Skip to main content
The Claude Agent SDK provides permission controls to manage how Claude uses tools. Use permission modes and rules to define what’s allowed automatically, and the canUseTool callback to handle everything else at runtime.
This page covers permission modes and rules. To build interactive approval flows where users approve or deny tool requests at runtime, see Handle approvals and user input.

​
How permissions are evaluated

When Claude requests a tool, the SDK checks permissions in this order:
1

Hooks

Run hooks first, which can allow, deny, or continue to the next step
2

Deny rules

Check deny rules (from disallowed_tools and settings.json). If a deny rule matches, the tool is blocked, even in bypassPermissions mode.
3

Permission mode

Apply the active permission mode. bypassPermissions approves everything that reaches this step. acceptEdits approves file operations. Other modes fall through.
4

Allow rules

Check allow rules (from allowed_tools and settings.json). If a rule matches, the tool is approved.
5

canUseTool callback

If not resolved by any of the above, call your canUseTool callback for a decision. In dontAsk mode, this step is skipped and the tool is denied.
Permission evaluation flow diagram This page focuses on allow and deny rules and permission modes. For the other steps:

​
Allow and deny rules

allowed_tools and disallowed_tools (TypeScript: allowedTools / disallowedTools) add entries to the allow and deny rule lists in the evaluation flow above. They control whether a tool call is approved, not whether the tool is available to Claude.
OptionEffect
allowed_tools=["Read", "Grep"]Read and Grep are auto-approved. Tools not listed here still exist and fall through to the permission mode and canUseTool.
disallowed_tools=["Bash"]Bash is always denied. Deny rules are checked first and hold in every permission mode, including bypassPermissions.
For a locked-down agent, pair allowedTools with permissionMode: "dontAsk". Listed tools are approved; anything else is denied outright instead of prompting: 
const options = {
  allowedTools: ["Read", "Glob", "Grep"],
  permissionMode: "dontAsk"
};
allowed_tools does not constrain bypassPermissions. allowed_tools only pre-approves the tools you list. Unlisted tools are not matched by any allow rule and fall through to the permission mode, where bypassPermissions approves them. Setting allowed_tools=["Read"] alongside permission_mode="bypassPermissions" still approves every tool, including Bash, Write, and Edit. If you need bypassPermissions but want specific tools blocked, use disallowed_tools.
You can also configure allow, deny, and ask rules declaratively in .claude/settings.json. The SDK does not load filesystem settings by default, so you must set setting_sources=["project"] (TypeScript: settingSources: ["project"]) in your options for these rules to apply. See Permission settings for the rule syntax.

​
Permission modes

Permission modes provide global control over how Claude uses tools. You can set the permission mode when calling query() or change it dynamically during streaming sessions.

​
Available modes

The SDK supports these permission modes:
ModeDescriptionTool behavior
defaultStandard permission behaviorNo auto-approvals; unmatched tools trigger your canUseTool callback
dontAskDeny instead of promptingAnything not pre-approved by allowed_tools or rules is denied; canUseTool is never called
acceptEditsAuto-accept file editsFile edits and filesystem operations (mkdir, rm, mv, etc.) are automatically approved
bypassPermissionsBypass all permission checksAll tools run without permission prompts (use with caution)
planPlanning modeNo tool execution; Claude plans without making changes
auto (TypeScript only)Model-classified approvalsA model classifier approves or denies each tool call. See Auto mode for availability
Subagent inheritance: When using bypassPermissions, all subagents inherit this mode and it cannot be overridden. Subagents may have different system prompts and less constrained behavior than your main agent. Enabling bypassPermissions grants them full, autonomous system access without any approval prompts.

​
Set permission mode

You can set the permission mode once when starting a query, or change it dynamically while the session is active.
Pass permission_mode (Python) or permissionMode (TypeScript) when creating a query. This mode applies for the entire session unless changed dynamically.
import asyncio
from claude_agent_sdk import query, ClaudeAgentOptions


async def main():
    async for message in query(
        prompt="Help me refactor this code",
        options=ClaudeAgentOptions(
            permission_mode="default",  # Set the mode here
        ),
    ):
        if hasattr(message, "result"):
            print(message.result)


asyncio.run(main())

​
Mode details

​
Accept edits mode (acceptEdits)

Auto-approves file operations so Claude can edit code without prompting. Other tools (like Bash commands that aren’t filesystem operations) still require normal permissions. Auto-approved operations:
  • File edits (Edit, Write tools)
  • Filesystem commands: mkdir, touch, rm, mv, cp
Use when: you trust Claude’s edits and want faster iteration, such as during prototyping or when working in an isolated directory.

​
Don’t ask mode (dontAsk)

Converts any permission prompt into a denial. Tools pre-approved by allowed_tools, settings.json allow rules, or a hook run as normal. Everything else is denied without calling canUseTool. Use when: you want a fixed, explicit tool surface for a headless agent and prefer a hard deny over silent reliance on canUseTool being absent.

​
Bypass permissions mode (bypassPermissions)

Auto-approves all tool uses without prompts. Hooks still execute and can block operations if needed.
Use with extreme caution. Claude has full system access in this mode. Only use in controlled environments where you trust all possible operations.allowed_tools does not constrain this mode. Every tool is approved, not just the ones you listed. Deny rules (disallowed_tools), explicit ask rules, and hooks are evaluated before the mode check and can still block a tool.

​
Plan mode (plan)

Prevents tool execution entirely. Claude can analyze code and create plans but cannot make changes. Claude may use AskUserQuestion to clarify requirements before finalizing the plan. See Handle approvals and user input for handling these prompts. Use when: you want Claude to propose changes without executing them, such as during code review or when you need to approve changes before they’re made. For the other steps in the permission evaluation flow: