@solana/keychain-para

Para MPC signer for Solana transactions using Para's REST API.

Installation

pnpm add @solana/keychain-para

Prerequisites

1. A Para account with API access
2. A Para secret API key (server-side only, starts with sk_)
3. A Solana wallet created via the Para REST API or dashboard

Usage

Create and Initialize

import { createParaSigner } from '@solana/keychain-para';

// Create and initialize the signer (fetches public key from Para API)
const signer = await createParaSigner({
    apiKey: 'your-para-secret-key',
    walletId: 'your-para-wallet-id',
});

console.log('Signer address:', signer.address);

Sign Messages

import { createSignableMessage } from '@solana/signers';

const message = createSignableMessage('Hello, Para!');
const [signatures] = await signer.signMessages([message]);

Sign Transactions

// Sign transactions using Para's API
const [signatures] = await signer.signTransactions([transaction]);

Check Availability

const available = await signer.isAvailable();
console.log('Para wallet available:', available);

With Rate Limiting

If you're signing multiple transactions/messages concurrently and want to avoid rate limits:

const signer = await createParaSigner({
    apiKey: 'your-para-secret-key',
    walletId: 'your-para-wallet-id',
    requestDelayMs: 100, // 100ms delay between concurrent requests
});

Configuration

ParaSignerConfig

| Field | Type | Required | Description | |-------|------|----------|-------------| | apiKey | string | Yes | Your Para secret API key (starts with sk_) | | walletId | string | Yes | The Para wallet UUID to use for signing | | apiBaseUrl | string | No | Custom API base URL (default: https://api.getpara.com) | | requestDelayMs | number | No | Delay in ms between concurrent signing requests (default: 0) |

How It Works

1. Initialization: Fetches the wallet's public key from Para's REST API during creation
2. Signing: Sends raw bytes (hex-encoded) to Para's /v1/wallets/:walletId/sign-raw endpoint
3. Response: Decodes the hex-encoded Ed25519 signature from Para's response

Para uses MPC (Multi-Party Computation) for key management — private keys are never assembled in a single location.

Error Handling

The signer will throw errors with specific codes from @solana/keychain-core:

• CONFIG_ERROR - Invalid configuration (missing apiKey or walletId)
• HTTP_ERROR - Network request failed
• REMOTE_API_ERROR - Para API returned an error
• PARSING_ERROR - Failed to parse Para response

import { SignerErrorCode } from '@solana/keychain-core';

try {
    await signer.signMessages([message]);
} catch (error) {
    if (error.code === SignerErrorCode.REMOTE_API_ERROR) {
        console.error('Para API error:', error.message);
    }
}

Security Notes

• Store your secret key securely (use environment variables)
• Never expose your secret key in client-side code — it starts with sk_ for a reason
• This signer is intended for server-side use or secure environments
• Para handles key management via MPC — your private keys never leave Para's infrastructure

Resources

• Para REST API Documentation
• Create a Wallet
• Sign Raw Data

License

MIT