httpbun.com

What It Is

Httpbun is a service for testing HTTP client behavior, targeting browsers, HTTP client libraries, developer tools, and other systems that issue HTTP requests. It is inspired by httpbin, but the author explicitly positions it as filling in some capabilities missing from httpbin, such as /mix, /run, a Mock OAuth2 provider, a Mock LLM API endpoint, custom path prefixes, and more flexible request handling.

Core Features and Ecosystem

Its most distinctive feature is the /mix endpoint, which can combine multiple response behaviors into a single URL—for example, setting the status code, response headers, cookies, redirects, or response body at the same time. /mix supports directives such as s, h, c, r, b64, t, and end. Among them, t can render base64-decoded content as a Golang text template for the response body, making it suitable for building dynamic mock responses. In addition, Httpbun offers RequestBin-like capabilities, /payload, support for request bodies on /get, arbitrary HTTP methods on endpoints such as /headers, and it does not hide certain response headers. It also provides a Mock OAuth2 provider and a Mock LLM API endpoint compatible with OpenAI SDK chat completions, though these features are currently marked as Beta.

Hosting, Pricing, and Documentation

The text lists several hosted versions: the canonical version is at httpbun.com, with additional backup domains such as ant, bat, cat, and dog that can be used to test load balancing and routing algorithms. self-signed-cert.httpbun.com is suitable for testing how clients handle self-signed HTTPS certificates. The page mentions GitHub Stars, indicating that the project at least has a public GitHub page, but it does not clearly state the license, the full open-source scope, or deployment steps. Pricing, SLA, support channels, and payment methods are not disclosed.

Pros, Cons, and Best-Fit Users

Its strengths are that its features are designed around real HTTP debugging scenarios, and its composable endpoint model is more flexible than traditional single-purpose test APIs. It also covers OAuth2 and LLM API mocking, matching current development and testing needs. The downsides are that some core extensions are still in Beta, there is limited information about enterprise-grade stability and long-term support, and the documentation captured here is incomplete. It is suitable for backend engineers, SDK developers, DevTools teams, and test engineers who need to quickly validate HTTP client behavior, load balancing, certificate handling, and API mocks.

Access from China

The text does not mention network accessibility from mainland China, mirrors, ICP filing, or payment methods, so its accessibility from China is unknown. If access is unstable, self-hosting or similar alternatives such as httpbin may be worth considering.