Cline complete introductory tutorial, 5 steps to get started with the free Claude Code alternative in 2026 VS Code

Cline is one of the fastest-growing AI programming tools in the open source community in 2026. It is positioned as a free alternative to Claude Code and exists in the form of a VS Code plug-in. It directly calls the large model API, and can read project code, execute commands, write files, and run tests in the editor. For developers who don’t want to pay to subscribe to Cursor or Claude Code, but still want to experience the full process of AI programming, Cline is currently one of the most cost-effective options. This article explains the 5 steps to get started, from installation, configuration, typical usage to precautions for getting started.

The first step is to understand the difference between Cline and other AI programming tools

Cline, Cursor, Claude Code, and GitHub Copilot are all AI programming tools, but their positioning is different. Cursor is an independent AI-first editor with deeply customized IDE experience and subscription system. Claude Code is Anthropic's official command line tool, which runs directly in the terminal. GitHub Copilot is mainly about completion and has limited chat capabilities.

Cline differs in two ways. First, it is a VS Code plug-in. You don’t need to switch editors, you can use it in the familiar VS Code. Second, it has its own Agent capability, which can continuously read files, write files, and execute commands instead of simple completion or dialogue.

The price is that users need to bring their own API Key, and large model calls are billed by tokens. If it is the Claude API, the cost of using it for one or two hours a day is usually between a few dollars and more than ten dollars, which is reasonable for individual developers.

The second step is to install the Cline plug-in and complete the configuration.

Open VS Code, search for Cline in the extension market on the sidebar, and click Install. After the installation is complete, the Cline icon will appear on the left side of VS Code. After clicking it, the configuration interface will pop up for the first time, requiring you to select a large model provider and API Key.

There are three main categories of choices. The first category is the official API of Anthropic, and the Claude Sonnet series is recommended for the most stable effect. The second category is OpenRouter, which can connect to multiple models with one Key and is suitable for experiments. The third category is various domestic model APIs, such as DeepSeek, Kimi, and GLM. The prices are lower but the coding capabilities vary by model.

Fill in the API Key and save. Open a project in the workspace and Cline will automatically recognize the project structure. If it is a large project, you can set the ignore file in the configuration to prevent the plug-in from reading irrelevant directories.

The third step, typical usage one, let Cline read the code and explain it

The easiest way to get started is to have Cline read your code and answer questions. Enter in the Cline chat panel: "Read the src/api directory and tell me what the API structure of this project is." Cline will automatically list the files in the directory, read them one by one, and then provide a structural analysis.

In this scenario, Cline is much better than naked ChatGPT because it can directly access local files and does not require you to manually copy and paste. The explanations given after reading several documents are usually more accurate and can help you quickly understand unfamiliar projects.

Note that Cline consumes tokens every time it reads a file by default. If the project is large, you can first limit the scope in the prompt, such as "read-only no more than 5 core files in the src/api directory" to avoid eating too many tokens at once.

The fourth step, typical usage two, let Cline write new code

The second common scenario is to have Cline write code directly. For example: "Create a new dateFormat.ts file under src/utils to provide tool functions for formatting dates. It must support Chinese and English."

Cline will first analyze the existing code style, TypeScript configuration, and referenced third-party libraries in the project, and then give you suggestions and wait for your confirmation before writing the file. This "plan first, do it later" process is important to avoid AI coding indiscriminately.

If Cline makes a mistake in writing, just say "that function just now has a bug, the xxx boundary is not handled", it will read back the file just written, correct it and write it again. The entire process does not require you to open a terminal or switch windows.

The easiest pitfall for novices is to ask Cline to write too many functions at once. It is recommended to only let it do one small step at a time, and then confirm it before continuing. This not only helps control quality, but also avoids consuming a large number of tokens at one time.

Step 5, typical usage three, let Cline execute commands and run tests

Cline's Agent capability is reflected in its ability to execute terminal commands. For example: "Install the axios package, then write a simple fetch example and put it in the examples directory."

Cline will first bring up the terminal, run npm install axios, and wait for completion before creating the sample file. The entire process is completed inside VS Code, and there is no need to cut the window.

The same logic applies to running tests. "Run the test of the current module to see if the modification just now breaks the existing use cases." Cline will execute npm test or the corresponding command, read the output, tell you which use cases failed and why, and automatically try to correct them.

This ability is very powerful but be careful. By default, Cline will ask for your confirmation before executing a command. Do not give it the highest permission to "execute any command" right away. Be sure to confirm manually before performing sensitive operations such as git push, rm files, or modifying the database.

What kind of developer is Cline suitable for?

Cline is most suitable for three types of developers.

The first category is full-stack developers who are already familiar with VS Code. Cline allows you to seamlessly access AI capabilities without changing editors, with the lowest migration cost.

The second category is the budget-conscious individual developer or student. A Cursor subscription costs $20 a month, and Claude Code’s API starts at least $17, which is not cheap for students. Cline uses API billing on a pay-as-you-go basis. When actual usage is small, the bill can be controlled to a few dollars a month.

The third category is intermediate developers who want Agent capabilities but don’t want to leave the VS Code ecosystem. Cline can both complete and execute commands, between Copilot and Cursor.

The group of people it is not suitable for is also clear. If you are a complete novice just learning programming, it may be more friendly to use the ChatGPT web version directly. If you need a flat-rate plan for team collaboration, Cursor or Copilot Enterprise Edition are more suitable.

How to choose between Cline and Claude Code

Many people are torn between the two. Simply put, Cline is suitable for GUI workflow, and Claude Code is suitable for command line workflow.

The advantage of Cline is good visualization. File trees and diffs are displayed in VS Code. The advantage of Claude Code is that the command line is native, running tests, writing scripts, and Git operations are smoother, and Anthropic official maintenance updates are faster.

If your project focuses on Web front-end, TypeScript, and complex React applications, and the visual experience of VS Code is important, choose Cline. If you focus on server-side Go/Python/Rust, command line tools, and embedded, it is more convenient to choose Claude Code.

There is no conflict between the two, and you can mix them in actual work: open Cline in VS Code to handle the UI, and open Claude Code in the command line to handle the backend.

Cline Costs and Considerations

At current prices for Claude Sonnet 4.5, the daily API cost for moderate-intensity use of Cline is roughly on the order of a few dollars, depending on project size and frequency of conversations. If you make just one or two small changes a day, it might be less than $1. If you continue to do large-scale refactoring, you may spend more than ten dollars a day.

Several tips for saving tokens. 1. Always clear the project ignore list in the configuration to prevent Cline from reading node_modules, dist, and log files. Second, clearly limit the scope in the prompt and do not let it scan the entire project. Third, open new conversations every few rounds for long conversations to avoid excessive context.

API Key security should also be paid attention to. Cline stores the Key in the VS Code configuration. If you synchronize the configuration to the cloud, make sure that the Key will not be leaked. It is best to use a transit agent such as OpenRouter that supports permission isolation and set a monthly budget limit to avoid abuse.

FAQ

Is Cline completely free?

The Cline plug-in itself is open source and free, but it needs to call the large model API, which costs money. The cheaper solution is to use domestic APIs such as DeepSeek, which costs a few yuan per million tokens; the expensive solution is to use Anthropic's official Claude Sonnet, which is US$1 per million tokens. The specific cost depends on your actual usage. If you just want to experience it, just recharge a few dollars and run around.

Which one is better, Cline or RooCode or Continue.dev?

All three are AI programming plug-ins in VS Code. Cline is the agent with the most complete capabilities, supporting automatic execution of commands and multi-step workflow. RooCode is a fork of Cline, with some details optimized more radically. Continue.dev is partial to chat completion, and its Agent capabilities are relatively weak. If you want a fully automatic Agent, choose Cline or RooCode. If you only want to chat and complete, choose Continue.

Can Cline be used in production code?

Yes but be careful. The code written by Cline is essentially a large model generation, and the quality depends on the model behind it and your prompt. It is recommended to think of it as an intern who can write code: every output must be reviewed before merging, especially codes involving the core of the business, money, and security. Letting Cline write test code, documents, and simple tool functions is low-risk; letting it directly change core modules related to payment, login, and encryption is high-risk.

What is the effect of using Cline with domestic models?

The DeepSeek series is close to the first-tier level in terms of coding capabilities, has outstanding cost performance, and is suitable for budget-sensitive scenarios. Kimi and GLM have advantages in Chinese understanding, but their coding capabilities are slightly weaker than DeepSeek. The Qwen series is also a good choice, especially Qwen Coder, which is specially optimized for coding tasks. If you only work on Chinese projects and routine tasks, the domestic model is completely sufficient; if you work on intensive English documents and complex algorithms, Claude still has an advantage.

Is Cline safe? Will it steal my code?

Cline itself is open source, and the code is hosted on GitHub and can be viewed. It does send your code to the large model API of choice, the privacy risk of this step depends on the API provider. If you are worried about code leakage, you have two options: One is to use tools such as Ollama to run local large models. The data does not leave the local area at all, but the effect is weaker than the cloud API. The second is to choose an API provider with enterprise-level compliance commitments. For example, Anthropic or OpenAI have corresponding data non-training commitments.