Typed, inspectable HTTP requests on top of fetch.

Build requests as immutable values, preview them, render cURL, validate responses, then execute.

Install · Example · Model · Features · Runtime · Guides

npm install avirx

import { avirx } from 'avirx';

const Book = {
    parse(input: unknown): { id: string; title: string } {
        if (typeof input !== 'object' || input === null) throw new Error('Expected a book.');
        const value = input as Record<string, unknown>;
        if (typeof value.id !== 'string' || typeof value.title !== 'string') {
            throw new Error('Expected a book id and title.');
        }
        return { id: value.id, title: value.title };
    },
};

const api = avirx('https://api.example.com');

const request = api
    .get('/books/{id}')
    .path({ id: 'book_123' })
    .query({ include: ['author', 'reviews'] });

console.log(await request.preview());
console.log(await request.curl());

const book = await request.as(Book);

Avirx treats requests as values. Build a request once, then inspect, clone, or execute it without hidden mutation.

const result = await api
    .get('/books/{id}')
    .path({ id: 'missing' })
    .result(Book);

if (!result.ok) {
    console.log(result.status);
}

• Immutable fluent request builders
• Typed path parameters from route strings
• Query, JSON body, multipart upload, and download helpers
• Runtime schema validation with any parser that exposes parse
• Result mode for expected HTTP failures
• Redacted preview and cURL output
• Auth, timeout, retry, hooks, cache, concurrency, and rate-limit policies
• Zero runtime dependencies

Avirx requires Node.js 18.17 or newer, or any runtime with compatible fetch, Request, Response, Headers, Blob, FormData, ReadableStream, performance.now(), and AbortSignal.any APIs. The package is ESM-only; TypeScript consumers require TypeScript 5.0.4 or newer.

• API and contracts
• Compatibility and v1 promises
• Runtime behavior
• Policies
• Comparison