Registry / ai-ml / fetch-stream-observable

fetch-stream-observable

library1.1.2jsnpmunverified

A lightweight library that wraps the Fetch API to return an Observable from the zen-observable package, enabling stream-based responses (e.g., OpenAI chat completions). Current stable version 1.1.2. Actively maintained with TypeScript support and a small bundle (3.7 KB min+gzip). Key differentiators: built-in OpenAI stream parsing, automatic fallback to non-streaming responses, and additive text concatenation. Ideal for real-time data consumption in frontend frameworks like React.

ai-ml messaging

npm install fetch-stream-observable

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INSTALL

IMPORT

SIG · FETCH-STREAM-OBSER

fetch-stream-observable

ai-mljavascriptv1.1.2

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

fetchObservable

✓ import { fetchObservable } from 'fetch-stream-observable'

✗ const { fetchObservable } = require('fetch-stream-observable')

The package exports only fetchObservable as a named export. CommonJS require works but is discouraged in TypeScript bundlers.

Observable

✓ import { Observable } from 'zen-observable'

✗ import { Observable } from 'fetch-stream-observable'

Observable type is from zen-observable, not re-exported by this package.

FetchObservableOptions

✓ import type { FetchObservableOptions } from 'fetch-stream-observable'

✗ import { FetchObservableOptions } from 'fetch-stream-observable'

Options type is available as a TypeScript type export; use type import to avoid runtime errors.

Demonstrates fetching a streaming response from OpenAI's API using fetchObservable, subscribing to chunks, and unsubscribing after timeout.

import { fetchObservable } from 'fetch-stream-observable'; const apiKey = process.env.OPENAI_API_KEY ?? ''; const subscription = fetchObservable('https://api.openai.com/v1/chat/completions', { method: 'POST', headers: { 'Content-Type': 'application/json', Authorization: `Bearer ${apiKey}`, }, body: JSON.stringify({ model: 'gpt-4', messages: [{ role: 'user', content: 'Hello' }], stream: true, }), }).subscribe((data: string) => { console.log('Received chunk:', data); }); // To unsubscribe after 10 seconds setTimeout(() => subscription.unsubscribe(), 10000);

Debug

Known issues

gotchaThe 'subscribe' callback receives the entire accumulated response string when doNotConcatTextStream is false (default) and streaming is used. This may cause performance issues with large responses.

fix

Set doNotConcatTextStream: true to receive partial chunks instead.

affects: >=1.0.0

gotchaIf the response is not a stream (e.g., JSON), the observable calls subscribe only once with the full response. Do not assume multiple emissions.

fix

Handle non-streaming responses in the same subscribe callback, but only expect one emission.

affects: >=1.0.0

gotchaThe package depends on zen-observable. If you use a different Observable library (e.g., RxJS), you cannot directly chain operators without converting.

fix

Convert to RxJS observable: import { from } from 'rxjs'; const rxObs = from(fetchObservable(...));

affects: >=1.0.0

deprecatedThe option 'doNotParseOpenAIStream' is poorly named and may be confusing. It is not deprecated in terms of removal, but its usage is recommended to be left as false for typical OpenAI usage.

fix

Set doNotParseOpenAIStream: false (default) to enable automatic parsing of OpenAI stream deltas.

affects: >=1.0.0

Errors

Common errors & fixes

Cannot find module 'zen-observable'

Missing peerDependency zen-observable when using npm <7 or yarn without auto-install.

fix

Install zen-observable explicitly: npm install zen-observable

TypeError: fetchObservable is not a function

Incorrect import syntax, e.g., using default import instead of named import.

fix

Use named import: import { fetchObservable } from 'fetch-stream-observable'

Property 'subscribe' does not exist on type 'FetchObservable'

Missing zen-observable import or incorrect TypeScript type inference.

fix

Ensure zen-observable is installed and its types are available (usually shipped with package).

Upgrade

Version history

1.1.2latest on npm

Audit

Dependencies

zen-observablerequiredCore dependency providing the Observable implementation used by the returned fetch observable.

Agent activity

22 hits · last 30 days

node

OpenAI (training)

Resources

packagefetch-stream-observable ↗