Feature: Wallet reputation scoring for x402 payment verification

[jacobsd32-cpu]

Context

MCPay handles MCP and x402 payment infrastructure. One missing piece in the payment flow is trust — when an MCP server receives a payment from an unknown wallet, there's no way to assess whether that wallet has a legitimate transaction history or is potentially fraudulent.

Proposal

Integrate DJD AgentScore to add optional reputation checks to the payment verification flow. AgentScore provides a 0–100 trust score for Base wallets, derived from on-chain x402 settlement history across 5 dimensions (identity, behavior, reliability, viability, capability).

How It Would Work

Before settling a payment, MCPay could optionally check the payer's reputation:

const resp = await fetch(`https://djd-agent-score.fly.dev/v1/score/basic?wallet=${payerWallet}`)
const { composite, tier, recommendation } = await resp.json()

// recommendation is one of: TRUST, PROCEED_WITH_CAUTION, REVIEW_REQUIRED, BLOCK
if (recommendation === 'BLOCK') {
  return { status: 402, error: 'Payment rejected — wallet has low trust score' }
}

This could be:

• A configurable middleware in the payment pipeline
• An optional flag in the facilitator config
• A standalone verification step

Resources

• Live API: https://djd-agent-score.fly.dev
• npm SDK: @anthropic-djd/agent-score-sdk
• MCP Server: Available on Smithery (so MCPay could even consume it as an MCP tool)
• No API key required for basic scoring

Happy to collaborate on the integration if there's interest.