A lightweight PHP utility to detect if your code is running inside an AI agent or automated development environment.

Requires PHP 8.2+

Installation

composer require shipfastlabs/agent-detector

Usage

use AgentDetector\AgentDetector;

$result = AgentDetector::detect();

if ($result->isAgent) {
    echo "Running inside: {$result->name}";
}

// Check for a specific known agent
if ($result->knownAgent() === \AgentDetector\KnownAgent::Claude) {
    echo "Hello from Claude!";
}

Or use the standalone function:

use function AgentDetector\detectAgent;

$result = detectAgent();

Supported Agents

Agent	Detection Method
Custom	`AI_AGENT` env var
Cursor	`CURSOR_AGENT` env var
Gemini	`GEMINI_CLI` env var
Codex	`CODEX_SANDBOX` or `CODEX_THREAD_ID` env var
Augment CLI	`AUGMENT_AGENT` env var
AMP	`AMP_CURRENT_THREAD_ID` env var
Opencode	`OPENCODE_CLIENT` or `OPENCODE` env var
Claude	`CLAUDECODE` or `CLAUDE_CODE` env var
Replit	`REPL_ID` env var
Devin	`/opt/.devin` file exists

Custom Agent

Set the AI_AGENT environment variable to any value to identify your custom agent:

AI_AGENT=my-custom-agent php your-script.php

Contributing

Please see CONTRIBUTING for details on how to contribute, including adding support for new agents.

Testing

composer test

Agent Detector was created by Pushpak Chhajed under the MIT license.

Agent Detector Laravel Package