Cline
Cline is the original open-source VS Code extension that gives Claude (or any LLM you configure) autonomous access to the terminal, filesystem, and browser to complete complex coding tasks. Cline is the upstream of Roo Code and Kilo Code, free, bring-your-own-key, and one of the most popular VS Code agents in the ecosystem. Released January 2024 and actively maintained.
Overview
Open-source VS Code extension that gives Claude or other LLMs autonomous access to the terminal, filesystem, and browser to complete complex coding tasks.
Compare Cline side-by-side with other CLI, IDE, cloud, and framework agents on pricing, model coverage, and release cadence.
Best LLMs for this agent
Cline is bring-your-own-key, and Claude Sonnet 4.6 is the default and most common model users run for autonomous VS Code agent work.
Claude Opus 4.6 is the Cline pairing for harder reasoning tasks when the agent needs more careful planning.
GPT-5 is a supported alternative when teams prefer OpenAI routing for Cline's terminal, filesystem, and browser workflows.
DeepSeek V4 Pro is the cost-sensitive open-weights option for Cline users who still want strong coding performance.
Gemini 3 is available through Cline's model-agnostic configuration for teams already standardized on Google's model stack.
Pricing and Provider Comparison
Hosted agents expose plan pricing. Bring-your-own-key agents pass the main cost through the model provider route you configure.
Agent access tiers
| Tier | Price | Includes |
|---|---|---|
| Free | Free | Open source, use your own API keys |
Provider routes for recommended models
| Model | Provider | Input / 1M | Output / 1M | Notes |
|---|---|---|---|---|
| Claude Sonnet 4.6 | Anthropic | $3.00 | $15.00 | Batch pricing listed; Cache reads listed |
| Claude Opus 4.6 | Anthropic | $5.00 | $25.00 | Batch pricing listed; Cache reads listed |
| GPT-5 | OpenAI API | $1.25 | $10.00 | Batch pricing listed; Cache reads listed |
| DeepSeek V4 Pro | DeepSeek Platform | $0.435 | $0.87 | Cache reads listed |
| Gemini 3 Pro | GCP Vertex AI | $1.25 | $5.00 | Published token price |
Featured Model Specs
| Model | Lab | Released | Context | Reasoning | Openness |
|---|---|---|---|---|---|
| Claude Sonnet 4.6 | Anthropic | 2026-02-17 | 1m | Yes | Proprietary |
| Claude Opus 4.6 | Anthropic | 2026-02-05 | 1m | Yes | Proprietary |
Model Compatibility Matrix
| Model | Lab | Default | Access tier | Notes |
|---|---|---|---|---|
| Claude Sonnet 4.6 | Anthropic | Yes | Pro | — |
| Claude Opus 4.6 | Anthropic | No | Pro | — |
Underlying Models
Compare to Similar Harnesses
FAQ
Which LLM does Cline use?
Cline is bring-your-own-key. The default - and the model most users run - is Claude Sonnet 4.6, with Claude Opus 4.6 for harder reasoning. Cline also supports GPT-5, DeepSeek V4, Gemini 3, and any OpenAI-compatible endpoint.
Is Cline free?
Yes. Cline is open source under a permissive license. You pay only for the LLM API tokens it consumes against the provider you choose.
How does Cline differ from Cursor?
Cline is a VS Code extension you add to your existing editor; Cursor is a forked editor with built-in agent features. Cline keeps you on stock VS Code and gives you full control over which LLM runs the agent.
Does Cline have agent mode?
Cline operates as an autonomous agent by default - it can read files, edit them, run terminal commands, and follow chained tasks without per-step prompting. Approval gates can be configured for safety.
What's the difference between Cline, Roo Code, and Kilo Code?
Roo Code and Kilo Code are forks of Cline. Roo adds extra agent modes; Kilo prioritizes reliability and team features. Cline is the upstream and the most widely deployed.