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Claude Code Integration

This guide shows how to integrate FGP daemons with Claude Code, Anthropic's CLI for Claude.

Why FGP with Claude Code?

Claude Code uses MCP (Model Context Protocol) for tool integrations. MCP stdio servers have cold-start overhead on first use (~1-2 seconds). FGP daemons stay warm across sessions.

Key benefits:

Scenario MCP Behavior FGP Behavior Improvement
First tool call ~1-2s cold start Instant (daemon warm) 10-20x faster
Subsequent calls ~25-50ms warm ~2-8ms 3-12x faster
New Claude session Cold start again Still warm Consistent

Note: Claude Code keeps MCP servers running within a session after first use. FGP's advantage is eliminating cold starts and providing faster warm calls.

Setup

1. Install FGP

curl -fsSL https://raw.githubusercontent.com/fast-gateway-protocol/fgp/master/install.sh | bash

This installs the fgp CLI and browser daemon to ~/.fgp/bin/.

2. Start the Browser Daemon

# Start in headless mode (default)
fgp start browser

# Or with visible browser for debugging
fgp start browser --no-headless

3. Configure Claude Code MCP Bridge

Add to your Claude Code settings (~/.claude.json or project .claude/settings.json):

{
  "mcpServers": {
    "fgp": {
      "command": "fgp",
      "args": ["mcp-bridge"],
      "env": {}
    }
  }
}

The MCP bridge translates MCP protocol to FGP protocol, so Claude Code can use FGP daemons like any MCP server.

Usage

Once configured, Claude Code can use FGP tools directly:

Browser Automation

User: Navigate to GitHub and search for "rust async"

Claude: I'll use the FGP browser daemon to do this.

[Calls fgp__browser__open with url="https://github.com"]
[Calls fgp__browser__fill with selector="input[name=q]" value="rust async"]
[Calls fgp__browser__press with key="Enter"]
[Calls fgp__browser__snapshot to see results]

Available Tools

Tool Description
fgp__browser__open Navigate to URL
fgp__browser__snapshot Get ARIA accessibility tree
fgp__browser__screenshot Capture PNG
fgp__browser__click Click element
fgp__browser__fill Fill input field
fgp__browser__press Press key
fgp__browser__select Select dropdown option
fgp__gmail__inbox List inbox messages
fgp__gmail__search Search emails
fgp__gmail__send Send email
fgp__calendar__today Today's events
fgp__calendar__upcoming Upcoming events
fgp__calendar__free_slots Find available times
fgp__github__repos List repositories
fgp__github__issues List issues
fgp__github__notifications Get notifications

Skill-Based Integration

For more control, create a Claude Code skill that wraps FGP commands.

Create the Skill

mkdir -p ~/.claude/skills/fgp-browser

Create ~/.claude/skills/fgp-browser/skill.md:

---
name: fgp-browser
description: Fast browser automation via FGP daemon
tools: [Bash]
---

# FGP Browser Skill

Use the FGP browser daemon for fast browser automation. The daemon must be running.

## Starting the daemon

\`\`\`bash
fgp start browser
\`\`\`

## Available commands

\`\`\`bash
# Navigate
fgp call browser open "https://example.com"

# Get page structure (returns ARIA tree with element refs like @e1, @e2)
fgp call browser snapshot

# Click element (by CSS selector or @ref)
fgp call browser click "button.submit"
fgp call browser click "@e5"

# Fill form field
fgp call browser fill "input#email" "user@example.com"

# Take screenshot
fgp call browser screenshot /tmp/page.png

# Press key
fgp call browser press "Enter"
\`\`\`

## Performance

FGP browser is 3-12x faster than warm Playwright MCP (2-8ms vs 25-30ms), and eliminates ~1-2s cold start.

Use the Skill

User: /fgp-browser Navigate to HN and screenshot the front page

Claude: [Invokes skill, runs fgp commands]

Direct Socket Communication

For advanced use cases, communicate directly with FGP sockets:

# Send NDJSON request
echo '{"id":"1","v":1,"method":"browser.open","params":{"url":"https://example.com"}}' | \
  nc -U ~/.fgp/services/browser/daemon.sock

Response: 

{"id":"1","ok":true,"result":{"title":"Example Domain"},"meta":{"server_ms":8.2}}

Multi-Session Workflows

FGP supports multiple isolated browser sessions for parallel workflows:

# Create sessions
fgp call browser session.new --name "gmail"
fgp call browser session.new --name "github"

# Work in parallel
fgp call browser open "https://gmail.com" --session "gmail" &
fgp call browser open "https://github.com" --session "github" &
wait

# Each session has isolated cookies, localStorage, etc.

Troubleshooting

Daemon not responding

# Check status
fgp status

# View logs
tail -f ~/.fgp/services/browser/daemon.log

# Restart daemon
fgp stop browser && fgp start browser

Chrome not found

FGP looks for Chrome/Chromium in standard locations. Set explicitly:

export CHROME_PATH="/path/to/chrome"
fgp start browser

Permission denied on socket

# Check socket permissions
ls -la ~/.fgp/services/browser/daemon.sock

# Remove stale socket
rm ~/.fgp/services/browser/daemon.sock
fgp start browser

Performance Comparison

Real-world benchmark (4-step workflow: navigate, snapshot, click, snapshot):

Tool Total Time Cold Start Per-Call (warm)
FGP Browser ~50ms 0ms ~8ms
Playwright MCP (warm) ~120ms 0ms (already warm) ~25-30ms
Playwright MCP (cold) ~2,100ms ~1,000ms ~25-30ms

Key takeaways: - FGP is 3-12x faster for warm-to-warm comparisons - FGP eliminates cold-start delays on first call and new sessions - For multi-step workflows, the consistent low latency compounds

Next Steps