In an exciting development for developers, Microsoft has just unveiled DevProxy version 0.25, an advanced command-line tool designed for API simulation. This latest release boasts significant improvements in configuration management along with a handful of new usability features, making it a must-try for developers looking to enhance their API-related work.

DevProxy, which was previously known as Microsoft 365 Developer Proxy, serves as a powerful ally for developers by simulating a plethora of API and network behaviors. At its core, the tool acts as a proxy that deliberately fails on half of the requests by default, allowing developers to test how their applications behave under stress. It can also replicate throttling, rate-limiting, and sluggish API responses, providing a realistic testing ground and enabling the mocking of specific API responses. In conjunction with the dev tunnels CLI—akin to ngrok—DevProxy allows users to inspect communications between cloud services, offering insights into the messages exchanged during cloud interactions.

One of the standout features in version 0.25 is the introduction of the command `config new`, which facilitates the effortless creation of valid configuration files within the current directory. This feature aims to streamline the process of generating configuration files tailored for various scenarios.

Moreover, developers will appreciate the improvements made to the help command: when executing `devproxy -h`, the tool now displays only the built-in commands while also revealing installed plugins. This enhancement simplifies the discovery of available plugin options, which is crucial for boosting productivity. For added convenience, users can specify a JSON schema URL for plugin configuration files, with IntelliSense support available in Visual Studio Code, further easing the development process.

Version 0.25 also enhances the synergy between the command-line parameter `--urls-to-watch` and the configuration file for mock plugin requests. Developers can now define request URLs within the configuration file as `https://*/*`, with the ability for the command-line parameter to take precedence, allowing for greater flexibility in testing.

It's essential to note that this new version introduces some breaking changes that may require adjustments for users transitioning from earlier versions. Notably, the commands previously named `preset get` and `config` have been renamed to `config get` and `config open`, creating a more cohesive naming convention throughout the tool. Additionally, the rate parameter, which dictates the request failure rate, has been shifted from a global setting to specific plugins, particularly impacting the configuration for the GraphRandomError and GenericRandomError plugins.

Lastly, a new timeout parameter can now be specified, allowing users to set a time limit for the operation of DevProxy. If the tool is idle for too long, it will automatically shut down, ensuring efficient resource management.

With these substantial updates, DevProxy 0.25 not only reinforces its role as an essential tool for API simulation but also strengthens its standing within the .NET Foundation, a non-profit organization committed to supporting and enhancing the .NET ecosystem. If you're a developer seeking to elevate your API testing and configuration management, now is the perfect time to check out this powerful tool!