Quickstart ↗

    mkdir my-agent && cd my-agent
    ```

For your own projects, you can run the SDK from any folder; it will have access to files in that directory and its subdirectories by default.
  <span class="step-end"></span>

  <span class="step-marker" data-step-title="Install the SDK"></span>
Install the Agent SDK package for your language:

<span class="tab-group-start"></span>
  <span class="tab-start" data-tab-title="TypeScript"></span>
    ```bash
        npm install @anthropic-ai/claude-agent-sdk
        ```
  <span class="tab-end"></span>
  <span class="tab-start" data-tab-title="Python (uv)"></span>
    [uv Python package manager](https://docs.astral.sh/uv/) is a fast Python package manager that handles virtual environments automatically:
    ```bash
        uv init && uv add claude-agent-sdk
        ```
  <span class="tab-end"></span>
  <span class="tab-start" data-tab-title="Python (pip)"></span>
    Create a virtual environment first, then install:
    ```bash
        python3 -m venv .venv && source .venv/bin/activate
        pip3 install claude-agent-sdk
        ```
  <span class="tab-end"></span>
<span class="tab-group-end"></span>
  <span class="step-end"></span>

  <span class="step-marker" data-step-title="Set your API key"></span>
Get an API key from the [Claude Console](https://platform.claude.com/), then create a `.env` file in your project directory:

```bash
    ANTHROPIC_API_KEY=your-api-key
    ```

The SDK also supports authentication via third-party API providers:

- **Amazon Bedrock**: set `CLAUDE_CODE_USE_BEDROCK=1` environment variable and configure AWS credentials
- **Google Vertex AI**: set `CLAUDE_CODE_USE_VERTEX=1` environment variable and configure Google Cloud credentials
- **Microsoft Azure**: set `CLAUDE_CODE_USE_FOUNDRY=1` environment variable and configure Azure credentials

See the setup guides for [Bedrock](https://code.claude.com/docs/en/amazon-bedrock), [Vertex AI](https://code.claude.com/docs/en/google-vertex-ai), or [Azure AI Foundry](https://code.claude.com/docs/en/azure-ai-foundry) for details.

<span class="callout-start" data-callout-type="note"></span>
Unless previously approved, Anthropic does not allow third party developers to offer claude.ai login or rate limits for their products, including agents built on the Claude Agent SDK. Please use the API key authentication methods described in this document instead.
<span class="callout-end"></span>
  <span class="step-end"></span>
<span class="steps-end"></span>

## Create a buggy file

This quickstart walks you through building an agent that can find and fix bugs in code. First, you need a file with some intentional bugs for the agent to fix. Create `utils.py` in the `my-agent` directory and paste the following code:

```python
def calculate_average(numbers):
    total = 0
    for num in numbers:
        total += num
    return total / len(numbers)


def get_user_name(user):
    return user["name"].upper()

import asyncio
from claude_agent_sdk import query, ClaudeAgentOptions, AssistantMessage, ResultMessage


async def main():
    # Agentic loop: streams messages as Claude works
    async for message in query(
        prompt="Review utils.py for bugs that would cause crashes. Fix any issues you find.",
        options=ClaudeAgentOptions(
            allowed_tools=["Read", "Edit", "Glob"],  # Tools Claude can use
            permission_mode="acceptEdits",  # Auto-approve file edits
        ),
    ):
        # Print human-readable output
        if isinstance(message, AssistantMessage):
            for block in message.content:
                if hasattr(block, "text"):
                    print(block.text)  # Claude's reasoning
                elif hasattr(block, "name"):
                    print(f"Tool: {block.name}")  # Tool being called
        elif isinstance(message, ResultMessage):
            print(f"Done: {message.subtype}")  # Final result


asyncio.run(main())

// Agentic loop: streams messages as Claude works
for await (const message of query({
  prompt: "Review utils.py for bugs that would cause crashes. Fix any issues you find.",
  options: {
    allowedTools: ["Read", "Edit", "Glob"], // Tools Claude can use
    permissionMode: "acceptEdits" // Auto-approve file edits
  }
})) {
  // Print human-readable output
  if (message.type === "assistant" && message.message?.content) {
    for (const block of message.message.content) {
      if ("text" in block) {
        console.log(block.text); // Claude's reasoning
      } else if ("name" in block) {
        console.log(`Tool: ${block.name}`); // Tool being called
      }
    }
  } else if (message.type === "result") {
    console.log(`Done: ${message.subtype}`); // Final result
  }
}

    python3 agent.py
    ```
  <span class="tab-end"></span>
  <span class="tab-start" data-tab-title="TypeScript"></span>
```bash
    npx tsx agent.ts
    ```
  <span class="tab-end"></span>
<span class="tab-group-end"></span>

After running, check `utils.py`. You'll see defensive code handling empty lists and null users. Your agent autonomously:

1. **Read** `utils.py` to understand the code
2. **Analyzed** the logic and identified edge cases that would crash
3. **Edited** the file to add proper error handling

This is what makes the Agent SDK different: Claude executes tools directly instead of asking you to implement them.

<span class="callout-start" data-callout-type="note"></span>
If you see "API key not found", make sure you've set the `ANTHROPIC_API_KEY` environment variable in your `.env` file or shell environment. See the [full troubleshooting guide](https://code.claude.com/docs/en/troubleshooting) for more help.
<span class="callout-end"></span>

### Try other prompts

Now that your agent is set up, try some different prompts:

- `"Add docstrings to all functions in utils.py"`
- `"Add type hints to all functions in utils.py"`
- `"Create a README.md documenting the functions in utils.py"`

### Customize your agent

You can modify your agent's behavior by changing the options. Here are a few examples:

**Add web search capability:**


```python
options = ClaudeAgentOptions(
    allowed_tools=["Read", "Edit", "Glob", "WebSearch"], permission_mode="acceptEdits"
)

const _ = {
  options: {
    allowedTools: ["Read", "Edit", "Glob", "WebSearch"],
    permissionMode: "acceptEdits"
  }
};

options = ClaudeAgentOptions(
    allowed_tools=["Read", "Edit", "Glob"],
    permission_mode="acceptEdits",
    system_prompt="You are a senior Python developer. Always follow PEP 8 style guidelines.",
)

const _ = {
  options: {
    allowedTools: ["Read", "Edit", "Glob"],
    permissionMode: "acceptEdits",
    systemPrompt: "You are a senior Python developer. Always follow PEP 8 style guidelines."
  }
};

options = ClaudeAgentOptions(
    allowed_tools=["Read", "Edit", "Glob", "Bash"], permission_mode="acceptEdits"
)

const _ = {
  options: {
    allowedTools: ["Read", "Edit", "Glob", "Bash"],
    permissionMode: "acceptEdits"
  }
};