FAQ

How do I add retries and timeouts to fetch()? Use rust-fetch's client instead: new WasmClient({ timeoutMs: 10_000, retries: 3 }) times out each attempt (including the body) and retries network errors, timeouts and 408/429/5xx responses with exponential backoff and jitter, honouring Retry-After. POST and PATCH aren't retried unless you opt in. See Timeouts and Retries.

Is rust-fetch an alternative to axios? Yes, for most uses: it rejects on HTTP errors, has interceptors, timeouts, upload and download progress, and adds built-in retries, typed errors and WebSockets, with the same client in browsers and Node.js. axios is much smaller in a browser bundle (about 21 KB against 131 KB brotli). See Compared with fetch() and axios.

Does it work in browsers and Node.js? Both, with the same API: browsers and Web Workers (through bundlers such as Vite and webpack; call init() first) and Node.js 20, 22 and 24. TypeScript definitions are included. See Supported environments.

Is it faster than fetch()? In Node.js, the published client matches fetch() one request at a time and is ahead with large bodies, many requests in flight and sustained load, but behind on concurrent HTTPS. The native transport, not in the npm package yet, reached up to 1.95× fetch()'s throughput. In browsers it uses fetch() itself. See Performance.

How do I track upload progress? Pass onUploadProgress: ({ loaded, total }) => … to post, put or patch. See Upload progress.

How do I stream a response from an LLM API? For Server-Sent Events APIs (OpenAI-compatible and others), use client.events(url, { method: 'POST', body, messageType: 'json' }) and for await over it; it stops at data: [DONE]. For newline-delimited JSON APIs such as Ollama, use responseType: 'ndjson'. Both work in browsers and Node.js. See Server-Sent Events.

How do I reconnect a WebSocket automatically?client.websocket(url, { reconnect: true }) reconnects after failures and unexpected drops with exponential backoff, and reports failures as typed errors. See WebSockets.

How do I type the response body in TypeScript?client.get<User>('/users/42') resolves to HttpResponse<User>. See TypeScript.

Do I need to know Rust? No. The npm package is used from JavaScript or TypeScript like any other; Rust is only how the core is built. Rust developers can also use the crate directly.

Node.js aborted with "Fatal error in , line 0 # unreachable code". Is that rust-fetch? Probably, on Node.js 20 or 22 with rust-fetch 2.5.2 or earlier. It's a bug in V8 before 13: it could crash the process when it deoptimized client.get() during the call into WebAssembly, as bursts of cancelled or timed-out requests did. The process exits with SIGTRAP, and the native stack trace names Deoptimizer. 2.6.0 prevents it on Node.js 20 to 23 by turning off the V8 optimization involved (Limitations). On an earlier version, upgrade, or turn that optimization off yourself:

• on the command line: node --no-turbo-inline-js-wasm-calls app.js (Node.js doesn't allow this flag in NODE_OPTIONS);

• or from code that runs before rust-fetch is imported, such as a module preloaded with NODE_OPTIONS="--import ./no-wasm-inlining.mjs":

  // no-wasm-inlining.mjs
  import v8 from 'node:v8';
  v8.setFlagsFromString('--no-turbo-inline-js-wasm-calls');

Either one stopped the crash on 2.5.2 (none in 30 runs on Node.js 20, against 11 without). Node.js 24 isn't affected.