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Announcement•

Dexter Contributes ERC-8004 Reputation Extension to Coinbase x402 Protocol

Dexter Contributes ERC-8004 Reputation Extension to Coinbase x402 Protocol

FOR IMMEDIATE RELEASE

First Implementation of Agent Reputation in the x402 Payment Standard – Now Open Source

From Dexter's production system to Coinbase's official x402 repository.

The News

Dexter has submitted a pull request to Coinbase's x402 protocol that adds native support for ERC-8004 agent reputation. This extension enables any x402 facilitator to:

  • Advertise agent credentials – Agents can include their ERC-8004 registry information in payment requests
  • Issue settlement attestations – Facilitators cryptographically sign proof of completed payments
  • Enable feedback collection – Standardized aggregator endpoints for post-settlement reviews

PR #1054: github.com/coinbase/x402/pull/1054

This isn't a proposal. This is battle-tested code extracted from Dexter's production facilitator and submitted upstream for inclusion in the official x402 SDK.

Why Contribute Upstream?

Dexter already has ERC-8004 reputation running in production. We could have kept it proprietary. Instead, we're contributing it to x402 because:

  1. Reputation needs network effects – The more facilitators that support reputation, the more valuable the data becomes
  2. Open standards win – Proprietary trust systems fragment the ecosystem
  3. We want competition – If other facilitators adopt this, it raises the bar for everyone

The agentic economy needs shared trust infrastructure, not walled gardens.

What the Extension Does

For Agents (Resource Servers)

Agents can advertise their ERC-8004 registrations in 402 Payment Required responses:

import { createReputationRequiredExtension } from "@x402/extensions/reputation";

const extension = createReputationRequiredExtension({
  registrations: [
    { agentRegistry: "base-mainnet:0x55e75...", agentId: "42" }
  ],
  feedbackAggregator: { endpoint: "https://api.dexter.cash/feedback" }
});

For Facilitators

Facilitators can sign attestations proving they settled a payment:

import { createReputationServerExtension } from "@x402/extensions/reputation";

const extension = createReputationServerExtension({
  facilitatorAddress: "0x...",
  signer: async (message) => sign(message, privateKey),
  network: "base-mainnet"
});

For Clients

Clients can process attestations and submit feedback:

import { createReputationClientExtension } from "@x402/extensions/reputation";

const extension = createReputationClientExtension({
  feedbackCallback: async (attestation, outcome) => {
    await submitFeedback(attestation, { rating: 95, tags: ["fast", "accurate"] });
  }
});

Technical Details

ComponentDescription
Extension Keyx-8004-reputation
Facilitator AttestationSigned proof: amount, payer, payee, asset, timestamp, network, taskRef
Signature SupportEd25519 (Solana), secp256k1 (EVM)
Feedback SchemaRating (0-100), tags, optional detailed URI

What This Means for the Ecosystem

Once merged, any x402 facilitator can:

  • Issue attestations – Cryptographic proof of payment settlement
  • Support agent reputation – Pass through ERC-8004 registry information
  • Enable feedback loops – Standardized endpoints for post-payment reviews

This creates interoperable trust infrastructure across the entire x402 ecosystem.

Timeline

  • January 2026: Dexter launches ERC-8004 Trust Layer in production
  • January 30, 2026: PR #1054 submitted to Coinbase x402
  • Status: Under review

About Dexter

Dexter built the first production implementation of ERC-8004 reputation integrated with x402 payments. We're now contributing that work back to the ecosystem.

  • Dexter Facilitator: x402 payment settlement for Solana, Base, and 6+ EVM chains
  • Dexter MCP: 70+ AI tools via Model Context Protocol
  • Dexter Trust Layer: ERC-8004 identity and reputation (production)
  • Dexter Marketplace: Discover and monetize AI services

Resources

Building trust infrastructure for the agentic economy. Open source. Battle tested.