Implementation:Promptfoo Promptfoo Environment Variables

Knowledge Sources	Promptfoo_Promptfoo
Domains	Configuration, Runtime
Last Updated	2026-02-14 07:45 GMT

Overview

Concrete tool for providing typed, centralized access to all environment variables used by promptfoo, including feature flags, API keys, and runtime configuration.

Description

The Environment_Variables module (envars.ts) acts as the single point of access for all environment variable reads across the codebase. It loads .env files via dotenv, defines a comprehensive typed EnvVars interface covering 100+ environment variables, and provides type-safe getter functions (getEnvString, getEnvBool, getEnvInt, getEnvFloat) that handle parsing, default values, and provider-specific overrides via the EnvOverrides object.

Usage

Import the getter functions whenever code needs to read an environment variable. This ensures consistent parsing and allows the EnvOverrides system to override values on a per-provider basis.

Code Reference

Source Location

• Repository: Promptfoo_Promptfoo
• File: src/envars.ts
• Lines: 1-553

Signature

export function getEnvString(
  key: keyof EnvVars,
  defaultValue?: string,
  env?: EnvOverrides
): string

export function getEnvBool(
  key: keyof EnvVars,
  defaultValue?: boolean,
  env?: EnvOverrides
): boolean

export function getEnvInt(
  key: keyof EnvVars,
  defaultValue?: number,
  env?: EnvOverrides
): number

export function getEnvFloat(
  key: keyof EnvVars,
  defaultValue?: number,
  env?: EnvOverrides
): number

export function isCI(): boolean

Import

import { getEnvString, getEnvBool, getEnvInt, getEnvFloat, isCI } from './envars';

I/O Contract

Inputs

Name	Type	Required	Description
key	keyof EnvVars	Yes	Environment variable name (type-checked)
defaultValue	string/boolean/number	No	Fallback if variable is unset
env	EnvOverrides	No	Provider-specific overrides object

Outputs

Name	Type	Description
value	string/boolean/number	Parsed environment variable value or default

Usage Examples

import { getEnvString, getEnvBool, getEnvInt } from './envars';

// Read API key with no default
const apiKey = getEnvString('OPENAI_API_KEY');

// Check feature flag with default
const cacheEnabled = getEnvBool('PROMPTFOO_CACHE_ENABLED', true);

// Get concurrency limit
const maxConcurrency = getEnvInt('PROMPTFOO_MAX_CONCURRENCY', 4);

// Check if running in CI
import { isCI } from './envars';
if (isCI()) {
  // Adjust behavior for CI environments
}

Related Pages

• Environment:Promptfoo_Promptfoo_Node_Runtime