Introduction — Shoal

Shoal is a feature-flag and remote-config service built for TypeScript teams. Ship code dark, release it to the right people, and roll back in one click.

Shoal separates deploying code from releasing it. You merge features behind a flag, ship them to production switched off, and turn them on for a teammate, a beta cohort or 5% of traffic — without another deploy.

QuickstartEvaluate your first flag in under five minutes.Core conceptsFlags, environments and targeting rules explained.Next.js guideServer components, middleware and edge evaluation.API referenceEvery REST endpoint with request and response examples.

How it works

Your app talks to Shoal through a small SDK. On start-up the SDK downloads the ruleset for its environment — a compact JSON document describing every flag — and evaluates flags locally. Evaluation never waits on the network, so a flag check costs microseconds.

app.ts

import { createClient } from "@shoal/sdk";

const shoal = createClient({ key: process.env.SHOAL_KEY! });

if (await shoal.isOn("new-checkout", { user: { id: "u_42", plan: "pro" } })) {
  renderNewCheckout();
}

When someone changes a flag in the dashboard, connected SDKs receive the update over a streaming connection within about a second.

Why Shoal

Typed flags. shoal generate writes a TypeScript union of your flag keys, so a typo is a compile error, not a silent false.
Local evaluation. No per-request network calls, no latency budget, works offline from the last known ruleset.
Edge-ready. The SDK runs in Node, Bun, Deno, browsers and edge runtimes with zero dependencies.
Audit everything. Every change records who, what and why, and can be reverted from the history view.