Example: Basic Claude Code API call using Python

from anthropic import Anthropic

client = Anthropic(api_key="YOUR_API_KEY")

response = client.messages.create(

model="claude-3-opus-20240229",

max_tokens=800,

messages=[

{"role": "user", "content": "Write a Python function that sorts a list of integers using merge sort."}

]

)

print(response.content[0].text)

When executed, Claude will return a complete implementation with comments explaining each step. You can adapt this approach for continuous integration tasks, static analysis, or internal developer tooling. The API’s flexibility means Claude can operate as a silent teammate within your workflow—always ready to assist but never intrusive.

For those who want to work directly in their editor, integrations with VS Code, Cursor, and Zed provide seamless access.

- VS Code Integration: After installing the Claude extension, authenticate with your API key. You can highlight code, open the command palette, and ask Claude to refactor, explain, or debug selected portions.
- Cursor Integration: Cursor is a Claude-native editor that combines text editing and conversational prompts in one interface. It offers deep context awareness, automatically feeding surrounding code into the model so that responses stay relevant.
- Zed Integration: Zed provides a similar conversational workflow but focuses on lightweight performance and fast iteration.

The table below summarizes the typical installation and access paths:

| Environment | Setup Method | Ideal Use Case | Advantages |
| --- | --- | --- | --- |
| Claude Web (claude.ai) | Sign up and open chat interface | Experimentation, learning prompt design | No setup required, accessible anywhere |
| Claude API | Install anthropic Python package and authenticate with API key | Automation, pipeline integration | Full programmatic control |
| VS Code Extension | Install from Marketplace, authenticate key | Everyday development, inline refactoring | Integrated workflow, contextual prompts |
| Cursor IDE | Download Cursor, sign in with Anthropic account | Deep project reasoning, full-context editing | Built for Claude-native coding |
| Zed Editor | Enable Claude integration via settings | Lightweight collaborative coding | Fast, minimalistic interface |

Whichever route you choose, the experience is unified: the same reasoning engine, the same commitment to accurate, safe, and context-aware code generation. Begin with the web interface to build intuition, then progress to local integrations and API calls as your needs grow. Once you’re comfortable, you’ll be able to weave Claude Code into your daily work naturally—running experiments, reviewing pull requests, and generating documentation all within the same conversational rhythm.

By the end of this setup process, you’ll have a ready-to-use Claude environment and a clear understanding of how each access method supports different stages of the software development lifecycle.

## 1.4 Setting Up in VS Code, Cursor, and Zed
Once you have access to Claude Code—either through the web interface or API—the next step is to embed it directly into your development environment. This integration allows you to collaborate with Claude where you write and test your code, enabling faster, more natural interactions. Among the supported environments, VS Code, Cursor, and Zed are the most popular, each catering to a slightly different style of developer workflow.

The setup process is simple and requires minimal configuration. The key is to ensure your Anthropic API key is active, stored securely, and accessible to your chosen editor. Once connected, Claude becomes part of your workspace, ready to review, explain, or generate code alongside you.

Setting Up Claude Code in VS Code

Visual Studio Code remains the most widely used text editor among developers, and Claude Code integrates seamlessly into it. You can either install the official extension (where available) or connect through an API integration layer that enables direct communication between your editor and Anthropic’s servers.

Steps to set up Claude in VS Code:

1. Open the Extensions Marketplace(Ctrl+Shift+X orCmd+Shift+X on macOS).
2. Search for “Claude Code” or “Anthropic AI Assistant.”
3. Click Install, then open the Extension Settings tab.
4. Locate the field labeled API Key, and paste in your Anthropic key.
5. Restart VS Code to initialize the connection.

Once activated, you can highlight any section of code and invoke Claude through the Command Palette (Ctrl+Shift+P) with commands like:

- “Ask Claude to Explain Selection”
- “Refactor with Claude”
- “Generate Unit Tests for This Function.”

Claude reads the selected code, interprets its purpose, and responds inline with annotated explanations or refactored implementations. Because VS Code maintains file context, Claude can reason about dependencies within the same workspace, providing more accurate insights than isolated prompts.

Setting Up Claude Code in Cursor

Cursor is a Claude-native IDE designed around conversational development. While VS Code integrates Claude as an extension, Cursor embeds it as a first-class collaborator. This means Claude can continuously reference the full project tree, interpret your edits, and maintain conversation state across files.

Steps to set up Claude in Cursor:

1. Download Cursor from the official site and install it on your system.
2. On first launch, sign in using your Anthropic account credentials.
3. Enable Claude integration in the settings under AI Assistants → Claude.
4. Verify your API key or Anthropic authentication token.
5. Open a project directory and start prompting directly in the sidebar or command panel.

Cursor differs from VS Code in that it allows conversational editing. You can write prompts such as:

“Claude, optimize this class for readability and add type hints.”

Claude will modify the file in place, showing proposed changes side-by-side. It can also summarize diffs, identify logic gaps, or rewrite documentation in natural language. Cursor’s deep context window allows Claude to process multiple files simultaneously, making it ideal for large-scale projects or architectural reviews.

Setting Up Claude Code in Zed

Zed is a lightweight, high-performance text editor favored by developers who value speed and focus. Its Claude integration brings reasoning capabilities without sacrificing responsiveness. Zed’s Claude extension allows conversational prompting directly in the sidebar while maintaining minimal memory overhead.

Steps to set up Claude in Zed:

1. Install Zed from the official website or package manager.
2. Launch Zed and open Settings → AI Integrations → Claude.
3. Paste your Anthropic API key or connect through the authenticated Anthropic account.
4. Save the configuration and restart Zed.

Once enabled, you can pressCtrl+Shift+Enter (orCmd+Shift+Enter on macOS) to trigger a Claude prompt. You can ask Claude to generate functions, explain algorithms, or even perform inline code reviews. The responses appear contextually, without slowing down the editing experience.

Zed’s Claude integration focuses on low-latency reasoning—responses arrive quickly, allowing for near real-time pair programming. Because Zed caches project context efficiently, Claude can maintain coherence even during fast-paced development sessions.

Comparison of Environments

| Editor | Integration Type | Context Handling | Ideal For | Key Strength |
| --- | --- | --- | --- | --- |
| VS Code | Extension | Per-file + workspace context | General-purpose development | Balanced features, strong UI integration |
| Cursor | Native integration | Deep, project-wide context | Large projects, collaborative development | Full Claude-native experience |
| Zed | Lightweight extension | Efficient contextual caching | High-speed local coding | Fast reasoning without overhead |

In practice, many developers start with VS Code because it’s familiar, then move to Cursor once they want deeper project-level collaboration. Zed suits those who prioritize performance and simplicity. Regardless of which you choose, Claude behaves consistently—an intelligent partner embedded within your daily environment, adapting to your workflow instead of forcing you to adapt to it.

Once you’ve completed your setup, take a few minutes to test Claude’s responsiveness by asking it to review a small script, generate a new function, or document an existing class. You’ll immediately experience how naturally it fits into your work—offering not just code, but reasoning, clarity, and structure right where you need it.