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cline
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Table of Contents
Cline
Cline is a model-agnostic autonomous coding agent that operates directly inside VS Code and the terminal1). It can create and edit files, execute commands, use a browser, and interact with any API — all with explicit user approval at every step. With over 59,000 GitHub stars, Cline is one of the most popular open-source AI coding assistants available.
GitHub: cline/cline | Website: https://cline.bot
Key Features
- Plan and Act Modes — Plan Mode performs read-only analysis; Act Mode executes changes with full tool access
- Model Agnostic — Works with Anthropic, OpenAI, Google Gemini, AWS Bedrock, Azure, Groq, Cerebras, and local models via Ollama or LM Studio
- File Management — Creates and edits files with diff views, auto-fixes linter/compiler errors, tracks changes in VS Code Timeline
- Command Execution — Runs terminal commands in real-time, monitoring output for package installs, builds, deploys, and tests
- Browser Integration — Launches headless browser to click, type, scroll, capture screenshots and console logs for debugging
- Checkpoints — Takes workspace snapshots at each step for easy comparison and rollback
- MCP Integration — Extends capabilities through Model Context Protocol tools and a built-in MCP Marketplace2)
- Rules System — Global and workspace-specific rules for consistent AI behavior across teams
- Cost Tracking — Monitors token usage and API costs per task and per request
Architecture
Cline is built in TypeScript as a VS Code extension with a modular architecture:
- Agent Loop — Iterative planning and execution cycle with human-in-the-loop approval
- Tool System — File operations, terminal execution, browser automation, and MCP bridges
- Context Providers — @url, @problems, @file, @folder for flexible context injection
- Checkpoint Engine — Git-based workspace snapshots for state management and rollback
- API Abstraction — Unified interface supporting 10+ LLM provider APIs
Usage Example
# Install via VS Code Extensions marketplace # Search for "Cline" (formerly "Claude Dev") # Or use via CLI npx cline "add authentication middleware to the Express app" # In VS Code, open the Cline sidebar and type: # "Refactor the database module to use async/await" # Cline will plan, show diffs, and ask for approval
How It Works
graph TD
A[User Task Description] --> B{Mode Selection}
B -->|Plan Mode| C[Read-Only Analysis]
C --> D[Action Plan Generation]
D --> E[User Review]
E --> F{Approved?}
F -->|Yes| G[Switch to Act Mode]
F -->|No| C
B -->|Act Mode| G
G --> H[Tool Selection]
H --> I[File Create/Edit]
H --> J[Terminal Command]
H --> K[Browser Action]
H --> L[MCP Tool Call]
I --> M[Show Diff for Approval]
J --> M
K --> M
L --> M
M --> N{User Approves?}
N -->|Yes| O[Apply Change]
N -->|No| P[Revise Approach]
O --> Q[Checkpoint Snapshot]
Q --> R{Task Complete?}
R -->|No| H
R -->|Yes| S[Summary Report]
P --> H
Notable Characteristics
- Originally released as “Claude Dev” by Saoud Rizwan, later renamed to Cline to reflect model-agnostic support.3)
- Pioneered the human-in-the-loop approval pattern for AI coding agents in IDEs
- Forked into Roo Code which added multi-mode agent architecture
- Over 6,000 forks on GitHub, one of the most forked AI coding tools
- Active community with regular releases and extensive marketplace of MCP extensions4)
References
See Also
- Roo Code — Multi-mode agent forked from Cline
- Gemini CLI — Google's terminal agent
- Trae Agent — ByteDance's research-friendly CLI agent
- Devon — Open-source pair programmer with TUI
- Droid (Factory) — Factory's multi-model CLI coding agent
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