{
  "slug": "agent-browser-responses-announce-webmcp-catalog-updates-faf6e866fdfc",
  "title": "agent-browser responses announce WebMCP catalog updates",
  "tools": [
    "agent-browser"
  ],
  "tags": [
    "agent"
  ],
  "introduced_at": "2026-09-16T13:24:39.000Z",
  "announced_at": "2026-09-16T13:24:39.000Z",
  "effective_at": null,
  "date_basis": "source-publication",
  "status": "unknown",
  "how": {
    "incantation": "When agent-browser responses announce WebMCP tools on first discovery or a catalog change, select a relevant tool and fetch its schema before invoking it. After compaction or joining an existing session, list tools to recover context.",
    "examples": [
      "agent-browser webmcp list <tool> --frame <frame-id> --json",
      "agent-browser webmcp list --json",
      "agent-browser webmcp list"
    ],
    "gotchas": [
      "Version: v0.38.0",
      "<tool> (required): Tool name selected from the response summary.",
      "--frame <frame-id>: Select the tool in the specified frame; use when duplicate names require frame-aware selection.",
      "--json: Request JSON output; with no tool, retrieves the full catalog.",
      "--no-webmcp: Disable WebMCP launch features and proactive context; enabled by default in agent-browser-managed Chrome.",
      "Prerequisite: WebMCP is enabled by default in agent-browser-managed Chrome; the README installation instructions require installing Chrome with `agent-browser install` for first use, unless an existing supported browser installation is detected.",
      "WebMCP is enabled by default in agent-browser-managed Chrome.",
      "Automatic summaries are limited to 16 tools and 4 KiB of JSON; descriptions are shortened to 160 bytes plus a truncation marker, and oversized records are omitted.",
      "Summaries contain names, brief descriptions, origins, and frame IDs; schemas and annotations are not included proactively.",
      "Unchanged catalogs and pages without tools add no context.",
      "After conversation compaction or joining an existing browser session, use `webmcp list` to recover context.",
      "A catalog update can be triggered by full-record changes even when the brief description stays the same; refresh previously fetched schemas after an update.",
      "The daemon subscribes to CDP WebMCP events once per page session; late events appear on the next ordinary action."
    ]
  },
  "why_it_matters": "When inspecting a page that exposes WebMCP tools, select a relevant tool from the response summary and retrieve its full schema before invoking it.",
  "sources": [
    "https://github.com/vercel-labs/agent-browser/releases/tag/v0.38.0",
    "https://github.com/vercel-labs/agent-browser/pull/1842",
    "https://github.com/vercel-labs/agent-browser/blob/v0.38.0/README.md"
  ],
  "rank": 0.95033,
  "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-d56cb04dda1b975a-5:gate",
    "evidence_hash": "a78eeaf06b04ec4434fed43f842b5a8fc3097ef2d667ca2c525fc6bf9efac0cb"
  },
  "review": {
    "draft_hash": "3231416295f29b2a23c48e0eee47b7a3a2075436938408d6cf9fd57b3afbe3da",
    "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 0.95 >= 0.9; 2 needed) and Jev gave 0.78 (>= 0.6 needed)."
  }
}