{
  "slug": "agent-browser-adds-experimental-webmcp-support-644a0cc149df",
  "title": "agent-browser adds experimental WebMCP support",
  "tools": [
    "agent-browser"
  ],
  "tags": [
    "agent"
  ],
  "introduced_at": "2026-09-01T04:44:03.000Z",
  "announced_at": "2026-09-01T04:44:03.000Z",
  "effective_at": null,
  "date_basis": "source-publication",
  "status": "unknown",
  "how": {
    "incantation": "When browsing with locally managed Chrome, discover current-page WebMCP tools with `agent-browser webmcp list` and invoke a selected tool with its parameters. To expose WebMCP through the MCP server, start it with `agent-browser mcp --tools webmcp`; disable WebMCP with `--no-webmcp` or `AGENT_BROWSER_NO_WEBMCP` when needed.",
    "examples": [
      "agent-browser open <url>\nagent-browser webmcp list\nagent-browser webmcp invoke <tool> --params '{\"key\":\"value\"}'",
      "agent-browser webmcp invoke <tool> --params @input.json --detach\nagent-browser webmcp result <invocation-id>\nagent-browser webmcp cancel <invocation-id>",
      "agent-browser mcp --tools webmcp"
    ],
    "gotchas": [
      "Version: v0.36.0",
      "Availability: Experimental; WebMCP is enabled by default for locally managed Chrome.",
      "<url>: Page URL to open; `open` without a URL launches about:blank.",
      "<tool> (required): Page-provided WebMCP tool name to invoke.",
      "--params <JSON|@file>: Tool input object as JSON or from a file; no default parameters are documented.",
      "--detach: Run invocation detached so its result can be retrieved later.",
      "--tools <profile>: Select MCP server tool profiles; `webmcp` enables page-tool discovery, invocation, detached results, and cancellation. Profiles can be combined; `all` enables every tool.",
      "--no-webmcp: Disable experimental WebMCP Chrome features; `AGENT_BROWSER_NO_WEBMCP` is the environment-variable alternative.",
      "Prerequisite: WebMCP is enabled by default for locally managed Chrome.",
      "Prerequisite: MCP server startup defaults to the `core` tools profile; select `webmcp` explicitly to expose its tools.",
      "WebMCP applies to locally managed Chrome by default.",
      "WebMCP can be disabled with `--no-webmcp` or `AGENT_BROWSER_NO_WEBMCP`.",
      "The MCP tool profile is opt-in.",
      "Support includes frame-aware tool selection, detached results, cancellation, and bounded metadata and output handling."
    ]
  },
  "why_it_matters": "Discover and invoke tools provided by the current page while browsing with locally managed Chrome.",
  "sources": [
    "https://github.com/vercel-labs/agent-browser/releases/tag/v0.36.0",
    "https://github.com/vercel-labs/agent-browser/blob/v0.36.0/skill-data/core/references/commands.md",
    "https://github.com/vercel-labs/agent-browser/blob/v0.36.0/cli/src/mcp.rs"
  ],
  "rank": 0.96037,
  "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-d2eb1d99faeb401b-0:gate",
    "evidence_hash": "764d8725cf446cac41ce7037be8cee7ceaf9488a4a799eed9475a81374efbb93"
  },
  "review": {
    "draft_hash": "41f0aa1b911ad3c448ca2277db72681a6ec2ed50664ed7cab737926bbd7563c7",
    "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 0.96 >= 0.9; 2 needed) and Jev gave 0.66 (>= 0.6 needed)."
  }
}