wing on Linux, fasthttp on macOS.

When to use which

Feature needed	Transport	Why
Maximum throughput (plaintext, JSON, DB)	Wing (default on Linux)	epoll+eventfd, zero-copy, no goroutine-per-conn
SSE (Server-Sent Events)	net/http	SSE requires http.Flusher streaming
Session cookies / Set-Cookie headers	net/http	Wing's fast path skips custom headers
HTTP/2, TLS termination	net/http	Wing is HTTP/1.1 only
WebSocket	net/http	WebSocket upgrade needs full HTTP semantics
Battle-tested HTTP/1.1 (chunked, expect-100)	fasthttp	Mature, widely deployed

Usage

// Default: Wing on Linux, fasthttp on macOS, net/http on Windows
app := kruda.New()

// Explicit net/http (for SSE, sessions, HTTP/2, TLS)
app := kruda.New(kruda.NetHTTP())

// Explicit fasthttp
app := kruda.New(kruda.FastHTTP())

// Explicit Wing
app := kruda.New(kruda.Wing())

Environment override

KRUDA_TRANSPORT=nethttp  ./myapp   # force net/http
KRUDA_TRANSPORT=wing     ./myapp   # force Wing
KRUDA_TRANSPORT=fasthttp ./myapp   # force fasthttp

Automatic fallback

• Wing + TLS config → auto-falls back to net/http (for HTTP/2)
• Wing on Windows → auto-falls back to net/http
• Unsupported OS → defaults to fasthttp (macOS) or net/http (Windows)

Wing limitations

Wing is optimized for raw throughput. It intentionally skips some HTTP features:

• No Set-Cookie in JSON fast path — Wing's JSON response builder bypasses custom headers for speed. Use kruda.NetHTTP() if your routes need cookies.
• No http.Flusher — SSE streaming requires flushing, which Wing doesn't support.
• No HTTP/2 — Wing speaks HTTP/1.1 only. Use kruda.NetHTTP() with TLS for HTTP/2.
• No chunked transfer encoding — Wing pre-computes Content-Length.

For apps that mix high-throughput API routes with session/SSE routes, run two instances or use net/http for the full app.