SOHO Pay — Credit Layer Payments

This skill orchestrates payments through the SOHO Pay Creditor smart contract using the spendWithAuthorization EIP-712 flow.

This skill is manual-invocation only. It must not be triggered autonomously by a model. Every invocation requires explicit user confirmation.

Architecture — Three-Party Separation

┌──────────────────┐     ┌──────────────────┐     ┌──────────────────┐
│  Wallet Signer   │     │   SoHo (Credit)  │     │   Blockchain     │
│  (user/operator) │     │                  │     │   (Base)         │
│                  │     │  Credit checks   │     │                  │
│  Signs EIP-712   │────▶│  JIT funding     │────▶│  Settlement      │
│  Owns keys       │     │  Authorization   │     │  Creditor.sol    │
│                  │     │                  │     │                  │
│  MPC / HSM /     │     │  NEVER signs     │     │                  │
│  Turnkey / Privy │     │  NEVER holds keys│     │                  │
└──────────────────┘     └──────────────────┘     └──────────────────┘

SoHo is a credit layer only. It does not custody, hold, generate, or control any signing keys or key shards, and it does not produce EIP-712 signatures.

All EIP-712 signatures come from a separate Wallet Signer owned and controlled by the user or agent operator (e.g., MPC provider like Turnkey/Privy/Fireblocks, or a user wallet).

The skill orchestrates between:

• Wallet Signer — signing (user/operator-controlled)
• SoHo — credit checks + just-in-time funding (credit layer only)
• Blockchain — settlement

Usage

node scripts/pay.js <amount> <merchantAddress> [payerAddress]

Example — Base Sepolia with local key (dev only)

export RPC_URL=https://sepolia.base.org
export CHAIN_ID=84532
export SIGNER_PROVIDER=LOCAL_PRIVATE_KEY
export SOHO_DEV_PRIVATE_KEY=0xabc...

node scripts/pay.js 10 0x1234567890abcdef1234567890abcdef12345678

Example — Base Sepolia with remote wallet signer (production pattern)

export RPC_URL=https://sepolia.base.org
export CHAIN_ID=84532
export SIGNER_PROVIDER=WALLET_SIGNER_REMOTE
export WALLET_SIGNER_SERVICE_URL=https://your-mpc-signer.example.com
export SIGNER_SERVICE_AUTH_TOKEN=sk_live_...

node scripts/pay.js 10 0xMERCHANT... 0xPAYER...

Workflow

1. Validate config — all env vars checked with Zod at startup; unknown chains rejected.
2. Parse inputs — amount and explicit merchant address (no name-to-address generation).
3. Pre-flight credit checks — SoHo credit layer verifies borrower registration, active status, credit limit.
4. Sign EIP-712 — Wallet Signer (user-controlled) produces signature. SoHo never signs.
5. Submit tx — call spendWithAuthorization on the Creditor contract.
6. Return result — transaction hash + block number.

Supported Networks

Unknown chain IDs are rejected at config validation time.

Contract Addresses (Base Sepolia)

Security Model

Key Custody Boundary

SoHo must NEVER custody, hold, generate, or control any signing keys or key shards.

Wallet Signer Providers

• Default and recommended: WALLET_SIGNER_REMOTE. The skill sends EIP-712 typed data to the user's wallet signing service and never touches private keys.
• Dev-only fallback: LOCAL_PRIVATE_KEY is gated to testnet chain IDs. Using it on mainnet requires DEV_ALLOW_LOCAL_KEY=YES and is strongly discouraged.

Mainnet Safety Gate

Transactions on Base Mainnet (CHAIN_ID=8453) are refused unless SOHO_MAINNET_CONFIRM=YES is set. This prevents accidental mainnet spends during development.

Recipient Address Policy

The skill never derives or generates an address from a merchant name. The merchantAddress argument must be an explicit, valid, checksummed EVM address. Any non-address input is rejected with an error.

Invocation Policy

• invocation: manual — the skill cannot be triggered autonomously.
• require_confirmation: true — the orchestrator must obtain user confirmation before execution.
• A runtime guard rejects execution if SOHO_AUTONOMOUS=true is detected in the environment.

Threat Model & Mitigations

Environment Variables

Required (all modes)

Required for WALLET_SIGNER_REMOTE

SoHo Credit Layer

Required for LOCAL_PRIVATE_KEY (dev / testnet only)

Conditional

Dependencies

Install with:

npm install