agent-payment-x402listed

# CIEL ADAPTATION: Agent Payment Execution (x402) This skill enables CIEL sub-agents to execute autonomous payments via the x402 HTTP payment protocol. It prioritizes safety through mandatory spending policies and non-custodial wallet management. ## Core Mandates ### 1. Policy-First Delegation The Orchestrator MUST set a `SpendingPolicy` before delegating any payment authority to a sub-agent. Sub-agents are prohibited from setting or escalating their own spending limits. - **Per-Task Budget**: Maximum spend for a single atomic action. - **Per-Session Budget**: Cumulative limit for the entire epic. - **Allowlist**: Restricted set of verified recipients or service endpoints. ### 2. Non-Custodial Security CIEL agents use non-custodial smart accounts (e.g., ERC-4337). Private keys are managed by the harness, and the sub-agent only has signed permission to spend within the pre-defined policy bounds. ### 3. Fail-Closed Protocol If the payment service (x402) is unreachable, the transaction MUST fail. CIEL agents MUST NOT attempt to bypass payment gates or fall back to unmetered access without explicit user authorization. ## Workflow 1. **Pre-Check**: Query remaining budget (`check_spending`) before initiating any paid action. 2. **Negotiation**: Handle `402 Payment Required` responses by negotiating price and checking against the Per-Task Budget. 3. **Execution**: Invoke `send_payment` via the designated MCP tool. 4. **Audit**: Log all transactions (`list_transactions`) t