Node.js quickstart
1. Install hypertune
hypertune
Once you have a Node.js application ready, install Hypertune's JavaScript SDK:
npm install hypertune
2. Set environment variables
Define the following environment variables in your .env
file:
HYPERTUNE_TOKEN=token
HYPERTUNE_OUTPUT_DIRECTORY_PATH=src/generated
Replace token
with your main project token which you can find in the Settings tab of your project.
3. Generate the client
Generate a type-safe client to access your flags by running:
npx hypertune
4. Use the client
Install the dotenv
package or ensure you have another way to load environment variables:
npm install dotenv
npm install -D @types/dotenv
Add a new file called loadEnv.ts
that loads environment variables with dotenv
:
import * as dotenv from "dotenv";
dotenv.config();
Add a new file called getHypertune.ts
that exports a getHypertune
function:
import { createSource } from "../generated/hypertune";
const hypertuneSource = createSource({
token: process.env.HYPERTUNE_TOKEN!,
});
export default async function getHypertune() {
// Get flag updates in serverless environments
// await hypertuneSource.initIfNeeded();
return hypertuneSource.root({
args: {
context: {
environment:
process.env.NODE_ENV === "development"
? "development"
: "production",
user: { id: "1", name: "Test", email: "[email protected]" },
},
},
});
}
To access flags, use the getHypertune
function:
import "./lib/loadEnv";
import express from "express";
import getHypertune from "./lib/getHypertune";
const app = express();
const port = 3000;
app.get("/", async (req, res) => {
const hypertune = await getHypertune();
const exampleFlag = hypertune.exampleFlag({ fallback: false });
res.json({ exampleFlag });
});
app.listen(port, () => {
console.log(`Server is listening on port ${port}`);
});
5. (Optional) Include a build-time logic snapshot
To improve reliability, you can include a snapshot of your flag logic in the generated client at build time. The SDK will instantly initialize from the snapshot first before fetching the latest flag logic from Hypertune Edge.
Add the following environment variable to your .env
file:
HYPERTUNE_INCLUDE_INIT_DATA=true
Then regenerate the client.
You can keep the snapshot fresh by setting up a webhook to regenerate the client on every Hypertune commit. In this case, you don't need to initialize from Hypertune Edge at all, eliminating network latency and bandwidth, improving both performance and efficiency.
That's it
Now you can update the logic for exampleFlag
from the Hypertune UI without updating your code or waiting for a new build, deployment or service restart.
To add a new flag, create it in the Hypertune UI then regenerate the client.
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