is-ai-agent

Detect whether a CLI is being invoked by an AI coding agent, and identify which one.

Inspired by the AGENT environment variable proposal. Lets your CLI adapt its output — structured errors, more verbose tracebacks, no interactive prompts — when it's running under an agent rather than a human.

Install

[dependencies]
is-ai-agent = "0.1"

Usage

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);
}

For tests or callers that want to consult a captured environment instead of the live process, use detect_with:

use is_ai_agent::detect_with;

let agent = detect_with(
    |name| if name == "AGENT" { Some("goose".into()) } else { None },
    |_| false,
);

Detection order

1. The proposed standard AGENT env var. Its value is mapped to a known agent (goose, amp, claude-code, cursor, gemini-cli, codex, augment, cline, opencode, trae, devin); generic values like 1 / true resolve to AgentId::Unknown.

2. Tool-specific env vars:

   Variable	Agent
   CLAUDECODE	Claude Code
   CURSOR_AGENT	Cursor
   GEMINI_CLI	Gemini CLI
   CODEX_SANDBOX	OpenAI Codex
   AUGMENT_AGENT	Augment
   CLINE_ACTIVE	Cline
   OPENCODE_CLIENT	OpenCode
   TRAE_AI_SHELL_ID	TRAE AI
   GOOSE_TERMINAL	Goose

3. Filesystem signals:

   Path	Agent
   /opt/.devin	Devin

The detected Agent carries the Signal that matched, so callers can see exactly how detection fired.

License

Dual-licensed under MIT or Apache-2.0, at your option.