diff --git a/eslint.config.mjs b/eslint.config.mjs
index d47e0dd..d0c58d1 100644
--- a/eslint.config.mjs
+++ b/eslint.config.mjs
@@ -9,7 +9,7 @@ export default [
   },
   eslint.configs.recommended,
   {
-    files: ["packages/*/src/**/*.ts"],
+    files: ["packages/*/src/**/*.ts", "samples/*/src/**/*.ts"],
     languageOptions: {
       parser: tsParser,
       ecmaVersion: 2020,
diff --git a/package-lock.json b/package-lock.json
index 264d096..2d13345 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -6,7 +6,8 @@
     "": {
       "name": "agent-sdk",
       "workspaces": [
-        "packages/*"
+        "packages/*",
+        "samples/*"
       ],
       "devDependencies": {
         "@changesets/changelog-github": "^0.5.2",
@@ -20,6 +21,10 @@
       "integrity": "sha512-nhCBV3quEgesuf7c7KYfperqSS14T8bYuvJ8PcLJp6znkZpFc0AuW4qBtr8eKVyPPe/8RSr7sglCWPU5eaxwKQ==",
       "license": "MIT"
     },
+    "node_modules/@agent-sdk/x402-browser-proxy": {
+      "resolved": "samples/x402-browser-proxy",
+      "link": true
+    },
     "node_modules/@babel/runtime": {
       "version": "7.28.6",
       "resolved": "https://registry.npmjs.org/@babel/runtime/-/runtime-7.28.6.tgz",
@@ -1789,6 +1794,49 @@
         "url": "https://paulmillr.com/funding/"
       }
     },
+    "node_modules/@spruceid/siwe-parser": {
+      "version": "2.1.2",
+      "resolved": "https://registry.npmjs.org/@spruceid/siwe-parser/-/siwe-parser-2.1.2.tgz",
+      "integrity": "sha512-d/r3S1LwJyMaRAKQ0awmo9whfXeE88Qt00vRj91q5uv5ATtWIQEGJ67Yr5eSZw5zp1/fZCXZYuEckt8lSkereQ==",
+      "license": "Apache-2.0",
+      "dependencies": {
+        "@noble/hashes": "^1.1.2",
+        "apg-js": "^4.3.0",
+        "uri-js": "^4.4.1",
+        "valid-url": "^1.0.9"
+      }
+    },
+    "node_modules/@stablelib/binary": {
+      "version": "1.0.1",
+      "resolved": "https://registry.npmjs.org/@stablelib/binary/-/binary-1.0.1.tgz",
+      "integrity": "sha512-ClJWvmL6UBM/wjkvv/7m5VP3GMr9t0osr4yVgLZsLCOz4hGN9gIAFEqnJ0TsSMAN+n840nf2cHZnA5/KFqHC7Q==",
+      "license": "MIT",
+      "dependencies": {
+        "@stablelib/int": "^1.0.1"
+      }
+    },
+    "node_modules/@stablelib/int": {
+      "version": "1.0.1",
+      "resolved": "https://registry.npmjs.org/@stablelib/int/-/int-1.0.1.tgz",
+      "integrity": "sha512-byr69X/sDtDiIjIV6m4roLVWnNNlRGzsvxw+agj8CIEazqWGOQp2dTYgQhtyVXV9wpO6WyXRQUzLV/JRNumT2w==",
+      "license": "MIT"
+    },
+    "node_modules/@stablelib/random": {
+      "version": "1.0.2",
+      "resolved": "https://registry.npmjs.org/@stablelib/random/-/random-1.0.2.tgz",
+      "integrity": "sha512-rIsE83Xpb7clHPVRlBj8qNe5L8ISQOzjghYQm/dZ7VaM2KHYwMW5adjQjrzTZCchFnNCNhkwtnOBa9HTMJCI8w==",
+      "license": "MIT",
+      "dependencies": {
+        "@stablelib/binary": "^1.0.1",
+        "@stablelib/wipe": "^1.0.1"
+      }
+    },
+    "node_modules/@stablelib/wipe": {
+      "version": "1.0.1",
+      "resolved": "https://registry.npmjs.org/@stablelib/wipe/-/wipe-1.0.1.tgz",
+      "integrity": "sha512-WfqfX/eXGiAd3RJe4VU2snh/ZPwtSjLG4ynQ/vYzvghTh7dHFcI1wl+nrkWG6lGhukOxOsUHfv8dUXr58D0ayg==",
+      "license": "MIT"
+    },
     "node_modules/@toon-format/toon": {
       "version": "2.1.0",
       "resolved": "https://registry.npmjs.org/@toon-format/toon/-/toon-2.1.0.tgz",
@@ -2477,6 +2525,91 @@
         "tslib": "1.14.1"
       }
     },
+    "node_modules/@x402/core": {
+      "version": "2.5.0",
+      "resolved": "https://registry.npmjs.org/@x402/core/-/core-2.5.0.tgz",
+      "integrity": "sha512-nUr8HW8WhkU1DvrpUfsRvALy5NF8UWKoFezZOtX61mohxp2lWZpJ2GnvscxDM8nmBAbtIollmksd5z5pj8InXw==",
+      "license": "Apache-2.0",
+      "dependencies": {
+        "zod": "^3.24.2"
+      }
+    },
+    "node_modules/@x402/core/node_modules/zod": {
+      "version": "3.25.76",
+      "resolved": "https://registry.npmjs.org/zod/-/zod-3.25.76.tgz",
+      "integrity": "sha512-gzUt/qt81nXsFGKIFcC3YnfEAx5NkunCfnDlvuBSSFS02bcXu4Lmea0AFIUwbLWxWPx3d9p8S5QoaujKcNQxcQ==",
+      "license": "MIT",
+      "funding": {
+        "url": "https://github.com/sponsors/colinhacks"
+      }
+    },
+    "node_modules/@x402/evm": {
+      "version": "2.5.0",
+      "resolved": "https://registry.npmjs.org/@x402/evm/-/evm-2.5.0.tgz",
+      "integrity": "sha512-MBSTQZwLobMVcmYO7itOMJRkxfHstsDyr7F94o9Rk/Oinz0kjvCe4DFgZmFXyz3nQUgQFmDVgTK5KIzfYR5uIA==",
+      "license": "Apache-2.0",
+      "dependencies": {
+        "@x402/core": "~2.5.0",
+        "@x402/extensions": "~2.5.0",
+        "viem": "^2.39.3",
+        "zod": "^3.24.2"
+      }
+    },
+    "node_modules/@x402/evm/node_modules/zod": {
+      "version": "3.25.76",
+      "resolved": "https://registry.npmjs.org/zod/-/zod-3.25.76.tgz",
+      "integrity": "sha512-gzUt/qt81nXsFGKIFcC3YnfEAx5NkunCfnDlvuBSSFS02bcXu4Lmea0AFIUwbLWxWPx3d9p8S5QoaujKcNQxcQ==",
+      "license": "MIT",
+      "funding": {
+        "url": "https://github.com/sponsors/colinhacks"
+      }
+    },
+    "node_modules/@x402/extensions": {
+      "version": "2.5.0",
+      "resolved": "https://registry.npmjs.org/@x402/extensions/-/extensions-2.5.0.tgz",
+      "integrity": "sha512-e7IQShbGUM/XQmzI8DQh2tX/k2XDUGI9DNF+ij2NHUyPEqAt5/mJCwOlaxS/60FWFdfFRfWjTsqaoS7Z8WLi+A==",
+      "license": "Apache-2.0",
+      "dependencies": {
+        "@scure/base": "^1.2.6",
+        "@x402/core": "~2.5.0",
+        "ajv": "^8.17.1",
+        "siwe": "^2.3.2",
+        "tweetnacl": "^1.0.3",
+        "viem": "^2.43.5",
+        "zod": "^3.24.2"
+      }
+    },
+    "node_modules/@x402/extensions/node_modules/ajv": {
+      "version": "8.18.0",
+      "resolved": "https://registry.npmjs.org/ajv/-/ajv-8.18.0.tgz",
+      "integrity": "sha512-PlXPeEWMXMZ7sPYOHqmDyCJzcfNrUr3fGNKtezX14ykXOEIvyK81d+qydx89KY5O71FKMPaQ2vBfBFI5NHR63A==",
+      "license": "MIT",
+      "dependencies": {
+        "fast-deep-equal": "^3.1.3",
+        "fast-uri": "^3.0.1",
+        "json-schema-traverse": "^1.0.0",
+        "require-from-string": "^2.0.2"
+      },
+      "funding": {
+        "type": "github",
+        "url": "https://github.com/sponsors/epoberezkin"
+      }
+    },
+    "node_modules/@x402/extensions/node_modules/json-schema-traverse": {
+      "version": "1.0.0",
+      "resolved": "https://registry.npmjs.org/json-schema-traverse/-/json-schema-traverse-1.0.0.tgz",
+      "integrity": "sha512-NM8/P9n3XjXhIZn1lLhkFaACTOURQXjWhV4BA/RnOv8xvgqtqpAX9IO4mRQxSx1Rlo4tqzeqb0sOlruaOy3dug==",
+      "license": "MIT"
+    },
+    "node_modules/@x402/extensions/node_modules/zod": {
+      "version": "3.25.76",
+      "resolved": "https://registry.npmjs.org/zod/-/zod-3.25.76.tgz",
+      "integrity": "sha512-gzUt/qt81nXsFGKIFcC3YnfEAx5NkunCfnDlvuBSSFS02bcXu4Lmea0AFIUwbLWxWPx3d9p8S5QoaujKcNQxcQ==",
+      "license": "MIT",
+      "funding": {
+        "url": "https://github.com/sponsors/colinhacks"
+      }
+    },
     "node_modules/abitype": {
       "version": "1.2.3",
       "resolved": "https://registry.npmjs.org/abitype/-/abitype-1.2.3.tgz",
@@ -2534,6 +2667,13 @@
         "acorn": "^6.0.0 || ^7.0.0 || ^8.0.0"
       }
     },
+    "node_modules/aes-js": {
+      "version": "4.0.0-beta.5",
+      "resolved": "https://registry.npmjs.org/aes-js/-/aes-js-4.0.0-beta.5.tgz",
+      "integrity": "sha512-G965FqalsNyrPqgEGON7nIx1e/OVENSgiEIzyC63haUMuvNnwIgIjMs52hlTCKhkBny7A2ORNlfY9Zu+jmGk1Q==",
+      "license": "MIT",
+      "peer": true
+    },
     "node_modules/ajv": {
       "version": "6.12.6",
       "resolved": "https://registry.npmjs.org/ajv/-/ajv-6.12.6.tgz",
@@ -2604,7 +2744,6 @@
       "version": "5.0.1",
       "resolved": "https://registry.npmjs.org/ansi-regex/-/ansi-regex-5.0.1.tgz",
       "integrity": "sha512-quJQXlTSUGL2LH9SUXo8VwsY4soanhgo6LNSm84E1LBcE8s3O0wpdiRzyR9z/ZZJMlMWv37qOOb9pdJlMUEKFQ==",
-      "dev": true,
       "license": "MIT",
       "engines": {
         "node": ">=8"
@@ -2614,7 +2753,6 @@
       "version": "4.3.0",
       "resolved": "https://registry.npmjs.org/ansi-styles/-/ansi-styles-4.3.0.tgz",
       "integrity": "sha512-zbB9rCJAT1rbjiVDb2hqKFHNYLxgtk8NURxZ3IZwD3F6NtxbXZQCnnSi1Lkx+IDohdPlFp222wVALIheZJQSEg==",
-      "dev": true,
       "license": "MIT",
       "dependencies": {
         "color-convert": "^2.0.1"
@@ -2658,6 +2796,12 @@
         "url": "https://github.com/sponsors/jonschlinkert"
       }
     },
+    "node_modules/apg-js": {
+      "version": "4.4.0",
+      "resolved": "https://registry.npmjs.org/apg-js/-/apg-js-4.4.0.tgz",
+      "integrity": "sha512-fefmXFknJmtgtNEXfPwZKYkMFX4Fyeyz+fNF6JWp87biGOPslJbCBVU158zvKRZfHBKnJDy8CMM40oLFGkXT8Q==",
+      "license": "BSD-2-Clause"
+    },
     "node_modules/argparse": {
       "version": "2.0.1",
       "resolved": "https://registry.npmjs.org/argparse/-/argparse-2.0.1.tgz",
@@ -2685,6 +2829,12 @@
         "node": ">=12"
       }
     },
+    "node_modules/async": {
+      "version": "3.2.6",
+      "resolved": "https://registry.npmjs.org/async/-/async-3.2.6.tgz",
+      "integrity": "sha512-htCUDlxyyCLMgaM3xXg0C0LW2xqfuQ6p05pCEIsXuyQ+a1koYKTuBMzRNwmybfLgvJDMd0r1LTn4+E0Ti6C2AA==",
+      "license": "MIT"
+    },
     "node_modules/atomic-sleep": {
       "version": "1.0.0",
       "resolved": "https://registry.npmjs.org/atomic-sleep/-/atomic-sleep-1.0.0.tgz",
@@ -2954,11 +3104,24 @@
         "node": ">=8"
       }
     },
+    "node_modules/cliui": {
+      "version": "8.0.1",
+      "resolved": "https://registry.npmjs.org/cliui/-/cliui-8.0.1.tgz",
+      "integrity": "sha512-BSeNnyus75C4//NQ9gQt1/csTXyo/8Sb+afLAkzAptFuMsod9HFokGNudZpi/oQV73hnVK+sR+5PVRMd+Dr7YQ==",
+      "license": "ISC",
+      "dependencies": {
+        "string-width": "^4.2.0",
+        "strip-ansi": "^6.0.1",
+        "wrap-ansi": "^7.0.0"
+      },
+      "engines": {
+        "node": ">=12"
+      }
+    },
     "node_modules/color-convert": {
       "version": "2.0.1",
       "resolved": "https://registry.npmjs.org/color-convert/-/color-convert-2.0.1.tgz",
       "integrity": "sha512-RRECPsj7iu/xb5oKYcsFHSppFNnsj/52OVTRKb4zP5onXwVF3zVmmToNcOfGC+CRDpfK/U584fMg38ZHCaElKQ==",
-      "dev": true,
       "license": "MIT",
       "dependencies": {
         "color-name": "~1.1.4"
@@ -2971,7 +3134,6 @@
       "version": "1.1.4",
       "resolved": "https://registry.npmjs.org/color-name/-/color-name-1.1.4.tgz",
       "integrity": "sha512-dOy+3AuW3a2wNbZHIuMZpTcgjGuLU/uBL/ubcZF9OXbDo8ff4O8yVp5Bf0efS8uEoYo5q4Fx7dY9OgQGXgAsQA==",
-      "dev": true,
       "license": "MIT"
     },
     "node_modules/commander": {
@@ -3255,6 +3417,12 @@
       "integrity": "sha512-WMwm9LhRUo+WUaRN+vRuETqG89IgZphVSNkdFgeb6sS/E4OrDIN7t48CAewSHXc6C8lefD8KKfr5vY61brQlow==",
       "license": "MIT"
     },
+    "node_modules/emoji-regex": {
+      "version": "8.0.0",
+      "resolved": "https://registry.npmjs.org/emoji-regex/-/emoji-regex-8.0.0.tgz",
+      "integrity": "sha512-MSjYzcWNOA0ewAHpz0MxpYFvwg6yjy1NG3xteoqz644VCo/RPgnr1/GGt+ic3iJTzQ8Eu3TdM14SawnVUmGE6A==",
+      "license": "MIT"
+    },
     "node_modules/encodeurl": {
       "version": "2.0.0",
       "resolved": "https://registry.npmjs.org/encodeurl/-/encodeurl-2.0.0.tgz",
@@ -3367,6 +3535,15 @@
         "@esbuild/win32-x64": "0.27.3"
       }
     },
+    "node_modules/escalade": {
+      "version": "3.2.0",
+      "resolved": "https://registry.npmjs.org/escalade/-/escalade-3.2.0.tgz",
+      "integrity": "sha512-WUj2qlxaQtO4g6Pq5c29GTcWGDyd8itL8zTlipgECz3JesAiiOKotd8JU6otB3PACgG6xkJUyVhboMS+bje/jA==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=6"
+      }
+    },
     "node_modules/escape-html": {
       "version": "1.0.3",
       "resolved": "https://registry.npmjs.org/escape-html/-/escape-html-1.0.3.tgz",
@@ -3633,6 +3810,114 @@
         "node": ">= 0.6"
       }
     },
+    "node_modules/ethers": {
+      "version": "6.16.0",
+      "resolved": "https://registry.npmjs.org/ethers/-/ethers-6.16.0.tgz",
+      "integrity": "sha512-U1wulmetNymijEhpSEQ7Ct/P/Jw9/e7R1j5XIbPRydgV2DjLVMsULDlNksq3RQnFgKoLlZf88ijYtWEXcPa07A==",
+      "funding": [
+        {
+          "type": "individual",
+          "url": "https://github.com/sponsors/ethers-io/"
+        },
+        {
+          "type": "individual",
+          "url": "https://www.buymeacoffee.com/ricmoo"
+        }
+      ],
+      "license": "MIT",
+      "peer": true,
+      "dependencies": {
+        "@adraffy/ens-normalize": "1.10.1",
+        "@noble/curves": "1.2.0",
+        "@noble/hashes": "1.3.2",
+        "@types/node": "22.7.5",
+        "aes-js": "4.0.0-beta.5",
+        "tslib": "2.7.0",
+        "ws": "8.17.1"
+      },
+      "engines": {
+        "node": ">=14.0.0"
+      }
+    },
+    "node_modules/ethers/node_modules/@adraffy/ens-normalize": {
+      "version": "1.10.1",
+      "resolved": "https://registry.npmjs.org/@adraffy/ens-normalize/-/ens-normalize-1.10.1.tgz",
+      "integrity": "sha512-96Z2IP3mYmF1Xg2cDm8f1gWGf/HUVedQ3FMifV4kG/PQ4yEP51xDtRAEfhVNt5f/uzpNkZHwWQuUcu6D6K+Ekw==",
+      "license": "MIT",
+      "peer": true
+    },
+    "node_modules/ethers/node_modules/@noble/curves": {
+      "version": "1.2.0",
+      "resolved": "https://registry.npmjs.org/@noble/curves/-/curves-1.2.0.tgz",
+      "integrity": "sha512-oYclrNgRaM9SsBUBVbb8M6DTV7ZHRTKugureoYEncY5c65HOmRzvSiTE3y5CYaPYJA/GVkrhXEoF0M3Ya9PMnw==",
+      "license": "MIT",
+      "peer": true,
+      "dependencies": {
+        "@noble/hashes": "1.3.2"
+      },
+      "funding": {
+        "url": "https://paulmillr.com/funding/"
+      }
+    },
+    "node_modules/ethers/node_modules/@noble/hashes": {
+      "version": "1.3.2",
+      "resolved": "https://registry.npmjs.org/@noble/hashes/-/hashes-1.3.2.tgz",
+      "integrity": "sha512-MVC8EAQp7MvEcm30KWENFjgR+Mkmf+D189XJTkFIlwohU5hcBbn1ZkKq7KVTi2Hme3PMGF390DaL52beVrIihQ==",
+      "license": "MIT",
+      "peer": true,
+      "engines": {
+        "node": ">= 16"
+      },
+      "funding": {
+        "url": "https://paulmillr.com/funding/"
+      }
+    },
+    "node_modules/ethers/node_modules/@types/node": {
+      "version": "22.7.5",
+      "resolved": "https://registry.npmjs.org/@types/node/-/node-22.7.5.tgz",
+      "integrity": "sha512-jML7s2NAzMWc//QSJ1a3prpk78cOPchGvXJsC3C6R6PSMoooztvRVQEz89gmBTBY1SPMaqo5teB4uNHPdetShQ==",
+      "license": "MIT",
+      "peer": true,
+      "dependencies": {
+        "undici-types": "~6.19.2"
+      }
+    },
+    "node_modules/ethers/node_modules/tslib": {
+      "version": "2.7.0",
+      "resolved": "https://registry.npmjs.org/tslib/-/tslib-2.7.0.tgz",
+      "integrity": "sha512-gLXCKdN1/j47AiHiOkJN69hJmcbGTHI0ImLmbYLHykhgeN0jVGola9yVjFgzCUklsZQMW55o+dW7IXv3RCXDzA==",
+      "license": "0BSD",
+      "peer": true
+    },
+    "node_modules/ethers/node_modules/undici-types": {
+      "version": "6.19.8",
+      "resolved": "https://registry.npmjs.org/undici-types/-/undici-types-6.19.8.tgz",
+      "integrity": "sha512-ve2KP6f/JnbPBFyobGHuerC9g1FYGn/F8n1LWTwNxCEzd6IfqTwUQcNXgEtmmQ6DlRrC1hrSrBnCZPokRrDHjw==",
+      "license": "MIT",
+      "peer": true
+    },
+    "node_modules/ethers/node_modules/ws": {
+      "version": "8.17.1",
+      "resolved": "https://registry.npmjs.org/ws/-/ws-8.17.1.tgz",
+      "integrity": "sha512-6XQFvXTkbfUOZOKKILFG1PDK2NDQs4azKQl26T0YS5CxqWLgXajbPZ+h4gZekJyRqFU8pvnbAbbs/3TgRPy+GQ==",
+      "license": "MIT",
+      "peer": true,
+      "engines": {
+        "node": ">=10.0.0"
+      },
+      "peerDependencies": {
+        "bufferutil": "^4.0.1",
+        "utf-8-validate": ">=5.0.2"
+      },
+      "peerDependenciesMeta": {
+        "bufferutil": {
+          "optional": true
+        },
+        "utf-8-validate": {
+          "optional": true
+        }
+      }
+    },
     "node_modules/eventemitter3": {
       "version": "5.0.1",
       "resolved": "https://registry.npmjs.org/eventemitter3/-/eventemitter3-5.0.1.tgz",
@@ -3995,6 +4280,15 @@
         "url": "https://github.com/sponsors/ljharb"
       }
     },
+    "node_modules/get-caller-file": {
+      "version": "2.0.5",
+      "resolved": "https://registry.npmjs.org/get-caller-file/-/get-caller-file-2.0.5.tgz",
+      "integrity": "sha512-DyFP3BM/3YHTQOCUL/w0OZHR0lpKeGrxotcHWcqNEdnltqFwXVfhEBQ94eIo34AfQpo0rGki4cyIiftY06h2Fg==",
+      "license": "ISC",
+      "engines": {
+        "node": "6.* || 8.* || >= 10.*"
+      }
+    },
     "node_modules/get-intrinsic": {
       "version": "1.3.0",
       "resolved": "https://registry.npmjs.org/get-intrinsic/-/get-intrinsic-1.3.0.tgz",
@@ -4032,6 +4326,19 @@
         "node": ">= 0.4"
       }
     },
+    "node_modules/get-tsconfig": {
+      "version": "4.13.6",
+      "resolved": "https://registry.npmjs.org/get-tsconfig/-/get-tsconfig-4.13.6.tgz",
+      "integrity": "sha512-shZT/QMiSHc/YBLxxOkMtgSid5HFoauqCE3/exfsEcwg1WkeqjG+V40yBbBrsD+jW2HDXcs28xOfcbm2jI8Ddw==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "resolve-pkg-maps": "^1.0.0"
+      },
+      "funding": {
+        "url": "https://github.com/privatenumber/get-tsconfig?sponsor=1"
+      }
+    },
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       "version": "6.0.2",
       "resolved": "https://registry.npmjs.org/glob-parent/-/glob-parent-6.0.2.tgz",
@@ -4188,6 +4495,49 @@
         "url": "https://opencollective.com/express"
       }
     },
+    "node_modules/http-mitm-proxy": {
+      "version": "1.1.0",
+      "resolved": "https://registry.npmjs.org/http-mitm-proxy/-/http-mitm-proxy-1.1.0.tgz",
+      "integrity": "sha512-GyjWXiukopLzp6Yg4Dk1M+6Yfp5c/rPtqXDGaRopeJH1bd9F6k2cyJrB98kKmJaMU2P7kA5LLHbtuFc8HcNvrA==",
+      "license": "MIT",
+      "dependencies": {
+        "async": "^3.2.5",
+        "debug": "^4.3.4",
+        "mkdirp": "^1.0.4",
+        "node-forge": "^1.3.1",
+        "semaphore": "^1.1.0",
+        "uuid": "^9.0.1",
+        "ws": "^8.14.2",
+        "yargs": "^17.7.2"
+      },
+      "bin": {
+        "http-mitm-proxy": "dist/bin/mitm-proxy.js"
+      },
+      "engines": {
+        "node": ">=16"
+      }
+    },
+    "node_modules/http-mitm-proxy/node_modules/ws": {
+      "version": "8.19.0",
+      "resolved": "https://registry.npmjs.org/ws/-/ws-8.19.0.tgz",
+      "integrity": "sha512-blAT2mjOEIi0ZzruJfIhb3nps74PRWTCz1IjglWEEpQl5XS/UNama6u2/rjFkDDouqr4L67ry+1aGIALViWjDg==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=10.0.0"
+      },
+      "peerDependencies": {
+        "bufferutil": "^4.0.1",
+        "utf-8-validate": ">=5.0.2"
+      },
+      "peerDependenciesMeta": {
+        "bufferutil": {
+          "optional": true
+        },
+        "utf-8-validate": {
+          "optional": true
+        }
+      }
+    },
     "node_modules/human-id": {
       "version": "4.1.3",
       "resolved": "https://registry.npmjs.org/human-id/-/human-id-4.1.3.tgz",
@@ -4331,6 +4681,15 @@
         "node": ">=0.10.0"
       }
     },
+    "node_modules/is-fullwidth-code-point": {
+      "version": "3.0.0",
+      "resolved": "https://registry.npmjs.org/is-fullwidth-code-point/-/is-fullwidth-code-point-3.0.0.tgz",
+      "integrity": "sha512-zymm5+u+sCsSWyD9qNaejV3DFvhCKclKdizYaJUuHA83RLjb7nSuGnddCHGv0hk+KY7BMAlsWeK4Ueg6EV6XQg==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=8"
+      }
+    },
     "node_modules/is-glob": {
       "version": "4.0.3",
       "resolved": "https://registry.npmjs.org/is-glob/-/is-glob-4.0.3.tgz",
@@ -4737,6 +5096,18 @@
         "url": "https://github.com/sponsors/isaacs"
       }
     },
+    "node_modules/mkdirp": {
+      "version": "1.0.4",
+      "resolved": "https://registry.npmjs.org/mkdirp/-/mkdirp-1.0.4.tgz",
+      "integrity": "sha512-vVqVZQyf3WLx2Shd0qJ9xuvqgAyKPLAiqITEtqW0oIUjzo3PePDd6fW9iFz30ef7Ysp/oiWqbhszeGWW2T6Gzw==",
+      "license": "MIT",
+      "bin": {
+        "mkdirp": "bin/cmd.js"
+      },
+      "engines": {
+        "node": ">=10"
+      }
+    },
     "node_modules/mlly": {
       "version": "1.8.0",
       "resolved": "https://registry.npmjs.org/mlly/-/mlly-1.8.0.tgz",
@@ -4846,6 +5217,15 @@
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       "license": "MIT"
     },
+    "node_modules/node-forge": {
+      "version": "1.3.3",
+      "resolved": "https://registry.npmjs.org/node-forge/-/node-forge-1.3.3.tgz",
+      "integrity": "sha512-rLvcdSyRCyouf6jcOIPe/BgwG/d7hKjzMKOas33/pHEr6gbq18IK9zV7DiPvzsz0oBJPme6qr6H6kGZuI9/DZg==",
+      "license": "(BSD-3-Clause OR GPL-2.0)",
+      "engines": {
+        "node": ">= 6.13.0"
+      }
+    },
     "node_modules/node-mock-http": {
       "version": "1.0.4",
       "resolved": "https://registry.npmjs.org/node-mock-http/-/node-mock-http-1.0.4.tgz",
@@ -5405,7 +5785,6 @@
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       "resolved": "https://registry.npmjs.org/punycode/-/punycode-2.3.1.tgz",
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-      "dev": true,
       "license": "MIT",
       "engines": {
         "node": ">=6"
@@ -5571,6 +5950,15 @@
         "node": ">= 12.13.0"
       }
     },
+    "node_modules/require-directory": {
+      "version": "2.1.1",
+      "resolved": "https://registry.npmjs.org/require-directory/-/require-directory-2.1.1.tgz",
+      "integrity": "sha512-fGxEI7+wsG9xrvdjsrlmL22OMTTiHRwAMroiEeMgq8gzoLC/PQr7RsRDSTLUg/bZAZtF+TVIkHc6/4RIKrui+Q==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=0.10.0"
+      }
+    },
     "node_modules/require-from-string": {
       "version": "2.0.2",
       "resolved": "https://registry.npmjs.org/require-from-string/-/require-from-string-2.0.2.tgz",
@@ -5590,6 +5978,16 @@
         "node": ">=4"
       }
     },
+    "node_modules/resolve-pkg-maps": {
+      "version": "1.0.0",
+      "resolved": "https://registry.npmjs.org/resolve-pkg-maps/-/resolve-pkg-maps-1.0.0.tgz",
+      "integrity": "sha512-seS2Tj26TBVOC2NIc2rOe2y2ZO7efxITtLZcGSOnHHNOQ7CkiUBfw0Iw2ck6xkIhPwLhKNLS8BO+hEpngQlqzw==",
+      "dev": true,
+      "license": "MIT",
+      "funding": {
+        "url": "https://github.com/privatenumber/resolve-pkg-maps?sponsor=1"
+      }
+    },
     "node_modules/reusify": {
       "version": "1.1.0",
       "resolved": "https://registry.npmjs.org/reusify/-/reusify-1.1.0.tgz",
@@ -5713,6 +6111,14 @@
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       "license": "MIT"
     },
+    "node_modules/semaphore": {
+      "version": "1.1.0",
+      "resolved": "https://registry.npmjs.org/semaphore/-/semaphore-1.1.0.tgz",
+      "integrity": "sha512-O4OZEaNtkMd/K0i6js9SL+gqy0ZCBMgUvlSqHKi4IBdjhe7wB8pwztUk1BbZ1fmrvpwFrPbHzqd2w5pTcJH6LA==",
+      "engines": {
+        "node": ">=0.8.0"
+      }
+    },
     "node_modules/semver": {
       "version": "7.7.4",
       "resolved": "https://registry.npmjs.org/semver/-/semver-7.7.4.tgz",
@@ -5890,6 +6296,21 @@
         "url": "https://github.com/sponsors/isaacs"
       }
     },
+    "node_modules/siwe": {
+      "version": "2.3.2",
+      "resolved": "https://registry.npmjs.org/siwe/-/siwe-2.3.2.tgz",
+      "integrity": "sha512-aSf+6+Latyttbj5nMu6GF3doMfv2UYj83hhwZgUF20ky6fTS83uVhkQABdIVnEuS8y1bBdk7p6ltb9SmlhTTlA==",
+      "license": "Apache-2.0",
+      "dependencies": {
+        "@spruceid/siwe-parser": "^2.1.2",
+        "@stablelib/random": "^1.0.1",
+        "uri-js": "^4.4.1",
+        "valid-url": "^1.0.9"
+      },
+      "peerDependencies": {
+        "ethers": "^5.6.8 || ^6.0.8"
+      }
+    },
     "node_modules/slash": {
       "version": "3.0.0",
       "resolved": "https://registry.npmjs.org/slash/-/slash-3.0.0.tgz",
@@ -5985,11 +6406,24 @@
       "dev": true,
       "license": "MIT"
     },
+    "node_modules/string-width": {
+      "version": "4.2.3",
+      "resolved": "https://registry.npmjs.org/string-width/-/string-width-4.2.3.tgz",
+      "integrity": "sha512-wKyQRQpjJ0sIp62ErSZdGsjMJWsap5oRNihHhu6G7JVO/9jIB6UyevL+tXuOqrng8j/cxKTWyWUwvSTriiZz/g==",
+      "license": "MIT",
+      "dependencies": {
+        "emoji-regex": "^8.0.0",
+        "is-fullwidth-code-point": "^3.0.0",
+        "strip-ansi": "^6.0.1"
+      },
+      "engines": {
+        "node": ">=8"
+      }
+    },
     "node_modules/strip-ansi": {
       "version": "6.0.1",
       "resolved": "https://registry.npmjs.org/strip-ansi/-/strip-ansi-6.0.1.tgz",
       "integrity": "sha512-Y38VPSHcqkFrCpFnQ9vuSXmquuv5oXOKpGeT6aGrr3o3Gc9AlVa6JBfUSOCnbxGGZF+/0ooI7KrPuUSztUdU5A==",
-      "dev": true,
       "license": "MIT",
       "dependencies": {
         "ansi-regex": "^5.0.1"
@@ -6304,6 +6738,26 @@
         "node": ">=8"
       }
     },
+    "node_modules/tsx": {
+      "version": "4.21.0",
+      "resolved": "https://registry.npmjs.org/tsx/-/tsx-4.21.0.tgz",
+      "integrity": "sha512-5C1sg4USs1lfG0GFb2RLXsdpXqBSEhAaA/0kPL01wxzpMqLILNxIxIOKiILz+cdg/pLnOUxFYOR5yhHU666wbw==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "esbuild": "~0.27.0",
+        "get-tsconfig": "^4.7.5"
+      },
+      "bin": {
+        "tsx": "dist/cli.mjs"
+      },
+      "engines": {
+        "node": ">=18.0.0"
+      },
+      "optionalDependencies": {
+        "fsevents": "~2.3.3"
+      }
+    },
     "node_modules/turbo": {
       "version": "2.8.7",
       "resolved": "https://registry.npmjs.org/turbo/-/turbo-2.8.7.tgz",
@@ -6406,6 +6860,12 @@
         "win32"
       ]
     },
+    "node_modules/tweetnacl": {
+      "version": "1.0.3",
+      "resolved": "https://registry.npmjs.org/tweetnacl/-/tweetnacl-1.0.3.tgz",
+      "integrity": "sha512-6rt+RN7aOi1nGMyC4Xa5DdYiukl2UWCbcJft7YhxReBGQD7OAM8Pbxw6YMo4r2diNEA8FEmu32YOn9rhaiE5yw==",
+      "license": "Unlicense"
+    },
     "node_modules/type-check": {
       "version": "0.4.0",
       "resolved": "https://registry.npmjs.org/type-check/-/type-check-0.4.0.tgz",
@@ -6622,12 +7082,29 @@
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-      "dev": true,
       "license": "BSD-2-Clause",
       "dependencies": {
         "punycode": "^2.1.0"
       }
     },
+    "node_modules/uuid": {
+      "version": "9.0.1",
+      "resolved": "https://registry.npmjs.org/uuid/-/uuid-9.0.1.tgz",
+      "integrity": "sha512-b+1eJOlsR9K8HJpow9Ok3fiWOWSIcIzXodvv0rQjVoOVNpWMpxf1wZNpt4y9h10odCNrqnYp1OBzRktckBe3sA==",
+      "funding": [
+        "https://github.com/sponsors/broofa",
+        "https://github.com/sponsors/ctavan"
+      ],
+      "license": "MIT",
+      "bin": {
+        "uuid": "dist/bin/uuid"
+      }
+    },
+    "node_modules/valid-url": {
+      "version": "1.0.9",
+      "resolved": "https://registry.npmjs.org/valid-url/-/valid-url-1.0.9.tgz",
+      "integrity": "sha512-QQDsV8OnSf5Uc30CKSwG9lnhMPe6exHtTXLRYX8uMwKENy640pU+2BgBL0LRbDh/eYRahNCS7aewCx0wf3NYVA=="
+    },
     "node_modules/vary": {
       "version": "1.1.2",
       "resolved": "https://registry.npmjs.org/vary/-/vary-1.1.2.tgz",
@@ -6976,6 +7453,23 @@
         "node": ">=0.10.0"
       }
     },
+    "node_modules/wrap-ansi": {
+      "version": "7.0.0",
+      "resolved": "https://registry.npmjs.org/wrap-ansi/-/wrap-ansi-7.0.0.tgz",
+      "integrity": "sha512-YVGIj2kamLSTxw6NsZjoBxfSwsn0ycdesmc4p+Q21c5zPuZ1pl+NfxVdxPtdHvmNVOQ6XSYG4AUtyt/Fi7D16Q==",
+      "license": "MIT",
+      "dependencies": {
+        "ansi-styles": "^4.0.0",
+        "string-width": "^4.1.0",
+        "strip-ansi": "^6.0.0"
+      },
+      "engines": {
+        "node": ">=10"
+      },
+      "funding": {
+        "url": "https://github.com/chalk/wrap-ansi?sponsor=1"
+      }
+    },
     "node_modules/wrappy": {
       "version": "1.0.2",
       "resolved": "https://registry.npmjs.org/wrappy/-/wrappy-1.0.2.tgz",
@@ -7018,6 +7512,15 @@
         "url": "https://github.com/sponsors/sindresorhus"
       }
     },
+    "node_modules/y18n": {
+      "version": "5.0.8",
+      "resolved": "https://registry.npmjs.org/y18n/-/y18n-5.0.8.tgz",
+      "integrity": "sha512-0pfFzegeDWJHJIAmTLRP2DwHjdF5s7jo9tuztdQxAhINCdvS+3nGINqPd00AphqJR/0LhANUS6/+7SCb98YOfA==",
+      "license": "ISC",
+      "engines": {
+        "node": ">=10"
+      }
+    },
     "node_modules/yaml": {
       "version": "2.8.2",
       "resolved": "https://registry.npmjs.org/yaml/-/yaml-2.8.2.tgz",
@@ -7033,6 +7536,33 @@
         "url": "https://github.com/sponsors/eemeli"
       }
     },
+    "node_modules/yargs": {
+      "version": "17.7.2",
+      "resolved": "https://registry.npmjs.org/yargs/-/yargs-17.7.2.tgz",
+      "integrity": "sha512-7dSzzRQ++CKnNI/krKnYRV7JKKPUXMEh61soaHKg9mrWEhzFWhFnxPxGl+69cD1Ou63C13NUPCnmIcrvqCuM6w==",
+      "license": "MIT",
+      "dependencies": {
+        "cliui": "^8.0.1",
+        "escalade": "^3.1.1",
+        "get-caller-file": "^2.0.5",
+        "require-directory": "^2.1.1",
+        "string-width": "^4.2.3",
+        "y18n": "^5.0.5",
+        "yargs-parser": "^21.1.1"
+      },
+      "engines": {
+        "node": ">=12"
+      }
+    },
+    "node_modules/yargs-parser": {
+      "version": "21.1.1",
+      "resolved": "https://registry.npmjs.org/yargs-parser/-/yargs-parser-21.1.1.tgz",
+      "integrity": "sha512-tVpsJW7DdjecAiFpbIB1e3qxIQsE6NoPc5/eTdrbbIC4h0LVsWhnoa3g+m2HclBIujHzsxZ4VJVA+GUuc2/LBw==",
+      "license": "ISC",
+      "engines": {
+        "node": ">=12"
+      }
+    },
     "node_modules/yocto-queue": {
       "version": "0.1.0",
       "resolved": "https://registry.npmjs.org/yocto-queue/-/yocto-queue-0.1.0.tgz",
@@ -7066,7 +7596,7 @@
     },
     "packages/cli-sdk": {
       "name": "@walletconnect/cli-sdk",
-      "version": "0.5.0",
+      "version": "0.6.0",
       "license": "SEE LICENSE IN LICENSE.md",
       "dependencies": {
         "@walletconnect/keyvaluestorage": "1.1.1",
@@ -7092,7 +7622,7 @@
     },
     "packages/companion-wallet": {
       "name": "@walletconnect/companion-wallet",
-      "version": "0.5.0",
+      "version": "0.6.0",
       "license": "SEE LICENSE IN LICENSE.md",
       "dependencies": {
         "@walletconnect/cli-sdk": "*",
@@ -7114,7 +7644,7 @@
     },
     "packages/pay-cli": {
       "name": "@walletconnect/pay-cli",
-      "version": "0.5.0",
+      "version": "0.6.0",
       "license": "SEE LICENSE IN LICENSE.md",
       "dependencies": {
         "@walletconnect/cli-sdk": "*",
@@ -7135,7 +7665,7 @@
     },
     "packages/staking-cli": {
       "name": "@walletconnect/staking-cli",
-      "version": "0.5.0",
+      "version": "0.6.0",
       "license": "SEE LICENSE IN LICENSE.md",
       "dependencies": {
         "@walletconnect/cli-sdk": "*",
@@ -7193,6 +7723,55 @@
         "typescript": "^5.5.0",
         "vitest": "^3.2.0"
       }
+    },
+    "samples/x402-browser-proxy": {
+      "name": "@agent-sdk/x402-browser-proxy",
+      "version": "0.0.0",
+      "dependencies": {
+        "@walletconnect/cli-sdk": "*",
+        "@x402/core": "^2.2.0",
+        "@x402/evm": "^2.2.0",
+        "commander": "^12.1.0",
+        "http-mitm-proxy": "^1.1.0"
+      },
+      "bin": {
+        "x402-browser-proxy": "dist/index.js"
+      },
+      "devDependencies": {
+        "@types/node": "^22.0.0",
+        "tsup": "^8.4.0",
+        "tsx": "^4.19.0",
+        "typescript": "^5.6.0"
+      },
+      "engines": {
+        "node": ">=18"
+      }
+    },
+    "samples/x402-browser-proxy/node_modules/@types/node": {
+      "version": "22.19.13",
+      "resolved": "https://registry.npmjs.org/@types/node/-/node-22.19.13.tgz",
+      "integrity": "sha512-akNQMv0wW5uyRpD2v2IEyRSZiR+BeGuoB6L310EgGObO44HSMNT8z1xzio28V8qOrgYaopIDNA18YgdXd+qTiw==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "undici-types": "~6.21.0"
+      }
+    },
+    "samples/x402-browser-proxy/node_modules/commander": {
+      "version": "12.1.0",
+      "resolved": "https://registry.npmjs.org/commander/-/commander-12.1.0.tgz",
+      "integrity": "sha512-Vw8qHK3bZM9y/P10u3Vib8o/DdkvA2OtPtZvD871QKjy74Wj1WSKFILMPRPSdUSx5RFK1arlJzEtA4PkFgnbuA==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=18"
+      }
+    },
+    "samples/x402-browser-proxy/node_modules/undici-types": {
+      "version": "6.21.0",
+      "resolved": "https://registry.npmjs.org/undici-types/-/undici-types-6.21.0.tgz",
+      "integrity": "sha512-iwDZqg0QAGrg9Rav5H4n0M64c3mkR59cJ6wQp+7C4nI0gsmExaedaYLNO44eT4AtBBwjbTiGPMlt2Md0T9H9JQ==",
+      "dev": true,
+      "license": "MIT"
     }
   }
 }
diff --git a/package.json b/package.json
index eb535f1..0f6db81 100644
--- a/package.json
+++ b/package.json
@@ -16,6 +16,7 @@
     "turbo": "^2.8.0"
   },
   "workspaces": [
-    "packages/*"
+    "packages/*",
+    "samples/*"
   ]
 }
diff --git a/samples/x402-browser-proxy/.gitignore b/samples/x402-browser-proxy/.gitignore
new file mode 100644
index 0000000..c0fcab0
--- /dev/null
+++ b/samples/x402-browser-proxy/.gitignore
@@ -0,0 +1 @@
+.http-mitm-proxy/
diff --git a/samples/x402-browser-proxy/README.md b/samples/x402-browser-proxy/README.md
new file mode 100644
index 0000000..19f3e80
--- /dev/null
+++ b/samples/x402-browser-proxy/README.md
@@ -0,0 +1,183 @@
+# x402 Browser Proxy
+
+A local MITM proxy that intercepts HTTP 402 (Payment Required) responses and automatically signs [x402](https://www.x402.org/) payments using a CWP (CLI Wallet Protocol) wallet provider.
+
+## How It Works
+
+```
+Any HTTP client → MITM proxy (port 8402) → origin server
+                        ↓ (on 402)
+                  parse x402 payment header
+                        ↓
+                  CWP sign-typed-data → wallet provider (e.g., companion-wallet)
+                        ↓
+                  retry request with payment signature
+                        ↓
+                  return 200 to client
+```
+
+The proxy sits between any HTTP client and the internet. When a server responds with `402 Payment Required` and an x402 payment header, the proxy automatically:
+
+1. Parses the payment requirements (amount, network, asset)
+2. Signs the payment via CWP (`wallet-companion sign-typed-data`)
+3. Retries the request with the payment signature
+4. Returns the paid response to the client
+
+No code changes needed in the client — just point it at the proxy.
+
+## Prerequisites
+
+- A CWP wallet provider installed and on PATH (e.g., `companion-wallet`)
+- The wallet must have an EVM account with funds on the target network
+- To install companion-wallet: `npm install -g @walletconnect/companion-wallet` (or `npm link` from `packages/companion-wallet`)
+
+## Quick Start
+
+```bash
+# From the repo root
+npm run build
+
+# Start the proxy (auto-discovers wallet-companion)
+cd samples/x402-browser-proxy
+npm run dev start
+```
+
+## Consuming the Proxy
+
+Any HTTP client can use the proxy. The key idea: route your traffic through `http://127.0.0.1:8402` and the proxy handles payments transparently.
+
+### curl
+
+```bash
+# Direct request — gets 402
+curl https://x402.payai.network/api/base/paid-content
+# → 402 Payment Required
+
+# Through proxy — gets 200 (proxy pays automatically)
+curl -x http://127.0.0.1:8402 https://x402.payai.network/api/base/paid-content
+# → 200 OK with paid content
+```
+
+### agent-browser
+
+```bash
+export AGENT_BROWSER_PROXY="http://127.0.0.1:8402"
+export AGENT_BROWSER_IGNORE_HTTPS_ERRORS=1
+agent-browser open "https://x402.payai.network/api/base/paid-content"
+```
+
+### Node.js / fetch
+
+```javascript
+import { ProxyAgent } from 'undici';
+
+const agent = new ProxyAgent('http://127.0.0.1:8402');
+const res = await fetch('https://x402.payai.network/api/base/paid-content', {
+  dispatcher: agent,
+});
+// res.status === 200 — proxy handled the 402 + payment
+```
+
+### Environment variables (system-wide)
+
+```bash
+export HTTP_PROXY="http://127.0.0.1:8402"
+export HTTPS_PROXY="http://127.0.0.1:8402"
+export NODE_TLS_REJECT_UNAUTHORIZED=0  # needed for HTTPS MITM
+
+# Now any tool that respects HTTP_PROXY will auto-pay x402 endpoints
+curl https://x402.payai.network/api/base/paid-content
+```
+
+### Python / requests
+
+```python
+import requests
+
+proxies = {"http": "http://127.0.0.1:8402", "https": "http://127.0.0.1:8402"}
+r = requests.get("https://x402.payai.network/api/base/paid-content",
+                  proxies=proxies, verify=False)
+# r.status_code == 200
+```
+
+## CLI Reference
+
+```bash
+# Start proxy with auto-discovered CWP provider
+npm run dev start
+
+# Start with a specific provider
+npm run dev start -- --wallet companion
+
+# Start with session-constrained signing (companion-wallet spending limits)
+npm run dev start -- --session <session-id>
+
+# Start with custom options
+npm run dev start -- --port 8402 --max-payment 100000 --host 127.0.0.1
+
+# List available CWP providers
+npm run dev list-wallets
+```
+
+### Options
+
+| Flag | Default | Description |
+|------|---------|-------------|
+| `-p, --port` | `8402` | Proxy listen port (env: `X402_PROXY_PORT`) |
+| `-m, --max-payment` | `100000` | Max payment in smallest unit (env: `X402_MAX_PAYMENT`) |
+| `--host` | `127.0.0.1` | Host to bind to |
+| `-w, --wallet` | auto | CWP provider name |
+| `-s, --session` | none | Companion-wallet session ID |
+
+## Testing
+
+### With the mock server
+
+```bash
+# Terminal 1: Start the mock x402 server
+node test-server.mjs
+
+# Terminal 2: Start the proxy
+npm run dev start
+
+# Terminal 3: Run tests
+node test-server.mjs --test
+```
+
+The test suite verifies:
+1. Direct request to mock server returns 402
+2. Same request through proxy returns 200 (payment signed and accepted)
+3. Same flow against the real PayAI endpoint (`x402.payai.network`)
+
+## How the CWP Bridge Works
+
+The core innovation is `cwp-signer.ts` — an adapter that implements the `ClientEvmSigner` interface (from `@x402/evm`) by delegating to `walletExec` from `@walletconnect/cli-sdk`:
+
+```typescript
+// @x402/evm expects: { address, signTypedData({domain, types, primaryType, message}) }
+// CWP provides:      wallet-companion sign-typed-data < {account, typedData: {...}}
+
+function createCwpSigner({ path, account, sessionId }): ClientEvmSigner {
+  return {
+    address: account,
+    async signTypedData({ domain, types, primaryType, message }) {
+      const result = await walletExec(path, "sign-typed-data", {
+        account,
+        typedData: { domain, types, primaryType, message },
+        ...(sessionId && { sessionId }),
+      });
+      return result.signature;
+    },
+  };
+}
+```
+
+This means any CWP-compatible wallet can sign x402 payments — not just `companion-wallet`.
+
+## Environment Variables
+
+| Variable | Description |
+|----------|-------------|
+| `X402_PROXY_PORT` | Default proxy port |
+| `X402_MAX_PAYMENT` | Default max payment amount |
+| `DEBUG` | Enable debug logging (verbose proxy + payment details) |
diff --git a/samples/x402-browser-proxy/package.json b/samples/x402-browser-proxy/package.json
new file mode 100644
index 0000000..6d5bc0c
--- /dev/null
+++ b/samples/x402-browser-proxy/package.json
@@ -0,0 +1,32 @@
+{
+  "name": "@agent-sdk/x402-browser-proxy",
+  "version": "0.0.0",
+  "private": true,
+  "description": "MITM proxy that intercepts HTTP 402 responses and auto-signs x402 payments via CWP",
+  "type": "module",
+  "main": "dist/index.js",
+  "bin": {
+    "x402-browser-proxy": "./dist/index.js"
+  },
+  "scripts": {
+    "build": "tsup",
+    "dev": "tsx src/index.ts",
+    "lint": "eslint src/"
+  },
+  "dependencies": {
+    "@walletconnect/cli-sdk": "*",
+    "@x402/evm": "^2.2.0",
+    "@x402/core": "^2.2.0",
+    "commander": "^12.1.0",
+    "http-mitm-proxy": "^1.1.0"
+  },
+  "devDependencies": {
+    "@types/node": "^22.0.0",
+    "tsup": "^8.4.0",
+    "tsx": "^4.19.0",
+    "typescript": "^5.6.0"
+  },
+  "engines": {
+    "node": ">=18"
+  }
+}
diff --git a/samples/x402-browser-proxy/src/cwp-signer.ts b/samples/x402-browser-proxy/src/cwp-signer.ts
new file mode 100644
index 0000000..941533b
--- /dev/null
+++ b/samples/x402-browser-proxy/src/cwp-signer.ts
@@ -0,0 +1,67 @@
+import { walletExec } from "@walletconnect/cli-sdk";
+import type { ClientEvmSigner } from "@x402/evm";
+
+export interface CwpSignerOptions {
+  /** Full path to the wallet-* executable */
+  path: string;
+  /** EVM account address */
+  account: `0x${string}`;
+  /** Optional companion-wallet session ID for spending limits */
+  sessionId?: string;
+}
+
+/**
+ * Recursively converts BigInt values to strings so the object is JSON-serializable.
+ * walletExec uses JSON.stringify internally, which throws on BigInt.
+ */
+function bigintToString(obj: unknown): unknown {
+  if (typeof obj === "bigint") return obj.toString();
+  if (Array.isArray(obj)) return obj.map(bigintToString);
+  if (obj !== null && typeof obj === "object") {
+    const result: Record<string, unknown> = {};
+    for (const [key, value] of Object.entries(obj)) {
+      result[key] = bigintToString(value);
+    }
+    return result;
+  }
+  return obj;
+}
+
+/**
+ * Creates a ClientEvmSigner that delegates signing to a CWP wallet provider.
+ *
+ * This bridges the x402 payment signing interface with the CLI Wallet Protocol,
+ * allowing any CWP-compatible wallet (e.g., companion-wallet) to sign x402 payments.
+ */
+export function createCwpSigner(options: CwpSignerOptions): ClientEvmSigner {
+  const { path: providerPath, account, sessionId } = options;
+
+  return {
+    address: account,
+
+    async signTypedData({
+      domain,
+      types,
+      primaryType,
+      message,
+    }: {
+      domain: Record<string, unknown>;
+      types: Record<string, unknown>;
+      primaryType: string;
+      message: Record<string, unknown>;
+    }): Promise<`0x${string}`> {
+      const result = (await walletExec(
+        providerPath,
+        "sign-typed-data",
+        {
+          account,
+          typedData: bigintToString({ domain, types, primaryType, message }) as Record<string, unknown>,
+          ...(sessionId && { sessionId }),
+        },
+        30000, // 30s timeout for signing
+      )) as { signature: `0x${string}` };
+
+      return result.signature;
+    },
+  };
+}
diff --git a/samples/x402-browser-proxy/src/index.ts b/samples/x402-browser-proxy/src/index.ts
new file mode 100644
index 0000000..98898a0
--- /dev/null
+++ b/samples/x402-browser-proxy/src/index.ts
@@ -0,0 +1,153 @@
+#!/usr/bin/env node
+
+import { program } from "commander";
+import {
+  discoverProviders,
+  getProvider,
+  getDefaultProvider,
+  walletExec,
+} from "@walletconnect/cli-sdk";
+import { createCwpSigner } from "./cwp-signer.js";
+import { initializeClient } from "./x402-client.js";
+import { startProxy } from "./proxy.js";
+import { logger } from "./logger.js";
+
+const DEFAULT_PORT = 8402;
+const DEFAULT_MAX_PAYMENT = BigInt("100000"); // 0.1 USDC (6 decimals)
+
+function getDefaultPort(): number {
+  const envPort = process.env.X402_PROXY_PORT;
+  if (envPort) {
+    const parsed = parseInt(envPort, 10);
+    if (!isNaN(parsed)) return parsed;
+  }
+  return DEFAULT_PORT;
+}
+
+function getDefaultMaxPayment(): bigint {
+  const envMax = process.env.X402_MAX_PAYMENT;
+  if (envMax) {
+    try {
+      return BigInt(envMax);
+    } catch {
+      logger.warn(`Invalid X402_MAX_PAYMENT value "${envMax}", using default`);
+    }
+  }
+  return DEFAULT_MAX_PAYMENT;
+}
+
+program
+  .name("x402-browser-proxy")
+  .description(
+    "MITM proxy that intercepts HTTP 402 responses and auto-signs x402 payments via CWP",
+  )
+  .version("0.0.0");
+
+program
+  .command("start")
+  .description("Start the x402 payment proxy")
+  .option(
+    "-p, --port <number>",
+    "Proxy port",
+    String(getDefaultPort()),
+  )
+  .option(
+    "-m, --max-payment <amount>",
+    "Maximum payment in smallest unit",
+    getDefaultMaxPayment().toString(),
+  )
+  .option("--host <address>", "Host to bind to", "127.0.0.1")
+  .option("-w, --wallet <name>", "CWP provider name (auto-discovers if omitted)")
+  .option("-s, --session <id>", "Companion-wallet session ID for spending limits")
+  .action(async (options) => {
+    const port = parseInt(options.port, 10) || getDefaultPort();
+    const maxPayment = BigInt(options.maxPayment || getDefaultMaxPayment());
+    const host = options.host || "127.0.0.1";
+
+    // Discover or select CWP provider
+    let provider;
+    if (options.wallet) {
+      provider = await getProvider(options.wallet);
+      if (!provider) {
+        logger.error(`CWP provider "${options.wallet}" not found`);
+        logger.info("Run 'x402-browser-proxy list-wallets' to see available providers");
+        process.exit(1);
+      }
+    } else {
+      provider = await getDefaultProvider();
+      if (!provider) {
+        logger.error("No CWP wallet providers found on PATH");
+        logger.info(
+          "Install a wallet provider (e.g., companion-wallet) and ensure wallet-<name> is on PATH",
+        );
+        process.exit(1);
+      }
+    }
+
+    logger.info(`Using CWP provider: ${provider.info?.name || provider.shortName} (${provider.binary})`);
+
+    // Get the wallet account address via CWP "accounts" operation
+    let account: `0x${string}`;
+    try {
+      const result = (await walletExec(provider.path, "accounts", undefined, 5000)) as {
+        accounts: Array<{ chain: string; address: `0x${string}` }>;
+      };
+      if (!result.accounts || result.accounts.length === 0) {
+        logger.error("No accounts found in wallet. Run 'wallet-companion generate' first.");
+        process.exit(1);
+      }
+      account = result.accounts[0].address;
+    } catch (err) {
+      logger.error(`Failed to get wallet accounts: ${err}`);
+      process.exit(1);
+    }
+
+    logger.info(`Wallet address: ${account}`);
+
+    // Create the CWP signer and initialize x402 client
+    const signer = createCwpSigner({
+      path: provider.path,
+      account,
+      sessionId: options.session,
+    });
+
+    const { httpClient, walletAddress } = initializeClient(signer);
+
+    if (options.session) {
+      logger.info(`Using session: ${options.session}`);
+    }
+
+    startProxy({ port, maxPayment, host, httpClient, walletAddress });
+  });
+
+program
+  .command("list-wallets")
+  .description("List available CWP wallet providers")
+  .action(async () => {
+    const providers = await discoverProviders();
+
+    if (providers.length === 0) {
+      console.log("No CWP wallet providers found on PATH.");
+      console.log(
+        "\nInstall a provider (e.g., companion-wallet) and ensure wallet-<name> is on PATH.",
+      );
+      return;
+    }
+
+    console.log("Available CWP wallet providers:\n");
+    for (const p of providers) {
+      const status = p.info
+        ? `${p.info.name} v${p.info.version}`
+        : `(error: ${p.error})`;
+      const chains = p.info?.chains?.join(", ") || "unknown";
+      const caps = p.info?.capabilities?.join(", ") || "unknown";
+      console.log(`  ${p.shortName}`);
+      console.log(`    Binary: ${p.path}`);
+      console.log(`    Status: ${status}`);
+      console.log(`    Chains: ${chains}`);
+      console.log(`    Capabilities: ${caps}`);
+      console.log("");
+    }
+  });
+
+program.parse();
diff --git a/samples/x402-browser-proxy/src/logger.ts b/samples/x402-browser-proxy/src/logger.ts
new file mode 100644
index 0000000..bdb7824
--- /dev/null
+++ b/samples/x402-browser-proxy/src/logger.ts
@@ -0,0 +1,59 @@
+const COLORS = {
+  reset: "\x1b[0m",
+  dim: "\x1b[2m",
+  cyan: "\x1b[36m",
+  yellow: "\x1b[33m",
+  red: "\x1b[31m",
+  green: "\x1b[32m",
+  magenta: "\x1b[35m",
+};
+
+function timestamp(): string {
+  return new Date().toISOString().replace("T", " ").substring(0, 19);
+}
+
+export const logger = {
+  info(message: string, ...args: unknown[]): void {
+    console.log(
+      `${COLORS.dim}[${timestamp()}]${COLORS.reset} ${COLORS.cyan}INFO${COLORS.reset}  ${message}`,
+      ...args,
+    );
+  },
+
+  warn(message: string, ...args: unknown[]): void {
+    console.log(
+      `${COLORS.dim}[${timestamp()}]${COLORS.reset} ${COLORS.yellow}WARN${COLORS.reset}  ${message}`,
+      ...args,
+    );
+  },
+
+  error(message: string, ...args: unknown[]): void {
+    console.error(
+      `${COLORS.dim}[${timestamp()}]${COLORS.reset} ${COLORS.red}ERROR${COLORS.reset} ${message}`,
+      ...args,
+    );
+  },
+
+  success(message: string, ...args: unknown[]): void {
+    console.log(
+      `${COLORS.dim}[${timestamp()}]${COLORS.reset} ${COLORS.green}OK${COLORS.reset}    ${message}`,
+      ...args,
+    );
+  },
+
+  payment(message: string, ...args: unknown[]): void {
+    console.log(
+      `${COLORS.dim}[${timestamp()}]${COLORS.reset} ${COLORS.magenta}PAY${COLORS.reset}   ${message}`,
+      ...args,
+    );
+  },
+
+  debug(message: string, ...args: unknown[]): void {
+    if (process.env.DEBUG) {
+      console.log(
+        `${COLORS.dim}[${timestamp()}] DEBUG ${message}${COLORS.reset}`,
+        ...args,
+      );
+    }
+  },
+};
diff --git a/samples/x402-browser-proxy/src/proxy.ts b/samples/x402-browser-proxy/src/proxy.ts
new file mode 100644
index 0000000..103c2b9
--- /dev/null
+++ b/samples/x402-browser-proxy/src/proxy.ts
@@ -0,0 +1,221 @@
+import { Proxy } from "http-mitm-proxy";
+import type { x402HTTPClient } from "@x402/core/client";
+import * as http from "http";
+import * as https from "https";
+import * as fs from "fs";
+import * as os from "os";
+import * as path from "path";
+import { logger } from "./logger.js";
+import { parsePaymentHeader, signPayment } from "./x402-client.js";
+import type { PaymentRequirements } from "@x402/core/types";
+
+const CERT_DIR = path.join(os.homedir(), ".x402-browser-proxy", "certs");
+
+export interface ProxyOptions {
+  port: number;
+  maxPayment: bigint;
+  host?: string;
+  httpClient: x402HTTPClient;
+  walletAddress: string;
+}
+
+export function startProxy(options: ProxyOptions): void {
+  const { port, maxPayment, host = "127.0.0.1", httpClient, walletAddress } = options;
+
+  if (!fs.existsSync(CERT_DIR)) {
+    fs.mkdirSync(CERT_DIR, { recursive: true });
+    logger.info(`Created certificate directory: ${CERT_DIR}`);
+  }
+
+  const proxy = new Proxy();
+  proxy.sslCaDir = CERT_DIR;
+
+  proxy.onError((_ctx, err) => {
+    if (err) {
+      logger.error(`Proxy error: ${err.message}`);
+    }
+  });
+
+  proxy.onRequest((ctx, callback) => {
+    if (process.env.DEBUG) {
+      const { clientToProxyRequest: req } = ctx;
+      const url = `${ctx.isSSL ? "https" : "http"}://${req.headers.host}${req.url}`;
+      logger.debug(`Request: ${req.method} ${url}`);
+    }
+    callback();
+  });
+
+  proxy.onResponse((ctx, callback) => {
+    const {
+      clientToProxyRequest: req,
+      serverToProxyResponse: serverRes,
+      proxyToClientResponse: clientRes,
+    } = ctx;
+
+    if (!serverRes) {
+      callback();
+      return;
+    }
+
+    const statusCode = serverRes.statusCode || 0;
+    const url = `${ctx.isSSL ? "https" : "http"}://${req.headers.host}${req.url}`;
+
+    if (statusCode === 402) {
+      logger.payment(`402 Payment Required: ${url}`);
+
+      const paymentHeader = (serverRes.headers["x-payment"] ||
+        serverRes.headers["payment-required"]) as string | undefined;
+
+      if (!paymentHeader) {
+        logger.warn(
+          "No X-Payment or Payment-Required header found in 402 response",
+        );
+        callback();
+        return;
+      }
+
+      const paymentRequired = parsePaymentHeader(paymentHeader);
+      if (!paymentRequired) {
+        logger.error("Failed to parse payment requirements");
+        callback();
+        return;
+      }
+
+      const accepts = paymentRequired.accepts || [];
+      if (accepts.length > 0) {
+        const paymentReq = accepts[0] as PaymentRequirements;
+        logger.payment(
+          `Payment details: scheme=${paymentReq.scheme}, network=${paymentReq.network}, amount=${paymentReq.amount}`,
+        );
+      }
+
+      signPayment(httpClient, paymentRequired, maxPayment)
+        .then((paymentHeaders) => {
+          if (!paymentHeaders) {
+            logger.warn("Payment rejected or signing failed");
+            callback();
+            return;
+          }
+
+          logger.payment(`Payment signed, retrying request...`);
+
+          retryWithPayment(ctx, paymentHeaders, url)
+            .then((retryRes) => {
+              if (retryRes) {
+                const retryStatus = retryRes.statusCode ?? 0;
+                if (retryStatus === 402) {
+                  logger.warn(
+                    `Retry still got 402 - payment may have been rejected: ${url}`,
+                  );
+                } else if (retryStatus >= 200 && retryStatus < 300) {
+                  logger.success(
+                    `Paid request successful: ${retryStatus} ${url}`,
+                  );
+                } else {
+                  logger.info(
+                    `Retry response: ${retryStatus} ${url}`,
+                  );
+                }
+                clientRes.writeHead(retryStatus, retryRes.headers);
+                retryRes.pipe(clientRes);
+              } else {
+                callback();
+              }
+            })
+            .catch((err) => {
+              logger.error(`Retry failed: ${err.message}`);
+              callback();
+            });
+        })
+        .catch((err) => {
+          logger.error(`Payment signing failed: ${err.message}`);
+          callback();
+        });
+    } else {
+      if (process.env.DEBUG) {
+        logger.debug(`Response: ${statusCode} ${url}`);
+      }
+      callback();
+    }
+  });
+
+  proxy.listen({ port, host }, () => {
+    logger.info(`x402 proxy started on ${host}:${port}`);
+    logger.info(`Wallet address: ${walletAddress}`);
+    logger.info(`Max payment: ${maxPayment.toString()}`);
+    logger.info(
+      `CA certificate: ${path.join(CERT_DIR, "certs", "ca.pem")}`,
+    );
+    console.log("");
+    console.log("Usage with agent-browser:");
+    console.log(`  export AGENT_BROWSER_PROXY="http://${host}:${port}"`);
+    console.log("  export AGENT_BROWSER_IGNORE_HTTPS_ERRORS=1");
+    console.log("");
+  });
+}
+
+type ProxyResponseContext = Parameters<Parameters<Proxy["onResponse"]>[0]>[0];
+
+async function retryWithPayment(
+  ctx: ProxyResponseContext,
+  paymentHeaders: Record<string, string>,
+  url: string,
+): Promise<http.IncomingMessage | null> {
+  return new Promise((resolve, reject) => {
+    const { clientToProxyRequest: originalReq } = ctx;
+    const parsedUrl = new URL(url);
+
+    const isHttps = parsedUrl.protocol === "https:";
+    const requestModule = isHttps ? https : http;
+
+    const headers: Record<string, string | string[] | undefined> = {
+      ...originalReq.headers,
+    };
+
+    for (const [key, value] of Object.entries(paymentHeaders)) {
+      headers[key.toLowerCase()] = value;
+    }
+
+    // Remove hop-by-hop headers
+    delete headers["proxy-connection"];
+    delete headers["connection"];
+    delete headers["keep-alive"];
+    delete headers["transfer-encoding"];
+
+    const options: http.RequestOptions = {
+      hostname: parsedUrl.hostname,
+      port: parsedUrl.port || (isHttps ? 443 : 80),
+      path: parsedUrl.pathname + parsedUrl.search,
+      method: originalReq.method,
+      headers,
+    };
+
+    if (process.env.DEBUG) {
+      logger.debug(`Retry request headers: ${JSON.stringify(headers)}`);
+    }
+
+    const retryReq = requestModule.request(options, (res) => {
+      const paymentResponse =
+        res.headers["payment-response"] || res.headers["x-payment-response"];
+      if (paymentResponse && process.env.DEBUG) {
+        try {
+          const decoded = Buffer.from(
+            paymentResponse as string,
+            "base64",
+          ).toString("utf-8");
+          logger.debug(`Payment response: ${decoded}`);
+        } catch {
+          logger.debug(`Payment response (raw): ${paymentResponse}`);
+        }
+      }
+      resolve(res);
+    });
+
+    retryReq.on("error", (err) => {
+      reject(err);
+    });
+
+    // Note: body is not forwarded on retry (x402 payments are typically GET requests)
+    retryReq.end();
+  });
+}
diff --git a/samples/x402-browser-proxy/src/x402-client.ts b/samples/x402-browser-proxy/src/x402-client.ts
new file mode 100644
index 0000000..12751cd
--- /dev/null
+++ b/samples/x402-browser-proxy/src/x402-client.ts
@@ -0,0 +1,109 @@
+import { ExactEvmScheme } from "@x402/evm";
+import type { ClientEvmSigner } from "@x402/evm";
+import { x402Client, x402HTTPClient } from "@x402/core/client";
+import type {
+  PaymentRequirements,
+  PaymentRequired,
+} from "@x402/core/types";
+import { logger } from "./logger.js";
+
+export interface X402ClientHandle {
+  httpClient: x402HTTPClient;
+  walletAddress: `0x${string}`;
+}
+
+/**
+ * Initialize the x402 client with a CWP-backed signer.
+ */
+export function initializeClient(signer: ClientEvmSigner): X402ClientHandle {
+  const client = new x402Client();
+  const evmScheme = new ExactEvmScheme(signer);
+  client.register("eip155:*", evmScheme);
+
+  const httpClient = new x402HTTPClient(client);
+
+  logger.info(`Initialized x402 client with wallet: ${signer.address}`);
+
+  return { httpClient, walletAddress: signer.address };
+}
+
+export function parsePaymentHeader(
+  headerValue: string,
+): PaymentRequired | null {
+  try {
+    const decoded = Buffer.from(headerValue, "base64").toString("utf-8");
+    const paymentRequired = JSON.parse(decoded) as PaymentRequired;
+
+    // If resource is missing but is in accepts[0].extra, copy it up
+    if (
+      !paymentRequired.resource &&
+      paymentRequired.accepts?.length > 0
+    ) {
+      const firstAccept = paymentRequired.accepts[0] as Record<string, unknown>;
+      const extra = firstAccept.extra as Record<string, string> | undefined;
+      if (extra?.resource) {
+        paymentRequired.resource = {
+          url: extra.resource,
+          description: extra.description || "",
+          mimeType: extra.mimeType || "application/json",
+        };
+      }
+    }
+
+    return paymentRequired;
+  } catch (error) {
+    logger.error("Failed to parse payment header:", error);
+    return null;
+  }
+}
+
+export async function signPayment(
+  httpClient: x402HTTPClient,
+  paymentRequired: PaymentRequired,
+  maxPayment: bigint,
+): Promise<Record<string, string> | null> {
+  const accepts = paymentRequired.accepts || [];
+  if (accepts.length === 0) {
+    logger.error("No payment options available in requirements");
+    return null;
+  }
+
+  const paymentReq = accepts[0] as PaymentRequirements;
+  const amount = BigInt(paymentReq.amount);
+
+  if (amount > maxPayment) {
+    logger.warn(
+      `Payment amount ${amount} exceeds max allowed ${maxPayment}. Rejecting.`,
+    );
+    return null;
+  }
+
+  const resourceUrl =
+    paymentRequired.resource?.url ||
+    (paymentReq.extra as Record<string, string> | undefined)?.resource ||
+    "unknown";
+  logger.payment(
+    `Signing payment: ${paymentReq.amount} on ${paymentReq.network} for ${resourceUrl}`,
+  );
+
+  try {
+    const paymentPayload = await httpClient.createPaymentPayload(paymentRequired);
+
+    if (process.env.DEBUG) {
+      logger.debug(
+        `Payment payload: ${JSON.stringify(paymentPayload, (_k, v) => (typeof v === "bigint" ? v.toString() : v))}`,
+      );
+    }
+
+    const headers = httpClient.encodePaymentSignatureHeader(paymentPayload);
+
+    if (process.env.DEBUG) {
+      logger.debug(`Payment headers: ${JSON.stringify(headers)}`);
+    }
+
+    return headers;
+  } catch (error) {
+    logger.error("Failed to sign payment:", error);
+    return null;
+  }
+}
diff --git a/samples/x402-browser-proxy/test-server.mjs b/samples/x402-browser-proxy/test-server.mjs
new file mode 100644
index 0000000..115a7f4
--- /dev/null
+++ b/samples/x402-browser-proxy/test-server.mjs
@@ -0,0 +1,294 @@
+// x402 proxy test script
+// Tests a local mock 402 server and optionally a real x402 endpoint
+//
+// Usage:
+//   node test-server.mjs              # Run local mock server only
+//   node test-server.mjs --test       # Run full test suite against running proxy
+//   node test-server.mjs --test-real  # Test only the real endpoint against running proxy
+
+import http from "http";
+
+const PORT = 3402;
+const PROXY_PORT = 8402;
+const REAL_ENDPOINT = "https://x402.payai.network/api/base/paid-content";
+
+// --- Test runner ---
+
+const args = process.argv.slice(2);
+const testMode = args.includes("--test");
+const testRealOnly = args.includes("--test-real");
+
+if (testMode || testRealOnly) {
+  runTests(testRealOnly).then((passed) => {
+    process.exit(passed ? 0 : 1);
+  });
+} else {
+  startMockServer();
+}
+
+async function runTests(realOnly) {
+  console.log("=== x402 Proxy Test Suite ===\n");
+
+  let allPassed = true;
+
+  if (!realOnly) {
+    console.log("--- Test 1: Local mock endpoint (HTTP) ---");
+    const mockResult = await testEndpoint(
+      `http://127.0.0.1:${PORT}/paid-content`,
+      false,
+    );
+    allPassed = allPassed && mockResult;
+  }
+
+  console.log(
+    `--- Test ${realOnly ? "1" : "2"}: Real endpoint (${REAL_ENDPOINT}) ---`,
+  );
+  const realResult = await testEndpoint(REAL_ENDPOINT, true);
+  allPassed = allPassed && realResult;
+
+  console.log("\n=== Results ===");
+  console.log(allPassed ? "All tests passed" : "Some tests failed");
+  return allPassed;
+}
+
+function testEndpoint(url, isHttps) {
+  return new Promise((resolve) => {
+    console.log(`  [1/2] Direct request (expect 402)...`);
+    directRequest(url, isHttps)
+      .then((directStatus) => {
+        if (directStatus === 402) {
+          console.log(`    OK: Got 402 Payment Required`);
+        } else {
+          console.log(`    FAIL: Expected 402, got ${directStatus}`);
+          resolve(false);
+          return;
+        }
+
+        console.log(`  [2/2] Request through proxy (expect 200)...`);
+        proxyRequest(url)
+          .then(({ status, body }) => {
+            if (status === 200) {
+              console.log(`    OK: Got 200 OK`);
+              try {
+                const data = JSON.parse(body);
+                if (data.premiumContent) {
+                  console.log(`    Content: "${data.premiumContent}"`);
+                } else if (data.message) {
+                  console.log(`    Content: "${data.message}"`);
+                }
+                if (data.payer) {
+                  console.log(`    Payer: ${data.payer}`);
+                }
+              } catch {
+                /* not JSON, that's ok */
+              }
+              resolve(true);
+            } else {
+              console.log(`    FAIL: Expected 200, got ${status}`);
+              console.log(`    Body: ${body.substring(0, 200)}`);
+              resolve(false);
+            }
+          })
+          .catch((err) => {
+            console.log(`    FAIL: Proxy request failed: ${err.message}`);
+            resolve(false);
+          });
+      })
+      .catch((err) => {
+        console.log(`    FAIL: Direct request failed: ${err.message}`);
+        resolve(false);
+      });
+  });
+}
+
+async function directRequest(url, isHttps) {
+  const mod = isHttps ? (await import("https")).default : http;
+  return new Promise((resolve, reject) => {
+    const req = mod.request(url, (res) => {
+      res.resume();
+      resolve(res.statusCode);
+    });
+    req.on("error", reject);
+    req.end();
+  });
+}
+
+function proxyRequest(targetUrl) {
+  return new Promise((resolve, reject) => {
+    const parsed = new URL(targetUrl);
+    const isHttps = parsed.protocol === "https:";
+
+    if (isHttps) {
+      const connectReq = http.request({
+        hostname: "127.0.0.1",
+        port: PROXY_PORT,
+        method: "CONNECT",
+        path: `${parsed.hostname}:${parsed.port || 443}`,
+      });
+
+      connectReq.on("connect", (_res, socket) => {
+        import("https").then(({ default: httpsModule }) => {
+          const req = httpsModule.request(
+            {
+              hostname: parsed.hostname,
+              path: parsed.pathname + parsed.search,
+              method: "GET",
+              socket: socket,
+              agent: false,
+              rejectUnauthorized: false,
+            },
+            (res) => {
+              let body = "";
+              res.on("data", (chunk) => (body += chunk));
+              res.on("end", () =>
+                resolve({ status: res.statusCode, body }),
+              );
+            },
+          );
+          req.on("error", reject);
+          req.end();
+        });
+      });
+
+      connectReq.on("error", reject);
+      connectReq.end();
+    } else {
+      const req = http.request(
+        {
+          hostname: "127.0.0.1",
+          port: PROXY_PORT,
+          path: targetUrl,
+          method: "GET",
+          headers: { Host: parsed.host },
+        },
+        (res) => {
+          let body = "";
+          res.on("data", (chunk) => (body += chunk));
+          res.on("end", () => resolve({ status: res.statusCode, body }));
+        },
+      );
+      req.on("error", reject);
+      req.end();
+    }
+  });
+}
+
+// --- Mock server ---
+
+const paymentRequired = {
+  x402Version: 2,
+  accepts: [
+    {
+      scheme: "exact",
+      network: "eip155:8453",
+      amount: "1000", // 0.001 USDC
+      payTo: "0x0000000000000000000000000000000000000001",
+      maxTimeoutSeconds: 300,
+      asset: "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913", // USDC on Base
+      extra: {
+        name: "USD Coin",
+        version: "2",
+        description: "Test x402 endpoint",
+        mimeType: "application/json",
+        resource: `http://localhost:${PORT}/paid-content`,
+      },
+    },
+  ],
+  resource: {
+    url: `http://localhost:${PORT}/paid-content`,
+    description: "Test x402 endpoint",
+    mimeType: "application/json",
+  },
+};
+
+function startMockServer() {
+  const server = http.createServer((req, res) => {
+    console.log(`${new Date().toISOString()} ${req.method} ${req.url}`);
+
+    const paymentSig =
+      req.headers["payment-signature"] || req.headers["x-payment"];
+
+    if (req.url === "/paid-content") {
+      if (paymentSig) {
+        console.log("  Payment signature received, accepting payment...");
+        try {
+          const decoded = JSON.parse(
+            Buffer.from(paymentSig, "base64").toString("utf-8"),
+          );
+          console.log(
+            `  Payer: ${decoded.payload?.authorization?.from}`,
+          );
+          console.log(`  Amount: ${decoded.accepted?.amount}`);
+
+          res.writeHead(200, {
+            "Content-Type": "application/json",
+            "Payment-Response": Buffer.from(
+              JSON.stringify({
+                success: true,
+                message:
+                  "Payment accepted (test mode - no actual payment processed)",
+              }),
+            ).toString("base64"),
+          });
+          res.end(
+            JSON.stringify(
+              {
+                message:
+                  "Payment successful! This is the paid content.",
+                payer: decoded.payload?.authorization?.from,
+                amount: decoded.accepted?.amount,
+                note: "This is a test server - no actual payment was processed",
+              },
+              null,
+              2,
+            ),
+          );
+          return;
+        } catch {
+          console.log("  Invalid payment signature format");
+        }
+      }
+
+      console.log("  No payment, returning 402...");
+      const paymentHeader = Buffer.from(
+        JSON.stringify(paymentRequired),
+      ).toString("base64");
+      res.writeHead(402, {
+        "Content-Type": "application/json",
+        "Payment-Required": paymentHeader,
+      });
+      res.end(JSON.stringify(paymentRequired, null, 2));
+      return;
+    }
+
+    if (req.url === "/health") {
+      res.writeHead(200, { "Content-Type": "application/json" });
+      res.end(JSON.stringify({ status: "ok", x402: true }));
+      return;
+    }
+
+    res.writeHead(404, { "Content-Type": "text/plain" });
+    res.end("Not found. Try /paid-content or /health");
+  });
+
+  server.listen(PORT, "127.0.0.1", () => {
+    console.log(`x402 test server running on http://127.0.0.1:${PORT}`);
+    console.log("");
+    console.log("Endpoints:");
+    console.log(
+      `  GET http://127.0.0.1:${PORT}/paid-content - Returns 402, then 200 with payment`,
+    );
+    console.log(
+      `  GET http://127.0.0.1:${PORT}/health - Health check`,
+    );
+    console.log("");
+    console.log("Test commands (with proxy running on :8402):");
+    console.log(
+      "  node test-server.mjs --test       # Full test suite (mock + real)",
+    );
+    console.log(
+      "  node test-server.mjs --test-real   # Real endpoint only",
+    );
+    console.log("");
+  });
+}
diff --git a/samples/x402-browser-proxy/tsconfig.json b/samples/x402-browser-proxy/tsconfig.json
new file mode 100644
index 0000000..5a24989
--- /dev/null
+++ b/samples/x402-browser-proxy/tsconfig.json
@@ -0,0 +1,8 @@
+{
+  "extends": "../../tsconfig.base.json",
+  "compilerOptions": {
+    "outDir": "dist",
+    "rootDir": "src"
+  },
+  "include": ["src"]
+}
diff --git a/samples/x402-browser-proxy/tsup.config.ts b/samples/x402-browser-proxy/tsup.config.ts
new file mode 100644
index 0000000..30dae56
--- /dev/null
+++ b/samples/x402-browser-proxy/tsup.config.ts
@@ -0,0 +1,8 @@
+import { defineConfig } from "tsup";
+
+export default defineConfig({
+  entry: ["src/index.ts"],
+  format: ["esm"],
+  banner: { js: "#!/usr/bin/env node" },
+  clean: true,
+});