Decoy

Decoy is a native macOS application designed for developers to create and manage local mock servers. It enables users to test webhooks, API wrappers, scrapers, and other integrations by simulating API and webhook endpoints directly on their Mac, without the need for Docker, cloud tunnels, or configuration files. The app focuses on simplicity and speed, offering instant startup and a streamlined interface built with SwiftUI.

my. Incoming requests to the mock server are displayed in real time, showing headers, body, source IP, timestamps, and UUIDs. JSON payloads are automatically formatted for readability, and binary data is presented as a hex dump. The tool allows users to customize responses by selecting from seven body types—plain text, JSON, HTML, XML, file, empty, or redirect—set any status code, add custom headers, and simulate latency to test timeout handling. js.

Additional features include the ability to export requests as code snippets in cURL, JavaScript fetch, or Ruby, support for parameterized paths (such as /users/:id), response snapshots to review what was sent back, and the option to serve files like images or PDFs. CORS headers are automatically handled, ensuring browser-based requests work seamlessly. The app also supports various redirect status codes, automatically setting the Location header as needed. All incoming requests are saved immediately to SQLite, preserving data even if the application quits unexpectedly.

99 and requires macOS 14 Sonoma or later. framework, and is designed to use minimal system resources while delivering fast, native performance.