fyrer Environment Variables: Precedence and .env Files

fyrer merges environment variables from multiple sources before running each task. Higher-precedence sources override lower ones, so you can set sensible defaults at the root level and override them precisely at the task level.

Precedence order

From lowest to highest precedence:

1. Root-level env (in fyrer.yml)
2. Package env_file (loaded from the file, relative to the package root)
3. Package-level env
4. Task env_file
5. Task-level env

Precedence table

Precedence	Source	Example
1 (lowest)	Root env in fyrer.yml	NODE_ENV: development
2	Package env_file	.env file at the package root
3	Package env	PORT: "3000" in package config
4	Task env_file	.env.local for a specific task
5 (highest)	Task env	PORT: "8080" in task config

.env file format

fyrer's .env parser is intentionally simple:

• Plain KEY=VALUE pairs, one per line.
• Blank lines are ignored.
• Lines starting with # are ignored (comments).
• No shell variable expansion — values are taken literally.

NODE_ENV=production
PORT=3000
# This is a comment

Per-task environment

Task-level env and env_file are useful when the same logical task (e.g., build) needs different settings depending on the context — for example, a production build that requires a different NODE_ENV or API endpoint than the development build:

tasks:
  build:
    cmd: bun build src/index.ts --outdir dist
    env:
      NODE_ENV: production
    env_file: .env.production
  dev:
    cmd: bun --watch src/index.ts
    env:
      NODE_ENV: development
    env_file: .env.local

✓

Add secret .env files to .gitignore. fyrer loads them at runtime but never echoes their contents in logs.