snapshot()

Serializes an agent's memory bundle to JSON, encrypts it, uploads it to 0G Storage, and mints a provenance NFT on 0G Chain. Returns a SnapshotResult when the on-chain transaction confirms.

Signature

snapshot(bundle: MemoryBundle, parentTokenId?: bigint): Promise<SnapshotResult>

Parameters

Parameter	Type	Description
bundle	MemoryBundle	The agent's memory state. See MemoryBundle →
parentTokenId	bigint (optional)	Token ID of a parent snapshot — for minting a fork. Pass 0n or omit for a root token.

Returns

Promise<SnapshotResult>

interface SnapshotResult {
  tokenId:     bigint;         // minted NFT token ID on MemoryRegistry
  contentHash: `0x${string}`; // keccak256(plaintext JSON) — also the decryption key seed
  storageUri:  string;         // "v2:0g://<rootHash>" — content address on 0G Storage
  txHash:      `0x${string}`; // on-chain transaction hash
  timestamp:   number;         // Date.now() at time of call
}

Example

import type { MemoryBundle } from '@mnemos-sdk/sdk';

const bundle: MemoryBundle = {
  data: {
    trades: [{ pair: 'ETH/USDC', amount: 1.5, side: 'buy' }],
    totalPnl: 42.0,
  },
  metadata: {
    category: 'trading',
    agentId: 'my-agent-v1',
    version: '1.0.0',
    createdAt: Date.now(),
    tags: ['defi', 'yield'],
  },
};

const result = await mnemos.snapshot(bundle);

console.log(result.tokenId);    // 3n
console.log(result.storageUri); // "v2:0g://0xabc..."
console.log(result.txHash);     // "0xdef..."

What Happens Internally

1. JSON.stringify(bundle) — serializes the bundle
2. contentHash = keccak256(plaintext) — derives both the on-chain identifier and the encryption key seed
3. NaCl secretbox encryption with a 24-byte random nonce (nonce || ciphertext stored together)
4. Upload to 0G Storage via Indexer.upload — returns a 0g://<rootHash> URI
5. MemoryRegistry.mintMemory(contentHash, "v2:" + uri) — mints the NFT
6. Waits for transaction receipt and parses the MemoryMinted event for the token ID

The call blocks until the transaction is confirmed on-chain (up to 120-second timeout, polling every 3 seconds).

Notes

• tokenId is extracted from the MemoryMinted event log. Keep it — you need it for listing, forking, or loading.
• The contentHash is public on-chain. Anyone with the contentHash can derive the decryption key. See Privacy & Access → for the full explanation.
• For recurring snapshots, use autoSnapshot() instead of calling snapshot() in a loop.

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Next: autoSnapshot() →