HTTP Client

Evaliphy provides a built-in HTTP client fixture to simplify calling your RAG application's API. It's a higher-level interface over the native Fetch API, automatically handling retries, timeouts, and logging.

Usage in Evaluations

The httpClient is provided as a fixture in the evaluate function.

import { evaluate } from 'evaliphy';

evaluate('My RAG Test', async ({ httpClient }) => {
  const response = await httpClient.post('/chat', {
    query: "What is Evaliphy?"
  });

  const data = await response.json();
  // ... assertions
});

Methods

post(url, payload, options?)

Sends a POST request. The payload is automatically serialized to JSON.

const response = await httpClient.post('/api/v1/query', { text: "Hello" });

get(url, options?)

Sends a GET request.

const response = await httpClient.get('/api/v1/status');

put(url, payload, options?)

Sends a PUT request.

patch(url, payload, options?)

Sends a PATCH request.

delete(url, options?)

Sends a DELETE request.

stream(url, payload, options?)

Initiates a streaming request, suitable for LLM completions or Server-Sent Events (SSE). Returns an async iterator.

const stream = await httpClient.stream('/api/v1/chat/stream', { query: "..." });
for await (const chunk of stream) {
  console.log(chunk);
}

Handling Responses

The httpClient methods return an EvalResponse object.

• response.json(): Parses the response body as JSON.
• response.text(): Returns the response body as text.
• response.status: The HTTP status code.
• response.ok: Boolean indicating if the request was successful (status 200-299).
• response.headers: The response headers.

Session Management

Use withSession to create a scoped client that includes a specific session header, useful for multi-turn conversations.

const sessionClient = httpClient.withSession('X-Session-ID', 'user-123');
await sessionClient.post('/chat', { message: "First turn" });
await sessionClient.post('/chat', { message: "Second turn" });

Configuration

The HTTP client is configured via the http property in evaliphy.config.ts. See the Configuration page for details.