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Agent Installation and Setup

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Alex: Welcome back. Today we're setting up accessibility agents across the tools people are most likely to use in this workshop: GitHub Copilot in VS Code, Claude Code, Gemini CLI, Claude Desktop, and Codex CLI.

Jamie: And before anybody worries that an agent is some separate mystery system, can we place it in the normal workflow?

Alex: Yes. An agent is a configured assistant you call while you work, usually from chat or a command line. It can help inspect code, draft changes, explain accessibility issues, or guide a test, but you still decide what to run, what to commit, and what evidence is ready to share.

Jamie: So the agent sits beside Git, GitHub, and VS Code. It doesn't replace the contribution workflow.

Appendix AA: Agent Installation & Setup Across All Platforms

Reference companion to: Chapter 19: Accessibility Agents | Appendix L: Agents Reference

Authoritative source: Accessibility Agents Repository | System Requirements

Installation, Configuration, and Troubleshooting for All Five Platforms

This appendix covers the step-by-step installation process for Accessibility Agents on GitHub Copilot (VS Code), Claude Code, Gemini CLI, Claude Desktop, and Codex CLI, plus system requirements, version checking, and troubleshooting for each platform.

Table of Contents

  1. System Requirements
  2. Version Checking Commands
  3. Platform-Specific Installation
  4. Post-Installation Verification
  5. Troubleshooting Compatibility Issues
  6. Keeping Tools Updated

1. System Requirements

Critical: Tool Currency

Accessibility Agents requires the latest versions of all tools. Older versions miss accessibility features, API capabilities, and bug fixes that agents depend on.

Version baseline (May 2026):

  • VS Code: 1.113 or later (stable or Insiders)
  • GitHub Copilot: Latest from VS Code Marketplace
  • Node.js: v18.0.0 or higher
  • Python: 3.8+
  • Operating Systems: Windows 10/11, macOS 10.15+, or Linux (Ubuntu 20.04+)

Operating System Requirements

OS Minimum Version Supported Architectures Notes
Windows Windows 10 Build 1909+ x64, Arm64 (preview) PowerShell 5.1+ required for command-line tools
macOS 10.15 (Catalina) Intel, Apple Silicon (M1/M2+) Requires command-line tools (run xcode-select --install)
Linux Ubuntu 20.04 LTS+ x64 (primary), ARM64 Debian, Fedora, RHEL derivatives supported

Per-Platform System Requirements

Platform Min RAM Disk Space Network Notes
GitHub Copilot (VS Code) 4 GB 2 GB available Required Inline suggestions, chat, Accessible View
Claude Code 4 GB 1 GB available Required Direct code generation and editing
Gemini CLI 2 GB 500 MB available Required Fast iteration, Google Search integration
Claude Desktop 4 GB 1 GB available Required Extended context windows, longer sessions
Codex CLI 2 GB 500 MB available Optional for local mode Experimental roles and TOML configuration

Required Tools by Platform

GitHub Copilot (VS Code)

VS Code 1.113+
  - GitHub Copilot extension (latest)
  - GitHub Copilot Chat extension (latest)
Node.js 18.0.0+ (for Playwright, axe-core, other tools)
Git 2.20+ (for repository operations)

Claude Code

Claude Code CLI (latest)
  - Installation: https://docs.anthropic.com/en/docs/claude-code
Claude subscription (Pro, Max, or Team)

Gemini CLI

Gemini CLI (latest)
  - Installation: https://github.com/google-gemini/gemini-cli
Google AI Studio API Key (free: https://ai.google.dev/)

Claude Desktop

Claude Desktop (latest)
  - Download: https://claude.ai/download
Claude subscription (Pro, Max, or Team)
MCP server configuration (`.mcp.json`)

Codex CLI

Codex CLI (latest)
  - Installation: npm install -g @codex-cli/core
Node.js 18.0.0+ required for npm

2. Version Checking Commands

Use these commands to verify your installed versions before starting.

GitHub Copilot (VS Code)

# Check VS Code version
code --version

# Verify GitHub Copilot extension is installed
code --list-extensions | grep -i copilot

# Check Node.js (used by Copilot and accessibility tools)
node --version
npm --version

# Verify Git
git --version

Expected output:

1.113.0 or higher (VS Code)
github.copilot
v18.0.0 or higher (Node.js)
v2.20.0 or higher (Git)

Claude Code

# Check Claude Code CLI version
claude code --version

# Verify you have an active subscription
claude code whoami

# Check Node.js
node --version

Gemini CLI

# Check Gemini CLI version
gemini --version

# Verify API key is configured
gemini config show

# Check Node.js
node --version

Claude Desktop

Check inside the application: Settings → About to see the current version.

Codex CLI

# Check Codex CLI version
codex --version

# Check Node.js
node --version
npm --version

3. Platform-Specific Installation

GitHub Copilot (VS Code) - Recommended for Most Workshops

Step 1: Install VS Code

  1. Download from code.visualstudio.com
  2. Run installer
  3. Open VS Code and verify it starts

Step 2: Install GitHub Copilot Extensions

  1. Open Extensions panel: Ctrl+Shift+X (or View → Extensions)
  2. Search for "GitHub Copilot"
  3. Install both:
    • GitHub Copilot (by GitHub)
    • GitHub Copilot Chat (by GitHub)
  4. Sign in with your GitHub account when prompted

Step 3: Install Node.js (for accessibility tools)

  1. Download from nodejs.org (v18 LTS or later)
  2. Run installer
  3. Verify: node --version and npm --version

Step 4: Clone Accessibility Agents Repository

cd /path/to/projects
git clone https://github.com/Community-Access/accessibility-agents.git
cd accessibility-agents

Step 5: Open in VS Code

code .

Step 6: Verify Agents Load

  1. Open Copilot Chat: Ctrl+Alt+I
  2. Type @ and look for agent autocomplete suggestions
  3. Verify .github/agents/ folder exists in the repository

Step 7: (Optional) Install Global Tools

# For accessibility scanning
npm install -g @axe-core/cli pa11y

# For Playwright testing
npm install -g playwright

Claude Code

Step 1: Install Claude Code CLI

npm install -g @anthropic-ai/claude-code

Step 2: Authenticate

claude code auth
# Follow the browser login flow

Step 3: Clone Repository

cd /path/to/projects
git clone https://github.com/Community-Access/accessibility-agents.git
cd accessibility-agents

Step 4: Run an Agent

claude code @daily-briefing morning briefing

Gemini CLI

Step 1: Install Gemini CLI

npm install -g @google/gemini-cli

Step 2: Set Up API Key

  1. Get API key from ai.google.dev

  2. Set environment variable:

    export GEMINI_API_KEY="your-api-key-here"

Step 3: Test Connection

gemini --version
gemini whoami

Step 4: Use with Accessibility Agents

gemini skill search accessibility-agents
gemini skill use community-access/accessibility-agents

Claude Desktop

Step 1: Download and Install

  1. Download from claude.ai
  2. Install application
  3. Open Claude Desktop

Step 2: Configure MCP Server

  1. Create or edit .mcp.json in your home folder (macOS/Linux: ~/.mcp.json, Windows: %USERPROFILE%\.mcp.json)

  2. Add the Accessibility Agents MCP server:

    {
  "mcpServers": {
    "accessibility-agents": {
      "command": "node",
      "args": ["/path/to/accessibility-agents/mcp-server/index.js"],
      "env": {
        "PORT": "3000"
      }
    }
  }
}

Step 3: Restart Claude Desktop

  1. Quit Claude Desktop completely
  2. Reopen Claude Desktop
  3. Verify MCP server connects (check logs)

Codex CLI

Step 1: Install Codex CLI

npm install -g @codex-cli/core

Step 2: Initialize Configuration

codex init
# Answer interactive setup questions

Step 3: Test Installation

codex --version
codex role list

Step 4: Use Accessibility Agents

codex role search accessibility
codex run @accessibility-lead

4. Post-Installation Verification

Verification Checklist

After installation, verify each platform is ready:

Check Command/Action Expected Result
Tools installed node --version, git --version v18+, v2.20+
Repository cloned ls -la accessibility-agents .github/agents/ folder exists
Agents discoverable Type @ in chat/CLI Autocomplete shows agent names
Network access Ping GitHub No firewall blocks
API keys valid (Claude/Gemini) claude code whoami / gemini whoami Authenticated successfully

Quick Test: Run One Agent

On GitHub Copilot (VS Code):

Open Chat (Ctrl+Alt+I) → Type: @daily-briefing morning briefing

On Claude Code:

claude code @daily-briefing morning briefing

On Gemini CLI:

gemini @daily-briefing morning briefing

On Claude Desktop: In chat input, type: @daily-briefing morning briefing

On Codex CLI:

codex run @daily-briefing morning briefing

If the agent responds with information, installation is successful.

5. Troubleshooting Compatibility Issues

GitHub Copilot (VS Code)

Issue Cause Solution
Agents not appearing after @ Extensions not installed or outdated Reinstall GitHub Copilot and GitHub Copilot Chat from VS Code Marketplace
"Cannot find agents" error .github/agents/ folder missing Clone the full accessibility-agents repository; do not copy files manually
Chat not working Copilot not signed in Click Copilot Chat panel → "Sign in with GitHub"
VS Code 1.113+ required notice Running older VS Code Update: Help → Check for Updates (or auto-install in settings)
Slow responses Network latency or token limit Check internet connection; restart VS Code; check OpenAI quota

Reset Copilot (if stuck):

# Delete VS Code cache
rm -rf ~/.config/Code/Cache  # macOS/Linux
rmdir /s %APPDATA%\Code\Cache  # Windows PowerShell

# Restart VS Code

Claude Code

Issue Cause Solution
"Not authenticated" error API key expired or invalid Run claude code auth and re-login
Agent not found CLI version mismatch Update: npm update -g @anthropic-ai/claude-code
Slow generation Large context or complex task Break task into smaller steps; try simpler prompt

Gemini CLI

Issue Cause Solution
API key error GEMINI_API_KEY not set export GEMINI_API_KEY="your-key" (on Linux/macOS) or set in Windows env vars
"Rate limit exceeded" Too many requests Wait 60 seconds; Gemini CLI has a 15 requests/minute limit
Model not found Old CLI version Update: npm update -g @google/gemini-cli

Claude Desktop

Issue Cause Solution
MCP server not connecting .mcp.json syntax error or wrong path Validate JSON syntax; verify file path; check server logs
"Port already in use" Another process on port 3000 Change port in .mcp.json to 3001 or find/kill process on 3000
Subscription required Free Claude account Upgrade to Claude Pro or Team subscription

Codex CLI

Issue Cause Solution
Role not found Accessibility Agents not installed as role Run codex init and add the agents GitHub URL during setup
TOML config syntax error Invalid TOML file Validate with online TOML validator; check indentation

Universal Troubleshooting

  1. Verify internet connection:

    ping github.com

  2. Check firewall/proxy:

    • Ensure ports 443 (HTTPS), 3000 (MCP) are not blocked
    • If behind proxy, configure Git: git config --global http.proxy [proxy-url]

  3. Clear caches and restart:

    • VS Code: Reload Window (Ctrl+Shift+P → "Reload Window")
    • CLI tools: Reinstall latest version

  4. Check subscription/quota:

    • GitHub Copilot: Requires active subscription (Free, Pro, or Team)
    • Claude Code: Requires Claude Pro/Team/Enterprise
    • Gemini: Free tier available but with rate limits

  5. Review logs:

    • VS Code: Help → Toggle Developer Tools → Console tab
    • Claude Desktop: Application menu → View Logs
    • CLI: Add --debug flag to commands

6. Keeping Tools Updated

Why Updates Matter

  • New accessibility features in platforms enable better agent behavior
  • Bug fixes prevent silent failures and context loss
  • API improvements improve performance and reliability
  • Security patches protect your data and credentials

Update Schedules by Platform

Platform Release Cycle Check Method
VS Code Monthly (stable), weekly (Insiders) Help → Check for Updates
GitHub Copilot Monthly VS Code Extensions view → GitHub Copilot → Update
Node.js Quarterly (LTS) npm outdated -g
Claude Code As needed npm outdated -g @anthropic-ai/claude-code
Gemini CLI As needed npm outdated -g @google/gemini-cli
Claude Desktop Monthly Application menu → Check for Updates

Update Commands

GitHub Copilot (VS Code):

# Update VS Code
code --update

# Update extensions
# Use VS Code UI: Extensions → click update on GitHub Copilot extensions

All npm-based tools (one command):

npm update -g

Individual tool updates:

npm update -g @anthropic-ai/claude-code
npm update -g @google/gemini-cli
npm update -g @codex-cli/core

Verify current versions after update:

code --version
node --version
claude code --version
gemini --version

Update Best Practices

  1. Update before starting a new project: Ensure latest fixes and features are available
  2. Keep Node.js current: Many CLI tools depend on Node.js features
  3. Check compatibility notes: Major version updates may introduce breaking changes
  4. Test in a branch: After updating, test one agent before relying on it
  5. Subscribe to release notes: Watch Accessibility Agents releases for new features and requirements

Learning Cards: Installation & Setup

Screen reader users
  • Installation steps are presented in sequence; follow them in order and do not skip any step
  • After installation, the quick verification test (running @daily-briefing) confirms setup is working -- if it produces a response, you are ready to proceed
  • Each platform has its own section; use headings (H key in browse mode) to jump to the section for your chosen platform
  • Troubleshooting tables are organized by platform; navigate to your platform's row for solutions
Low vision users
  • The system requirements table can be magnified independently; zoom in on the "Minimum Version" and "Notes" columns if you need specific details
  • Installation commands are in code blocks with clear context; copy the command that matches your platform
  • After each installation step, there is a verification check (run node --version, etc.) -- write down the output so you can confirm success
  • The troubleshooting section is organized as a decision tree by platform; skip to your platform's section
Sighted users
  • Skim the System Requirements section to choose your target platform
  • Follow the numbered steps in the Platform-Specific Installation section for your platform
  • Run the verification commands after each step to confirm success before moving to the next step
  • If something does not work, jump to Troubleshooting and find your issue in the table for your platform

References

Authoritative Sources

Use these official references when you need the current source of truth for facts in this chapter.

Section-Level Source Map

Use this map to verify facts for each major section in this file.