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:

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

.env

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.

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fyrer Environment Variables: Precedence and .env Files

Precedence order

Precedence table

.env file format

Per-task environment

​Precedence order

​Precedence table

​.env file format

​Per-task environment

Precedence order

Precedence table

.env file format

Per-task environment