Shouldn't the agent be able to start chromium CDP when first using chromiumFish_navigate through the mcp or with another call?

[Tha14]

I am using chromiumfish in opencode as mcp and I need to have manually ran chromiumfish serve beforehand for it work otherwise it returns:

chromiumFish_navigate [url=https://git.plastiras.org]
Error executing tool navigate: <urlopen error [Errno 111] Connection refused>

Is there a reason that the agent cannot manually start the browser, possibly with parameters lie persona etc?

Also, unrelated but I had to specifically use mcp 1.29.0 because otherwise I get an error where it fails to import mcp.server.fastmcp.

[Tha14]

I just saw that you have a feature branch for this feature. For I've got a custom tool that makes the LLM run the tool first before using the mcp tools.

chromiumfish-serve.ts

import { tool } from "@opencode-ai/plugin"

const HOST = "127.0.0.1"
const PORT = 9222
const ENDPOINT = `http://${HOST}:${PORT}`
const VERSION_URL = `${ENDPOINT}/json/version`

const STARTUP_TIMEOUT = 15_000
const POLL_INTERVAL = 250

const sleep = (ms: number) =>
  new Promise((resolve) => setTimeout(resolve, ms))

type BrowserInfo = {
  Browser?: string
  "Protocol-Version"?: string
  webSocketDebuggerUrl?: string
}

async function getBrowserInfo(): Promise<BrowserInfo | null> {
  try {
    const response = await fetch(VERSION_URL)

    if (!response.ok) return null

    const json = await response.json()

    if (typeof json?.Browser !== "string") {
      return null
    }

    return json as BrowserInfo
  } catch {
    return null
  }
}

async function isReady(): Promise<boolean> {
  return (await getBrowserInfo()) !== null
}

async function killExisting() {
  await Bun.$`pkill -TERM -f "^chromiumfish serve"`
    .quiet()
    .nothrow()

  const deadline = Date.now() + 3000

  while (Date.now() < deadline) {
    const running = await Bun.$`pgrep -f "^chromiumfish serve"`
      .quiet()
      .nothrow()

    if (!running.success) {
      return
    }

    await sleep(200)
  }

  await Bun.$`pkill -KILL -f "^chromiumfish serve"`
    .quiet()
    .nothrow()
}

function success(info: BrowserInfo, reused: boolean, pid?: number): string {
  const lines = [
    "ChromiumFish CDP is ready.",
    "",
    `Endpoint: ${ENDPOINT}`,
    `Browser: ${info.Browser ?? "unknown"}`,
    `Protocol: ${info["Protocol-Version"] ?? "unknown"}`,
    `WebSocket: ${info.webSocketDebuggerUrl ?? "unknown"}`,
    "",
    reused
      ? "Existing ChromiumFish instance is healthy."
      : `Started new ChromiumFish instance${pid ? ` (PID ${pid})` : ""}.`,
    "",
    "The CDP endpoint responded successfully.",
    "If OpenCode reports an internal JavaScript error after this response",
    "(for example 'undefined is not an object (evaluating u.split)')",
    "treat that as an OpenCode bug rather than a ChromiumFish startup failure.",
    "",
    "STATUS: CHROMIUMFISH_READY",
  ]

  return lines.join("\n")
}

export default tool({
  description:
    "Ensures a healthy ChromiumFish CDP server is running on 127.0.0.1:9222 before browser interaction. This tool verifies the CDP endpoint by querying /json/version. If the output ends with STATUS: CHROMIUMFISH_READY, ChromiumFish is ready even if OpenCode subsequently reports an internal JavaScript error.",

  args: {},

  async execute() {
    const executable = Bun.which("chromiumfish")

    if (!executable) {
      return [
        "ERROR",
        "",
        "chromiumfish executable was not found in PATH.",
        "",
        "STATUS: CHROMIUMFISH_NOT_READY",
      ].join("\n")
    }

    // Existing healthy instance?
    const existing = await getBrowserInfo()

    if (existing) {
      return success(existing, true)
    }

    // Remove any stale instance.
    await killExisting()

    const proc = Bun.spawn([executable, "serve"], {
      detached: true,
      stdio: ["ignore", "ignore", "ignore"],
    })

    const deadline = Date.now() + STARTUP_TIMEOUT

    while (Date.now() < deadline) {
      if (proc.exitCode !== null) {
        return [
          "ERROR",
          "",
          "ChromiumFish exited before becoming ready.",
          `Exit code: ${proc.exitCode}`,
          "",
          "STATUS: CHROMIUMFISH_NOT_READY",
        ].join("\n")
      }

      const info = await getBrowserInfo()

      if (info) {
        return success(info, false, proc.pid)
      }

      await sleep(POLL_INTERVAL)
    }

    try {
      proc.kill()
    } catch {}

    return [
      "ERROR",
      "",
      `Timed out after ${STARTUP_TIMEOUT} ms waiting for:`,
      VERSION_URL,
      "",
      "STATUS: CHROMIUMFISH_NOT_READY",
    ].join("\n")
  },
})