is-ai-agent for Rust: detect if your CLI is invoked by an agent

I published a new Rust crate is-ai-agent. It lets you detect when your CLI is being called an AI agent, by detecting standard/common environment variables that various agents set.

It’s a very simple API:

use is_ai_agent::{detect, is_ai_agent};

if is_ai_agent() {
    // emit structured/agent-friendly output
}

if let Some(agent) = detect() {
    eprintln!("running under {}", agent.name);
}

It’s not perfect, as there’s no standard signal for agents to identify themselves yet. There is an ongoing discussion for creating a standard AGENT variable, but it seems that only a few of the smaller open source agents have adopted it so far.

For now, this is the environment variable and agent coverage:

Variable	Agent
CLAUDECODE, CLAUDE_CODE	Claude Code
CURSOR_TRACE_ID	Cursor (editor)
CURSOR_AGENT, CURSOR_EXTENSION_HOST_ROLE=agent-exec	Cursor CLI
GEMINI_CLI	Gemini CLI
CODEX_SANDBOX, CODEX_CI, CODEX_THREAD_ID	OpenAI Codex
ANTIGRAVITY_AGENT	Antigravity
AUGMENT_AGENT	Augment
CLINE_ACTIVE	Cline
OPENCODE_CLIENT	OpenCode
TRAE_AI_SHELL_ID	TRAE AI
GOOSE_TERMINAL	Goose
REPL_ID	Replit
COPILOT_MODEL, COPILOT_ALLOW_ALL, COPILOT_GITHUB_TOKEN	GitHub Copilot

I needed this for clickhousectl, so I’ll be keeping the rules up to date.

There’s a similar lib for TypeScript with @vercel/detect-agent.