std-env

Runtime-agnostic JS utils for detecting environments, runtimes, CI providers, and AI coding agents.

Runtime Detection

Detects the current JavaScript runtime based on global variables, following the WinterCG Runtime Keys proposal.

import { runtime, runtimeInfo } from "std-env";

console.log(runtime); // "" | "node" | "deno" | "bun" | "workerd" ...
console.log(runtimeInfo); // { name: "node" }

Individual named exports: isNode, isBun, isDeno, isNetlify, isEdgeLight, isWorkerd, isFastly, isNub

[!NOTE] isNode is also true in Bun/Deno with Node.js compatibility mode. Use runtime === "node" for strict checks.

isNub detects Nub, which augments Node.js rather than replacing it. It is additive: isNode is also true and runtime stays "node".

See ./src/runtimes.ts for the full list.

Provider Detection

Detects the current CI/CD provider based on environment variables.

import { isCI, provider, providerInfo } from "std-env";

console.log({ isCI, provider, providerInfo });
// { isCI: true, provider: "github_actions", providerInfo: { name: "github_actions", ci: true } }

Use detectProvider() to re-run detection. See ./src/providers.ts for the full list.

Agent Detection

Detects if the environment is running inside an AI coding agent.

import { isAgent, agent, agentInfo } from "std-env";

console.log({ isAgent, agent, agentInfo });
// { isAgent: true, agent: "claude", agentInfo: { name: "claude" } }

Set the AI_AGENT env var to explicitly specify the agent name. GitHub Copilot aliases github_copilot_vscode_agent and github_copilot_cloud_agent are normalized to copilot. Use detectAgent() to re-run detection.

Supported agents: cursor, claude, copilot, devin, replit, gemini, codex, auggie, opencode, kiro, goose, pi, junie

Flags

import { env, isDevelopment, isProduction } from "std-env";

See ./src/flags.ts for details.

Environment

License

MIT