feat: add Triple Arbiter facilitator

[mintmas]

Add Triple Arbiter facilitator to ecosystem

Summary

Adds Triple Arbiter — an x402 settlement facilitator on Base mainnet that pairs EIP-3009 transferWithAuthorization USDC settlements with EAS-compatible threat-intel attestations.

Category

Facilitators

Key facts

• Non-custodial — facilitator never takes custody of user funds. Settlement is a direct USDC transfer from payer to merchant authorized via EIP-3009.
• Fee — 50 bps facilitator fee, $2 minimum transfer. ProsharkyHook (ISettlementHook at 0x05E09a53e188DA1622AcFc9498703F0aE10f9202 on Base) adds optional 10 bps on-chain capture — 50% undercut vs Coinbase's 20 bps facilitator surcharge — with 2 bps auto-allocated to EAS attestation gas reserve.
• Network — Base mainnet (chain_id 8453), USDC 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913
• Scheme / asset — exact / EIP-3009
• Discovery — /.well-known/x402-facilitator.json served per spec
• Attestation feed — Triple Arbiter pairs each settlement receipt with an EAS attestation (UID emitted per tx). Agents can subscribe to our attestation feed to score counterparty reputation before settling, or to detect revoked issuers in real-time. Feed endpoint: https://mardi-worldwide-sacred-model.trycloudflare.com/attestations (EAS-compatible JSON).

Verification

$ curl -s https://mardi-worldwide-sacred-model.trycloudflare.com/health
OK

$ curl -s https://mardi-worldwide-sacred-model.trycloudflare.com/.well-known/x402-facilitator.json | jq .
{
  "schema_ref": "https://docs.x402.org/schemas/facilitator/v1.json",
  "name": "Triple Arbiter",
  "facilitator": {
    "address": "0xbe5df0394dbd9cc19127cf93cd9b543f2eb63b97",
    "network": "base",
    "chain_id": 8453,
    "asset": "USDC",
    "asset_address": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "fee_bps": 50,
    "min_transfer_usd": "2.00",
    "custody": "none",
    "relay_pattern": "eip-3009-transferWithAuthorization"
  }
}

Why it's distinct

Most facilitators ship settlement only. Triple Arbiter pairs each x402 settlement receipt with an optional EAS attestation (deprecation of compromised issuers, threat-intel feed for agent-to-agent trust), which is the non-obvious part of the integration — merchants can consume the attestation feed to filter requests before settlement.

Files added

• typescript/site/app/ecosystem/partners-data/triple-arbiter/metadata.json
• typescript/site/public/logos/triple-arbiter.svg

Tests

Facilitator endpoint verified live:

• GET /health → 200 OK
• GET /.well-known/x402-facilitator.json → valid JSON matching x402 facilitator schema

Checklist

• I have formatted and linted my code
• All new and existing tests pass
• My commits are signed (required for merge)
• I added a changelog fragment for user-facing changes (ecosystem listing — docs-only change)

[vercel]

@mintmas is attempting to deploy a commit to the Coinbase Team on Vercel.

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