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Cline
Open-source autonomous coding agent for VS Code that runs on your own model API keys.
Free plan Claimed API Self-hosted
Toolglade’s take
Cline is one of the strongest open-source coding agents available, and its BYOK design means total cost transparency, but you take on model billing yourself and heavy use of frontier models can add up fast.
About Cline
Cline is a free, open-source autonomous coding agent for VS Code that plans and executes multi-step development tasks with human approval at each step. It has no subscription and no built-in model billing; instead you connect your own API key (BYOK) from providers like Anthropic, OpenAI, Google, or a local Ollama model and pay for token usage directly. With 5M+ installs and MCP extensibility, it is a leading open-source alternative to closed AI IDEs.
Cline is an open-source AI coding agent that runs as an extension in VS Code (and other editors), with a CLI and an embeddable SDK added in 2026. It uses a Plan & Act workflow: Plan Mode analyzes a request and proposes an approach without touching files, then Act Mode executes it by editing code, running commands, and completing multi-step tasks. Every file edit, terminal command, and browser action passes through an approval gate, keeping a human in the loop so the agent rarely takes destructive actions without explicit sign-off. With more than 5 million installs and 58,000+ GitHub stars by early 2026, it became one of the fastest-growing open-source projects in GitHub's 2025 Octoverse report. The defining trait of Cline is its bring-your-own-key (BYOK) model. The extension itself is completely free and open-source, but it has no built-in inference; instead you connect your own API key from providers such as Anthropic, OpenAI, Google Gemini, OpenRouter, AWS Bedrock, DeepSeek, xAI, Mistral, or a local model via Ollama or LM Studio, and you pay those providers directly for token usage. This gives full transparency and control over cost and model choice, plus deep extensibility through an MCP marketplace, project Rules, and Skills, but it also means the running cost depends entirely on which model you pick and how much you use it.
TL;DR
Cline is a free, open-source autonomous coding agent for VS Code with 5M+ installs. It plans and executes multi-step coding tasks with human approval at every step. It has no subscription; instead it uses a bring-your-own-key (BYOK) model where you connect your own provider API key and pay for tokens directly. It is one of the leading open-source alternatives to closed AI IDEs like Cursor.
Company overview
Cline is an open-source AI coding agent created by Saoud Rizwan and Nik Pash and developed by Cline (the company behind it). It became the fastest-growing AI open-source project in GitHub's 2025 Octoverse report, growing from about 1M installs in March 2025 to 5M by January 2026, with 58,000+ GitHub stars. The company raised roughly $32M across seed and Series A rounds in July 2025, led by Emergence Capital and Pace Capital, and Sacra estimated it reached about $5M ARR by August 2025.
The product spans a VS Code extension, a CLI, and an embeddable SDK (launched May 2026) built on a modular agent runtime. Despite being open-source and free, the company monetizes through optional infrastructure and enterprise offerings while the core agent remains BYOK.
Product features
Cline's core is a Plan & Act workflow: Plan Mode proposes an approach without editing files, and Act Mode executes it by editing code, running terminal commands, and completing multi-step tasks. Every action passes an approval gate for human-in-the-loop control. It supports 30+ model providers including Anthropic, OpenAI, Google Gemini, AWS Bedrock, Azure OpenAI, OpenRouter, DeepSeek, xAI, Mistral, and local models via Ollama and LM Studio.
Extensibility comes from full MCP support and an MCP marketplace, plus Rules and Skills that let teams define conventions and task-specific behavior. Multi-model routing can send planning to a stronger model and editing to a cheaper one to control cost.
Target market
Cline targets professional and hobbyist software developers who work in VS Code and want an autonomous, transparent coding agent without a locked-in subscription. It especially appeals to engineers who want to control their own model spend and provider choice, privacy-conscious teams that need local or self-hostable options, and developers who want MCP-based extensibility. It is less suited to non-technical users or teams wanting a fully packaged, seat-managed collaboration product.
Buyer personas
End users
Software developers and engineers using VS Code who want an autonomous agent to build features, refactor, and debug across their codebase while keeping control over model choice and cost.
Buyers
Since the tool is free and BYOK, there is no traditional purchase; the effective spend decision sits with individual developers or engineering leads who approve model provider budgets and API key usage.
Key influencers
Engineering leads, open-source advocates, and platform or DevEx teams who evaluate agent tooling, MCP integrations, and privacy or self-hosting requirements.
Ideal customer profile
Technical individuals or teams already working in VS Code who want a powerful open-source coding agent, value cost transparency and provider flexibility, and are comfortable managing their own model API keys or running local models.
Funding & performance
Approximately $32M raised across combined Seed and Series A rounds in July 2025, led by Emergence Capital and Pace Capital.
Pros & cons
Pros
- Completely free and open-source with no subscription to the tool itself
- BYOK model gives full transparency and control over model choice and cost
- Supports 30+ providers plus local models for privacy
- Human-in-the-loop approval gates prevent destructive actions
- Plan & Act workflow separates strategy from execution
- Extensible via MCP marketplace, Rules, and Skills
Cons
- You pay for model tokens yourself, and costs can climb with frequent frontier-model use
- Requires setting up and managing your own API keys
- No built-in team collaboration or hosted account features
- Approval-gate workflow can feel slower than fully automated agents
- Quality and cost depend heavily on which model you choose
Pricing plans
Open Source
Free
- free extension
- bring your own model API key
- pay model providers directly
Key features
API
Self-hosted
Multi-language
Integrations
VS Code, Anthropic, OpenAI, OpenRouter, MCP
Input types
text, code
Output types
code, text
Best For
autonomous coding in VS Code, developers who want to control model costs, extending an agent with MCP tools, privacy-conscious teams using local models
Compare key features
View all alternatives →Feature
Cline
Aider
GitHub Copilot
Pricing
Free
Free
Freemium
Free plan
Yes
Yes
Yes
Free trial
No
No
No
API
Yes
No
No
Self-hosted
Yes
Yes
No
Team support
No
No
Yes
Frequently asked questions
Is Cline free?+
Yes. Cline is a free, open-source extension with no subscription or license fee. The only cost is the model usage you pay your own API provider directly, since Cline uses a bring-your-own-key model. If you run a local model with Ollama or LM Studio, it can be entirely free.
Cline vs Cursor: what's the difference?+
Cursor is a closed-source AI IDE with a paid subscription that bundles model access into monthly plans. Cline is an open-source agent that runs inside your existing VS Code and is free to install, but you supply your own model API key and pay providers directly. Cline offers more transparency and provider choice; Cursor offers a more packaged, all-in-one experience.
What are the best Cline alternatives?+
Popular open-source alternatives include Roo Code, Kilo Code, and Aider, which share the BYOK and agentic approach. Closed alternatives include Cursor, GitHub Copilot, and Windsurf. Roo Code and Kilo Code are forks or close cousins of Cline and are the most direct comparisons.
How much does Cline cost to run?+
The extension itself is free. Your running cost is whatever your chosen model provider charges for token usage. Using a frontier model like Claude for heavy, multi-file tasks can add up quickly, while cheaper models or a local Ollama model can reduce or eliminate cost. Cline's Plan/Act and multi-model routing can help keep spend down.
Does Cline support MCP?+
Yes. Cline has full Model Context Protocol (MCP) support and an MCP marketplace, letting you connect it to external tools, services, and custom workflows. This is one of its core extensibility features alongside project Rules and Skills.
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