Built-in tools - Amazon Q Developer
Available toolsFile reading (fs_read)File writing (fs_write)Command execution (execute_bash)AWS API calls (use_aws)Tool permissionsComplete exampleSecurity improvements

Built-in tools

Amazon Q Developer CLI includes several built-in tools that agents can use to perform various tasks. This section describes the most commonly used tools and their configuration options.

Available tools

The following built-in tools are available:

  • fs_read - Read files, directories, and images

  • fs_write - Create and edit files

  • execute_bash - Execute shell commands

  • use_aws - Make AWS CLI API calls

  • knowledge - Store and retrieve information across sessions

  • introspect - Provide information about Q CLI capabilities

File reading (fs_read)

The fs_read tool allows Amazon Q to read files, directories, and images. This tool is trusted by default.

Configuration

You can configure which paths are allowed or denied:

{
  "toolsSettings": {
    "fs_read": {
      "allowedPaths": ["~/projects", "./src/**"],
      "deniedPaths": ["/etc/**", "~/.ssh/**"]
    }
  }
}

  • allowedPaths - Paths that can be read without prompting. Supports glob patterns.

  • deniedPaths - Paths that are denied. Deny rules are evaluated before allow rules.

File writing (fs_write)

The fs_write tool allows Amazon Q to create and edit files. This tool prompts for permission by default.

Configuration

You can configure which paths are allowed for writing:

{
  "toolsSettings": {
    "fs_write": {
      "allowedPaths": ["~/projects/output.txt", "./src/**"],
      "deniedPaths": ["/system/**", "~/.config/**"]
    }
  }
}

  • allowedPaths - Paths that can be written to without prompting. Supports glob patterns.

  • deniedPaths - Paths that are denied for writing.

Command execution (execute_bash)

The execute_bash tool allows Amazon Q to execute shell commands. This tool prompts for permission by default.

Configuration

You can configure which commands are allowed or denied:

{
  "toolsSettings": {
    "execute_bash": {
      "allowedCommands": ["git status", "git fetch"],
      "deniedCommands": ["git commit .*", "git push .*"],
      "autoAllowReadonly": true
    }
  }
}

  • allowedCommands - Commands that are allowed without prompting. Supports regex patterns.

  • deniedCommands - Commands that are denied. Evaluated before allow rules.

  • autoAllowReadonly - Whether to allow read-only commands without prompting.

AWS API calls (use_aws)

The use_aws tool allows Amazon Q to make AWS CLI API calls. This tool prompts for permission by default.

Configuration

You can configure which AWS services are allowed:

{
  "toolsSettings": {
    "use_aws": {
      "allowedServices": ["s3", "lambda", "ec2"],
      "deniedServices": ["eks", "rds"],
      "autoAllowReadonly": true
    }
  }
}

  • allowedServices - AWS services that can be accessed without prompting.

  • deniedServices - AWS services to deny access to.

  • autoAllowReadonly - Whether to allow read-only operations (get, describe, list) without prompting.

Tool permissions

Tools can be explicitly allowed in the allowedTools section of your agent configuration:

{
  "allowedTools": [
    "fs_read",
    "knowledge",
    "use_aws"
  ]
}

Default permission behaviors:

  • fs_read and report_issue are trusted by default

  • execute_bash, fs_write, and use_aws prompt for permission by default

  • Tools not in allowedTools will prompt for permission unless configured with appropriate toolsSettings

Complete example

Here's an example agent configuration with tool settings:

{
  "name": "development-assistant",
  "description": "Agent for development tasks with restricted tool access",
  "allowedTools": ["fs_read", "fs_write", "execute_bash"],
  "toolsSettings": {
    "fs_read": {
      "allowedPaths": ["~/projects/**"],
      "deniedPaths": ["~/.ssh/**", "/etc/**"]
    },
    "fs_write": {
      "allowedPaths": ["~/projects/**"],
      "deniedPaths": ["~/projects/production/**"]
    },
    "execute_bash": {
      "allowedCommands": ["git status", "git diff", "npm test"],
      "deniedCommands": ["git push .*", "rm -rf .*"],
      "autoAllowReadonly": true
    }
  }
}

Security improvements

Recent security improvements include:

  • fs_read: Default trust permission now limited to current working directory only

  • execute_bash: autoAllowReadonly now defaults to false for enhanced security

  • use_aws: New autoAllowReadonly setting available for configuration

Configure these settings in your agent's toolsSettings section as needed.