Core Server (http/server)

While most users will build APIs with the http/fiber framework, http/server gives you direct access to the the raw accept loop, request parser, and response builder.

Minimal Hello World

import { Server, Request, Response } from "http";

fn main(): i32 {
    let! srv = Server.new("0.0.0.0", 8080);
    srv.serve(handler);
    return 0;
}

fn handler(req: &Request, res: &Response!) {
    res.sendString(req.fd, "Hello, Vex!");
}

---

Request Parsing

Every incoming connection is consumed by the zero-copy parseRequest(fd) function. It reads up to 8KB from the socket and extracts the full request in a single pass using a byte-level scanner—no regex, no intermediate string allocations.

Request Struct

Field	Type	Description
method	string	"GET", "POST", "PUT", "DELETE", "PATCH", "HEAD", "OPTIONS"
path	string	URL path without query string (e.g. /api/users)
query	string	Raw query string (e.g. page=1&sort=name)
version	string	"HTTP/1.1" or "HTTP/1.0"
headers	Headers	Parsed header collection (case-insensitive)
body	string	Request body (for POST/PUT/PATCH)
fd	i32	Socket file descriptor
streamId	i32	HTTP/2 stream ID (0 for HTTP/1.1)
valid	bool	true if parsing succeeded
contentLength	i64	Parsed Content-Length value (-1 if absent)
keepAlive	bool	true if Connection != close

Request Accessor Methods

req.header("Authorization")    // Get header value (case-insensitive)
req.hasHeader("X-Custom")      // Check if header exists
req.isMethod("POST")           // Match method (case-sensitive)
req.hasBody()                  // true if body.len() > 0
req.contentType()              // Get Content-Type header value
req.isJSON()                   // true if Content-Type == "application/json"

Async Variant

For goroutine-per-connection servers, use the non-blocking parser:

let req = parseRequestAsync(fd);  // yields to scheduler on EAGAIN

---

Headers (Headers Collection)

Headers are stored as parallel Vec<string> arrays (names + values) with byte-level case-insensitive comparison. No Map overhead, no hash computation—just linear scan optimized for the typical 5–15 header count.

Method	Description
Headers.new()	Create empty collection
hdrs.get(name): string	Get value (case-insensitive), returns "" if not found
hdrs.has(name): bool	Check existence
hdrs.set(name, value)	Set/replace (removes existing, then appends)
hdrs.add(name, value)	Append (allows duplicates, e.g. Set-Cookie)
hdrs.del(name)	Remove all matching (in-place, zero-alloc)
hdrs.clear()	Remove all headers
hdrs.shrinkToFit()	Release excess capacity
hdrs.len(): i32	Count of headers

---

Cookies

The cookie.vx module provides full HTTP cookie parsing and Set-Cookie header serialization.

Building Cookies

import { Cookie } from "http";

// Simple session cookie
let session = Cookie.new("session_id", "abc123");
// → "session_id=abc123; Path=/; HttpOnly; SameSite=Lax"

// Persistent cookie (expires in 1 hour)
let remember = Cookie.persistent("remember", "yes", 3600);
// → "remember=yes; Max-Age=3600; Path=/; HttpOnly; SameSite=Lax"

// Deletion cookie
let logout = Cookie.delete("session_id");
// → "session_id=; Max-Age=0; Path=/"

// Set on response
res.header("Set-Cookie", session.toString());

Parsing Incoming Cookies

import { parseCookies } from "http";

let pairs = parseCookies(req.header("Cookie"));
// "session_id=abc123; theme=dark"
// → [CookiePair{name:"session_id", value:"abc123"}, CookiePair{name:"theme", value:"dark"}]

Cookie Fields

Field	Type	Description
name	string	Cookie name
value	string	Cookie value
path	string	Path attribute (default "/")
domain	string	Domain attribute (empty = current)
maxAge	i32	Max-Age in seconds (-1 = session, 0 = delete)
secure	bool	HTTPS only flag
httpOnly	bool	No JS access flag
sameSite	string	"Strict", "Lax", "None", or ""

---

Response Builder

import { Response, respondText, respondJSON, respondError, respondRedirect } from "http";

// Builder pattern
let! res = Response.new();
res.status(201)
   .header("X-Request-ID", "req-001")
   .contentType("application/json");
res.sendJSON(req.fd, "{\"created\": true}");

// One-liner convenience functions
respondText(fd, "Hello!");                    // 200 text/plain
respondJSON(fd, "{\"ok\":true}");             // 200 application/json
respondError(fd, 404, "Not Found");           // 404 with message
respondRedirect(fd, "/login");                // 302 redirect

---

Internal Parser Architecture

Underneath, request parsing is handled by a dedicated parser/ subsystem:

File	Purpose
parser/scanner.vx	Low-level byte scanner with position tracking
parser/request.vx	HTTP/1.1 request line + header parser
parser/fiber_request.vx	Optimized Fiber-compatible incremental parser
parser/headers.vx	Header-specific parsing logic
parser/body.vx	Body extraction with Content-Length validation
parser/chunked.vx	Transfer-Encoding: chunked decoder
parser/response.vx	Client-side response parser
parser/h2.vx	HTTP/2 frame parser
parser/hpack.vx	HPACK header compression (RFC 7541)
parser/huffman.vx	Huffman coding tables for HPACK
parser/ws.vx	WebSocket frame parser
parser/stream.vx	Streaming parser for large payloads