diff --git a/cmd/http/main.ha b/cmd/http/main.ha
index 8c05575..b7e9c16 100644
--- a/cmd/http/main.ha
+++ b/cmd/http/main.ha
@@ -4,18 +4,14 @@ use net::uri;
 use os;
 
 export fn main() void = {
-	const req = &http::request {
-		method = http::GET,
-		target = &uri::uri {
-			scheme = "http",
-			host = ip::LOCAL_V6,
-			path = "/",
-			...
-		},
-		body = void,
+	const client = http::newclient("Hare test client");
+	defer http::client_finish(&client);
+
+	const req = http::get(&client, &uri::uri {
+		scheme = "http",
+		host = ip::LOCAL_V6,
+		path = "/",
 		...
-	};
-	http::add_header(&req.header, "User-Agent", "Hare test client");
-	http::add_header(&req.header, "Content-Length", "100");
+	});
 	http::write_header(os::stdout, &req.header)!;
 };
diff --git a/net/http/client.ha b/net/http/client.ha
index e69de29..43a77ac 100644
--- a/net/http/client.ha
+++ b/net/http/client.ha
@@ -0,0 +1,143 @@
+use fmt;
+use io;
+use net::ip;
+use net::uri;
+use strconv;
+use strings;
+
+export type client = struct {
+	default_header: header,
+};
+
+// Creates a new HTTP [[client]] with the provided User-Agent string, which is
+// borrowed from the caller. Pass the return value to [[client_finish]] to free
+// resourfces associated with the HTTP client after use.
+export fn newclient(ua: str) client = {
+	let client = client { ... };
+	client_add_header(&client, "User-Agent", ua);
+	return client;
+};
+
+// Frees resources associated with an HTTP [[client]].
+export fn client_finish(client: *client) void = {
+	for (let i = 0z; i < len(client.default_header); i += 1) {
+		free(client.default_header[i].1);
+	};
+	free(client.default_header);
+};
+
+// Adds a default header which is included on all HTTP requests using a given
+// [[client]].
+export fn client_add_header(client: *client, name: str, val: str) void = {
+	add_header(&client.default_header, name, val);
+};
+
+fn new_request(client: *client, method: str, target: *uri::uri) request = {
+	let req = request {
+		method = method,
+		target = alloc(uri::dup(target)),
+		header = alloc(client.default_header...),
+		body = void,
+	};
+	if (req.target.port == 0) {
+		switch (req.target.scheme) {
+		case "http" =>
+			req.target.port = 80;
+		case "https" =>
+			req.target.port = 443;
+		};
+	};
+
+	let host = match (req.target.host) {
+	case let host: str =>
+		yield host;
+	case let ip: ip::addr =>
+		yield ip::string(ip);
+	};
+
+	if (req.target.scheme == "http" && req.target.port != 80) {
+		host = fmt::asprintf("{}:{}", host, req.target.port);
+	} else if (target.scheme == "https" && target.port != 443) {
+		host = fmt::asprintf("{}:{}", host, req.target.port);
+	} else {
+		host = strings::dup(host);
+	};
+
+	append(req.header, ("Host", host));
+
+	return req;
+};
+
+fn new_request_body(
+	client: *client,
+	method: str,
+	target: *uri::uri,
+	body: io::handle,
+) request = {
+	let req = new_request(client, method, target);
+	req.body = body;
+	request_set_content_length(&req, body);
+	return req;
+};
+
+fn request_set_content_length(req: *request, body: io::handle) void = {
+	const prev = match (io::seek(body, 0, io::whence::CUR)) {
+	case let off: io::off =>
+		yield off;
+	case io::error =>
+		return;
+	};
+	const ln = io::seek(body, 0, io::whence::END)!;
+	io::seek(body, prev, io::whence::SET)!;
+	add_header(&req.header, "Content-Length", strconv::ztos(ln: size));
+};
+
+// Prepares a new HTTP GET request for the given client and fills in the default
+// headers, such as User-Agent and Host. Provide the return value to [[do]] to
+// execute the request and free associated resources, or use [[request_finish]]
+// to free resources without executing the request.
+//
+// The URI parameter is borrowed from the caller for the lifetime of the request
+// object.
+export fn get(client: *client, target: *uri::uri) request = {
+	return new_request(client, GET, target);
+};
+
+// Prepares a new HTTP HEAD request for the given client and fills in the
+// default headers, such as User-Agent and Host. Provide the return value to
+// [[do]] to execute the request and free associated resources, or use
+// [[request_finish]] to free resources without executing the request.
+//
+// The URI parameter is borrowed from the caller for the lifetime of the request
+// object.
+export fn head(client: *client, target: *uri::uri) request = {
+	return new_request(client, HEAD, target);
+};
+
+// Prepares a new HTTP POST request for the given client and fills in the
+// default headers, such as User-Agent and Host. Provide the return value to
+// [[do]] to execute the request and free associated resources, or use
+// [[request_finish]] to free resources without executing the request.
+//
+// If the provided I/O handle is seekable, the Content-Length header is added
+// automatically.
+//
+// The URI parameter is borrowed from the caller for the lifetime of the request
+// object.
+export fn post(client: *client, target: *uri::uri, body: io::handle) request = {
+	return new_request_body(client, POST, target, body);
+};
+
+// Prepares a new HTTP PUT request for the given client and fills in the
+// default headers, such as User-Agent and Host. Provide the return value to
+// [[do]] to execute the request and free associated resources, or use
+// [[request_finish]] to free resources without executing the request.
+//
+// If the provided I/O handle is seekable, the Content-Length header is added
+// automatically.
+//
+// The URI parameter is borrowed from the caller for the lifetime of the request
+// object.
+export fn put(client: *client, target: *uri::uri, body: io::handle) request = {
+	return new_request_body(client, POST, target, body);
+};
diff --git a/net/http/header.ha b/net/http/header.ha
index 12f8200..da92f47 100644
--- a/net/http/header.ha
+++ b/net/http/header.ha
@@ -1,19 +1,20 @@
-use io;
 use fmt;
+use io;
+use strings;
 
 // List of HTTP headers.
 export type header = [](str, str);
 
-// Adds a given HTTP header, which may be added more than once. The provided
-// name and value are borrowed from the caller. The provided header name should
-// be canonicalized by the caller.
+// Adds a given HTTP header, which may be added more than once. The value is
+// duplicated, but the name is borrowed from the caller. The name should be
+// canonicalized by the caller.
 export fn add_header(head: *header, name: str, val: str) void = {
-	append(head, (name, val));
+	append(head, (name, strings::dup(val)));
 };
 
 // Sets the value of a given HTTP header, removing any previous values. The
-// provided name and value are borrowed from the caller. The provided header
-// name should be canonicalized by the caller.
+// value is duplicated, but the name is borrowed from the caller. The name
+// should be canonicalized by the caller.
 export fn set_header(head: *header, name: str, val: str) void = {
 	del_header(head, name);
 	add_header(head, name, val);
@@ -24,6 +25,7 @@ export fn set_header(head: *header, name: str, val: str) void = {
 export fn del_header(head: *header, name: str) void = {
 	for (let i = 0z; i < len(head); i += 1) {
 		if (head[i].0 == name) {
+			free(head[i].1);
 			delete(head[i]);
 			i -= 1;
 		};
diff --git a/net/http/request.ha b/net/http/request.ha
index d710a81..d081a8d 100644
--- a/net/http/request.ha
+++ b/net/http/request.ha
@@ -18,3 +18,14 @@ export type request = struct {
 	// I/O reader for the request body.
 	body: (io::handle | void),
 };
+
+// Frees state associated with an HTTP [[request]].
+export fn request_finish(req: *request) void = {
+	for (let i = 0z; i < len(req.header); i += 1) {
+		free(req.header[i].1);
+	};
+	free(req.header);
+
+	uri::finish(req.target);
+	free(req.target);
+};