{
  "slug": "agent-browser-derive-client-skill-generates-api-clients-from-har-traffic-977ec7481b59",
  "title": "agent-browser derive-client skill generates API clients from HAR traffic",
  "tools": [
    "agent-browser"
  ],
  "tags": [
    "agent"
  ],
  "introduced_at": "2026-07-19T17:03:44.000Z",
  "announced_at": "2026-07-19T17:03:44.000Z",
  "effective_at": null,
  "date_basis": "source-publication",
  "status": "unknown",
  "how": {
    "incantation": "When reverse-engineering a site’s internal API, load the derive-client skill and record the browser flows you need in a HAR. Use the HAR to identify endpoints, derive a standalone client or CLI, and verify its calls against the live API.",
    "examples": [
      "agent-browser skills get derive-client",
      "agent-browser network har start --content text\n# Exercise the site flows to capture\nagent-browser network har stop /tmp/site.har",
      "agent-browser network har start --content all"
    ],
    "gotchas": [
      "Version: v0.32.3",
      "derive-client (required): Skill name for the workflow that derives an internal API client from recorded browser traffic.",
      "--content text: Default mode; embeds text-like response bodies, up to 2 MB per body.",
      "--content all: Embeds all response bodies; binary bodies are base64-encoded. Mutually exclusive with other --content modes.",
      "--content none: Disables response-body embedding. Mutually exclusive with other --content modes.",
      "<output.har>: Path where `network har stop` saves the HAR.",
      "Prerequisite: Install agent-browser and a discovery skill with `npx skills add vercel-labs/agent-browser`; the agent-browser CLI serves the version-matched skill content.",
      "Prerequisite: If the site requires login, log in before starting the HAR; the skill says session cookies are exported separately.",
      "Prerequisite: Exercise each client flow at least twice with different inputs; verify every generated function against the live API."
    ]
  },
  "why_it_matters": "Generate a reusable API client while reverse-engineering a site's internal API.",
  "sources": [
    "https://github.com/vercel-labs/agent-browser/releases/tag/v0.32.3",
    "https://github.com/vercel-labs/agent-browser/pull/1578",
    "https://github.com/vercel-labs/agent-browser/blob/v0.32.3/docs/src/app/skills/page.mdx",
    "https://github.com/vercel-labs/agent-browser/blob/v0.32.3/skill-data/derive-client/SKILL.md"
  ],
  "rank": 0.93053,
  "judge": {
    "publish": true,
    "judge_model": "codex-cli/gpt-6-luna+typesafe/jev-1.13.0",
    "prompt_version": "extract-v7+enrich-v2+judge-v2x3+jev-publish-v1"
  },
  "review_state": "approved",
  "provenance": {
    "run_id": "wave2a-20261017",
    "verdict_id": "wave2a-20261017:wave2a-20261017-39ce2064f965ffd7-1:gate",
    "evidence_hash": "0838bc111f3e5b1e5f07180029b11e34bde880607dc31435d8c3a79814d803d2"
  },
  "review": {
    "draft_hash": "94f3d0f549b95b463db26abcbce594fc8ff9552fcafc093a7f6b6766d735c922",
    "reviewer": "publication-gate",
    "reviewed_at": "2026-10-07T00:00:00.000Z",
    "decision": "wave2a-20261017:gate",
    "reason": "3 of 3 judge runs approved with p_yes >= 0.9 (mean 0.93 >= 0.9; 2 needed) and Jev gave 0.79 (>= 0.6 needed)."
  }
}