---
title: Browser Automation
description: Control browsers with multiple providers, local Chromium-family browsers via CDP, or cloud browsers for web interaction, form filling, scraping, and more.
sidebar_label: Browser
sidebar_position: 5
---

# Browser Automation

Hermes Agent includes a full browser automation toolset with multiple backend options:

- **Browserbase cloud mode** via [Browserbase](https://browserbase.com) for managed cloud browsers and anti-bot tooling
- **Browser Use cloud mode** via [Browser Use](https://browser-use.com) as an alternative cloud browser provider
- **Firecrawl cloud mode** via [Firecrawl](https://firecrawl.dev) for cloud browsers with built-in scraping
- **Camofox local mode** via [Camofox](https://github.com/jo-inc/camofox-browser) for local anti-detection browsing (Firefox-based fingerprint spoofing)
- **Local Chromium-family CDP** — connect browser tools to your own Chrome, Brave, Chromium, or Edge instance using `/browser connect`
- **Local browser mode** via the `agent-browser` CLI and a local Chromium installation

In all modes, the agent can navigate websites, interact with page elements, fill forms, and extract information.

## Overview

Pages are represented as **accessibility trees** (text-based snapshots), making them ideal for LLM agents. Interactive elements get ref IDs (like `@e1`, `@e2`) that the agent uses for clicking and typing.

Key capabilities:

- **Multi-provider cloud execution** — Browserbase, Browser Use, or Firecrawl — no local browser needed
- **Local Chromium-family integration** — attach to your running Chrome, Brave, Chromium, or Edge browser via CDP for hands-on browsing
- **Built-in stealth** — random fingerprints, CAPTCHA solving, residential proxies (Browserbase)
- **Session isolation** — each task gets its own browser session
- **Automatic cleanup** — inactive sessions are closed after a timeout
- **Vision analysis** — screenshot + AI analysis for visual understanding

## Setup

:::tip Nous Subscribers
If you have a paid [Nous Portal](https://portal.nousresearch.com) subscription, you can use browser automation through the **[Tool Gateway](tool-gateway.md)** without any separate API keys. New installs can run `hermes setup --portal` to log in and turn on every gateway tool at once; existing installs can pick **Nous Subscription** as the browser provider via `hermes model` or `hermes tools`.
:::

### Browserbase cloud mode

To use Browserbase-managed cloud browsers, add:

```bash
# Add to ~/.hermes/.env
BROWSERBASE_API_KEY=***
BROWSERBASE_PROJECT_ID=your-project-id-here
```

Get your credentials at [browserbase.com](https://browserbase.com).

### Browser Use cloud mode

To use Browser Use as your cloud browser provider, add:

```bash
# Add to ~/.hermes/.env
BROWSER_USE_API_KEY=***
```

Get your API key at [browser-use.com](https://browser-use.com). Browser Use provides a cloud browser via its REST API. If both Browserbase and Browser Use credentials are set, Browserbase takes priority.

### Firecrawl cloud mode

To use Firecrawl as your cloud browser provider, add:

```bash
# Add to ~/.hermes/.env
FIRECRAWL_API_KEY=fc-***
```

Get your API key at [firecrawl.dev](https://firecrawl.dev). Then select Firecrawl as your browser provider:

```bash
hermes setup tools
# → Browser Automation → Firecrawl
```

Optional settings:

```bash
# Self-hosted Firecrawl instance (default: https://api.firecrawl.dev)
FIRECRAWL_API_URL=http://localhost:3002

# Session TTL in seconds (default: 300)
FIRECRAWL_BROWSER_TTL=600
```

### Hybrid routing: cloud for public URLs, local for LAN/localhost

When a cloud provider is configured, Hermes auto-spawns a **local Chromium sidecar**
for URLs that resolve to a private/loopback/LAN address (`localhost`, `127.0.0.1`,
`192.168.x.x`, `10.x.x.x`, `172.16-31.x.x`, `*.local`, `*.lan`, `*.internal`,
IPv6 loopback `::1`, link-local `169.254.x.x`). Public URLs continue to use the
cloud provider in the same conversation.

This solves the common "I'm developing locally but using Browserbase" workflow —
the agent can screenshot your dashboard at `http://localhost:3000` AND scrape
`https://github.com` without you switching providers or disabling the SSRF guard.
The cloud provider never sees the private URL.

The feature is **on by default**. To disable it (all URLs go to the configured
cloud provider, as before):

```yaml
# ~/.hermes/config.yaml
browser:
  cloud_provider: browserbase
  auto_local_for_private_urls: false
```

With auto-routing disabled, private URLs are rejected with
`"Blocked: URL targets a private or internal address"` unless you also set
`browser.allow_private_urls: true` (which lets the cloud provider attempt them —
usually won't work since Browserbase etc. can't reach your LAN).

Requirements: the local sidecar uses the same `agent-browser` CLI as pure local
mode, so you need it installed (`hermes setup tools → Browser Automation`
auto-installs it). Post-navigation redirects from a public URL onto a private
address are still blocked (you can't use a redirect-to-internal trick to reach
your LAN through the public path).

### Camofox local mode

[Camofox](https://github.com/jo-inc/camofox-browser) is a self-hosted Node.js server wrapping Camoufox (a Firefox fork with C++ fingerprint spoofing). It provides local anti-detection browsing without cloud dependencies.

```bash
# Clone the Camofox browser server first
git clone https://github.com/jo-inc/camofox-browser
cd camofox-browser

# Build and start with Docker using the default container settings
# (auto-detects arch: aarch64 on M1/M2, x86_64 on Intel)
make up

# Stop and remove the default container
make down

# Force a clean rebuild (for example, after upgrading VERSION/RELEASE)
make reset

# Just download binaries without building
make fetch

# Override arch or version explicitly
make up ARCH=x86_64
make up VERSION=135.0.1 RELEASE=beta.24
```

`make up` starts the default container immediately. If you want custom runtime settings such as a larger Node heap, VNC, or a persistent profile directory, build the image first and then run it yourself:

```bash
# Build the image without starting the default container
make build

# Start with persistence, VNC live view, and a larger Node heap
mkdir -p ~/.camofox-docker
docker run -d \
  --name camofox-browser \
  --restart unless-stopped \
  -p 9377:9377 \
  -p 6080:6080 \
  -p 5901:5900 \
  -e CAMOFOX_PORT=9377 \
  -e ENABLE_VNC=1 \
  -e VNC_BIND=0.0.0.0 \
  -e VNC_RESOLUTION=1920x1080 \
  -e MAX_OLD_SPACE_SIZE=2048 \
  -v ~/.camofox-docker:/root/.camofox \
  camofox-browser:135.0.1-aarch64
```

With VNC enabled, the browser runs in headed mode and can be watched live in your browser at `http://localhost:6080` (noVNC). You can also connect a native VNC client to `localhost:5901`.

If you already ran `make up`, stop and remove that default container before starting the custom one:

```bash
make down
# then run the custom docker run command above
```

Then set in `~/.hermes/.env`:

```bash
CAMOFOX_URL=http://localhost:9377
```

If Camofox is running in Docker and you want it to open web apps served from the host machine, enable loopback rewriting. `CAMOFOX_URL` should still point at the host-published control API, but page URLs such as `http://127.0.0.1:3000` must be opened from inside the container as `http://host.docker.internal:3000`:

```yaml
# ~/.hermes/config.yaml
browser:
  camofox:
    rewrite_loopback_urls: true
    loopback_host_alias: host.docker.internal  # default; use a LAN IP if needed
```

Equivalent env vars:

```bash
CAMOFOX_REWRITE_LOOPBACK_URLS=true
CAMOFOX_LOOPBACK_HOST_ALIAS=host.docker.internal
```

The rewrite only applies to page navigation URLs with loopback hosts (`localhost`, `127.0.0.1`, `::1`). It does not change `CAMOFOX_URL`. Leave it disabled for non-Docker Camofox installs, where the browser already runs on the host and loopback URLs are correct.

Or configure via `hermes tools` → Browser Automation → Camofox.

When `CAMOFOX_URL` is set, all browser tools automatically route through Camofox instead of Browserbase or agent-browser.

#### Persistent browser sessions

By default, each Camofox session gets a random identity — cookies and logins don't survive across agent restarts. To enable persistent browser sessions, add the following to `~/.hermes/config.yaml`:

```yaml
browser:
  camofox:
    managed_persistence: true
```

Then fully restart Hermes so the new config is picked up.

:::warning Nested path matters
Hermes reads `browser.camofox.managed_persistence`, **not** a top-level `managed_persistence`. A common mistake is writing:

```yaml
# ❌ Wrong — Hermes ignores this
managed_persistence: true
```

If the flag is placed at the wrong path, Hermes silently falls back to a random ephemeral `userId` and your login state will be lost on every session.
:::

##### What Hermes does
- Sends a deterministic profile-scoped `userId` to Camofox so the server can reuse the same Firefox profile across sessions.
- Skips server-side context destruction on cleanup, so cookies and logins survive between agent tasks.
- Scopes the `userId` to the active Hermes profile, so different Hermes profiles get different browser profiles (profile isolation).

##### What Hermes does not do
- It does not force persistence on the Camofox server. Hermes only sends a stable `userId`; the server must honor it by mapping that `userId` to a persistent Firefox profile directory.
- If your Camofox server build treats every request as ephemeral (e.g. always calls `browser.newContext()` without loading a stored profile), Hermes cannot make those sessions persist. Make sure you are running a Camofox build that implements userId-based profile persistence.

##### Verify it's working

1. Start Hermes and your Camofox server.
2. Open Google (or any login site) in a browser task and sign in manually.
3. End the browser task normally.
4. Start a new browser task.
5. Open the same site again — you should still be signed in.

If step 5 logs you out, the Camofox server isn't honoring the stable `userId`. Double-check your config path, confirm you fully restarted Hermes after editing `config.yaml`, and verify your Camofox server version supports persistent per-user profiles.

##### Where state lives

Hermes derives the stable `userId` from the profile-scoped directory `~/.hermes/browser_auth/camofox/` (or the equivalent under `$HERMES_HOME` for non-default profiles). The actual browser profile data lives on the Camofox server side, keyed by that `userId`. To fully reset a persistent profile, clear it on the Camofox server and remove the corresponding Hermes profile's state directory.

#### Externally managed Camofox sessions

When another app drives the visible Camofox browser (a desktop assistant, a custom integration, another agent), configure Hermes to operate inside that same identity instead of spawning its own isolated profile.

Three knobs control the behavior:

| Setting | Env var | Effect |
|---------|---------|--------|
| `browser.camofox.user_id` | `CAMOFOX_USER_ID` | Camofox `userId` Hermes uses when creating tabs. Setting this opts the session into "externally managed" mode. |
| `browser.camofox.session_key` | `CAMOFOX_SESSION_KEY` | `sessionKey` (a.k.a. `listItemId`) sent on tab creation. Used to match an existing tab during adoption. Defaults to a per-task value if unset. |
| `browser.camofox.adopt_existing_tab` | `CAMOFOX_ADOPT_EXISTING_TAB` | When true, Hermes calls `GET /tabs?userId=<user_id>` on first use and reuses an existing tab before creating a new one. |

Env vars take precedence over `config.yaml`. Either form works:

```yaml
browser:
  camofox:
    user_id: shared-camofox
    session_key: visible-tab
    adopt_existing_tab: true
```

```bash
CAMOFOX_USER_ID=shared-camofox
CAMOFOX_SESSION_KEY=visible-tab
CAMOFOX_ADOPT_EXISTING_TAB=true
```

**What changes when `user_id` is set:**

- Hermes skips destructive cleanup at task end (same as `managed_persistence: true`). The other app's tab/cookies/profile survive.
- Hermes does **not** call `DELETE /sessions/<user_id>` — that endpoint wipes all user data, so it would nuke the external app's session if it fired.

**How tab adoption works (when `adopt_existing_tab: true`):**

1. On the first browser tool call after a process start, Hermes issues `GET /tabs?userId=<user_id>` (5-second timeout).
2. If any tab in the response has `listItemId == session_key`, Hermes adopts the most recently created one in that group.
3. Otherwise, Hermes adopts the most recently created tab for the user (any `listItemId`).
4. If no tabs exist or the request fails, Hermes falls back to creating a new tab on the next operation.

Adoption only fires until `tab_id` is populated for the session. If the external app closes the adopted tab mid-run, the next browser tool call will surface a Camofox error — Hermes does not re-poll for a fresh tab on every call.

**Picking `session_key`:** if you want Hermes to reliably attach to a *specific* existing tab, set `session_key` to the `listItemId` the external app used when creating it. If you leave `session_key` unset and only set `user_id`, Hermes generates a per-task `session_key` (`task_<id>`) — Hermes will share cookies and the profile with the external app, but will open its own tab alongside instead of reusing one.

**Concurrency note:** the external app and Hermes can drive the same Camofox `userId` simultaneously, but Camofox does not coordinate per-tab focus between clients. Coordinate ownership at the application layer (e.g. the external app pauses while Hermes runs).

#### VNC live view

When Camofox runs in headed mode (with a visible browser window), it exposes a VNC port in its health check response. Hermes automatically discovers this and includes the VNC URL in navigation responses, so the agent can share a link for you to watch the browser live.

### Local Chromium-family browser via CDP (`/browser connect`)

Instead of a cloud provider, you can attach Hermes browser tools to your own running Chrome, Brave, Chromium, or Edge instance via the Chrome DevTools Protocol (CDP). This is useful when you want to see what the agent is doing in real-time, interact with pages that require your own cookies/sessions, or avoid cloud browser costs.

:::note
`/browser connect` is an **interactive-CLI slash command** — it is not dispatched by the gateway. If you try to run it inside a WebUI, Telegram, Discord, or other gateway chat, the message will be sent to the agent as plain text and the command will not execute. Start Hermes from the terminal (`hermes` or `hermes chat`) and issue `/browser connect` there.
:::

In the CLI, use:

```
/browser connect                 # Auto-launch/connect to a local Chromium-family browser at http://127.0.0.1:9222
/browser connect ws://host:port  # Connect to a specific CDP endpoint
/browser status                  # Check current connection
/browser disconnect              # Detach and return to cloud/local mode
```

If a browser isn't already running with remote debugging, Hermes will attempt to auto-launch a supported Chromium-family browser with `--remote-debugging-port=9222`. Detection includes Brave, Google Chrome, Chromium, and Microsoft Edge, with common Linux install paths such as `/opt/brave-bin/brave` and `/snap/bin/brave`.

:::tip
To start a Chromium-family browser manually with CDP enabled, use a dedicated user-data-dir so the debug port actually comes up even if the browser is already running with your normal profile:

```bash
# Linux — Brave
brave-browser \
  --remote-debugging-port=9222 \
  --user-data-dir=$HOME/.hermes/chrome-debug \
  --no-first-run \
  --no-default-browser-check &

# Linux — Google Chrome
google-chrome \
  --remote-debugging-port=9222 \
  --user-data-dir=$HOME/.hermes/chrome-debug \
  --no-first-run \
  --no-default-browser-check &

# macOS — Brave
"/Applications/Brave Browser.app/Contents/MacOS/Brave Browser" \
  --remote-debugging-port=9222 \
  --user-data-dir="$HOME/.hermes/chrome-debug" \
  --no-first-run \
  --no-default-browser-check &

# macOS — Google Chrome
"/Applications/Google Chrome.app/Contents/MacOS/Google Chrome" \
  --remote-debugging-port=9222 \
  --user-data-dir="$HOME/.hermes/chrome-debug" \
  --no-first-run \
  --no-default-browser-check &
```

Then launch the Hermes CLI and run `/browser connect`.

**Why `--user-data-dir`?** Without it, launching a Chromium-family browser while a regular instance is already running typically opens a new window on the existing process — and that existing process was not started with `--remote-debugging-port`, so port 9222 never opens. A dedicated user-data-dir forces a fresh browser process where the debug port actually listens. `--no-first-run --no-default-browser-check` skips the first-launch wizard for the fresh profile.
:::

When connected via CDP, all browser tools (`browser_navigate`, `browser_click`, etc.) operate on your live browser instance instead of spinning up a cloud session.

### WSL2 + Windows Chrome: prefer MCP over `/browser connect`

If Hermes runs inside WSL2 but the Chrome window you want to control runs on the Windows host, `/browser connect` is often not the best path.

Why:

- `/browser connect` expects Hermes itself to reach a usable CDP endpoint
- modern Chrome live-debugging sessions often expose a host-local endpoint that is not directly reachable from WSL the same way a classic `9222` port is
- even when Windows Chrome is debuggable, the cleanest integration is often to let a Windows-side browser MCP server attach to Chrome and let Hermes talk to that MCP server

For that setup, prefer `chrome-devtools-mcp` through Hermes MCP support.

See the MCP guide for the practical setup:

- [Use MCP with Hermes](../../guides/use-mcp-with-hermes.md#wsl2-bridge-hermes-in-wsl-to-windows-chrome)

### Local browser mode

If you do **not** set any cloud credentials and don't use `/browser connect`, Hermes can still use the browser tools through a local Chromium install driven by `agent-browser`.

### Optional Environment Variables

```bash
# Residential proxies for better CAPTCHA solving (default: "true")
BROWSERBASE_PROXIES=true

# Advanced stealth with custom Chromium — requires Scale Plan (default: "false")
BROWSERBASE_ADVANCED_STEALTH=false

# Session reconnection after disconnects — requires paid plan (default: "true")
BROWSERBASE_KEEP_ALIVE=true

# Custom session timeout in seconds (max 21600 = 6 hours) (default: project default)
# Examples: 600 (10min), 1800 (30min), 21600 (6h max)
BROWSERBASE_SESSION_TIMEOUT=1800

# Inactivity timeout before auto-cleanup in seconds (default: 120)
BROWSER_INACTIVITY_TIMEOUT=120

# Extra Chromium launch flags (comma- or newline-separated). Hermes auto-injects
# `--no-sandbox,--disable-dev-shm-usage` when it detects root or AppArmor-restricted
# unprivileged user namespaces (Ubuntu 23.10+, DGX Spark, many container images),
# so most users don't need to set this. Set it manually only if you need a flag
# Hermes doesn't add automatically; setting it disables the auto-injection.
AGENT_BROWSER_ARGS=--no-sandbox
```

### Install agent-browser CLI

```bash
npm install -g agent-browser
# Or install locally in the repo:
npm install
```

:::info
The `browser` toolset must be included in your config's `toolsets` list or enabled via `hermes config set toolsets '["hermes-cli", "browser"]'`.
:::

## Available Tools

### `browser_navigate`

Navigate to a URL. Must be called before any other browser tool. Initializes the Browserbase session.

```
Navigate to https://github.com/NousResearch
```

:::tip
For simple information retrieval, prefer `web_search` or `web_extract` — they are faster and cheaper. Use browser tools when you need to **interact** with a page (click buttons, fill forms, handle dynamic content).
:::

### `browser_snapshot`

Get a text-based snapshot of the current page's accessibility tree. Returns interactive elements with ref IDs like `@e1`, `@e2` for use with `browser_click` and `browser_type`.

- **`full=false`** (default): Compact view showing only interactive elements
- **`full=true`**: Complete page content

Snapshots over 8000 characters are automatically summarized by an LLM.

### `browser_click`

Click an element identified by its ref ID from the snapshot.

```
Click @e5 to press the "Sign In" button
```

### `browser_type`

Type text into an input field. Clears the field first, then types the new text.

```
Type "hermes agent" into the search field @e3
```

### `browser_scroll`

Scroll the page up or down to reveal more content.

```
Scroll down to see more results
```

### `browser_press`

Press a keyboard key. Useful for submitting forms or navigation.

```
Press Enter to submit the form
```

Supported keys: `Enter`, `Tab`, `Escape`, `ArrowDown`, `ArrowUp`, and more.

### `browser_back`

Navigate back to the previous page in browser history.

### `browser_get_images`

List all images on the current page with their URLs and alt text. Useful for finding images to analyze.

### `browser_vision`

Take a screenshot and analyze it with vision AI. Use this when text snapshots don't capture important visual information — especially useful for CAPTCHAs, complex layouts, or visual verification challenges.

The screenshot is saved persistently and the file path is returned alongside the AI analysis. On messaging platforms (Telegram, Discord, Slack, WhatsApp), you can ask the agent to share the screenshot — it will be sent as a native photo attachment via the `MEDIA:` mechanism.

```
What does the chart on this page show?
```

Screenshots are stored in `~/.hermes/cache/screenshots/` and automatically cleaned up after 24 hours.

### `browser_console`

Get browser console output (log/warn/error messages) and uncaught JavaScript exceptions from the current page. Essential for detecting silent JS errors that don't appear in the accessibility tree.

```
Check the browser console for any JavaScript errors
```

Use `clear=True` to clear the console after reading, so subsequent calls only show new messages.

`browser_console` also evaluates JavaScript when called with an `expression` argument — same shape as DevTools console, the result comes back parsed (JSON-serialized objects become dicts; primitive values stay primitive).

```
browser_console(expression="document.querySelector('h1').textContent")
browser_console(expression="JSON.stringify(performance.timing)")
```

When a CDP supervisor is active for the current session (typical for any session that's run `browser_navigate` against a CDP-capable backend), evaluation runs over the supervisor's persistent WebSocket — no subprocess startup cost. Falls through to the standard agent-browser CLI path otherwise. Behaviour is identical either way; only latency changes.

### `browser_cdp`

Raw Chrome DevTools Protocol passthrough — the escape hatch for browser operations not covered by the other tools. Use for native dialog handling, iframe-scoped evaluation, cookie/network control, or any CDP verb the agent needs.

**Only available when a CDP endpoint is reachable at session start** — meaning `/browser connect` has attached to a running Chrome, Brave, Chromium, or Edge browser, or `browser.cdp_url` is set in `config.yaml`. The default local agent-browser mode, Camofox, and cloud providers (Browserbase, Browser Use, Firecrawl) do not currently expose CDP to this tool — cloud providers have per-session CDP URLs but live-session routing is a follow-up.

**CDP method reference:** https://chromedevtools.github.io/devtools-protocol/ — the agent can `web_extract` a specific method's page to look up parameters and return shape.

Common patterns:

```
# List tabs (browser-level, no target_id)
browser_cdp(method="Target.getTargets")

# Handle a native JS dialog on a tab
browser_cdp(method="Page.handleJavaScriptDialog",
            params={"accept": true, "promptText": ""},
            target_id="<tabId>")

# Evaluate JS in a specific tab
browser_cdp(method="Runtime.evaluate",
            params={"expression": "document.title", "returnByValue": true},
            target_id="<tabId>")

# Get all cookies
browser_cdp(method="Network.getAllCookies")
```

Browser-level methods (`Target.*`, `Browser.*`, `Storage.*`) omit `target_id`. Page-level methods (`Page.*`, `Runtime.*`, `DOM.*`, `Emulation.*`) require a `target_id` from `Target.getTargets`. Each stateless call is independent — sessions do not persist between calls.

**Cross-origin iframes:** pass `frame_id` (from `browser_snapshot.frame_tree.children[]` where `is_oopif=true`) to route the CDP call through the supervisor's live session for that iframe. This is how `Runtime.evaluate` inside a cross-origin iframe works on Browserbase, where stateless CDP connections would hit signed-URL expiry. Example:

```
browser_cdp(
  method="Runtime.evaluate",
  params={"expression": "document.title", "returnByValue": True},
  frame_id="<frame_id from browser_snapshot>",
)
```

Same-origin iframes don't need `frame_id` — use `document.querySelector('iframe').contentDocument` from a top-level `Runtime.evaluate` instead.

### `browser_dialog`

Responds to a native JS dialog (`alert` / `confirm` / `prompt` / `beforeunload`). Before this tool existed, dialogs would silently block the page's JavaScript thread and subsequent `browser_*` calls would hang or throw; now the agent sees pending dialogs in `browser_snapshot` output and responds explicitly.

**Workflow:**
1. Call `browser_snapshot`. If a dialog is blocking the page, it shows up as `pending_dialogs: [{"id": "d-1", "type": "alert", "message": "..."}]`.
2. Call `browser_dialog(action="accept")` or `browser_dialog(action="dismiss")`. For `prompt()` dialogs, pass `prompt_text="..."` to supply the response.
3. Re-snapshot — `pending_dialogs` is empty; the page's JS thread has resumed.

**Detection happens automatically** via a persistent CDP supervisor — one WebSocket per task that subscribes to Page/Runtime/Target events. The supervisor also populates a `frame_tree` field in the snapshot so the agent can see the iframe structure of the current page, including cross-origin (OOPIF) iframes.

**Availability matrix:**

| Backend | Detection via `pending_dialogs` | Response (`browser_dialog` tool) |
|---|---|---|
| Local Chrome via `/browser connect` or `browser.cdp_url` | ✓ | ✓ full workflow |
| Browserbase | ✓ | ✓ full workflow (via injected XHR bridge) |
| Camofox / default local agent-browser | ✗ | ✗ (no CDP endpoint) |

**How it works on Browserbase.** Browserbase's CDP proxy auto-dismisses real native dialogs server-side within ~10ms, so we can't use `Page.handleJavaScriptDialog`. The supervisor injects a small script via `Page.addScriptToEvaluateOnNewDocument` that overrides `window.alert`/`confirm`/`prompt` with a synchronous XHR. We intercept those XHRs via `Fetch.enable` — the page's JS thread stays blocked on the XHR until we call `Fetch.fulfillRequest` with the agent's response. `prompt()` return values round-trip back into page JS unchanged.

**Dialog policy** is configured in `config.yaml` under `browser.dialog_policy`:

| Policy | Behavior |
|--------|----------|
| `must_respond` (default) | Capture, surface in snapshot, wait for explicit `browser_dialog()` call. Safety auto-dismiss after `browser.dialog_timeout_s` (default 300s) so a buggy agent can't stall forever. |
| `auto_dismiss` | Capture, dismiss immediately. Agent still sees the dialog in `browser_state` history but doesn't have to act. |
| `auto_accept` | Capture, accept immediately. Useful when navigating pages with aggressive `beforeunload` prompts. |

**Frame tree** inside `browser_snapshot.frame_tree` is capped to 30 frames and OOPIF depth 2 to keep payloads bounded on ad-heavy pages. A `truncated: true` flag surfaces when limits were hit; agents needing the full tree can use `browser_cdp` with `Page.getFrameTree`.

## Practical Examples

### Filling Out a Web Form

```
User: Sign up for an account on example.com with my email john@example.com

Agent workflow:
1. browser_navigate("https://example.com/signup")
2. browser_snapshot()  → sees form fields with refs
3. browser_type(ref="@e3", text="john@example.com")
4. browser_type(ref="@e5", text="SecurePass123")
5. browser_click(ref="@e8")  → clicks "Create Account"
6. browser_snapshot()  → confirms success
```

### Researching Dynamic Content

```
User: What are the top trending repos on GitHub right now?

Agent workflow:
1. browser_navigate("https://github.com/trending")
2. browser_snapshot(full=true)  → reads trending repo list
3. Returns formatted results
```

## Session Recording

Automatically record browser sessions as WebM video files:

```yaml
browser:
  record_sessions: true  # default: false
```

When enabled, recording starts automatically on the first `browser_navigate` and saves to `~/.hermes/browser_recordings/` when the session closes. Works in both local and cloud (Browserbase) modes. Recordings older than 72 hours are automatically cleaned up.

## Stealth Features

Browserbase provides automatic stealth capabilities:

| Feature | Default | Notes |
|---------|---------|-------|
| Basic Stealth | Always on | Random fingerprints, viewport randomization, CAPTCHA solving |
| Residential Proxies | On | Routes through residential IPs for better access |
| Advanced Stealth | Off | Custom Chromium build, requires Scale Plan |
| Keep Alive | On | Session reconnection after network hiccups |

:::note
If paid features aren't available on your plan, Hermes automatically falls back — first disabling `keepAlive`, then proxies — so browsing still works on free plans.
:::

## Session Management

- Each task gets an isolated browser session via Browserbase
- Sessions are automatically cleaned up after inactivity (default: 2 minutes)
- A background thread checks every 30 seconds for stale sessions
- Emergency cleanup runs on process exit to prevent orphaned sessions
- Sessions are released via the Browserbase API (`REQUEST_RELEASE` status)

## Limitations

- **Text-based interaction** — relies on accessibility tree, not pixel coordinates
- **Snapshot size** — large pages may be truncated or LLM-summarized at 8000 characters
- **Session timeout** — cloud sessions expire based on your provider's plan settings
- **Cost** — cloud sessions consume provider credits; sessions are automatically cleaned up when the conversation ends or after inactivity. Use `/browser connect` for free local browsing.
- **No file downloads** — cannot download files from the browser
