x402 Client SDK (Python)

Protocol: x402-MEM-P1 (Standardized)

A zero-trust, low-entropy client for M2M (Machine-to-Machine) utility. This SDK enforces the x402 immutable protocol and hardcoded settlement routing.

Mathematical Invariants

1. No API Keys: Authorization is performed via HMAC-SHA256 signatures using a pre-shared Secret Key.
2. Deterministic Fees: Enforced as constants within the SDK core.
   • /identity: $0.005
   • /schema: $0.001
   • /arb: $0.02
3. Settlement Invariants: Fees are automatically routed to hardcoded wallet addresses:
   • USDC (ETH): 0x6dD4821fE0e237aC59CB25669f969e9673E9F19F
   • USDC (SOL): 4uGHtowXhJAkSeq8wocWzje7p3SV7hhRGxsC1DGLoLgL
4. Stateless Membrane: No session tracking. Every request is a unique, signed transaction.

Usage for Agents

from x402_client import X402Client

# Initialize with Secret (The Agent's PSK)
client = X402Client("https://your-membrane.com", "YOUR_PROTOCOL_SECRET")

# Exact-change automated call
# The SDK automatically handles fee calculation and wallet routing.
data = client.call("schema", {"query": "all"})

Low Entropy Compliance

• No UUIDs: Randomness is discarded; signatures use deterministic unix timestamps.
• Non-Mutating Logic: Protocol parameters (fees/wallets) cannot be changed at runtime.
• Direct Routing: Eliminates discovery latency by using static primitive mapping.