Key takeaways
- 63K+ GitHub stars and ~4.3M VS Code installs as of June 2026 — the leading open-source AI coding extension, now backed by $32M from Emergence and Pace
- Human-in-the-loop by design — approve every file change and terminal command before execution
- No longer VS Code-only — CLI 2.0 (headless, CI/CD, parallel agents), JetBrains early access, and an SDK shipped since early 2026
FAQ
What is Cline?
Cline is an open-source VS Code extension that provides autonomous AI coding capabilities with human approval for every file change and terminal command.
Is Cline free?
Yes, Cline is free and open source (Apache 2.0). You bring your own API keys for providers like Anthropic, OpenAI, or OpenRouter, or use Cline's usage-based provider — either way you pay only for inference.
How is Cline different from GitHub Copilot?
Copilot is autocomplete-focused; Cline is an autonomous agent that can create files, run commands, and use the browser — with your approval at each step.
What's the relationship between Cline and Roo Code?
Roo Code forked from Cline in late 2024, but shut down its extension in May 2026 to pursue cloud agents — officially recommending its users migrate back to Cline, the open-source upstream project.
Executive Summary
Cline is an open-source AI coding agent — available as a VS Code extension, CLI, JetBrains extension (early access), and SDK — with a key differentiator: human-in-the-loop approval for every action. With 63,000+ GitHub stars as of June 2026, Cline is the most-starred open-source AI coding extension in the VS Code ecosystem.[1] Originally called "Claude Dev," it supports any LLM provider and has pioneered features like browser automation and MCP tool creation that others have since adopted. In July 2025 the company raised $32M in combined seed and Series A funding led by Emergence Capital and Pace Capital.[2]
| Attribute | Value |
|---|---|
| Company | Cline Bot Inc. |
| Founded | 2024 |
| Funding | $32M (seed + Series A, July 2025)[2] |
| GitHub Stars | 63,000+ (June 2026)[1] |
| License | Apache 2.0 |
Product Overview
Cline (an acronym for "CLI aNd Editor") is a VS Code extension that acts as an AI assistant capable of handling complex software development tasks step-by-step.[3] Unlike autocomplete tools, Cline can create and edit files, run terminal commands, use the browser, and even create new tools — all with your explicit approval at each step.
The human-in-the-loop design is intentional: while autonomous AI agents traditionally run in sandboxed environments, Cline provides a GUI to approve every action, making agentic AI accessible and safe for everyday development.
Key Capabilities
| Capability | Description |
|---|---|
| File Operations | Create, edit, delete files with diff preview |
| Terminal Commands | Execute shell commands and monitor output |
| Browser Automation | Launch browser, click, type, capture screenshots |
| MCP Tools | Create and use custom tools via Model Context Protocol |
| Image Input | Convert mockups to functional apps |
| Plan/Act Modes | Separate planning and execution phases for complex tasks |
| Rules & Skills | Repo-level .clinerules and SKILL.md files encode team coding standards |
| Headless/CI | CLI 2.0 (Feb 2026) runs headless with JSON output, stdin/stdout piping, and parallel isolated agent instances |
Product Surfaces
| Surface | Description | Availability |
|---|---|---|
| VS Code Extension | Primary interface in the IDE sidebar (~4.3M installs)[3] | GA |
| Cline CLI | Terminal interface; CLI 2.0 (Feb 2026) added headless mode, JSON output, CI/CD integration, and parallel agent instances | GA |
| JetBrains Extension | IntelliJ-family IDE support, bundled with Enterprise[4] | Early Access |
| SDK | Embed the Cline agent in other applications | GA |
| Enterprise Edition | SSO/OIDC, RBAC, audit logs, team dashboard | Enterprise |
Technical Architecture
Cline runs entirely locally as a VS Code extension.[5] It connects directly to your chosen LLM provider — no intermediate servers see your code or prompts. The extension uses VS Code's shell integration API for terminal monitoring and Playwright for browser automation.
Key Technical Details
| Aspect | Detail |
|---|---|
| Deployment | Local (VS Code/JetBrains extension, CLI) |
| Model(s) | Any provider — Anthropic, OpenAI, Gemini, Bedrock, Azure, Vertex, xAI, Mistral, DeepSeek, Cerebras, OpenRouter, Ollama/local models |
| Integrations | VS Code, terminal, browser, MCP servers |
| Open Source | Yes (Apache 2.0) |
Browser automation: Using Claude's Computer Use capability, Cline can launch a headless browser to test web apps, capture screenshots, and fix visual bugs.[1]
MCP integration: Cline can create custom tools by generating MCP servers on the fly. Ask "add a tool that fetches Jira tickets" and Cline builds and installs it.
Strengths
- Human-in-the-loop safety — Every action requires explicit approval; safe by design
- Massive adoption — 63K+ stars and ~4.3M VS Code marketplace installs as of June 2026; the company claims 8M+ installs across all platforms[3]
- Browser automation — Built-in capability to test web apps and fix visual bugs
- MCP extensibility — Create custom tools without leaving the workflow
- Multi-provider support — Works with any LLM provider, including local models
- Active development — Rapid feature releases, responsive to community needs
- Enterprise ready — SSO/OIDC, RBAC, audit logs, SLAs, dedicated support[6]
- Well capitalized — $32M raised from Emergence Capital and Pace Capital; public endorsements from SAP and Samsung[2]
Cautions
- VS Code-centric — Primary experience is VS Code (and forks); JetBrains support is early access and gated behind Enterprise
- Token-intensive — Agentic workflows can consume significant tokens
- No bundled inference — Usage-based only; bring your own API keys or pay per use through Cline's provider[4]
- Fork ecosystem consolidating — Roo Code, the largest fork, shut down in May 2026 and pointed users back to Cline; other forks (Kilo Code) remain[7]
- Approval friction — Human-in-the-loop can slow down for routine tasks (YOLO mode available but risky)
Pricing & Licensing
| Tier | Price | Includes |
|---|---|---|
| Open Source | Free | VS Code extension, CLI, MCP marketplace, multi-root workspaces, BYOK or Cline provider (usage-based)[4] |
| Enterprise | Custom | JetBrains extension, SSO/OIDC, RBAC, SLAs, centralized billing, team dashboard, audit logs[4] |
Licensing model: Free and open source (Apache 2.0) — you pay for inference only, either directly to your LLM provider (BYOK) or through Cline's usage-based provider. No subscription fees.[4]
Hidden costs: Complex agentic tasks can consume $5-50+ in API costs per session depending on model and task complexity (estimate as of February 2026).
Competitive Positioning
Direct Competitors
| Competitor | Differentiation |
|---|---|
| Roo Code | Former Cline fork; shut down May 2026 and recommended users migrate back to Cline[7] |
| Kilo Code | Roo Code fork that remains active; Cline is the original upstream |
| GitHub Copilot | Copilot is autocomplete-first; Cline is a full autonomous agent |
| Cursor | Cursor is a full IDE; Cline is an extension for your existing VS Code |
| Aider | Aider is terminal-native; Cline now has a CLI too, but leads with GUI approvals |
When to Choose Cline Over Alternatives
- Choose Cline when: You want agentic AI in VS Code with explicit approval for every action
- Choose Cursor when: You want an AI-native IDE rather than an extension
- Choose Aider when: You prefer a minimal terminal workflow with git-native commits
- Choose Claude Code when: You want a deeply integrated agent from a model provider rather than a model-agnostic tool
Ideal Customer Profile
Best fit:
- VS Code users who want agentic AI without switching editors
- Developers who value explicit approval over autonomous execution
- Teams needing enterprise security (VPC, SSO, audit trails)
- Web developers who benefit from browser automation
- Power users who want to extend capabilities via MCP
Poor fit:
- Teams wanting fully autonomous background agents
- JetBrains users on individual plans (Cline's JetBrains extension is early access, Enterprise-only)
- Users seeking a simple autocomplete experience
Viability Assessment
| Factor | Assessment |
|---|---|
| Financial Health | Strong — $32M seed + Series A (July 2025) led by Emergence Capital and Pace Capital[2] |
| Market Position | Leader — Most-starred VS Code AI extension; ~4.3M marketplace installs[3] |
| Innovation Pace | Rapid — Pioneered browser automation and MCP in coding agents; CLI 2.0, SDK, and JetBrains early access shipped since early 2026 |
| Community/Ecosystem | Active — Large Discord community, near-daily GitHub releases[8] |
| Long-term Outlook | Positive — Funded, enterprise tier provides revenue path, fork ecosystem consolidating back to Cline |
Cline has achieved remarkable growth in under two years. Fragmentation risk has receded: Roo Code, the largest fork, shut down its extension in May 2026 to pivot to cloud agents and officially recommended its users return to Cline.[7]
Bottom Line
Cline is the leading open-source agentic coding tool in the VS Code ecosystem, now extending to CLI, JetBrains, and SDK surfaces. Its human-in-the-loop design makes it accessible to developers who want AI assistance without giving up control, while features like browser automation and MCP extensibility push the boundaries of what coding assistants can do — and with $32M in funding and its largest fork folding back in, its position has only strengthened.
Recommended for: VS Code users who want powerful agentic AI with explicit approval for every action, teams standardizing on a model-agnostic open-source agent, and CI/CD automation via the headless CLI.
Not recommended for: Teams that want fully autonomous background agents, individual JetBrains users (extension is Enterprise-only early access), or anyone seeking simple autocomplete.
Outlook: Cline will continue leading the open-source coding-agent space. The $32M raise, enterprise tier, and Roo Code's exit consolidate its position; the open question is whether IDE-resident agents hold ground as competitors bet on fully cloud-based autonomy.
Research by Ry Walker Research • methodology