MCP 服务器

Scout

single-binary MCP server that gives AI agents a browser. 66 tools for navigation, form filling, data extraction, screenshots, and DOM diffing — built on pure Chrome DevTools Protocol.

README

<h1 align="center">Scout</h1>

<p align="center">AI-powered browser automation for Go. Pure CDP over WebSocket — no rod, no chromedp, no Node.js.</p>

A single scout binary gives you a full CLI, a 66-tool MCP server, and a Go library with Gin-like middleware composition.

brew install felixgeelhaar/tap/scout

Quick Start

# CLI — visible browser, one-shot commands
scout observe https://example.com          # structured page snapshot
scout markdown https://news.ycombinator.com # page as compact markdown
scout screenshot https://github.com         # save screenshot
scout extract https://example.com h1        # extract element text
scout frameworks https://react.dev          # detect React, Vue, etc.

# MCP Server — give AI agents browser superpowers
claude mcp add scout -- scout mcp serve

# Browser UI — conversational browser automation
scout ui serve --provider=ollama --model=mistral
cd ui && npm install && npm run dev  # open http://localhost:3000

Install

# Homebrew
brew install felixgeelhaar/tap/scout

# Direct binary
curl -fsSL https://raw.githubusercontent.com/felixgeelhaar/scout/main/install.sh | bash

# Go
go install github.com/felixgeelhaar/scout/cmd/scout@latest

# As a library
go get github.com/felixgeelhaar/scout

MCP Server — 66 Tools

Single binary, zero runtime dependencies. Configure in any MCP client:

claude mcp add scout -- scout mcp serve           # Claude Code

{"mcpServers": {"scout": {"command": "scout", "args": ["mcp", "serve"]}}}

Tool Categories

Category	Tools
Navigation	`navigate`, `observe`, `observe_diff`, `observe_with_budget`
Interaction	`click`, `click_label`, `type`, `hover`, `double_click`, `right_click`, `select_option`, `scroll_to`, `scroll_by`, `focus`, `drag_drop`, `dispatch_event`
Forms	`fill_form`, `fill_form_semantic`, `discover_form`
Extraction	`extract`, `extract_all`, `extract_table`, `auto_extract`, `scroll_and_collect`, `markdown`, `readable_text`, `accessibility_tree`
Capture	`screenshot`, `annotated_screenshot`, `pdf`
Network	`enable_network_capture`, `network_requests`
Tabs	`open_tab`, `switch_tab`, `close_tab`, `list_tabs`
Frameworks	`wait_spa`, `detect_frameworks`, `component_state`, `app_state`
Playback	`start_recording`, `stop_recording`, `save_playbook`, `replay_playbook`
Smart Helpers	`dismiss_cookies`, `check_readiness`, `suggest_selectors`, `session_history`
Vision	`hybrid_observe`, `find_by_coordinates`
Batch	`execute_batch`
Iframe	`switch_to_frame`, `switch_to_main_frame`
Trace	`start_trace`, `stop_trace`
Diagnostics	`detect_dialog`, `detect_auth_wall`, `console_errors`, `compare_tabs`, `upload_file`
Utility	`has_element`, `wait_for`, `configure`, `web_vitals`, `select_by_prompt`

All tools have MCP annotations (ReadOnly, OpenWorld, ClosedWorld, Idempotent) for smart auto-approval. Read-only tools like observe, extract, and screenshot run without permission prompts.

Runtime Configuration

Switch between headless and visible browser without restarting:

Agent: configure(headless: false)   → browser window appears
Agent: navigate("https://...")       → watch it work
Agent: configure(headless: true)     → back to headless

Browser UI

A conversational browser automation interface. Type natural language, watch the browser respond in real-time.

# Start the AG-UI server (Go backend)
scout ui serve --provider=ollama --model=mistral    # local, no API key
scout ui serve --provider=claude                     # needs ANTHROPIC_API_KEY
scout ui serve --provider=openai --model=gpt-4o     # needs OPENAI_API_KEY
scout ui serve --provider=groq --base-url=https://api.groq.com/openai --model=llama-3.3-70b-versatile

# Start the Vue frontend
cd ui && npm install && npm run dev                  # http://localhost:3000

The UI streams AG-UI protocol events over SSE:

Chat panel with markdown rendering and quick-action pills
Live browser viewport with screenshot streaming and URL bar
Activity timeline showing tool calls in real-time
Stop button to cancel mid-stream

The Go server handles the agentic loop: LLM decides which scout tools to call, executes them, streams browser state deltas back to the frontend. Supports any OpenAI-compatible endpoint via --base-url.

Agent Package

High-level Go API for AI agents. Structured output, auto-wait, goroutine-safe.

session, _ := agent.NewSession(agent.SessionConfig{Headless: true})
defer session.Close()

// Navigate and observe
session.Navigate("https://example.com")
obs, _ := session.Observe()               // links, inputs, buttons, text + action costs

// DOM diff — only what changed (saves 50-80% tokens)
session.Click("#submit")
_, diff, _ := session.ObserveDiff()
// diff.Classification: "modal_appeared"
// diff.Summary: "Modal/dialog appeared: Login required"

// Semantic form filling — no CSS selectors
session.FillFormSemantic(map[string]string{
    "Email": "user@example.com", "Password": "secret",
})

// Visual grounding — click by number, not selector
result, _ := session.AnnotatedScreenshot()  // numbered labels on elements
session.ClickLabel(7)                        // click element [7]

// Multi-tab coordination
session.OpenTab("pricing", "https://example.com/pricing")
session.SwitchTab("default")

// Framework detection (19 frameworks)
frameworks, _ := session.DetectedFrameworks() // ["react", "nextjs"]
state, _ := session.ComponentState("#app")    // read React/Vue state

// Network capture — read API responses directly
session.EnableNetworkCapture("/api/")
captured := session.CapturedRequests("/api/users")

// Action replay — record once, replay without LLM
session.StartRecordingPlaybook("login-flow")
// ... do stuff ...
pb, _ := session.StopRecordingPlaybook()
agent.SavePlaybook(pb, "login.json")
// Later: session.ReplayPlaybook(pb)  // 100x cheaper

// Persistent profiles
session.SaveProfile("session.json")   // cookies + localStorage
session.LoadProfile("session.json")

// Content distillation (5 levels)
session.Markdown()          // ~2-8KB compact markdown
session.ReadableText()      // ~1-4KB main content only
session.AccessibilityTree() // ~1-4KB semantic tree
session.ObserveWithBudget(500) // fit in ~500 tokens

Core Library

Gin-like Engine/Context/Group/HandlerFunc with middleware composition:

engine := browse.Default(browse.WithHeadless(true))
engine.MustLaunch()
defer engine.Close()

engine.Use(middleware.Stealth())
engine.Use(middleware.Retry(middleware.RetryConfig{MaxAttempts: 3}))
engine.Use(middleware.Timeout(30 * time.Second))

admin := engine.Group("admin", middleware.BasicAuth("admin", "secret"))
admin.Task("export", func(c *browse.Context) {
    c.MustNavigate("https://app.example.com/admin")
    table, _ := c.ExtractTable("#users")
    c.Set("data", table)
})

engine.RunGroup("admin")

Middleware

Category	Middleware
Resilience	`Retry`, `Timeout`, `CircuitBreaker`, `RateLimit`, `Bulkhead`
Auth	`BearerAuth`, `BasicAuth`, `CookieAuth`, `HeaderAuth`
Anti-detection	`Stealth` (10 patches: webdriver, plugins, WebGL, etc.)
Network	`BlockResources`, `WaitNetworkIdle`
Utilities	`ScreenshotOnError`, `SlowMotion`, `Viewport`

CLI

CLI defaults to visible browser (--headless to hide):

scout navigate <url>                  # page info as JSON
scout observe <url>                   # structured observation
scout markdown <url>                  # compact markdown
scout screenshot <url> [--output f]   # save screenshot
scout pdf <url> [--output f]          # save PDF
scout extract <url> <selector>        # extract text
scout eval <url> <expression>         # run JavaScript
scout form discover <url>             # discover form fields
scout frameworks <url>                # detect frameworks
scout watch <url> [--interval=5s]     # live-watch page changes
scout pipe <command> [selector]       # batch process URLs from stdin
scout record <url> [--output f]       # interactive recording → playbook
scout mcp serve                       # start MCP server
scout version                         # print version

Architecture

scout/
├── browse.go, engine.go, context.go   # Gin-like API
├── page.go, selection.go              # CDP page & element interaction
├── recorder.go                        # Video recording (screencast → MP4/GIF)
├── middleware/                        # stealth, resilience, auth, network
├── agent/                             # AI agent API (50+ methods)
│   ├── session.go                     # Session lifecycle, Navigate, Click, Type
│   ├── observe.go, diff.go            # Observe, ObserveDiff, cost estimation
│   ├── content.go                     # Markdown, ReadableText, AccessibilityTree
│   ├── form.go                        # DiscoverForm, FillFormSemantic, MatchFormField
│   ├── annotate.go                    # AnnotatedScreenshot, ClickLabel
│   ├── network.go                     # EnableNetworkCapture, CapturedRequests
│   ├── spa.go                         # DetectedFrameworks, ComponentState, GetAppState
│   ├── tabs.go                        # OpenTab, SwitchTab, CloseTab, ListTabs
│   ├── playbook.go                    # StartRecording, ReplayPlaybook, SavePlaybook
│   ├── interact.go                    # Hover, DragDrop, SelectOption, ScrollTo
│   ├── profile.go                     # CaptureProfile, ApplyProfile, SaveProfile
│   ├── selector.go                    # Playwright :text() selector translation
│   ├── budget.go                      # ObserveWithBudget, EstimateTokens
│   ├── nlselect.go                    # SelectByPrompt, fuzzy NL element matching
│   ├── batch.go                       # ExecuteBatch, sequential multi-action
│   ├── vision.go                      # HybridObserve, FindByCoordinates
│   ├── trace.go                       # StartTrace, StopTrace, action tracing
│   ├── iframe.go                      # SwitchToFrame, SwitchToMainFrame
│   └── vitals.go                      # WebVitals (LCP/CLS/INP)
├── internal/cdp/                      # WebSocket CDP client (context-aware)
├── internal/launcher/                 # Chrome process management
├── cmd/scout/                         # CLI + MCP server (66 tools)
└── docs/                              # Landing page (GitHub Pages)

License

MIT