Architecture Overview

lateo/
├── contracts/              Soroban smart contracts (Rust)
│   ├── pool/               Privacy pool — transact(), disburse()
│   ├── circom-groth16-verifier/   On-chain Groth16 verification
│   ├── asp-membership/     Binary Merkle tree for inclusion proofs
│   └── asp-non-membership/ Sparse Merkle tree for exclusion proofs
├── circuits/               Circom circuits (Groth16, BN254)
│   └── src/policyTransaction.circom
├── proxy/                  Privacy proxy server (TypeScript)
│   ├── zk-pool-service.ts  ZK proof generation + on-chain submission
│   ├── batch-operator.ts   Temporal batching for x402 payments
│   ├── witness-builder.ts  Circuit witness construction
│   └── storage.ts          SQLite + AES-256-GCM encryption
├── dashboard/              React dashboard
├── landing/                Landing page
├── zksearch/               x402-protected search service
├── mcp-server/             MCP server for AI agent integration
└── target/wasm-prover-nodejs/   ark-groth16 compiled to WASM

1. Frontend → POST /api/deposit/prepare { amount, publicKey }
2. Proxy: generates Groth16 proof + builds unsigned transact() XDR
3. Frontend → Freighter signTransaction(XDR) → user approves
4. Frontend → POST /api/deposit/submit { signedTransactionXDR }
5. Proxy → submits signed tx to Stellar
6. ON-CHAIN (atomic):
   ├── pool.transact() verifies Groth16 proof
   ├── pool.transact() transfers USDC from sender to pool
   ├── pool.transact() inserts commitments into Merkle tree
   └── If ANY step fails → entire tx reverts → no USDC moves
7. Proxy → credits balance ONLY after on-chain confirmation

1. Agent → POST /api/pay { serviceUrl }
2. Proxy: verifies agent balance
3. Proxy: enqueues in BatchOperator
4. BatchOperator: accumulates payments for batch window (15s)
5. BatchOperator: executes x402 payments from pool wallet
6. On-chain: Pool → Service (individual agent not identifiable)

1. User → POST /api/withdraw { amount, destination }
2. Proxy: selects unspent notes for the withdrawal amount
3. Proxy: generates Groth16 proof with nullifiers
4. Proxy: operator signs transact() with negative ext_amount
5. ON-CHAIN (atomic):
   ├── pool.transact() verifies Groth16 proof
   ├── pool.transact() verifies nullifiers not already spent
   ├── pool.transact() marks nullifiers as spent
   ├── pool.transact() transfers USDC from pool to recipient
   ├── pool.transact() inserts change commitments
   └── If ANY step fails → entire tx reverts → no USDC moves
6. Proxy → debits balance ONLY after on-chain confirmation