obsidian/raw/_processed/Configure permissions.md

title	source	author	published	created	description	tags
Configure permissions	https://code.claude.com/docs/en/agent-sdk/permissions			2026-04-17	Control how your agent uses tools with permission modes, hooks, and declarative allow/deny rules.	clippings

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:

!

Permission evaluation flow diagram

This page focuses on allow and deny rules and permission modes. For the other steps:

• Hooks: run custom code to allow, deny, or modify tool requests. See Control execution with hooks.
• canUseTool callback: prompt users for approval at runtime. See Handle approvals and user input.

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.

Option	Effect
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. These rules are read when the project setting source is enabled, which it is for default query() options. If you set setting_sources (TypeScript: settingSources) explicitly, include "project" for them 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:

Mode	Description	Tool behavior
default	Standard permission behavior	No auto-approvals; unmatched tools trigger your canUseTool callback
dontAsk	Deny instead of prompting	Anything not pre-approved by allowed_tools or rules is denied; canUseTool is never called
acceptEdits	Auto-accept file edits	File edits and filesystem operations (mkdir, rm, mv, etc.) are automatically approved
bypassPermissions	Bypass all permission checks	All tools run without permission prompts (use with caution)
plan	Planning mode	No tool execution; Claude plans without making changes
auto (TypeScript only)	Model-classified approvals	A model classifier approves or denies each tool call. See Auto mode for availability

Subagent inheritance: When the parent uses bypassPermissions, acceptEdits, or auto, all subagents inherit that mode and it cannot be overridden per subagent. Subagents may have different system prompts and less constrained behavior than your main agent, so inheriting 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.

• At query time
• During streaming

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, rmdir, mv, cp, sed

Both apply only to paths inside the working directory or additionalDirectories. Paths outside that scope and writes to protected paths still prompt.

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.

Related resources

For the other steps in the permission evaluation flow:

• Handle approvals and user input: interactive approval prompts and clarifying questions
• Hooks guide: run custom code at key points in the agent lifecycle
• Permission rules: declarative allow/deny rules in settings.json