@iyulab/http-client

An HTTP client library for browsers.
Supports general requests, file upload/download, and multiple stream response formats using both Fetch API and XMLHttpRequest.

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📦 Installation

npm install @iyulab/http-client

🤖 Skills Usage

This package includes an Agent Skill that helps AI coding agents understand and use this library.

Via GitHub (recommended):

npx skills add iyulab/node-http-client

Via local node_modules:

npx skills add ./node_modules/@iyulab/http-client/skills/iyulab-http-client

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🚀 Usage Examples

Basic HTTP Requests

import { HttpClient } from "@iyulab/http-client";

const client = new HttpClient({
  baseUrl: "https://api.example.com",
  headers: {
    "Authorization": "Bearer your-token",
  },
});

// GET request
const res = await client.get("/users");
const users = await res.json();
console.log(users);

// POST request
const postRes = await client.post("/messages", { text: "Hello" });

File Upload

const file = new File(["hello"], "hello.txt");
for await (const response of client.upload({
  method: "POST",
  path: "/upload",
  body: file,
})) {
  if (response.type === "progress") {
    console.log(`Progress: ${response.progress}%`);
  } else if (response.type === "success") {
    console.log("Upload success:", response.status);
  } else {
    console.error("Upload failed:", response.message);
  }
}

File Download

client.download({
  path: "/files/sample.pdf",
});

Stream Response Handling

const response = await client.get("/stream");

// Auto-detection (based on Content-Type header)
for await (const item of response.stream({ format: 'auto' })) {
  console.log(item.type, item.data);
}

// SSE stream
for await (const event of response.streamAsSse()) {
  console.log(`[${event.event}]`, event.data);
}

// JSON Object stream
for await (const json of response.streamAsJson()) {
  console.log(JSON.parse(json.data));
}

// Text stream
for await (const line of response.streamAsText()) {
  console.log(line.data);
}

Request Cancellation and Timeout

import { CancelToken, CanceledError } from "@iyulab/http-client";

const token = new CancelToken();

setTimeout(() => token.cancel("User cancelled"), 2000);

try {
  await client.get("/slow-endpoint", token);
} catch (error: any) {
  if (error instanceof CanceledError) {
    console.error("Request was cancelled:", error.message);
  } else {
    console.error("Error during request:", error);
  }
}

Interceptors (onRequest / onResponse / onError)

const client = new HttpClient({
  baseUrl: "https://api.example.com",
  onRequest: (_req, headers) => {
    headers.set("Authorization", `Bearer ${getToken()}`);
  },
  onResponse: async (res) => {
    // res.response gives body access (json/text/...) before the caller receives it.
    // Throwing here short-circuits the pipeline: send() rejects with that error
    // instead of returning a response, and onError still runs afterward.
    if (res.status === 401) {
      const body = await res.response.json<{ message?: string }>().catch(() => null);
      throw new SessionExpiredError(body?.message);
    }
  },
  onError: ({ error }) => {
    console.error("Request failed:", error);
  },
});

⚠️ The response body can only be consumed once (Fetch API constraint). If onResponse reads it via res.response, don't try to read it again from the value send()/get()/post() returns — this pattern is meant for hooks that fully handle the error case (parse, then throw) rather than pass the body through.

🔧 Configuration Options

You can configure the client through the HttpClientConfig interface:

Option	Description
baseUrl	Base URL to be applied to all requests
headers	Request headers (e.g. Authorization, Content-Type, etc.)
credentials	Whether to include credentials (include, omit, same-origin)
mode	Request mode (cors, same-origin, etc.)
cache	Cache policy settings
timeout	Request timeout (in milliseconds)
keepalive	Whether to keep requests alive during page unload
onRequest	Called before each request; can mutate headers
onResponse	Called after each response, before it's returned; response.response gives body access. Throwing here short-circuits the pipeline (see Interceptors)
onError	Called when a request throws (network error, timeout, or a hook throwing)

📄 License

MIT © iyulab

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