Replace GitHub Copilot with Claude Code + Cline

A.R.C. Freshness Analysis

Tool Stack

1. 1
   Audit What Copilot Was Actually Doing for You

   Before switching, document how you used Copilot. There are three distinct modes: inline completions (tab-complete as you type), chat (ask questions, get code explanations), and PR summaries (GitHub-native). Each maps to a different replacement. Most developers only used inline completions — if that's you, the migration is straightforward. If you relied heavily on Copilot Chat inside VS Code, Cline replaces that. If you used Copilot's PR summary feature, that gap needs a separate tool (not covered in this blueprint).
2. 2
   Cancel Copilot and Set Up Claude Code CLI

   Cancel your GitHub Copilot subscription (Settings → Billing → Copilot). Then install Claude Code: it runs as a CLI tool in your terminal, not as an IDE plugin. It has access to your full repo, can read and edit files, run tests, and perform multi-step tasks from a single prompt. Install: npm install -g @anthropic-ai/claude-code. Authenticate with your Anthropic API key or Claude Pro subscription. Run claude in any repo directory to start.
3. 3
   Install Cline for In-Editor Assistance

   Cline is the VS Code extension that replaces Copilot's inline and chat modes — but it's model-agnostic, so you point it at Claude, not GitHub. Install from the VS Code marketplace (search "Cline"). In settings, configure it to use the Anthropic API (enter your API key) and set the model to claude-sonnet-4-6 for the best balance of speed and quality. Cline can read your open files, run terminal commands, and make multi-file edits — it's significantly more capable than Copilot Chat.
4. 4
   Learn the New Mental Model: Completion vs. Agent

   Copilot was a completion engine — it predicted your next line. Claude Code and Cline are agents — you give them a task and they execute it. The shift requires a different prompting style. Instead of typing and waiting for a suggestion, you describe the outcome: "Add input validation to the user registration form and write a test for the error case." Claude Code handles multi-file changes, runs your tests, reads error output, and iterates. This is a different workflow, not just a faster autocomplete.
5. 5
   Set Up Cost Controls and Usage Monitoring

   Unlike Copilot's flat subscription, Claude Code and Cline use API tokens — usage scales with how much you prompt. Set a monthly budget in your Anthropic dashboard (console.anthropic.com → Billing → Usage limits). For a typical developer using Claude Code several hours per day, expect $15–35/mo at API pricing, or use Claude Pro ($20/mo flat) which includes Claude Code usage. Track your spend for the first two weeks before settling on a plan.
6. 6
   Run A.R.C. Audit on Your New Coding Stack

   Full Stack Integrity Audit on your AI coding setup. Architecture (how well Claude Code + Cline integrate with your existing workflow and toolchain), Reliability (API uptime, context window limits, fallback behavior when the model makes mistakes), Context (momentum trajectory — are these tools likely to be the standard in 12 months?). Upgrade to unlock the full diagnostic.