CallApi

An advanced fetch library that actually solves real problems.

Documentation · Getting Started · Plugins

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Why?

Fetch is too basic for real apps. You end up writing the same boilerplate: error handling, retries, deduplication, response parsing etc. CallApi handles all of that and practically more.

Drop-in replacement for fetch. Under 6KB. Zero dependencies.

import { callApi } from "@zayne-labs/callapi";

const { data, error } = await callApi("/api/users");

Features

Request Deduplication - User spam-clicks a button? Handled. No race conditions.

const req1 = callApi("/api/user");
const req2 = callApi("/api/user"); // Shares req1's response

Smart Response Parsing - Looks at Content-Type, does the right thing.

const { data } = await callApi("/api/data"); // JSON? Parsed.

Error Handling - Structured errors you can actually use.

const { data, error } = await callApi("/api/users");
if (error) {
	console.log(error.name); // "HTTPError", "ValidationError"
	console.log(error.errorData); // Actual API response
}

Retries - Exponential backoff, custom conditions.

await callApi("/api/data", {
	retryAttempts: 3,
	retryStrategy: "exponential",
	retryStatusCodes: [429, 500, 502, 503],
});

Schema Validation - TypeScript types + runtime validation.

import { z } from "zod";
import { defineSchema, createFetchClient } from "@zayne-labs/callapi";

const api = createFetchClient({
	schema: defineSchema({
		"/users/:id": {
			data: z.object({
				id: z.number(),
				name: z.string(),
			}),
		},
	}),
});

const user = await api("/users/123"); // Fully typed + validated

Hooks - Intercept at any point.

const api = createFetchClient({
	onRequest: ({ request }) => {
		request.headers.set("Authorization", `Bearer ${token}`);
	},
	onError: ({ error }) => {
		Sentry.captureException(error);
	},
	onResponseStream: ({ event }) => {
		console.log(`Downloaded ${event.progress}%`);
	},
});

Plugins - Extend with middleware.

const cachingPlugin = definePlugin({
	id: "caching-plugin",
	name: "Caching plugin",

	middlewares: (ctx) => {
		const cache = new Map();

		return {
			fetchMiddleware: (fetchImpl) => async (input, init) => {
				const key = input.toString();

				if (cache.has(key)) {
					return cache.get(key).clone();
				}

				const response = await fetchImpl(input, init);
				cache.set(key, response.clone());

				return response;
			},
		};
	},
});

const callBackendApi = createFetchClient({
	plugins: [cachingPlugin],
});

URL Helpers - Dynamic params, query strings, method prefixes.

await callApi("/users/:id", { params: { id: 123 } });
await callApi("/search", { query: { q: "test" } });
await callApi("@delete/users/123");

And so much more.

Installation

npm install @zayne-labs/callapi

import { callApi, createFetchClient } from "@zayne-labs/callapi";

// Simple
const { data } = await callApi("/api/users");

// Configured
const api = createFetchClient({
	baseURL: "https://api.example.com",
	retryAttempts: 2,
	timeout: 10000,
	onError: ({ error }) => trackError(error),
});

CDN

<script type="module">
	import { callApi } from "https://esm.run/@zayne-labs/callapi";
</script>

What makes it worth considering?

• TypeScript-first - Full inference everywhere
• Familiar API - If you know fetch, you know CallApi
• Actually small - Zero dependencies and Under 6KB, unlike other 50kb libs in the wild
• Fast - Built on native Web APIs
• Works everywhere - Browsers, Node 18+, Deno, Bun, Cloudflare Workers

License

MIT © Ryan Zayne