Cline integration guide

Powerful extensionVSCode extensionUpdated: 2025-11-27

Introduction

Cline is one of the most capable AI coding extensions for VSCode, able to understand and carry out complex programming tasks. Backed by SeaWhale AI models, it becomes a highly effective coding assistant.

Key capabilities

🤖 Code generation — write complete code from a description
📝 Automated execution — run commands, create files and modify code
🔍 Project understanding — analyze project structure and context
💡 Plan/Act modes — switch freely between planning and execution
🛠️ Tool integration — terminal, filesystem, browser and more
🌐 Many languages — Python, JavaScript, Java, Go and more

Cline vs other tools

Feature	Cline	GitHub Copilot	Cursor
Type	VSCode extension	IDE integration	Standalone editor
Automation	⭐⭐⭐⭐⭐	⭐⭐⭐	⭐⭐⭐⭐
File operations	Fully automatic	Manual	Semi-automatic
Command execution	Supported	Not supported	Supported
Model choice	Configurable	Fixed	Fixed
Cost	Pay as you go	Subscription	Subscription

Why Cline + SeaWhale AI?

🎯 More flexible: many models, switch whenever you like
💰 More economical: usage-based billing, no subscription
🚀 More capable: coder-specialized models tuned for code
🔒 More private: data is not stored, protecting your code

Before you begin

1. Software requirements

Software	Version	Download
VSCode	1.80.0+	Download VSCode
Node.js	16.0+ (optional)	Download Node.js

Checking your VSCode version

bash

# Open VSCode
# Menu bar -> Help -> About
# Or press: Ctrl+Shift+P (Windows/Linux) / Cmd+Shift+P (macOS)
# Type "About" to see version information

2. Get a SeaWhale AI API key

Open the SeaWhale AI console
Sign up and log in
Generate an API key on the API management page
Make sure your account has enough balance or free credit

New user credit

🎁 New accounts receive free credit
💰 Usable across all model inference services

3. Choose a model

Through SeaWhale AI, Cline supports:

Recommended models

Family	Model name	Strengths	Best for
Claude Sonnet	`claude-sonnet-4-5`	• Strong at code • Accurate reasoning • 200K context	Complex projects Refactoring
Claude Opus	`claude-opus-4.5`	• Highest capability • Deep reasoning	Architecture Complex algorithms
Gemini Pro	`gemini-2.5-pro`	• Multimodal • Long context • Fast responses	Document analysis Rapid development
Gemini Flash	`gemini-2.5-flash`	• Great value • Low latency	Everyday work Code completion

Suggested configurations

Everyday development (recommended)

Main model: claude-sonnet-4-5
Fast model: gemini-2.5-flash
Why: excellent at code, accurate reasoning, quick responses

Demanding projects

Main model: claude-opus-4.5
Fast model: gemini-2.5-pro
Why: highest capability, deep reasoning

Installation

1. Install the Cline extension

Option 1: extension marketplace (recommended)

Open VSCode
Click the Extensions icon in the sidebar (or press Ctrl+Shift+X / Cmd+Shift+X)
Search for "Cline"
Find the Cline extension and click Install

Cline installation

Option 2: command line

bash

# Using the VSCode CLI
code --install-extension saoudrizwan.claude-dev

Installation notes

✅ A Cline icon appears in the sidebar after installation
✅ You need to configure an API key before first use
✅ Install the latest version for the best experience

2. Open Cline

There are two ways to open Cline:

Option 1: sidebar icon

Click the Cline icon in the VSCode sidebar

Option 2: command palette

Press Ctrl+Shift+P (Windows/Linux) or Cmd+Shift+P (macOS)
Type "Cline: Open"
Press Enter

Configuration

1. First-time setup

With Cline open:

Click "API Configuration"
Fill in the settings from the table below

Existing users

If you have used Cline before, click the ⚙️ settings button in the top right to open the configuration screen.

2. Configuration parameters

Setting	Recommended value	Description
API Provider	`OpenAI Compatible`	Recommended — supports more models
Base URL	`https://api.seawhaleai.com/v2`	The SeaWhale AI compatible endpoint
API Key	`sk-******`	Your SeaWhale AI API key
Model ID	`claude-sonnet-4-5`	A code-focused model is recommended

Cline settings

About the API Provider setting

OpenAI Compatible (recommended)

✅ Wider model choice
✅ More complete feature support
✅ Continuously updated
⚠️ Requires the correct Base URL

3. Step-by-step setup

Step 1: choose the API provider

API Provider: OpenAI Compatible

Step 2: set the Base URL

text

Base URL: https://api.seawhaleai.com/v2

Step 3: enter your API key

API Key: sk-*****

Security

🔒 Never share your API key
🔒 Never commit it to a public repository
🔒 Rotate your API key periodically
🔒 Regenerate it immediately if it leaks

Step 4: pick a model

Recommended:

Model ID: claude-sonnet-4-5

Step 5: finish

Click "Done" in the top right to save

Usage guide

Plan vs Act mode

Cline offers two working modes for different situations:

Mode	How it works	Characteristics	Best for
Plan mode	Plans without acting	• Gathers information • Breaks down tasks • Designs an approach • Does not modify files	Requirements analysis Design Architecture discussion
Act mode	Executes directly	• Creates files • Modifies code • Runs commands • Automates work	Implementation Bulk refactoring Automated tasks

Switching modes

Switch between Plan and Act at any time at the bottom of the Cline chat panel.

Auto-approve permissions

The Auto-approve control above the input box governs how much Cline does without asking:

Permission	What it allows	Impact when enabled	Recommendation
Read	Read files	Higher token usage	✅ Reasonable to enable
Write	Write files	Modifies code automatically	⚠️ Enable with care
Execute	Run commands	Runs scripts automatically	⚠️ Enable once understood

Important

⚠️ Auto-approve can substantially increase token usage
⚠️ Write permission modifies code automatically and may overwrite existing files
⚠️ Execute permission runs commands automatically — make sure that is safe
✅ Enable these only after you understand how Cline behaves
✅ Beginners should start in Plan mode and confirm each action manually

Worked examples

Example 1: Plan mode — designing an approach

Scenario: design a quicksort algorithm

markdown

Write me a debounce function

Cline settings

Advantages of Plan mode

💡 Plan first, execute second — clearer thinking
💰 Lower token usage
🛡️ No accidental file changes
📚 Good for learning and discussion

Example 2: Act mode — automatic implementation

Scenario: generate and create the code file automatically

markdown

Write me a debounce function

Cline settings

Things to watch in Act mode

⚠️ Files are created and modified automatically
⚠️ Token usage is higher
⚠️ Use Auto-approve carefully
✅ Best for automation and bulk operations

Saving tokens

Using Cline thoughtfully can substantially reduce token usage and cost.

1. Reduce irrelevant file scanning

Cline scans project files to build context, which consumes a lot of tokens.

How to optimize

✅ Start in the specific directory

bash

# Wrong: starting from a parent directory
cd ~/projects
code .

# Right: starting inside the project
cd ~/projects/my-app
code .

✅ Exclude files with .gitignore

gitignore

# Exclude dependency directories
node_modules/
venv/
__pycache__/
.pytest_cache/

# Exclude build output
dist/
build/
*.pyc
*.pyo

# Exclude large files
*.pdf
*.zip
*.tar.gz
*.mp4
*.mov

# Exclude logs
*.log
logs/

✅ Use .clineignore

Create a .clineignore file in your project root:

# Cline-specific ignore file
test/
docs/
*.md
*.txt

2. Compact conversation history

Cline keeps prior conversation as context, so longer conversations cost more.

Ways to compact

Method	Action	Effect	When to use
Compact button	Click "Compact Task"	Summarizes and shrinks history	Long conversations
Command	Type `/compact`	Triggers compaction manually	Any time
New session	Click "New Chat"	Clears history entirely	Starting a new task

When to compact

✅ After finishing a complete feature
✅ Once the conversation passes about 10 turns
✅ Before switching to a new task
✅ When token usage climbs noticeably

3. Give precise instructions

Vague instructions make Cline scan more files and try more approaches.

Comparison

❌ Vague	✅ Precise
"Optimize code"	"Refactor parse_json in src/utils/parser.py to handle errors with try-except"
"Fix the bug"	"Fix the division-by-zero at line 45 of app.py by checking divisor != 0"
"Add a feature"	"Add a validate_email method to the User class using a regex for the format"
"Improve performance"	"Optimize the queries in database.py and add an index on the user_id field"

4. Break large tasks apart

❌ Everything at once (expensive)

Build a complete e-commerce system with user management, product management,
order management, payment integration, analytics and an admin dashboard.

✅ Step by step (cheaper)

Step 1: design the database schema (users, products, orders)
Step 2: implement the registration and sign-in APIs
Step 3: implement product CRUD endpoints
Step 4: implement the shopping cart
Step 5: implement order creation and payment

5. Use Plan mode for discussion

For work that does not need to run immediately, Plan mode cuts token usage substantially.

Scenario	Recommended mode	Why
Technical questions	Plan	You want advice, not code changes
Code review	Plan	Analyze the code and suggest improvements
Architecture design	Plan	Discuss the approach before building
Learning	Plan	Explain concepts without writing code
Automated development	Act	Create or modify files in bulk
Rapid implementation	Act	Generate code immediately

6. Token usage comparison

Task type	Plan mode	Act mode	Savings
Simple questions	200–500	1000–2000	60–75%
Code explanation	500–1000	2000–5000	60–80%
Design work	1000–2000	5000–10000	70–80%
Code generation	—	2000–5000	—
Project refactoring	—	10000+	—

Best practice

While discussing → use Plan mode
Once the approach is settled → switch to Act mode
Compact regularly → use the Compact feature
When the task is done → start a new session

FAQ

Q1: Why do I get a 401 "Incorrect API key provided" error?

Error message:

401 Incorrect API key provided

Possible causes:

Cause 1: the API key does not match the Base URL

Base URL	Required API key
`https://api.seawhaleai.com/v2`	SeaWhale AI key

Fix:

Check that the Base URL and API key belong together

Q2: Why are tokens consumed so quickly?

Why it happens:

Automatic file scanning
- Cline reads relevant project files
- Large projects can mean hundreds of files
- Files are re-read for each conversation
Multiple API calls
- Act mode calls the API repeatedly
- Each operation is a separate request
- Automatic retries add more calls
Accumulating context
- Conversation history keeps occupying tokens
- Longer conversations cost more
- Uncompacted history is retained indefinitely

Fixes:

Problem	Fix	Effect
Too much file scanning	Exclude irrelevant files with .gitignore	50–80% less
Very long history	Use Compact regularly	30–50% less
Irrelevant files in scope	Open VSCode inside the specific project	40–60% less
Simple Q&A	Use Plan mode	60–80% less
All Auto-approve enabled	Enable permissions only when needed	20–40% less

Q3: How else can I save tokens?

See the saving tokens section. The main techniques:

✅ Environment

Start inside the specific project directory
Configure .gitignore and .clineignore
Delete or move large files

✅ Habits

Give precise, specific instructions
Break complex tasks into smaller ones
Use Plan mode for simple questions
Compact conversation history regularly

✅ Permissions

Turn off Auto-approve where it is not needed
Confirm important operations manually
Be careful with Execute permission

Q4: How does Cline differ from Claude Code?

Feature	Cline	Claude Code
Type	VSCode extension	CLI tool
Interface	Graphical	Terminal
Automation	Visual controls	Command driven
File operations	Creates/modifies automatically	Conversational
Learning curve	Lower	Higher
Best for	Project development	Scripting
IDE integration	Native to VSCode	Runs standalone

Which to choose:

🎯 VSCode users → Cline (seamless integration)
🎯 Terminal enthusiasts → Claude Code (command line)
🎯 Prefer a GUI → Cline (visual)
🎯 Automation scripts → Claude Code (batch friendly)

Best practices

1. Suggested project structure

A clear structure helps Cline understand your project:

my-project/
├── .vscode/
│   └── settings.json      # VSCode configuration
├── .cline/
│   └── config.json        # Cline configuration (if any)
├── .gitignore             # Git ignore file
├── .clineignore           # Cline ignore file
├── src/                   # Source code
│   ├── main.py
│   ├── utils/
│   └── models/
├── tests/                 # Tests
├── docs/                  # Documentation
├── README.md              # Project readme
└── requirements.txt       # Dependencies

2. Suggested workflow

A recommended way to work with Cline:

1. Discuss requirements in Plan mode
   ↓
2. Settle on an approach
   ↓
3. Switch to Act mode
   ↓
4. Generate the code
   ↓
5. Test and verify
   ↓
6. Does it pass?
   → Yes: compact the history → move on to the next task
   → No: keep debugging

3. Security recommendations

Security

🔒 Never hard-code API keys in your source
🔒 Never commit API keys to Git
🔒 Rotate API keys periodically
🔒 Monitor API usage
🔒 Be careful with Auto-approve on sensitive projects
🔒 Review code before committing

If your API key leaks:

Open the SeaWhale AI console immediately
Delete the exposed API key
Generate a new one
Update your local configuration
Review your call history for anything unexpected

Cline integration guide ​

Introduction ​

Key capabilities ​

Cline vs other tools ​

Before you begin ​

1. Software requirements ​

2. Get a SeaWhale AI API key ​

3. Choose a model ​

Recommended models ​

Installation ​

1. Install the Cline extension ​

Option 1: extension marketplace (recommended) ​

Option 2: command line ​

2. Open Cline ​

Configuration ​

1. First-time setup ​

2. Configuration parameters ​

3. Step-by-step setup ​

Step 1: choose the API provider ​

Step 2: set the Base URL ​

Step 3: enter your API key ​

Step 4: pick a model ​

Step 5: finish ​

Usage guide ​

Plan vs Act mode ​

Auto-approve permissions ​

Worked examples ​

Example 1: Plan mode — designing an approach ​

Example 2: Act mode — automatic implementation ​

Saving tokens ​

1. Reduce irrelevant file scanning ​

How to optimize ​

2. Compact conversation history ​

Ways to compact ​

3. Give precise instructions ​

Comparison ​

4. Break large tasks apart ​

5. Use Plan mode for discussion ​

6. Token usage comparison ​

FAQ ​

Q1: Why do I get a 401 "Incorrect API key provided" error? ​

Cause 1: the API key does not match the Base URL ​

Q2: Why are tokens consumed so quickly? ​

Q3: How else can I save tokens? ​

Q4: How does Cline differ from Claude Code? ​

Best practices ​

1. Suggested project structure ​

2. Suggested workflow ​

3. Security recommendations ​

Cline integration guide

Introduction

Key capabilities

Cline vs other tools

Before you begin

1. Software requirements

2. Get a SeaWhale AI API key

3. Choose a model

Recommended models

Installation

1. Install the Cline extension

Option 1: extension marketplace (recommended)

Option 2: command line

2. Open Cline

Configuration

1. First-time setup

2. Configuration parameters

3. Step-by-step setup

Step 1: choose the API provider

Step 2: set the Base URL

Step 3: enter your API key

Step 4: pick a model

Step 5: finish

Usage guide

Plan vs Act mode

Auto-approve permissions

Worked examples

Example 1: Plan mode — designing an approach

Example 2: Act mode — automatic implementation

Saving tokens

1. Reduce irrelevant file scanning

How to optimize

2. Compact conversation history

Ways to compact

3. Give precise instructions

Comparison

4. Break large tasks apart

5. Use Plan mode for discussion

6. Token usage comparison

FAQ

Q1: Why do I get a 401 "Incorrect API key provided" error?

Cause 1: the API key does not match the Base URL

Q2: Why are tokens consumed so quickly?

Q3: How else can I save tokens?

Q4: How does Cline differ from Claude Code?

Best practices

1. Suggested project structure

2. Suggested workflow

3. Security recommendations