Configure permissions

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:

Hooks

Run hooks first. A hook can deny the call outright or pass it on. A hook that returns allow does not skip the deny and ask rules below; those are evaluated regardless of the hook result.

Deny rules

Check deny rules (from disallowed_tools and settings.json). If a deny rule matches, the tool is blocked, even in bypassPermissions mode. Bare-name deny rules like Bash remove the tool from Claude’s context before this evaluation begins, so only scoped rules like Bash(rm *) are checked at this step.

Permission mode

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

Allow rules

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

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.

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. Allow rules only affect approval: a tool not listed in allowed_tools is still available to Claude and falls through to the permission mode. Deny rules behave differently depending on whether they name a tool or scope a pattern within one.

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"]`	The `Bash` tool definition is removed from the request. Claude does not see the tool and cannot attempt it.
`disallowed_tools=["Bash(rm *)"]`	`Bash` stays available. Calls matching `rm *` are denied in every permission mode, including `bypassPermissions`. Other `Bash` calls fall through to the permission mode.

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	Read-only tools run; Claude analyzes and plans without editing your source files
`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())

Call set_permission_mode() (Python) or setPermissionMode() (TypeScript) to change the mode mid-session. The new mode takes effect immediately for all subsequent tool requests. This lets you start restrictive and loosen permissions as trust builds, for example switching to acceptEdits after reviewing Claude’s initial approach.

import asyncio
from claude_agent_sdk import ClaudeSDKClient, ClaudeAgentOptions


async def main():
    async with ClaudeSDKClient(
        options=ClaudeAgentOptions(
            permission_mode="default",  # Start in default mode
        )
    ) as client:
        await client.query("Help me refactor this code")

        # Change mode dynamically mid-session
        await client.set_permission_mode("acceptEdits")

        # Process messages with the new permission mode
        async for message in client.receive_response():
            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`)

Restricts Claude to read-only tools. Claude can read files and run read-only shell commands to explore the codebase but does not edit your source files. 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:

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

Agent SDK

Core concepts

Input and output

Extend with tools

Customize behavior

Control and observability

Deployment

SDK references

How permissions are evaluated

Allow and deny rules

Permission modes

Available modes

Set permission mode

Mode details

Accept edits mode (`acceptEdits`)

Don’t ask mode (`dontAsk`)

Bypass permissions mode (`bypassPermissions`)

Plan mode (`plan`)

Agent SDK

Core concepts

Input and output

Extend with tools

Customize behavior

Control and observability

Deployment

SDK references

Documentation Index

​How permissions are evaluated

​Allow and deny rules

​Permission modes

​Available modes

​Set permission mode

​Mode details

​Accept edits mode (acceptEdits)

​Don’t ask mode (dontAsk)

​Bypass permissions mode (bypassPermissions)

​Plan mode (plan)

​Related resources

How permissions are evaluated

Allow and deny rules

Permission modes

Available modes

Set permission mode

Mode details

Accept edits mode (`acceptEdits`)

Don’t ask mode (`dontAsk`)

Bypass permissions mode (`bypassPermissions`)

Plan mode (`plan`)

Related resources