The Para Server SDK enables secure server-side blockchain operations across different JavaScript runtime environments.
With nearly identical functionality to client-side implementations, the server SDK allows you to perform signing
operations server-side by either importing client-side sessions or using pregenerated wallets.
Installation
Install the Para Server SDK in your preferred JavaScript runtime environment:
npm install @getpara/server-sdk --save-exact
Why --save-exact? The Para Server SDK may publish breaking changes in minor versions during active development.
Pinning the exact version prevents unexpected breakage when you install or update dependencies.
Initialization
Initialize the Para Server SDK with your API key. The initialization process varies slightly depending on your runtime
environment:
import { Para as ParaServer } from "@getpara/server-sdk";
// Standard initialization for Node.js
const paraServer = new ParaServer("YOUR_API_KEY");
Runtime Compatibility
The Server SDK works across multiple JavaScript runtimes. Some runtimes require additional constructor options:
| Runtime | disableWebSockets | Notes |
|---|
| Node.js | Not needed | Full support out of the box |
| Bun | Required | Bun’s WebSocket implementation is incompatible with the SDK’s internal transport |
| Deno | Required | Same as Bun — the SDK falls back to HTTP polling |
| Cloudflare Workers | Required | Workers runtime doesn’t support persistent WebSocket connections |
If you omit disableWebSockets: true in Bun, Deno, or Cloudflare Workers, the SDK may fail silently or hang
during signing operations. Always set this option for non-Node.js runtimes.
Signing performance tip: Para’s signing infrastructure runs in us-east-1. For the lowest latency on server-side signing operations, deploy your application servers in or near that region.
If you’re using a legacy API key (one without an environment prefix) you must provide the
Environment as the first argument to the
ParaServer constructor. You can retrieve your updated API key from the Para Developer Portal at
https://developer.getpara.com/Pre-warm the MPC signer: The first signing operation loads the MPC WASM module and spawns a worker thread, which
adds latency. Call initializeWorker() after setup to pre-warm the signer so subsequent signing calls are fast:const paraServer = new ParaServer("YOUR_API_KEY");
await paraServer.initializeWorker();
Authentication Methods
After initializing the Para Server SDK, you need to authenticate it before performing any operations. The server SDK
supports two authentication methods:
Option 1: Importing Client Sessions
Import an active session from your client application when your backend needs to act for an authenticated user.
In your client application, export the authenticated session and send it to your backend:
const serializedSession = await para.waitAndExportSession();
await fetch("/api/import-session", {
method: "POST",
headers: { "Content-Type": "application/json" },
body: JSON.stringify({ session: serializedSession }),
});
waitAndExportSession() waits for the SDK to reach an authenticated state before exporting. Use it for client-to-server handoff flows immediately after login.
const sessionWithoutSigners = await para.waitAndExportSession({
excludeSigners: true,
});
Do not use { excludeSigners: true } when the server needs to sign messages or transactions for the user.
ParaServer instance:
import { Para as ParaServer } from "@getpara/server-sdk";
app.post("/api/import-session", async (req, res) => {
const paraServer = new ParaServer("YOUR_API_KEY");
await paraServer.importSession(req.body.session);
const isActive = await paraServer.isSessionActive();
return res.status(200).json({ isActive });
});
Create a new ParaServer instance for each imported user session. A server SDK instance holds one active session at a time.
Option 2: Using Pregenerated Wallets
Generate and use deterministic wallets server-side without requiring client-side authentication. This pregen wallet will load the para server instance with a wallet that can be used for all operations that the Para Server SDK supports.
import { WalletType } from "@getpara/server-sdk";
await paraServer.createPregenWallet({
type: 'EVM', // or 'SOLANA', 'COSMOS', 'STELLAR'
pregenId: { email: "user@example.com" },
});
When using pregenerated wallets, you’ll need to manage the user share of the wallet and store it securely.
Examples
Explore our example implementations of the Para Server SDK across different runtime environments:
Troubleshooting
If you encounter issues while setting up the Para Server SDK, check out our troubleshooting guide:
Next Steps
Once your Para Server SDK is set up and authenticated, you can start performing blockchain operations. The server SDK
provides the same functionality as the client SDK, allowing you to:
