SOCKS5h Proxy

SOCKS5h is the SOCKS5 proxy variant that keeps hostname resolution on the proxy side instead of the client side. In httpx.zig, you opt into that behavior by setting the proxy kind to .socks5h.

Why Use SOCKS5h

• Avoids local DNS lookups for proxied requests.
• Works well when the proxy can resolve private or internal hostnames.
• Matches the socks5h:// convention used by common HTTP tooling.

Client Example

const httpx = @import("httpx");

pub fn main() !void {
    var gpa: std.heap.DebugAllocator(.{}) = .init;
    defer _ = gpa.deinit();
    const allocator = gpa.allocator();

    var client = httpx.Client.initWithConfig(allocator, .{
        .proxy = .{
            .kind = .socks5h,
            .host = "127.0.0.1",
            .port = 1080,
        },
    });
    defer client.deinit();

    const response = try client.get("https://example.com", .{});
    defer response.deinit();
}

Behavioral Notes

• http proxy mode keeps the standard forward-proxy behavior.
• TLS requests still use CONNECT tunnels when needed.
• socks5h sends the hostname to the proxy so the proxy performs DNS resolution.

What to Verify

• The client connects through the SOCKS5h endpoint without resolving the target host locally.
• Requests to internal names or privacy-sensitive hostnames succeed when the proxy can resolve them.
• Existing HTTP proxy behavior remains unchanged for .kind = .http.