Cline — The VS Code Agent That Puts You Back in Control

Cline (formerly Claude Dev) is a VS Code extension that turns Claude — or any other capable LLM — into an autonomous coding agent. Not autocomplete. Not chat. An agent that reads your files, runs terminal commands, controls a browser, and makes multi-file edits in response to high-level instructions.

The key design decision that sets Cline apart: it asks for your approval before taking each consequential action. That single choice makes the difference between a tool you’d trust for production tasks and one you’d only use in a throwaway sandbox.

How It Works

Install the Cline extension, configure your API key (Claude, OpenAI, Gemini, Bedrock — your choice), and describe a task:

“Add JWT authentication to the Express API. Create middleware, update the user routes, add tests, and make sure the existing tests still pass.”

Cline will:

1. Explore relevant files using its understanding of your project structure
2. Show you a plan before touching anything (in Plan mode)
3. Make file edits — showing you diffs before applying
4. Run terminal commands (with your approval each time)
5. Check test output and iterate if they fail

Throughout, you approve or reject each step. You can edit Cline’s proposed changes before accepting. You can roll back to any checkpoint if it goes in the wrong direction.

The Approval Model

The approval-first approach is Cline’s defining characteristic. Before Cline runs npm install, creates a file outside your project, or executes any terminal command, it pauses and shows you what it wants to do.

This is different from fully autonomous agents that execute first and report back. It’s slower — but for tasks that involve real infrastructure, databases, or production code, it’s the right tradeoff.

You can configure auto-approve for specific action types (read-only file operations, for example) while keeping approvals on for anything destructive. The granularity is good.

Plan Mode

Plan mode adds a dedicated planning step before execution. Cline reads the relevant code, thinks through the task, and presents a structured plan — which files it will touch, what it will change, what commands it might run — before doing anything.

You review the plan. You can edit it, reject it, or ask Cline to revise. Only once you approve does execution begin.

For complex tasks, this dramatically improves outcomes. The model reasons better when planning is separated from doing, and you catch misunderstandings before they result in 30 edited files that miss the point.

MCP Integration

Cline has one of the deepest MCP integrations of any IDE tool. It can:

• Use MCP servers — connect to filesystem, database, browser, or any other MCP tool
• Act as an MCP server — expose Cline’s capabilities to other agents or tools

This means Cline can slot into larger agentic systems. You can orchestrate Cline alongside other MCP-aware tools, or use it as a standalone agent that reaches out to MCP services for data it needs.

Checkpoints

Every meaningful state change in a Cline session creates a checkpoint. If the agent goes sideways — wrong interpretation, bad refactor, deleted the wrong file — you can restore to any previous state in one click.

This matters more than it sounds. Without checkpoints, mistakes in long autonomous sessions mean manually reverting git history or losing work. With checkpoints, experimentation is safe.

Model Configuration

Cline works with any LLM through a range of provider integrations:

• Anthropic direct — Claude Sonnet 4.6 / Opus 4.6, Claude Haiku 4.5
• OpenAI — GPT-5.4, o1, o3-mini
• Google — Gemini 3.1 Flash, Gemini Pro
• AWS Bedrock / GCP Vertex — for enterprise deployments with managed credentials
• Ollama / LM Studio — local models for air-gapped or cost-free use cases

The choice of model significantly affects both capability and cost. Sonnet 4.6 produces the best results for complex tasks; Haiku 4.5 works for simpler edits at 10-20x lower cost.

Cline vs GitHub Copilot

Copilot is an autocomplete tool with some chat capability. Cline is an autonomous agent. If you want suggestions as you type, Copilot. If you want an agent that executes tasks end-to-end, Cline.

Cline vs Cursor

Cursor is a full IDE fork with integrated AI everywhere — autocomplete, Composer, chat. Cline is an extension you add to VS Code (or Cursor itself). They’re not mutually exclusive — many developers run Cline inside Cursor and get both: Cursor’s autocomplete plus Cline’s autonomous task execution.