mcp-api-tester Tools & Interfaces

For testing LLM APIs, an "MCP server" isn't a standard term. It's likely you're looking for a way to **mock**, **simulate**, or **proxy** an LLM API endpoint. Here are a few ways to approach this, along with their Chinese translations: **1. Mock Server (模拟服务器 - mó nǐ fú wù qì):** * **Concept:** A mock server simulates the behavior of a real LLM API. You define the expected requests and the corresponding responses. This is ideal for testing your application's logic without actually calling the LLM. * **Tools:** * **Mockoon:** A popular and easy-to-use mock server application. * **WireMock:** A more powerful and flexible tool, often used in Java environments. * **JSON Server:** A simple way to create a REST API from a JSON file. * **How it works:** You configure the mock server to listen on a specific port and define routes that match the API endpoints you want to test. When your application makes a request to the mock server, it returns the pre-defined response. **2. Proxy Server (代理服务器 - dài lǐ fú wù qì):** * **Concept:** A proxy server sits between your application and the real LLM API. It can intercept requests and responses, allowing you to: * **Inspect traffic:** See exactly what data is being sent and received. * **Modify requests/responses:** Change the data being sent to the LLM or the data being returned to your application. * **Simulate errors:** Force the API to return error codes to test your application's error handling. * **Rate limiting:** Simulate rate limits to test your application's behavior under load. * **Tools:** * **Charles Proxy:** A popular commercial proxy tool. * **Fiddler:** A free proxy tool from Telerik. * **mitmproxy:** A free and open-source interactive HTTPS proxy. * **How it works:** You configure your application to use the proxy server as its HTTP/HTTPS proxy. The proxy server then intercepts all traffic and allows you to inspect and modify it. **3. Local LLM (本地LLM - běn dì LLM):** * **Concept:** Run a smaller, open-source LLM locally on your machine. This allows you to test your application against a real LLM without relying on an external API. * **Tools:** * **llama.cpp:** A library for running LLaMA models on CPUs. * **Ollama:** A tool for running and managing LLMs locally. * **GPT4All:** A project that provides a GUI and API for running LLMs locally. * **How it works:** You download and install the local LLM and then configure your application to connect to it. This gives you full control over the LLM and allows you to test your application in a completely isolated environment. **4. API Simulation Library (API 模拟库 - API mó nǐ kù):** * **Concept:** Libraries that allow you to create mock API responses directly within your code. * **Examples:** * **Python:** `unittest.mock` (built-in), `responses` * **JavaScript:** `nock`, `jest.fn()` * **How it works:** You use the library to replace the actual API call with a mock function that returns a pre-defined response. This is useful for unit testing individual components of your application. **Which approach is best for you depends on your specific needs:** * **Simple testing with static responses:** Mock server (Mockoon, JSON Server) * **Inspecting and modifying API traffic:** Proxy server (Charles, Fiddler, mitmproxy) * **Testing against a real LLM without external dependencies:** Local LLM (llama.cpp, Ollama, GPT4All) * **Unit testing individual components:** API simulation library (unittest.mock, responses, nock) **Example Scenario (使用 Mockoon 的例子 - shǐ yòng Mockoon de lì zi):** Let's say you want to test your application's interaction with an LLM API that generates text completions. The API endpoint is `https://api.example.com/completions` and it expects a JSON payload like this: ```json { "prompt": "The quick brown fox", "max_tokens": 50 } ``` You can use Mockoon to create a mock server that listens on port 3000 and defines a route for `/completions`. The mock server would return a JSON response like this: ```json { "completion": "The quick brown fox jumps over the lazy dog." } ``` Your application would then be configured to send requests to `http://localhost:3000/completions` instead of `https://api.example.com/completions`. This allows you to test your application's logic without actually calling the real LLM API. **In summary (总结 - zǒng jié):** Instead of a specific "MCP server," you're likely looking for a way to simulate or mock an LLM API. Consider using a mock server, proxy server, local LLM, or API simulation library, depending on your testing requirements. Each approach offers different levels of control and complexity. Choose the one that best suits your needs.