response

The response global object provides methods to control the HTTP response sent back to the client.

Methods

response.setHeader(name, value)

Sets a response header. Can be called multiple times for different headers. The default Content-Type is text/html.

response.setHeader("Content-Type", "application/json");
response.setHeader("X-Powered-By", "js-cgi");
response.setHeader("Cache-Control", "no-cache");

response.setStatus(code)

Sets the HTTP response status code. Default is 200.

// Redirect
response.setStatus(301);
response.setHeader("Location", "/new-page");

// Not found
response.setStatus(404);
print("<h1>Page not found</h1>");

// JSON API error
response.setStatus(400);
response.setHeader("Content-Type", "application/json");
print(JSON.stringify({ error: "Invalid request" }));

response.setCookie(name, value, options?)

Sets a cookie on the response. The optional third argument controls cookie attributes.

Options

Examples

// Simple cookie
response.setCookie("theme", "dark");

// Cookie with options
response.setCookie("session", "abc123", {
    maxAge: 86400,
    httpOnly: true,
    secure: true,
    sameSite: "Strict"
});

// Delete a cookie
response.setCookie("theme", "", { maxAge: 0 });

Common Patterns

JSON API Response

response.setHeader("Content-Type", "application/json");
response.setStatus(200);
print(JSON.stringify({ users: [{ id: 1, name: "Alice" }] }));

Redirect

response.setStatus(302);
response.setHeader("Location", "/login");

File Download

response.setHeader("Content-Type", "application/octet-stream");
response.setHeader("Content-Disposition", "attachment; filename=\"data.csv\"");
print("name,email\nAlice,alice@example.com");