@solana/keychain-cdp

@solana/keychain-cdp

Coinbase Developer Platform (CDP) signer for Solana transactions using CDP's managed wallet infrastructure.

Installation

pnpm add @solana/keychain-cdp

Usage

Create and Initialize

import { createCdpSigner } from '@solana/keychain-cdp';

// API keys are created at https://portal.cdp.coinbase.com
const signer = await createCdpSigner({
    cdpApiKeyId: process.env.CDP_API_KEY_ID!,
    cdpApiKeySecret: process.env.CDP_API_KEY_SECRET!,
    cdpWalletSecret: process.env.CDP_WALLET_SECRET!,
    address: process.env.CDP_SOLANA_ADDRESS!,
});

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

Sign Messages

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

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

Sign Transactions

import {
    createTransactionMessage,
    pipe,
    setTransactionMessageFeePayerSigner,
    setTransactionMessageLifetimeUsingBlockhash,
    signTransactionMessageWithSigners,
} from '@solana/kit';

const transaction = pipe(
    createTransactionMessage({ version: 0 }),
    tx => setTransactionMessageFeePayerSigner(signer, tx),
    tx => setTransactionMessageLifetimeUsingBlockhash({ blockhash, lastValidBlockHeight }, tx),
);
const signed = await signTransactionMessageWithSigners(transaction);

Check Availability

const available = await signer.isAvailable();
console.log('CDP API available:', available);

API Reference

createCdpSigner(config)

Creates and initializes a new CdpSigner instance.

Config options:

• cdpApiKeyId (string, required): CDP API key ID
• cdpApiKeySecret (string, required): Base64-encoded Ed25519 key (64 bytes: seed || pubkey)
• cdpWalletSecret (string, required): Base64-encoded PKCS#8 DER EC (P-256) private key
• address (string, required): Solana account address managed by CDP
• baseUrl (string, optional): Custom API base URL (defaults to https://api.cdp.coinbase.com)
• requestDelayMs (number, optional): Delay in ms between concurrent signing requests to avoid rate limits (default: 0)

Returns: Promise<CdpSigner>

Methods

• signMessages(messages): Signs one or more messages (UTF-8 strings only)
• signTransactions(transactions): Signs one or more transactions
• isAvailable(): Checks if the CDP API is reachable
• address: Read-only property containing the signer's Solana address

How It Works

1. Initialization: Validates Ed25519 API key (seed/pubkey match) and loads P-256 wallet key
2. Authentication: Every signing request sends two JWTs — an Ed25519 auth JWT and an ES256 wallet JWT with request body hash
3. Signing: Sends transactions/messages to CDP's signing API endpoint
4. Extraction: For transactions, uses extractSignatureFromWireTransaction to extract the signer's signature from CDP's signed wire transaction. For messages, decodes the base58-encoded signature directly from the response.

Security Notes

• Store your cdpApiKeySecret and cdpWalletSecret securely (use environment variables)
• Never expose credentials in client-side code
• This signer is intended for server-side use or secure environments
• CDP handles key management — your signing keys never leave CDP's infrastructure