Overview

Summary

The Outputs namespace contains classes for serializing JSON responses that hooks send to Claude Code via stdout. All output classes inherit from HookOutputBase which provides Continue, StopReason, SuppressOutput, and SystemMessage properties.

Usage

Creating and Serializing Output

// Simple output - allow operation to continue
var output = new PreToolUseHookOutput<object> { Continue = true };
Console.WriteLine(ClaudeHooksSerializer.SerializePreToolUseOutput(output));

// Block an operation
var blockOutput = new StopHookOutput
{
    Decision = HookDecision.Block,
    Reason = "Tests must pass before stopping"
};
Console.WriteLine(ClaudeHooksSerializer.SerializeStopOutput(blockOutput));

Exit Codes

0: Success - stdout is parsed as JSON
2: Blocking error - stderr is shown to Claude/user
Other: Non-blocking error - shown in verbose mode only

Common Base Properties

All outputs inherit from HookOutputBase:

Continue - Whether to continue (default: true)
StopReason - Message when Continue is false
SuppressOutput - Hide from transcript
SystemMessage - Warning message for Claude

Types

Classes

Name	Summary
HookOutputBase	Base class containing common fields for all hook outputs. Hook outputs are written to stdout as JSON when the hook exits with code 0.
HookSpecificOutputBase	Base class for hook-specific output data. Contains the hook event name and serves as base for specific output types.
NotificationHookOutput	Represents the output for a Notification hook. The Notification hook typically only uses base output fields.
PermissionRequestDecision	Represents the decision object for a PermissionRequest hook response. Contains the behavior decision and optional parameters.
PermissionRequestHookOutput	Represents the complete output for a PermissionRequest hook. Combines base output fields with PermissionRequest-specific output.
PermissionRequestSpecificOutput	Represents the hook-specific output for a PermissionRequest hook. Contains the decision object with behavior and optional parameters.
PostToolUseHookOutput	Represents the complete output for a PostToolUse hook. Combines base output fields with PostToolUse-specific output.
PostToolUseSpecificOutput	Represents the hook-specific output for a PostToolUse hook. Contains additional context to provide to Claude after tool execution.
PreCompactHookOutput	Represents the output for a PreCompact hook. The PreCompact hook typically only uses base output fields.
PreToolUseHookOutput	Represents the complete output for a PreToolUse hook. Combines base output fields with PreToolUse-specific output.
PreToolUseSpecificOutput	Represents the hook-specific output for a PreToolUse hook. Contains permission decisions and optional input modifications.
SessionEndHookOutput	Represents the output for a SessionEnd hook. The SessionEnd hook typically only uses base output fields.
SessionStartHookOutput	Represents the complete output for a SessionStart hook. Combines base output fields with SessionStart-specific output.
SessionStartSpecificOutput	Represents the hook-specific output for a SessionStart hook. Contains additional context to add to the session start.
StopHookOutput	Represents the output for a Stop hook. Used to optionally block Claude from stopping and continue processing.
SubagentStopHookOutput	Represents the output for a SubagentStop hook. Used to optionally block a subagent from stopping and continue processing.
UserPromptSubmitHookOutput	Represents the complete output for a UserPromptSubmit hook. Combines base output fields with UserPromptSubmit-specific output.
UserPromptSubmitSpecificOutput	Represents the hook-specific output for a UserPromptSubmit hook. Contains additional context to add to Claude’s processing of the user prompt.

Getting Started

Guides

API Reference

Summary

Usage

Creating and Serializing Output

Exit Codes

Common Base Properties

Types

Classes

​Summary

​Usage

​Creating and Serializing Output

​Exit Codes

​Common Base Properties

​Types

​ Classes

Summary

Usage

Creating and Serializing Output

Exit Codes

Common Base Properties

Types

Classes