CodeSampleX

Sample

pac-proxy-agent 7.2.0: PacProxyAgent

Verified sample for npm pac-proxy-agent 7.2.0: PacProxyAgent. The contract ran on node 22 · linux alpine/x64 · docker and passed.

sha256:0f34e152a0c2ad4409405bdfd575d4fb871b8d4a67beae38151bdec712971800

This network offers one thing: a sample that builds. It ran the sample in a sandbox and kept the signed receipt. It grades nothing and warrants nothing — whether the same code builds where you are is not something it measured. How many distinct signing keys filed a passing contract receipt. One is the author alone; more than one means somebody else built it too. A key is self-generated with nothing registered behind it, so it counts keys, not people. MIT-0

Execution evidence

The declared environment and the signed runs are kept apart, so you can see exactly what this sample ran and where.

Evidence basis
Signed contract pass
Verification receipts
1
Signing keys that built it
1
Declared environment linux 24 · ubuntu · glibc 2.39 x64 npm

Verification-run environments

Environment Contract Stages Run
node 22 · linux alpine/x64 · docker ed25519:c1973797be207ac4 PASS compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS
CONTAINER_RUN · node-typescript@1node:22-alpine@sha256:c610fcdfb1d5…		 2026-08-27

Case

HOW
Goal
verify pac-proxy-agent.PacProxyAgent in pkg:npm/pac-proxy-agent@7.2.0
Packages
Symbols
  • pac-proxy-agent.PacProxyAgent
Created
2026-08-27T11:32:53Z

Contract

  1. PacProxyAgent instantiates with a PAC URI
  2. PacProxyAgent routes requests DIRECT according to PAC script logic
  3. PacProxyAgent routes requests via PROXY according to PAC script logic

Files

  • PROMPT.md
  • README.md
  • csx.json
  • index.mjs
  • package-lock.json
  • package.json
  • spec.json
  • test/contract.mjs

Download the source artifact (tar.gz)

Source

PROMPT.md
Clean-room public code sample — generation instructions

Write a brand-new, minimal, self-contained code sample in this clean-room directory.
Do not copy, paraphrase, or reference any existing project source. Work only from this spec.

A csx.json manifest scaffold already exists. Do not recreate it from memory. Preserve its case.goal, packages and symbols; fill its empty case.contract with exact assertions and correct its environment, commands and verifierAdapter for the files you generate.

Goal: verify pac-proxy-agent.PacProxyAgent in pkg:npm/pac-proxy-agent@7.2.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/pac-proxy-agent@7.2.0
Demonstrate these symbols/APIs:
  - pac-proxy-agent.PacProxyAgent

Rules:
  - One focused purpose; the smallest project that proves the goal.
  - Include a contract test (test/contract.*) that runs OFFLINE and exits 0 exactly when the goal behavior works.
  - Pin every dependency with a lockfile so resolution is reproducible.
  - No secrets, credentials, or tokens. No real URLs (only example.com or localhost). No absolute paths.
  - No personal names, emails, company names, or project identifiers of any kind.
  - No binaries and no generated output (node_modules, dist, target, venv, .git, .env).
  - Keep it under 200 files and 256KB packed.
README.md
# pac-proxy-agent sample

Demonstrates configuring and using `PacProxyAgent` from `pac-proxy-agent` to route HTTP requests according to PAC (Proxy Auto-Configuration) script logic.
csx.json
{"case":{"caseId":"case:sha256:1f6f73b31270d3f030bbb0720a9580bf5ccf59e91dc1f3e8927198f6abe5899f","contract":["PacProxyAgent instantiates with a PAC URI","PacProxyAgent routes requests DIRECT according to PAC script logic","PacProxyAgent routes requests via PROXY according to PAC script logic"],"goal":"verify pac-proxy-agent.PacProxyAgent in pkg:npm/pac-proxy-agent@7.2.0","kind":"HOW","packages":["pkg:npm/pac-proxy-agent@7.2.0"],"schemaVersion":1,"symbols":["pac-proxy-agent.PacProxyAgent"]},"contractCommand":["node","test/contract.mjs"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"npm","libc":"glibc","libcVersion":"2.39","os":"linux","osVersionBucket":"24","packageManager":"npm","schemaVersion":1},"license":"MIT-0","packages":["pkg:npm/pac-proxy-agent@7.2.0"],"schemaVersion":1,"subject":"pkg:npm/pac-proxy-agent@7.2.0","symbols":["pac-proxy-agent.PacProxyAgent"],"verifierAdapter":"node-typescript@1"}
index.mjs
import http from 'node:http';
import { PacProxyAgent } from 'pac-proxy-agent';

export function createPacAgent(pacScript) {
  const uri = `data:text/javascript;charset=utf-8,${encodeURIComponent(pacScript)}`;
  return new PacProxyAgent(uri);
}

export async function fetchWithPac(url, pacScript) {
  const agent = createPacAgent(pacScript);
  return new Promise((resolve, reject) => {
    http.get(url, { agent }, (res) => {
      let data = '';
      res.on('data', (chunk) => { data += chunk; });
      res.on('end', () => resolve({ statusCode: res.statusCode, data }));
    }).on('error', reject);
  });
}
package-lock.json
{
  "name": "sample-pac-proxy-agent",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-pac-proxy-agent",
      "version": "1.0.0",
      "dependencies": {
        "pac-proxy-agent": "7.2.0"
      }
    },
    "node_modules/@tootallnate/quickjs-emscripten": {
      "version": "0.23.0",
      "resolved": "https://registry.npmjs.org/@tootallnate/quickjs-emscripten/-/quickjs-emscripten-0.23.0.tgz",
      "integrity": "sha512-C5Mc6rdnsaJDjO3UpGW/CQTHtCKaYlScZTly4JIu97Jxo/odCiH0ITnDXSJPTOrEKk/ycSZ0AOgTmkDtkOsvIA==",
      "license": "MIT"
    },
    "node_modules/agent-base": {
      "version": "7.1.4",
      "resolved": "https://registry.npmjs.org/agent-base/-/agent-base-7.1.4.tgz",
      "integrity": "sha512-MnA+YT8fwfJPgBx3m60MNqakm30XOkyIoH1y6huTQvC0PwZG7ki8NacLBcrPbNoo8vEZy7Jpuk7+jMO+CUovTQ==",
      "license": "MIT",
      "engines": {
        "node": ">= 14"
      }
    },
    "node_modules/ast-types": {
      "version": "0.13.4",
      "resolved": "https://registry.npmjs.org/ast-types/-/ast-types-0.13.4.tgz",
      "integrity": "sha512-x1FCFnFifvYDDzTaLII71vG5uvDwgtmDTEVWAxrgeiR8VjMONcCXJx7E+USjDtHlwFmt9MysbqgF9b9Vjr6w+w==",
      "license": "MIT",
      "dependencies": {
        "tslib": "^2.0.1"
      },
      "engines": {
        "node": ">=4"
      }
    },
    "node_modules/basic-ftp": {
      "version": "5.3.1",
      "resolved": "https://registry.npmjs.org/basic-ftp/-/basic-ftp-5.3.1.tgz",
      "integrity": "sha512-bopVNp6ugyA150DDuZfPFdt1KZ5a94ZDiwX4hMgZDzF+GttD80lEy8kj98kbyhLXnPvhtIo93mdnLIjpCAeeOw==",
      "license": "MIT",
      "engines": {
        "node": ">=10.0.0"
      }
    },
    "node_modules/data-uri-to-buffer": {
      "version": "6.0.2",
      "resolved": "https://registry.npmjs.org/data-uri-to-buffer/-/data-uri-to-buffer-6.0.2.tgz",
      "integrity": "sha512-7hvf7/GW8e86rW0ptuwS3OcBGDjIi6SZva7hCyWC0yYry2cOPmLIjXAUHI6DK2HsnwJd9ifmt57i8eV2n4YNpw==",
      "license": "MIT",
      "engines": {
        "node": ">= 14"
      }
    },
    "node_modules/debug": {
      "version": "4.4.3",
      "resolved": "https://registry.npmjs.org/debug/-/debug-4.4.3.tgz",
      "integrity": "sha512-RGwwWnwQvkVfavKVt22FGLw+xYSdzARwm0ru6DhTVA3umU5hZc28V3kO4stgYryrTlLpuvgI9GiijltAjNbcqA==",
      "license": "MIT",
      "dependencies": {
        "ms": "^2.1.3"
      },
      "engines": {
        "node": ">=6.0"
      },
      "peerDependenciesMeta": {
        "supports-color": {
          "optional": true
        }
      }
    },
    "node_modules/degenerator": {
      "version": "5.0.1",
      "resolved": "https://registry.npmjs.org/degenerator/-/degenerator-5.0.1.tgz",
      "integrity": "sha512-TllpMR/t0M5sqCXfj85i4XaAzxmS5tVA16dqvdkMwGmzI+dXLXnw3J+3Vdv7VKw+ThlTMboK6i9rnZ6Nntj5CQ==",
      "license": "MIT",
      "dependencies": {
        "ast-types": "^0.13.4",
        "escodegen": "^2.1.0",
        "esprima": "^4.0.1"
      },
      "engines": {
        "node": ">= 14"
      }
    },
    "node_modules/escodegen": {
      "version": "2.1.0",
      "resolved": "https://registry.npmjs.org/escodegen/-/escodegen-2.1.0.tgz",
      "integrity": "sha512-2NlIDTwUWJN0mRPQOdtQBzbUHvdGY2P1VXSyU83Q3xKxM7WHX2Ql8dKq782Q9TgQUNOLEzEYu9bzLNj1q88I5w==",
      "license": "BSD-2-Clause",
      "dependencies": {
        "esprima": "^4.0.1",
        "estraverse": "^5.2.0",
        "esutils": "^2.0.2"
      },
      "bin": {
        "escodegen": "bin/escodegen.js",
        "esgenerate": "bin/esgenerate.js"
      },
      "engines": {
        "node": ">=6.0"
      },
      "optionalDependencies": {
        "source-map": "~0.6.1"
      }
    },
    "node_modules/esprima": {
      "version": "4.0.1",
      "resolved": "https://registry.npmjs.org/esprima/-/esprima-4.0.1.tgz",
      "integrity": "sha512-eGuFFw7Upda+g4p+QHvnW0RyTX/SVeJBDM/gCtMARO0cLuT2HcEKnTPvhjV6aGeqrCB/sbNop0Kszm0jsaWU4A==",
      "license": "BSD-2-Clause",
      "bin": {
        "esparse": "bin/esparse.js",
        "esvalidate": "bin/esvalidate.js"
      },
      "engines": {
        "node": ">=4"
      }
    },
    "node_modules/estraverse": {
      "version": "5.3.0",
      "resolved": "https://registry.npmjs.org/estraverse/-/estraverse-5.3.0.tgz",
      "integrity": "sha512-MMdARuVEQziNTeJD8DgMqmhwR11BRQ/cBP+pLtYdSTnf3MIO8fFeiINEbX36ZdNlfU/7A9f3gUw49B3oQsvwBA==",
      "license": "BSD-2-Clause",
      "engines": {
        "node": ">=4.0"
      }
    },
    "node_modules/esutils": {
      "version": "2.0.3",
      "resolved": "https://registry.npmjs.org/esutils/-/esutils-2.0.3.tgz",
      "integrity": "sha512-kVscqXk4OCp68SZ0dkgEKVi6/8ij300KBWTJq32P/dYeWTSwK41WyTxalN1eRmA5Z9UU/LX9D7FWSmV9SAYx6g==",
      "license": "BSD-2-Clause",
      "engines": {
        "node": ">=0.10.0"
      }
    },
    "node_modules/get-uri": {
      "version": "6.0.5",
      "resolved": "https://registry.npmjs.org/get-uri/-/get-uri-6.0.5.tgz",
      "integrity": "sha512-b1O07XYq8eRuVzBNgJLstU6FYc1tS6wnMtF1I1D9lE8LxZSOGZ7LhxN54yPP6mGw5f2CkXY2BQUL9Fx41qvcIg==",
      "license": "MIT",
      "dependencies": {
        "basic-ftp": "^5.0.2",
        "data-uri-to-buffer": "^6.0.2",
        "debug": "^4.3.4"
      },
      "engines": {
        "node": ">= 14"
      }
    },
    "node_modules/http-proxy-agent": {
      "version": "7.0.2",
      "resolved": "https://registry.npmjs.org/http-proxy-agent/-/http-proxy-agent-7.0.2.tgz",
      "integrity": "sha512-T1gkAiYYDWYx3V5Bmyu7HcfcvL7mUrTWiM6yOfa3PIphViJ/gFPbvidQ+veqSOHci/PxBcDabeUNCzpOODJZig==",
      "license": "MIT",
      "dependencies": {
        "agent-base": "^7.1.0",
        "debug": "^4.3.4"
      },
      "engines": {
        "node": ">= 14"
      }
    },
    "node_modules/https-proxy-agent": {
      "version": "7.0.6",
      "resolved": "https://registry.npmjs.org/https-proxy-agent/-/https-proxy-agent-7.0.6.tgz",
      "integrity": "sha512-vK9P5/iUfdl95AI+JVyUuIcVtd4ofvtrOr3HNtM2yxC9bnMbEdp3x01OhQNnjb8IJYi38VlTE3mBXwcfvywuSw==",
      "license": "MIT",
      "dependencies": {
        "agent-base": "^7.1.2",
        "debug": "4"
      },
      "engines": {
        "node": ">= 14"
      }
    },
    "node_modules/ip-address": {
      "version": "10.5.0",
      "resolved": "https://registry.npmjs.org/ip-address/-/ip-address-10.5.0.tgz",
      "integrity": "sha512-R5SnVLJmgYYvf2F2ZgwSBnelz5G4q5AxIC277GDfUaNbrZKNANcBC7RHqYYePlszf4kBolVkJauG0ZjHHFh55g==",
      "license": "MIT",
      "engines": {
        "node": ">= 12"
      }
    },
    "node_modules/ms": {
      "version": "2.1.3",
      "resolved": "https://registry.npmjs.org/ms/-/ms-2.1.3.tgz",
      "integrity": "sha512-6FlzubTLZG3J2a/NVCAleEhjzq5oxgHyaCU9yYXvcLsvoVaHJq/s5xXI6/XXP6tz7R9xAOtHnSO/tXtF3WRTlA==",
      "license": "MIT"
    },
    "node_modules/netmask": {
      "version": "2.1.1",
      "resolved": "https://registry.npmjs.org/netmask/-/netmask-2.1.1.tgz",
      "integrity": "sha512-eonl3sLUha+S1GzTPxychyhnUzKyeQkZ7jLjKrBagJgPla13F+uQ71HgpFefyHgqrjEbCPkDArxYsjY8/+gLKA==",
      "license": "MIT",
      "engines": {
        "node": ">= 0.4.0"
      }
    },
    "node_modules/pac-proxy-agent": {
      "version": "7.2.0",
      "resolved": "https://registry.npmjs.org/pac-proxy-agent/-/pac-proxy-agent-7.2.0.tgz",
      "integrity": "sha512-TEB8ESquiLMc0lV8vcd5Ql/JAKAoyzHFXaStwjkzpOpC5Yv+pIzLfHvjTSdf3vpa2bMiUQrg9i6276yn8666aA==",
      "license": "MIT",
      "dependencies": {
        "@tootallnate/quickjs-emscripten": "^0.23.0",
        "agent-base": "^7.1.2",
        "debug": "^4.3.4",
        "get-uri": "^6.0.1",
        "http-proxy-agent": "^7.0.0",
        "https-proxy-agent": "^7.0.6",
        "pac-resolver": "^7.0.1",
        "socks-proxy-agent": "^8.0.5"
      },
      "engines": {
        "node": ">= 14"
      }
    },
    "node_modules/pac-resolver": {
      "version": "7.0.1",
      "resolved": "https://registry.npmjs.org/pac-resolver/-/pac-resolver-7.0.1.tgz",
      "integrity": "sha512-5NPgf87AT2STgwa2ntRMr45jTKrYBGkVU36yT0ig/n/GMAa3oPqhZfIQ2kMEimReg0+t9kZViDVZ83qfVUlckg==",
      "license": "MIT",
      "dependencies": {
        "degenerator": "^5.0.0",
        "netmask": "^2.0.2"
      },
      "engines": {
        "node": ">= 14"
      }
    },
    "node_modules/smart-buffer": {
      "version": "4.2.0",
      "resolved": "https://registry.npmjs.org/smart-buffer/-/smart-buffer-4.2.0.tgz",
      "integrity": "sha512-94hK0Hh8rPqQl2xXc3HsaBoOXKV20MToPkcXvwbISWLEs+64sBq5kFgn2kJDHb1Pry9yrP0dxrCI9RRci7RXKg==",
      "license": "MIT",
      "engines": {
        "node": ">= 6.0.0",
        "npm": ">= 3.0.0"
      }
    },
    "node_modules/socks": {
      "version": "2.8.9",
      "resolved": "https://registry.npmjs.org/socks/-/socks-2.8.9.tgz",
      "integrity": "sha512-LJhUYUvItdQ0LkJTmPeaEObWXAqFyfmP85x0tch/ez9cahmhlBBLbIqDFnvBnUJGagb0JbIQrkBs1wJ+yRYpEw==",
      "license": "MIT",
      "dependencies": {
        "ip-address": "^10.1.1",
        "smart-buffer": "^4.2.0"
      },
      "engines": {
        "node": ">= 10.0.0",
        "npm": ">= 3.0.0"
      }
    },
    "node_modules/socks-proxy-agent": {
      "version": "8.0.5",
      "resolved": "https://registry.npmjs.org/socks-proxy-agent/-/socks-proxy-agent-8.0.5.tgz",
      "integrity": "sha512-HehCEsotFqbPW9sJ8WVYB6UbmIMv7kUUORIF2Nncq4VQvBfNBLibW9YZR5dlYCSUhwcD628pRllm7n+E+YTzJw==",
      "license": "MIT",
      "dependencies": {
        "agent-base": "^7.1.2",
        "debug": "^4.3.4",
        "socks": "^2.8.3"
      },
      "engines": {
        "node": ">= 14"
      }
    },
    "node_modules/source-map": {
      "version": "0.6.1",
      "resolved": "https://registry.npmjs.org/source-map/-/source-map-0.6.1.tgz",
      "integrity": "sha512-UjgapumWlbMhkBgzT7Ykc5YXUT46F0iKu8SGXq0bcwP5dz/h0Plj6enJqjz1Zbq2l5WaqYnrVbwWOWMyF3F47g==",
      "license": "BSD-3-Clause",
      "optional": true,
      "engines": {
        "node": ">=0.10.0"
      }
    },
    "node_modules/tslib": {
      "version": "2.8.1",
      "resolved": "https://registry.npmjs.org/tslib/-/tslib-2.8.1.tgz",
      "integrity": "sha512-oJFu94HQb+KVduSUQL7wnpmqnfmLsOA/nAh6b6EH0wCEoK0/mPeXU6c3wKDV83MkOuHPRHtSXKKU99IBazS/2w==",
      "license": "0BSD"
    }
  }
}
package.json
{
  "name": "sample-pac-proxy-agent",
  "version": "1.0.0",
  "type": "module",
  "private": true,
  "dependencies": {
    "pac-proxy-agent": "7.2.0"
  }
}
spec.json
{
  "schemaVersion": 1,
  "goal": "verify pac-proxy-agent.PacProxyAgent in pkg:npm/pac-proxy-agent@7.2.0",
  "kind": "HOW",
  "packages": [
    "pkg:npm/pac-proxy-agent@7.2.0"
  ],
  "symbols": [
    "pac-proxy-agent.PacProxyAgent"
  ]
}
test/contract.mjs
import http from 'node:http';
import assert from 'node:assert';
import { PacProxyAgent } from 'pac-proxy-agent';

async function runContract() {
  const pacCode = `
    function FindProxyForURL(url, host) {
      if (url.indexOf('/direct') !== -1) {
        return 'DIRECT';
      }
      return 'PROXY 127.0.0.1:__PROXY_PORT__';
    }
  `;

  let originHit = 0;
  const originServer = http.createServer((req, res) => {
    originHit++;
    res.writeHead(200, { 'Content-Type': 'text/plain' });
    res.end('origin-response');
  });

  let proxyHit = 0;
  const proxyServer = http.createServer((req, res) => {
    proxyHit++;
    res.writeHead(200, { 'Content-Type': 'text/plain' });
    res.end('proxy-response');
  });

  await new Promise((resolve) => originServer.listen(0, '127.0.0.1', resolve));
  await new Promise((resolve) => proxyServer.listen(0, '127.0.0.1', resolve));

  const originPort = originServer.address().port;
  const proxyPort = proxyServer.address().port;

  const resolvedPac = pacCode.replace('__PROXY_PORT__', proxyPort);
  const uri = `data:text/javascript;charset=utf-8,${encodeURIComponent(resolvedPac)}`;

  const agent = new PacProxyAgent(uri);
  assert.ok(agent instanceof PacProxyAgent, 'agent should be an instance of PacProxyAgent');

  const directBody = await new Promise((resolve, reject) => {
    http.get(`http://127.0.0.1:${originPort}/direct`, { agent }, (res) => {
      let data = '';
      res.on('data', (chunk) => { data += chunk; });
      res.on('end', () => resolve(data));
    }).on('error', reject);
  });
  assert.strictEqual(directBody, 'origin-response', 'DIRECT request should reach origin server');
  assert.strictEqual(originHit, 1, 'Origin server should receive 1 direct request');
  assert.strictEqual(proxyHit, 0, 'Proxy server should not receive direct request');

  const proxyBody = await new Promise((resolve, reject) => {
    http.get(`http://127.0.0.1:${originPort}/proxied`, { agent }, (res) => {
      let data = '';
      res.on('data', (chunk) => { data += chunk; });
      res.on('end', () => resolve(data));
    }).on('error', reject);
  });
  assert.strictEqual(proxyBody, 'proxy-response', 'PROXIED request should reach proxy server');
  assert.strictEqual(proxyHit, 1, 'Proxy server should receive 1 proxied request');

  await new Promise((resolve) => originServer.close(resolve));
  await new Promise((resolve) => proxyServer.close(resolve));

  console.log('All PacProxyAgent contract tests passed.');
}

runContract().catch((err) => {
  console.error('Contract test failed:', err);
  process.exit(1);
});

Origin Seeder

anonymous