> ## Documentation Index
> Fetch the complete documentation index at: https://fyrer.vinm.me/llms.txt
> Use this file to discover all available pages before exploring further.

# Configuring Packages in fyrer.yml: A Full Reference

> Reference for all package configuration fields in fyrer.yml: name, root, env, env_file, and tasks — the building blocks of your monorepo.

Each entry in the `packages` list represents one directory of your monorepo. A package groups related tasks and gives them a shared name, root path, and environment. Tasks within the same package can reference each other by their bare name, while tasks in other packages are referenced as `package:task`.

## Package fields

<ParamField body="name" type="string" required>
  Unique name for the package. Used in task specifiers like `web:dev` and as the prefix in log output.
</ParamField>

<ParamField body="root" type="string" required>
  Relative path from the `fyrer.yml` directory to the package root. Must exist. Cannot be absolute.
</ParamField>

<ParamField body="env" type="map<string, string>">
  Environment variables applied to all tasks in this package. Takes precedence over root-level `env`.
</ParamField>

<ParamField body="env_file" type="string">
  Path to a `.env` file, relative to the package root. Loaded for all tasks in this package.
</ParamField>

<ParamField body="tasks" type="map<string, TaskConfig>">
  Map of task name → task configuration. See the [Tasks reference](/configuration/tasks).
</ParamField>

## Example

The following snippet is drawn from the [acme-corp example](https://github.com/07CalC/fyrer/tree/main/examples/acme-corp) and shows four packages across multiple languages:

```yaml fyrer.yml theme={null}
packages:
  # TypeScript / Bun — shared UI library
  - name: ui
    root: ./packages/ui
    env:
      NODE_ENV: production
    env_file: .env
    tasks:
      build:
        cmd: bun build src/index.ts --outdir dist
        inputs:
          - src/**
          - package.json
          - tsconfig.json
        outputs:
          - dist/**
        ignore:
          - node_modules/**
        cache: true

  # TypeScript / Bun — web application
  - name: web
    root: ./apps/web
    env:
      PORT: "3000"
      API_URL: http://localhost:8080
    env_file: .env
    tasks:
      dev:
        cmd: bun --watch src/index.ts
        depends_on:
          - ui:build
        persistent: true

  # Rust / Cargo — API server
  - name: api
    root: ./apps/api
    env_file: .env
    tasks:
      dev:
        cmd: cargo run
        depends_on:
          - shared:build
        persistent: true

  # Go — background worker
  - name: worker
    root: ./apps/worker
    env:
      ADDR: ":9000"
    tasks:
      build:
        cmd: go build -o bin/worker .
        depends_on:
          - core:build
        outputs:
          - bin/worker
        cache: true
```

## Validation rules

* **Package names must be unique** across the entire `packages` list.
* **`root` must be a relative path** — absolute paths are rejected.
* **`root` must exist** on disk at the time fyrer starts.
* **`env_file` must be relative** and must exist on disk at the time fyrer starts.

<Tip>
  Use short, lowercase package names (e.g., `api`, `web`, `ui`) — they appear in log prefixes and task specifiers like `web:dev`.
</Tip>