snap-solana-sdk

Shielded agent-to-agent payments on Solana with automatic Groth16 proof generation.

Status: snap-solana-sdk is for the SNAP limited release. It is not audited production software.

Quick Start

SNAP is live on Solana mainnet. Install and try it:

npm install snap-solana-sdk @solana/web3.js @coral-xyz/anchor

import { SNAPClient } from "snap-solana-sdk";
import { Connection, Keypair, PublicKey } from "@solana/web3.js";

const connection = new Connection("https://api.mainnet-beta.solana.com");
const wallet = Keypair.generate();

const snap = new SNAPClient(connection, wallet);

// Deposit into the shielded pool
const POOL = new PublicKey("B8SyffZKt8LABKogWjH9rZcjY5PV2hyYRCbTxxbcrpFf");
const note = await snap.deposit(POOL);

// Share `note` with the recipient off-chain
const serialized = SNAPClient.serializeNote(note);

// Recipient withdraws with ZK proof
const restored = SNAPClient.deserializeNote(serialized);
const recipientKeypair = Keypair.generate();
const recipientSnap = new SNAPClient(connection, recipientKeypair);
const tx = await recipientSnap.withdraw(POOL, restored, recipientKeypair);

Mainnet Details

| Field | Value | |-------|-------| | Program ID | 9uePoqdgaXpqFLQM2ED1GGQrwSEiqe3r6tW1AfsnrrbS | | 0.1 SOL pool | B8SyffZKt8LABKogWjH9rZcjY5PV2hyYRCbTxxbcrpFf | | 1 USDC pool | 5LeuHrPBgHNhgbCy996MEjcsBk5gNHhVj6AiuuCHZ8od | | 10 USDC pool | ECuHf8kgiWfmL3Q6id4WGBQWvuukhzqvF5vsxuPAKZBv | | Network | Solana Mainnet | | Explorer | View Program |

Public API

import { SNAPClient } from "snap-solana-sdk";

const snap = new SNAPClient(connection, wallet);

const note = await snap.deposit(poolAddress, 0.1);
const txSig = await snap.withdraw(poolAddress, note, recipientKeypair);

Notes

• deposit() always uses the pool's fixed denomination. If you pass amount, it must match the pool denomination.
• withdraw() rebuilds the Poseidon Merkle tree, generates the witness, produces the Groth16 proof, formats it for Solana, and submits the transaction.
• withdrawViaRelayer() signs the relayer request with a one-time Ed25519 session key derived from the agent spending key or a Keypair-backed wallet seed. That signature is only the transport envelope: the relayer also verifies the proof off-chain and binds the signed request to the exact proof/root/nullifier/recipient/fee/timestamp tuple before it submits anything.
• maxDepositDelayMs and maxWithdrawDelayMs add cryptographically random timing jitter with crypto.getRandomValues() to reduce simple timing-correlation attacks.
• serializeNote() returns a JSON-safe string. Anyone with the note can withdraw the funds, so it must stay off-chain and private.

Security Model

Bearer Notes

Anyone with the note can withdraw the funds. A note contains the secret and nullifier that generate the ZK proof. There is no additional key-based authorization on-chain. Protect notes like private keys.

Viewing Keys

The viewing key can decrypt an agent's note history for audit purposes. It cannot spend funds or recover the spending key. This supports the selective-disclosure compliance model described in docs/COMPLIANCE.md.

Spending Keys

The spending key seeds the agent's Solana wallet and signs relayer request payloads. It does NOT control on-chain withdrawals. The note controls that. This is a transport credential, not a protocol authorization key.

Assets

The package ships the proving artifacts in assets/:

• withdraw.wasm
• withdraw_final.zkey

They are loaded at runtime from the installed package directory.