# Slash Commands in the SDK

> Learn how to use slash commands to control Claude Code sessions through the SDK

Slash commands provide a way to control Claude Code sessions with special commands that start with `/`. These commands can be sent through the SDK to perform actions like clearing conversation history, compacting messages, or getting help.

## Discovering Available Slash Commands

The Claude Agent SDK provides information about available slash commands in the system initialization message. Access this information when your session starts:

options: { maxTurns: 1 }    options: { maxTurns: 1 }
  })) {
    if (message.type === "system" && message.subtype === "init") {

```python
console.log("Available slash commands:", message.slash_commands);      console.log("Available slash commands:", message.slash_commands);
      // Example output: ["/compact", "/clear", "/help"]
    }
  ```

  ```python Python theme={null}
  import asyncio
  from claude_agent_sdk import query

  async def main():
      async for message in query(
```

```python
prompt="Hello Claude",          prompt="Hello Claude",
          options={"max_turns": 1}
      ):
          if message.type == "system" and message.subtype == "init":
              print("Available slash commands:", message.slash_commands)

              # Example output: ["/compact", "/clear", "/help"]

  asyncio.run(main())
  ```

## Sending Slash Commands

Send slash commands by including them in your prompt string, just like regular text:

options: { maxTurns: 1 }    options: { maxTurns: 1 }
  })) {
    if (message.type === "result") {

```python
console.log("Command executed:", message.result);      console.log("Command executed:", message.result);
    }
  ```

  ```python Python theme={null}
  import asyncio
  from claude_agent_sdk import query

  async def main():

      # Send a slash command
```

```python
async for message in query(      async for message in query(
          prompt="/compact",
          options={"max_turns": 1}
      ):
          if message.type == "result":
              print("Command executed:", message.result)

  asyncio.run(main())
  ```

## Common Slash Commands

### `/compact` - Compact Conversation History

The `/compact` command reduces the size of your conversation history by summarizing older messages while preserving important context:

options: { maxTurns: 1 }    options: { maxTurns: 1 }
  })) {
    if (message.type === "system" && message.subtype === "compact_boundary") {

```python
console.log("Compaction completed");      console.log("Compaction completed");
      console.log("Pre-compaction tokens:", message.compact_metadata.pre_tokens);
      console.log("Trigger:", message.compact_metadata.trigger);
    }
  ```

  ```python Python theme={null}
  import asyncio
  from claude_agent_sdk import query

  async def main():
      async for message in query(
```

```python
prompt="/compact",          prompt="/compact",
          options={"max_turns": 1}
      ):
          if (message.type == "system" and
              message.subtype == "compact_boundary"):
              print("Compaction completed")
              print("Pre-compaction tokens:",
                    message.compact_metadata.pre_tokens)
              print("Trigger:", message.compact_metadata.trigger)

  asyncio.run(main())
  ```

### `/clear` - Clear Conversation

The `/clear` command starts a fresh conversation by clearing all previous history:

options: { maxTurns: 1 }    options: { maxTurns: 1 }
  })) {
    if (message.type === "system" && message.subtype === "init") {

```python
console.log("Conversation cleared, new session started");      console.log("Conversation cleared, new session started");
      console.log("Session ID:", message.session_id);
    }
  ```

  ```python Python theme={null}
  import asyncio
  from claude_agent_sdk import query

  async def main():

      # Clear conversation and start fresh
```python
async for message in query(      async for message in query(
          prompt="/clear",
          options={"max_turns": 1}
      ):
          if message.type == "system" and message.subtype == "init":
              print("Conversation cleared, new session started")
              print("Session ID:", message.session_id)

  asyncio.run(main())
  ```

## Creating Custom Slash Commands

In addition to using built-in slash commands, you can create your own custom commands that are available through the SDK. Custom commands are defined as markdown files in specific directories, similar to how subagents are configured.

### File Locations

Custom slash commands are stored in designated directories based on their scope:

* **Project commands**: `.claude/commands/` - Available only in the current project
* **Personal commands**: `~/.claude/commands/` - Available across all your projects

### File Format

Each custom command is a markdown file where:

* The filename (without `.md` extension) becomes the command name
* The file content defines what the command does
* Optional YAML frontmatter provides configuration

#### Basic Example

Create `.claude/commands/refactor.md`:

```markdown  theme={null}
Refactor the selected code to improve readability and maintainability.
Focus on clean code principles and best practices.
```

This creates the `/refactor` command that you can use through the SDK.

#### With Frontmatter

Create `.claude/commands/security-check.md`:

```markdown  theme={null}
---
allowed-tools: Read, Grep, Glob
description: Run security vulnerability scan
model: claude-sonnet-4-5
---

Analyze the codebase for security vulnerabilities including:

- SQL injection risks
- XSS vulnerabilities
- Exposed credentials
- Insecure configurations
```

### Using Custom Commands in the SDK

Once defined in the filesystem, custom commands are automatically available through the SDK:

options: { maxTurns: 3 }    options: { maxTurns: 3 }
  })) {
    if (message.type === "assistant") {

```python
console.log("Refactoring suggestions:", message.message);      console.log("Refactoring suggestions:", message.message);
    }

  // Custom commands appear in the slash_commands list
  for await (const message of query({
    prompt: "Hello",
```python
options: { maxTurns: 1 }    options: { maxTurns: 1 }
  })) {
    if (message.type === "system" && message.subtype === "init") {
```

// Will include both built-in and custom commands      // Will include both built-in and custom commands
      console.log("Available commands:", message.slash_commands);
      // Example: ["/compact", "/clear", "/help", "/refactor", "/security-check"]
    }

  ```text

  ```python Python theme={null}
  import asyncio
  from claude_agent_sdk import query

  async def main():

# Use a custom command
```python
async for message in query(      async for message in query(
          prompt="/refactor src/auth/login.py",
          options={"max_turns": 3}
      ):
          if message.type == "assistant":
              print("Refactoring suggestions:", message.message)

      # Custom commands appear in the slash_commands list
      async for message in query(
          prompt="Hello",
          options={"max_turns": 1}
      ):
          if message.type == "system" and message.subtype == "init":
              # Will include both built-in and custom commands
              print("Available commands:", message.slash_commands)
              # Example: ["/compact", "/clear", "/help", "/refactor", "/security-check"]

  asyncio.run(main())
  ```

## Advanced Features

### Arguments and Placeholders

Custom commands support dynamic arguments using placeholders:

Create `.claude/commands/fix-issue.md`:

```markdown  theme={null}
---
argument-hint: [issue-number] [priority]
description: Fix a GitHub issue
---

Fix issue #$1 with priority $2.
Check the issue description and implement the necessary changes.
```

Use in SDK:

options: { maxTurns: 5 }    options: { maxTurns: 5 }
  })) {
    // Command will process with $1="123" and $2="high"

```python
if (message.type === "result") {    if (message.type === "result") {
      console.log("Issue fixed:", message.result);
    }
  ```

  ```python Python theme={null}
  import asyncio
  from claude_agent_sdk import query

  async def main():

      # Pass arguments to custom command
```python
async for message in query(      async for message in query(
          prompt="/fix-issue 123 high",
          options={"max_turns": 5}
      ):

# Command will process with $1="123" and $2="high"

          if message.type == "result":
              print("Issue fixed:", message.result)

  asyncio.run(main())
  ```

## Bash Command Execution

Custom commands can execute bash commands and include their output:

Create `.claude/commands/git-commit.md`:

```markdown  theme={null}
---
allowed-tools: Bash(git add:*), Bash(git status:*), Bash(git commit:*)
description: Create a git commit
---

## Context

- Current status: !`git status`
- Current diff: !`git diff HEAD`

## Task

Create a git commit with appropriate message based on the changes.
```

### File References

Include file contents using the `@` prefix:

Create `.claude/commands/review-config.md`:

```markdown  theme={null}
---
description: Review configuration files
---

Review the following configuration files for issues:

- Package config: @package.json
- TypeScript config: @tsconfig.json
- Environment config: @.env

Check for security issues, outdated dependencies, and misconfigurations.
```

### Organization with Namespacing

Organize commands in subdirectories for better structure:

```bash  theme={null}
.claude/commands/
├── frontend/
│   ├── component.md      # Creates /component (project:frontend)
│   └── style-check.md     # Creates /style-check (project:frontend)
├── backend/
│   ├── api-test.md        # Creates /api-test (project:backend)
│   └── db-migrate.md      # Creates /db-migrate (project:backend)
└── review.md              # Creates /review (project)
```

The subdirectory appears in the command description but doesn't affect the command name itself.

### Practical Examples

#### Code Review Command

Create `.claude/commands/code-review.md`:

```markdown  theme={null}
---
allowed-tools: Read, Grep, Glob, Bash(git diff:*)
description: Comprehensive code review
---

## Changed Files

!`git diff --name-only HEAD~1`

## Detailed Changes

!`git diff HEAD~1`

## Review Checklist

Review the above changes for:

1. Code quality and readability
2. Security vulnerabilities
3. Performance implications
4. Test coverage
5. Documentation completeness

Provide specific, actionable feedback organized by priority.
```

#### Test Runner Command

Create `.claude/commands/test.md`:

```markdown  theme={null}
---
allowed-tools: Bash, Read, Edit
argument-hint: [test-pattern]
description: Run tests with optional pattern
---

Run tests matching pattern: $ARGUMENTS

1. Detect the test framework (Jest, pytest, etc.)
2. Run tests with the provided pattern
3. If tests fail, analyze and fix them
4. Re-run to verify fixes
```

Use these commands through the SDK:

options: { maxTurns: 3 }    options: { maxTurns: 3 }
  })) {
    // Process review feedback
  }

  // Run specific tests
  for await (const message of query({
    prompt: "/test auth",

```python
options: { maxTurns: 5 }    options: { maxTurns: 5 }
  })) {
    // Handle test results
  }
  ```

  ```python Python theme={null}
  import asyncio
  from claude_agent_sdk import query

  async def main():

# Run code review
```python
async for message in query(      async for message in query(
          prompt="/code-review",
          options={"max_turns": 3}
      ):

          # Process review feedback

          pass

      # Run specific tests
      async for message in query(
          prompt="/test auth",
          options={"max_turns": 5}
      ):
          # Handle test results
          pass

  asyncio.run(main())
  ```

## See Also

- [Slash Commands](/en/docs/claude-code/slash-commands) - Complete slash command documentation
- [Subagents in the SDK](/en/api/agent-sdk/subagents) - Similar filesystem-based configuration for subagents
- [TypeScript SDK reference](/en/docs/claude-code/typescript-sdk-reference) - Complete API documentation
- [SDK overview](/en/api/agent-sdk/overview) - General SDK concepts
- [CLI reference](/en/docs/claude-code/cli-reference) - Command-line interface