feat: implement ERC-8004 reputation and fix EVM domain discovery

specs/schemes/exact/scheme_exact_evm.md

@@ -8,8 +8,10 @@ This is implemented via one of two asset transfer methods, depending on the toke
 
 | AssetTransferMethod | Use Case                                                     | Recommendation                                 |
 | :------------------ | :----------------------------------------------------------- | :--------------------------------------------- |
-| **1. EIP-3009**     | Tokens with native `transferWithAuthorization` (e.g., USDC). | **Recommended** (Simplest, truly gasless).     |
-| **2. Permit2**      | Tokens without EIP-3009. Uses a Proxy + Permit2.             | **Universal Fallback** (Works for any ERC-20). |
+| **1. EIP-3009**     | Tokens with native `transferWithAuthorization` (e.g., USDC). | **Standard** (EOA only, truly gasless).        |
+| **2. Permit2**      | Tokens without EIP-3009 or **Smart Wallets**.                | **Universal** (Works for any ERC-20 & Wallets). |
+
+**Note**: EIP-3009 (AssetTransferMethod 1) typically only supports ECDSA (EOA) signatures and may fail for contract-based wallets (e.g., Coinbase Smart Wallet). If you are building for AI agents using CDP or Smart Wallets, use **Permit2**.
 
 If no `assetTransferMethod` is specified in the payload, the implementation should prioritize `eip3009` (if compatible) and then `permit2`.
 

typescript/.changeset/tough-balloons-shake.md

@@ -0,0 +1,8 @@
+---
+"@x402/extensions": minor
+"@x402/evm": minor
+---
+
+Added support for ERC-8004 Trustless Agents reputation extension in `@x402/extensions`. This enables AI agents to advertise their on-chain identity and reputation registry, supporting both EVM and Solana (SATI) standards. Includes server-side declaration helpers, client-side bidirectional reputation support, and an automated feedback tool for generating CAIP-220 compliant reputation signals from payment settlements.
+
+Enhanced `@x402/evm` with automatic EIP-712 domain discovery for EIP-3009 tokens. This improves verification robustness for tokens with misconfigured domain parameters (like USDC on Base Sepolia) and provides better support for contract-based wallets.

typescript/packages/extensions/README.md

@@ -659,6 +659,69 @@ Extension identifier constant (`"sign-in-with-x"`).
 | `eip6492` | Counterfactual smart wallet verification |
 | `siws` | Sign-In-With-Solana |
 
+## ERC-8004 Reputation Extension
+
+The ERC-8004 Reputation extension enables autonomous AI agents to build and verify on-chain reputation based on payment outcomes. It links the x402 payment protocol with the [ERC-8004: Trustless Agents](https://eips.ethereum.org/EIPS/eip-8004) standard.
+
+### How It Works
+
+1. **Discovery**: Servers advertise their on-chain agent identity in the `PaymentRequired` response.
+2. **Identification**: Clients (other agents) can optionally provide their own identity in the `PaymentPayload`.
+3. **Feedback**: After settlement, either party can submit reputation feedback to an ERC-8004 Reputation Registry (on EVM or Solana).
+4. **Trust**: Reputation signals are weighted by payment proofs, ensuring high-integrity "proof-of-service" ratings.
+
+### Server Usage
+
+Declare your agent identity and reputation registry:
+
+```typescript
+import { declareReputation, reputationResourceServerExtension } from "@x402/extensions/8004-reputation";
+
+const routes = {
+  "GET /service": {
+    accepts: [{ scheme: "exact", price: "$0.01", network: "eip155:8453", payTo }],
+    extensions: {
+      ...declareReputation({
+        identity: {
+          agentRegistry: "eip155:8453:0xIdentityRegistryAddress",
+          agentId: "42" // NFT Token ID
+        },
+        reputationRegistry: "0xReputationRegistryAddress",
+        endpoint: "https://my-agent.com"
+      })
+    }
+  }
+};
+
+const resourceServer = new x402ResourceServer(facilitatorClient)
+  .registerExtension(reputationResourceServerExtension);
+```
+
+### Client Usage
+
+Identify as an agent when making a payment:
+
+```typescript
+import { withClientReputation } from "@x402/extensions/8004-reputation";
+
+// When server requests payment
+const serverReputation = paymentRequired.extensions["8004-reputation"].info;
+
+const payload = {
+  ...paymentPayload,
+  extensions: {
+    ...withClientReputation(serverReputation, {
+      agentRegistry: "eip155:8453:0xMyRegistry",
+      agentId: "99"
+    })
+  }
+};
+```
+
+### `ERC8004_REPUTATION`
+
+The extension identifier constant (`"8004-reputation"`).
+
 ## Troubleshooting
 
 ### Bazaar Extension Not Being Extracted

typescript/packages/extensions/package.json

@@ -91,6 +91,16 @@
         "types": "./dist/cjs/payment-identifier/index.d.ts",
         "default": "./dist/cjs/payment-identifier/index.js"
       }
+    },
+    "./8004-reputation": {
+      "import": {
+        "types": "./dist/esm/8004-reputation/index.d.mts",
+        "default": "./dist/esm/8004-reputation/index.mjs"
+      },
+      "require": {
+        "types": "./dist/cjs/8004-reputation/index.d.ts",
+        "default": "./dist/cjs/8004-reputation/index.js"
+      }
     }
   },
   "files": [

typescript/packages/extensions/src/8004-reputation/client.ts

@@ -0,0 +1,34 @@
+import { ERC8004_REPUTATION, type AgentIdentity, type ReputationInfo } from "./types";
+
+/**
+ * Creates client-side reputation info to be included in PaymentPayload.
+ * Allows the client (agent) to advertise their own identity to the server.
+ *
+ * @param serverInfo - The server's reputation info from the PaymentRequired response
+ * @param clientIdentity - The client's own agent identity
+ * @returns The consolidated reputation info
+ */
+export function createClientReputationInfo(
+  serverInfo: ReputationInfo,
+  clientIdentity: AgentIdentity,
+): ReputationInfo {
+  return {
+    ...serverInfo,
+    client: {
+      agentIdentity: clientIdentity,
+    },
+  };
+}
+
+/**
+ * Helper to wrap the reputation info for inclusion in PaymentPayload extensions.
+ *
+ * @param serverInfo - The server's reputation info from the PaymentRequired response
+ * @param clientIdentity - The client's own agent identity
+ * @returns An extension object containing the reputation info
+ */
+export function withClientReputation(serverInfo: ReputationInfo, clientIdentity: AgentIdentity) {
+  return {
+    [ERC8004_REPUTATION]: createClientReputationInfo(serverInfo, clientIdentity),
+  };
+}

typescript/packages/extensions/src/8004-reputation/declare.ts

@@ -0,0 +1,47 @@
+import { type DeclareReputationOptions, type ReputationExtension } from "./types";
+
+/**
+ * Creates an ERC-8004 reputation extension declaration for x402 resource servers.
+ *
+ * @param options - Configuration options for the reputation declaration.
+ * @returns The reputation extension declaration for ERC-8004.
+ */
+export function declareReputation(options: DeclareReputationOptions): ReputationExtension {
+  return {
+    info: {
+      identity: options.identity,
+      reputationRegistry: options.reputationRegistry,
+      ...(options.endpoint ? { endpoint: options.endpoint } : {}),
+    },
+    schema: {
+      $schema: "https://json-schema.org/draft/2020-12/schema",
+      type: "object",
+      properties: {
+        identity: {
+          type: "object",
+          properties: {
+            agentRegistry: { type: "string" },
+            agentId: { type: "string" },
+          },
+          required: ["agentRegistry", "agentId"],
+        },
+        reputationRegistry: { type: "string" },
+        endpoint: { type: "string" },
+        client: {
+          type: "object",
+          properties: {
+            agentIdentity: {
+              type: "object",
+              properties: {
+                agentRegistry: { type: "string" },
+                agentId: { type: "string" },
+              },
+              required: ["agentRegistry", "agentId"],
+            },
+          },
+        },
+      },
+      required: ["identity", "reputationRegistry"],
+    },
+  };
+}

typescript/packages/extensions/src/8004-reputation/feedback.ts

@@ -0,0 +1,46 @@
+import { z } from "zod";
+
+/**
+ * CAIP-220 format for task reference (e.g., eip155:1:tx/0x...)
+ */
+export const TaskReferenceSchema = z.string().regex(/^[a-z0-9]+:[a-z0-9]+:tx\/[a-zA-Z0-9]+$/);
+
+/**
+ * Proof of participation for verified interactions.
+ */
+export const ProofOfParticipationSchema = z.object({
+  /**
+   * Reference to the payment transaction.
+   */
+  taskRef: TaskReferenceSchema,
+  /**
+   * Optional signature from the agent to prove service was delivered.
+   */
+  agentSignature: z.string().optional(),
+});
+
+/**
+ * Feedback file structure following ERC-8004.
+ */
+export const FeedbackFileSchema = z.object({
+  agentRegistry: z.string(),
+  agentId: z.string(),
+  clientAddress: z.string(),
+  createdAt: z.string(), // ISO 8601
+  value: z.number(),
+  valueDecimals: z.number().min(0).max(18),
+  tag1: z.string().optional(),
+  tag2: z.string().optional(),
+  endpoint: z.string().optional(),
+  proofOfPayment: z
+    .object({
+      fromAddress: z.string(),
+      toAddress: z.string(),
+      chainId: z.string(),
+      txHash: z.string(),
+    })
+    .optional(),
+  participation: ProofOfParticipationSchema.optional(),
+});
+
+export type FeedbackFile = z.infer<typeof FeedbackFileSchema>;

typescript/packages/extensions/src/8004-reputation/feedbackTool.ts

@@ -0,0 +1,77 @@
+import { type SettleResponse } from "@x402/core/types";
+import { type ReputationInfo, ERC8004_REPUTATION } from "./types";
+import { type FeedbackFile, FeedbackFileSchema } from "./feedback";
+
+/**
+ * Options for creating a feedback file.
+ */
+export interface CreateFeedbackOptions {
+  /** The settlement response from the facilitator */
+  settleResponse: SettleResponse;
+  /** The server's reputation info (containing its identity) */
+  serverReputation: ReputationInfo;
+  /** The reputation score (0-100 or specific to valueDecimals) */
+  value: number;
+  /** Decimals for the value (default: 0) */
+  valueDecimals?: number;
+  /** Optional tags for filtering */
+  tag1?: string;
+  /** Optional tags for filtering */
+  tag2?: string;
+  /** Optional comment/detailed feedback */
+  comment?: string;
+}
+
+/**
+ * Helper to create a standardized ERC-8004 feedback file from an x402 settlement.
+ *
+ * This tool automates the extraction of network identifiers and transaction
+ * hashes into the CAIP-220 compliant taskRef format.
+ *
+ * @param options - Options for creating the feedback file.
+ * @returns A validated feedback file for standardized reporting.
+ */
+export function createFeedbackFile(options: CreateFeedbackOptions): FeedbackFile {
+  const { settleResponse, serverReputation, value, valueDecimals = 0, tag1, tag2 } = options;
+
+  // Construct CAIP-220 taskRef: {namespace}:{chainId}:tx/{hash}
+  // settleResponse.network is already CAIP-2 (e.g., eip155:8453)
+  const taskRef = `${settleResponse.network}:tx/${settleResponse.transaction}`;
+
+  const feedback: FeedbackFile = {
+    agentRegistry: serverReputation.identity.agentRegistry,
+    agentId: serverReputation.identity.agentId,
+    clientAddress: settleResponse.payer || "unknown",
+    createdAt: new Date().toISOString(),
+    value,
+    valueDecimals,
+    tag1,
+    tag2,
+    endpoint: serverReputation.endpoint,
+    proofOfPayment: {
+      fromAddress: settleResponse.payer || "unknown",
+      toAddress: "unknown", // Normally extracted from paymentRequirements if available
+      chainId: settleResponse.network.split(":")[1] || "unknown",
+      txHash: settleResponse.transaction,
+    },
+    participation: {
+      taskRef,
+    },
+  };
+
+  // Validate against schema
+  return FeedbackFileSchema.parse(feedback);
+}
+
+/**
+ * Extracts ERC-8004 identity from a PaymentRequired response.
+ *
+ * @param extensions - The extensions object from the PaymentRequired response.
+ * @returns The reputation info if present, otherwise undefined.
+ */
+export function getAgentReputation(
+  extensions: Record<string, unknown>,
+): ReputationInfo | undefined {
+  const extension = extensions[ERC8004_REPUTATION] as { info: ReputationInfo } | undefined;
+  return extension?.info;
+}

typescript/packages/extensions/src/8004-reputation/index.ts

@@ -0,0 +1,6 @@
+export * from "./types";
+export * from "./declare";
+export * from "./server";
+export * from "./client";
+export * from "./feedback";
+export * from "./feedbackTool";

typescript/packages/extensions/src/8004-reputation/server.ts

@@ -0,0 +1,18 @@
+import type { ResourceServerExtension } from "@x402/core/types";
+import { ERC8004_REPUTATION } from "./types";
+
+/**
+ * Resource server extension for ERC-8004 Reputation.
+ *
+ * This extension allows agents to advertise their ERC-8004 identity
+ * and reputation registry in 402 PaymentRequired responses.
+ */
+export const reputationResourceServerExtension: ResourceServerExtension = {
+  key: ERC8004_REPUTATION,
+
+  enrichPaymentRequiredResponse: async declaration => {
+    // Return the extension declaration as-is.
+    // The declaration is created via declareReputation() and contains info + schema.
+    return declaration;
+  },
+};