Cline

Overview

Cline is an open-source development agent engineered to read and modify entire codebases, run terminal commands, control the browser for testing, and integrate external tools. It can be used as an extension in major code editors, as a native desktop application, or directly from the command line.

Its workflow centers on separating planning (Plan mode) from execution (Act mode). Before altering the project, the agent analyzes relevant files and proposes an implementation strategy. During the action stage, every code edit or terminal command creates a checkpoint with a visual diff, allowing developers to approve actions step by step, enable auto-approval for trusted routines, or revert changes with a single click.

Because it does not lock users into a single AI vendor, developers can bring their own API keys (BYOK) from cloud providers, run local models on their own machines, or purchase inference directly through the platform account. For engineering teams and continuous automation, the ecosystem also includes a CLI for scripts and CI/CD pipelines, a web Kanban board to coordinate parallel agents, and an SDK to embed the agent engine into custom applications.

Features and functionality

• Plan and Act modes: separates architectural alignment and implementation strategy from hands-on code execution.
• Coordinated multi-file editing with checkpoints: applies changes across multiple files while maintaining type and import consistency, offering in-editor diffs and instant per-step rollback.
• Interactive terminal execution: runs development servers, test suites, and scripts in the terminal, reading real-time output to diagnose and fix errors.
• Project rules and Skills: uses .clinerules files, reusable skills, and hooks to enforce repository coding standards, architecture guidelines, and deployment conventions.
• Model and provider freedom: works with your own API keys from various cloud providers, OpenAI-compatible endpoints, local models via Ollama or LM Studio, and built-in platform inference.
• Extensibility via MCP and SDK: connects Model Context Protocol (MCP) servers to access databases, APIs, and infrastructure, and provides an SDK for building custom agents.

Use cases

• Understanding and navigating legacy projects: map dependencies, directory structures, and execution flows across large codebases using @ context mentions.
• Multi-file refactoring: update interfaces, migrate libraries, and adjust interdependent modules with visual diff tracking and linter validation.
• End-to-end feature development: plan the solution in Plan mode, approve file creation, and run automated tests in the terminal until the expected behavior is verified.
• Terminal and CI/CD automation: use the CLI in scripts, scheduled jobs, and continuous integration pipelines for recurring code reviews, diagnostics, and maintenance.
• Parallel task orchestration: use the Kanban board or agent teams to split tasks across independent worktrees with organized history.