ThomsenDrake · ThomsenDrake · Mar 16, 2026 · Mar 16, 2026 · Mar 16, 2026
diff --git a/README.md b/README.md
@@ -45,6 +45,8 @@ cargo tauri build
 
 Requires: Rust stable, Node.js 20+, and platform-specific Tauri dependencies ([see Tauri prerequisites](https://v2.tauri.app/start/prerequisites/)).
 
+If you want the desktop app to control a live Chrome session through Chrome DevTools MCP, keep a local Node/npm install available at runtime. OpenPlanter shells out to `npx -y chrome-devtools-mcp@latest`; it does not bundle the server or launch Chrome for you.
+
 ## CLI Agent
 
 The Python CLI agent can be used independently of the desktop app.
@@ -71,6 +73,8 @@ Or run a single task headlessly:
 openplanter-agent --task "Cross-reference vendor payments against lobbying disclosures and flag overlaps" --workspace ./data
 ```
 
+Chrome DevTools MCP support in the CLI/TUI also uses local `npx`, so install Node.js 20+ if you want to enable Chrome tools there.
+
 ### Docker
 
 ```bash
@@ -142,6 +146,53 @@ The agent has access to 20 tools, organized around its investigation workflow:
 
 In **recursive mode** (the default), the agent spawns sub-agents via `subtask` and `execute` to parallelize entity resolution, cross-dataset linking, and evidence-chain construction across large investigations.
 
+When Chrome DevTools MCP is enabled, OpenPlanter discovers Chrome's published MCP tools at solve start and appends them natively to the built-in tool set for the main agent, recursive subtasks, and execute flows.
+
+## Chrome DevTools MCP
+
+OpenPlanter can attach to the official Chrome DevTools MCP server and reuse an active Chrome debugging session. The integration is native in both runtimes, but the server itself is still the upstream package started locally through `npx`.
+
+### Requirements
+
+- Node.js and npm available on your `PATH`
+- Chrome 144 or newer
+- Remote debugging enabled in Chrome at `chrome://inspect/#remote-debugging`
+
+### How OpenPlanter Connects
+
+- Auto-connect mode: OpenPlanter starts `chrome-devtools-mcp` with `--autoConnect` and reuses a running Chrome session after you approve Chrome's debugging prompt.
+- Browser URL mode: OpenPlanter passes `--browserUrl <endpoint>` to attach to an existing remote debugging endpoint. This takes precedence over auto-connect when configured.
+- Channel selection: `stable` is the default channel; you can switch to `beta`, `dev`, or `canary` when needed.
+
+If Chrome MCP cannot start because Node/npm is missing, Chrome remote debugging is disabled, or Chrome is not available, OpenPlanter keeps running with its built-in tools and reports Chrome MCP as `unavailable`.
+
+### Desktop Usage
+
+Use the desktop slash command:
+
+```text
+/chrome status
+/chrome on
+/chrome off
+/chrome auto --save
+/chrome url http://127.0.0.1:9222 --save
+/chrome channel beta --save
+```
+
+The sidebar and `/status` output both show the current Chrome MCP runtime state.
+
+### CLI Usage
+
+Use per-run flags:
+
+```bash
+openplanter-agent --chrome-mcp --chrome-auto-connect
+openplanter-agent --chrome-mcp --chrome-browser-url http://127.0.0.1:9222
+openplanter-agent --chrome-mcp --chrome-channel beta
+```
+
+The TUI also supports `/chrome status|on|off|auto|url <endpoint>|channel <stable|beta|dev|canary> [--save]`.
+
 ## CLI Reference
 
 ```
@@ -181,6 +232,10 @@ OPENPLANTER_WORKSPACE=workspace
 | `--provider NAME` | `auto`, `openai`, `anthropic`, `openrouter`, `cerebras`, `ollama` |
 | `--model NAME` | Model name or `newest` to auto-select |
 | `--reasoning-effort LEVEL` | `low`, `medium`, `high`, or `none` |
+| `--chrome-mcp` / `--no-chrome-mcp` | Enable or disable native Chrome DevTools MCP tools |
+| `--chrome-auto-connect` / `--no-chrome-auto-connect` | Use Chrome MCP auto-connect or require an explicit browser URL |
+| `--chrome-browser-url URL` | Attach Chrome MCP to an existing remote debugging browser URL |
+| `--chrome-channel CHANNEL` | Chrome release channel for auto-connect: `stable`, `beta`, `dev`, `canary` |
 | `--list-models` | Fetch available models from the provider API |
 
 ### Execution
@@ -204,7 +259,7 @@ OPENPLANTER_WORKSPACE=workspace
 
 ### Persistent Defaults
 
-Use `--default-model`, `--default-reasoning-effort`, or per-provider variants like `--default-model-openai` to save workspace defaults to `.openplanter/settings.json`. View them with `--show-settings`.
+Use `--default-model`, `--default-reasoning-effort`, Chrome MCP slash commands with `--save`, or per-provider variants like `--default-model-openai` to save workspace defaults to `.openplanter/settings.json`. View them with `--show-settings`.
 
 ## Configuration
 

diff --git a/agent/__main__.py b/agent/__main__.py
@@ -85,6 +85,40 @@ def build_parser() -> argparse.ArgumentParser:
     parser.add_argument("--openrouter-api-key", help="OpenRouter API key override.")
     parser.add_argument("--cerebras-api-key", help="Cerebras API key override.")
     parser.add_argument("--exa-api-key", help="Exa API key override.")
+    parser.add_argument(
+        "--chrome-mcp",
+        dest="chrome_mcp_enabled",
+        action="store_true",
+        help="Enable native Chrome DevTools MCP tools for this run.",
+    )
+    parser.add_argument(
+        "--no-chrome-mcp",
+        dest="chrome_mcp_enabled",
+        action="store_false",
+        help="Disable native Chrome DevTools MCP tools for this run.",
+    )
+    parser.add_argument(
+        "--chrome-auto-connect",
+        dest="chrome_auto_connect",
+        action="store_true",
+        help="Ask the Chrome DevTools MCP server to auto-connect to a running Chrome instance.",
+    )
+    parser.add_argument(
+        "--no-chrome-auto-connect",
+        dest="chrome_auto_connect",
+        action="store_false",
+        help="Disable Chrome MCP auto-connect and rely on --chrome-browser-url instead.",
+    )
+    parser.add_argument(
+        "--chrome-browser-url",
+        help="Remote debugging browser URL for Chrome DevTools MCP (preferred over auto-connect).",
+    )
+    parser.add_argument(
+        "--chrome-channel",
+        choices=["stable", "beta", "dev", "canary"],
+        help="Chrome channel to target when Chrome MCP auto-connect is used.",
+    )
+    parser.set_defaults(chrome_mcp_enabled=None, chrome_auto_connect=None)
     parser.add_argument("--voyage-api-key", help="Voyage API key override.")
     parser.add_argument(
         "--configure-keys",
@@ -167,7 +201,7 @@ def _resolve_provider(requested: str, creds: CredentialBundle) -> str:
         return "openrouter"
     if creds.cerebras_api_key:
         return "cerebras"
-    return "openai"
+    return "anthropic"
 
 
 def _print_models(cfg: AgentConfig, requested_provider: str) -> int:
@@ -329,6 +363,16 @@ def _apply_runtime_overrides(cfg: AgentConfig, args: argparse.Namespace, creds:
         cfg.model = args.model
     if args.reasoning_effort:
         cfg.reasoning_effort = None if args.reasoning_effort == "none" else args.reasoning_effort
+    if args.chrome_mcp_enabled is not None:
+        cfg.chrome_mcp_enabled = bool(args.chrome_mcp_enabled)
+    if args.chrome_auto_connect is not None:
+        cfg.chrome_mcp_auto_connect = bool(args.chrome_auto_connect)
+    if args.chrome_browser_url is not None:
+        cfg.chrome_mcp_browser_url = args.chrome_browser_url.strip() or None
+        if cfg.chrome_mcp_browser_url:
+            cfg.chrome_mcp_enabled = True
+    if args.chrome_channel:
+        cfg.chrome_mcp_channel = args.chrome_channel
     if args.recursive:
         cfg.recursive = True
     if args.acceptance_criteria:
@@ -419,6 +463,40 @@ def _apply_persistent_settings(
         and settings.default_reasoning_effort
     ):
         cfg.reasoning_effort = settings.default_reasoning_effort
+    if (
+        args.chrome_mcp_enabled is None
+        and os.getenv("OPENPLANTER_CHROME_MCP_ENABLED") is None
+        and settings.chrome_mcp_enabled is not None
+    ):
+        cfg.chrome_mcp_enabled = settings.chrome_mcp_enabled
+    if (
+        args.chrome_auto_connect is None
+        and os.getenv("OPENPLANTER_CHROME_MCP_AUTO_CONNECT") is None
+        and settings.chrome_mcp_auto_connect is not None
+    ):
+        cfg.chrome_mcp_auto_connect = settings.chrome_mcp_auto_connect
+    if (
+        args.chrome_browser_url is None
+        and os.getenv("OPENPLANTER_CHROME_MCP_BROWSER_URL") is None
+        and settings.chrome_mcp_browser_url
+    ):
+        cfg.chrome_mcp_browser_url = settings.chrome_mcp_browser_url
+    if (
+        args.chrome_channel is None
+        and os.getenv("OPENPLANTER_CHROME_MCP_CHANNEL") is None
+        and settings.chrome_mcp_channel
+    ):
+        cfg.chrome_mcp_channel = settings.chrome_mcp_channel
+    if (
+        os.getenv("OPENPLANTER_CHROME_MCP_CONNECT_TIMEOUT_SEC") is None
+        and settings.chrome_mcp_connect_timeout_sec is not None
+    ):
+        cfg.chrome_mcp_connect_timeout_sec = settings.chrome_mcp_connect_timeout_sec
+    if (
+        os.getenv("OPENPLANTER_CHROME_MCP_RPC_TIMEOUT_SEC") is None
+        and settings.chrome_mcp_rpc_timeout_sec is not None
+    ):
+        cfg.chrome_mcp_rpc_timeout_sec = settings.chrome_mcp_rpc_timeout_sec
 
     return settings
 
@@ -432,6 +510,24 @@ def _print_settings(settings: PersistentSettings) -> None:
     print(f"  default_model_openrouter: {settings.default_model_openrouter or '(unset)'}")
     print(f"  default_model_cerebras: {settings.default_model_cerebras or '(unset)'}")
     print(f"  default_model_ollama: {settings.default_model_ollama or '(unset)'}")
+    print(
+        "  chrome_mcp_enabled: "
+        f"{settings.chrome_mcp_enabled if settings.chrome_mcp_enabled is not None else '(unset)'}"
+    )
+    print(
+        "  chrome_mcp_auto_connect: "
+        f"{settings.chrome_mcp_auto_connect if settings.chrome_mcp_auto_connect is not None else '(unset)'}"
+    )
+    print(f"  chrome_mcp_browser_url: {settings.chrome_mcp_browser_url or '(unset)'}")
+    print(f"  chrome_mcp_channel: {settings.chrome_mcp_channel or '(unset)'}")
+    print(
+        "  chrome_mcp_connect_timeout_sec: "
+        f"{settings.chrome_mcp_connect_timeout_sec if settings.chrome_mcp_connect_timeout_sec is not None else '(unset)'}"
+    )
+    print(
+        "  chrome_mcp_rpc_timeout_sec: "
+        f"{settings.chrome_mcp_rpc_timeout_sec if settings.chrome_mcp_rpc_timeout_sec is not None else '(unset)'}"
+    )
 
 
 def _has_non_interactive_command(args: argparse.Namespace) -> bool:
@@ -566,6 +662,7 @@ def main() -> None:
 
     engine = build_engine(cfg)
     model_name = _get_model_display_name(engine)
+    chrome_status = engine.tools.chrome_mcp_status()
 
     try:
         runtime = SessionRuntime.bootstrap(
@@ -585,6 +682,7 @@ def main() -> None:
     if cfg.reasoning_effort:
         startup_info["Reasoning"] = cfg.reasoning_effort
     startup_info["Mode"] = "recursive" if cfg.recursive else "flat"
+    startup_info["ChromeMCP"] = f"{chrome_status.status}: {chrome_status.detail}"
     startup_info["Workspace"] = str(cfg.workspace)
     startup_info["WorkspaceSource"] = workspace_resolution.source
     if workspace_resolution.guardrail_action != "none":

diff --git a/agent/builder.py b/agent/builder.py
@@ -173,6 +173,12 @@ def build_engine(cfg: AgentConfig) -> RLMEngine:
         mistral_transcription_chunk_overlap_seconds=cfg.mistral_transcription_chunk_overlap_seconds,
         mistral_transcription_max_chunks=cfg.mistral_transcription_max_chunks,
         mistral_transcription_request_timeout_sec=cfg.mistral_transcription_request_timeout_sec,
+        chrome_mcp_enabled=cfg.chrome_mcp_enabled,
+        chrome_mcp_auto_connect=cfg.chrome_mcp_auto_connect,
+        chrome_mcp_browser_url=cfg.chrome_mcp_browser_url,
+        chrome_mcp_channel=cfg.chrome_mcp_channel,
+        chrome_mcp_connect_timeout_sec=cfg.chrome_mcp_connect_timeout_sec,
+        chrome_mcp_rpc_timeout_sec=cfg.chrome_mcp_rpc_timeout_sec,
         max_observation_chars=cfg.max_observation_chars,
     )