ClaudeEssentials

AOT-ready .NET models for building Claude Code hook processors.

What It Does

Claude Code hooks let you intercept and customize Claude's behavior. ClaudeEssentials provides strongly-typed C# models for all hook events, with source-generated JSON serialization for instant startup.

Installation

dotnet add package ClaudeEssentials

Quick Example

using CloudNimble.ClaudeEssentials.Hooks;
using CloudNimble.ClaudeEssentials.Hooks.Enums;
using CloudNimble.ClaudeEssentials.Hooks.Outputs;

// Read JSON from stdin
var json = Console.In.ReadToEnd();
var input = ClaudeHooksSerializer.DeserializePreToolUseInput(json);

// Auto-approve read-only tools
var output = new PreToolUseHookOutput<object>
{
    Continue = true,
    HookSpecificOutput = new PreToolUseSpecificOutput<object>
    {
        PermissionDecision = input.ToolName is "Read" or "Glob"
            ? PermissionDecision.Allow
            : PermissionDecision.Ask
    }
};

// Write response to stdout
Console.WriteLine(ClaudeHooksSerializer.SerializePreToolUseOutput(output));

Supported Hooks

Hook	Purpose
PreToolUse	Approve, deny, or modify tool calls before execution
PostToolUse	Add context or take action after tools complete
Stop	Enforce policies before Claude ends a session
SessionStart	Inject project context when sessions begin
Notification	React to permission prompts and notifications
UserPromptSubmit	Process user prompts before they're sent
PreCompact	Customize context compaction behavior

Features

• AOT Ready - Source-generated serialization, zero reflection
• Strongly Typed - Full IntelliSense and compile-time safety
• Lightweight - No dependencies beyond System.Text.Json

Documentation

Full documentation available at easyaf.dev/claudeessentials

License

MIT