Cloud Parts

Cline

An open-source coding agent that started as a VS Code extension and now runs the same engine in JetBrains, a terminal CLI, a desktop app and an SDK, with whatever model you bring.

What it is
AI coding agents (editor agents)
Type
Open source
Made by
Cline Bot Inc.
License
Apache 2.0
Facts checked
9 October 2026
Website Source code

What it is

Cline is an agent loop around a language model. You describe a task; Cline reads files, searches the code, edits files, runs terminal commands, drives a browser and calls MCP servers, and in the editor it asks you to approve each step unless you switch on auto-approve. Plan mode can read and search but can’t change files or run commands, so you work out an approach first; Act mode keeps that conversation and carries it out. You can give each mode its own model. After every tool use Cline commits your files to a separate shadow Git repository, so you can compare or restore any checkpoint without touching your own Git history.

Cline doesn’t sell its own model. You bring an API key for Anthropic, OpenAI, Google, Bedrock, OpenRouter, a local runtime such as Ollama or LM Studio, or one of dozens of other providers, or use Cline’s pay-as-you-go provider or its $9.99 a month ClinePass for open-weight models. In 2026 the team pulled the agent out of the extension into an open-source TypeScript runtime, @cline/sdk. The CLI, the Mac desktop app and, since August 2026, the VS Code extension run on it, and the CLI also speaks the Agent Client Protocol, so Zed, Neovim and Emacs can use it as their agent.

Why teams pick it

  • Open source under Apache 2.0 down to the prompts and the agent runtime, so security teams can read exactly what it sends and does
  • Model-agnostic with no markup on bring-your-own keys: frontier APIs, open-weight models or a local model on your own hardware
  • Plan and Act modes plus shadow-Git checkpoints make it cheap to explore first and to roll back a bad edit
  • One engine across VS Code, JetBrains, the terminal, a desktop app and your own code through the SDK

Watch out for

  • You pay the provider for every token the agent spends, so the bill depends on the model and how long the agent runs; only ClinePass, for open-weight models, has a flat monthly price
  • The CLI starts in Act mode with auto-approve on by default, and YOLO mode approves everything, so headless runs belong in a sandbox
  • .clineignore never stopped the agent reading files through shell commands, and Cline is removing it; there is no built-in hard boundary around secrets
  • Checkpoints commit after every tool use, which the docs warn can use a lot of storage and slow Cline down on very large repositories
  • The 2026 move to the SDK dropped some extension features, such as Explain Changes and the Focus Chain todo list

The Cline family

1 technologies built from or on Cline

Alternatives

What all editor agents have in common →
Augment CodeCommercialA commercial coding agent for VS Code, JetBrains and the terminal built around a Context Engine that keeps a live semantic index of your codebase. On 8 October 2026 Harness bought the Context Engine, the Auggie CLI and the Cosmos cloud agents.

How it fits with other technologies

The Cline CLI: plan first, then run headless in a script or CI job · bash

npm install -g cline
cline auth                       # pick a provider and model, or sign in to Cline

cline -p "How do requests reach the billing service?"   # Plan mode: reads, never edits

# Headless: pipe input in, approve tools automatically, stream the answer to stdout
git diff origin/main | cline -y "Review these changes for bugs"

cline --acp                      # what Zed or Neovim launch to use Cline as their agent

See it in a real stack

No architecture uses Cline yet. Drop it into the playground and wire it up yourself.Open playground →
Where it came from2024–2026

In July 2024 Saoud Rizwan spent a week building a demo for an Anthropic hackathon: give a model the same tools a developer uses, meaning file access, terminal commands and a way to move around a codebase. The demo didn’t win, but it shipped as a VS Code extension called Claude Dev, built right after Claude 3.5 Sonnet came out. In version 2.0 (October 2024) it was renamed Cline and opened up to other models through OpenRouter. MCP support arrived in December 2024, and search-and-replace diffs in version 3.0 the same month.

Being open source made Cline easy to copy and extend. Roo Code forked it in late 2024, and Kilo Code forked Roo Code in 2025. Cline raised $32 million in seed and Series A funding in July 2025, when it had 2.7 million installs, and launched a JetBrains plugin that September. GitHub’s Octoverse 2025 named it the fastest-growing AI open-source project, with contributors up 4,704% in a year.

The original harness was built for 2024 models: tools were described in the system prompt and called through XML tags parsed out of the model’s text. By 2026 models were trained to call tools natively, and the extension’s roughly 76,000-line core had grown around the IDE. Cline rebuilt the agent as a separate SDK in 2026, moved the CLI (Cline CLI 2.0, February 2026) and then the VS Code extension onto it. During the switch, tasks that stopped after three consecutive mistakes fell from 6.34% to 0.62%.

Why it’s built this way

Ask before every action, and plan before acting
An agent that edits files and runs commands can do damage. Approval prompts, a read-only Plan mode and checkpoints keep the developer in control, and auto-approve lets them loosen it per tool when they trust it.
Bring your own model and key, with no markup
Cline’s founders argued that a tool which resells inference is tempted to swap in cheaper models or throttle context. Charging nothing on top of the provider’s price let users run the strongest model at its true cost, and let enterprises keep code on their own infrastructure.
Open source, prompts included
Security and compliance teams can audit exactly what the agent sends, which made adoption easier in regulated companies, and community contributions such as Memory Bank came straight back into the product.
Pull the agent out of the editor into an SDK
The agent loop had grown inside the VS Code extension, which made it hard to reuse in JetBrains, a CLI or other people’s tools. A separate runtime lets every surface share one harness and get model improvements at once.

Timeline

  1. 2024

    Built in July for an Anthropic hackathon and released as Claude Dev; renamed Cline in October

  2. 2024

    MCP support and search-and-replace diff editing in December

  3. 2025

    $32 million seed and Series A in July; JetBrains plugin in September

  4. 2026

    Cline CLI 2.0 in February; the open-source Cline SDK in May

  5. 2026

    VS Code extension moved onto the SDK by August 23; Cline Desktop in September

Sources16 · facts checked 9 October 2026

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