Cline

Cline is an open-source AI coding agent by Cline, available as a VS Code extension and CLI on macOS, Windows, and Linux. It executes end-to-end coding tasks (planning, file edits, terminal commands, browser automation) with human-in-the-loop approval at every step.

With 59,000+ GitHub stars on its Apache-2.0 licensed repo and active v3.x releases through 2026, Cline is the leading open-source alternative to closed agents like Cursor and GitHub Copilot.

What Cline does:

• •Plan/Act dual-mode workflow assign one model (Claude Opus 4.7) to plan the architecture, then a faster cheaper model (DeepSeek, Gemini Flash) to execute the plan. Plan mode never edits files; Act mode does the writes.
• •BYOK any model provider bring your own API keys for Claude, OpenAI, Gemini, DeepSeek, Groq, OpenRouter, or local Ollama. Cline takes zero margin on inference; you pay the upstream provider directly.
• •1,000+ MCP server marketplace connect to Stripe, GitHub, Supabase, Postgres, Brave Search, Browser Use, Firecrawl, and the rest of the Model Context Protocol ecosystem during a task.
• •Built-in browser automation Cline opens a real Chromium instance to test your app, fill forms, click around, and verify UI changes as part of multi-step tasks. No separate Playwright setup needed.
• •Context-aware codebase reading Cline reads your files, imports, and existing patterns before writing anything, so suggestions match your style rather than producing generic boilerplate.
• •Human-in-the-loop approvals by default Cline asks before every file write, terminal command, or browser action. Auto-approve is configurable per-action-type so you choose where to remove friction.
• •Self-hostable and open-source the Apache-2.0 license means you can fork, audit, run on air-gapped infrastructure, or ship Cline embedded in a paid product without licensing fees.
• •JetBrains plugin (Teams plan) developers on IntelliJ, WebStorm, PyCharm get the same Plan/Act workflow inside JetBrains IDEs as part of the Teams subscription.
• •Cline Kanban board multi-agent orchestration board lets you queue and parallelize tasks across the same workspace, useful for large refactors or feature branches.
• •Lifecycle hooks hook into pre-task, post-task, file-write, and command-run events to run linters, formatters, or custom validation before Cline commits to a change.

Pricing:

• •Free $0/mo: full open-source VS Code extension and CLI with BYOK model support. Pay only the upstream API provider for tokens used. Forever free for individuals.
• •Teams $20/user/mo: shared team settings, RBAC, JetBrains plugin, audit logs, and centralized billing. First 10 seats are free.
• •Enterprise custom pricing/yr: SSO, SLAs, dedicated support, on-premise deployment guidance, and procurement contracts.

Limitations:

• •VS Code (and Teams JetBrains) only Cline does not run in Vim, Neovim, Emacs, Sublime, or as a standalone web app. Developers on other editors are locked out unless they switch.
• •Inference costs are unpredictable BYOK is great for transparency but a heavy day with Claude Opus on a complex refactor can rack up $5-15 in API fees. Power users routinely spend $200-500/month on inference, on top of the free Cline extension.
• •No autocomplete or ghost text Cline is a task-completion agent, not an inline copilot. Many developers run Continue or GitHub Copilot alongside Cline just for tab-completion suggestions.
• •Rate-limit pauses on long tasks when you hit Anthropic or OpenAI rate limits during a complex multi-file change, Cline pauses or fails silently and needs a manual restart, which is friction on big jobs.
• •Context-window pressure on large codebases on projects with hundreds of files, Cline's context fills fast, it may forget earlier decisions, and re-briefing mid-task burns more paid API tokens.