System Configuration

config/system.yaml controls how the Dune engine behaves — caching, content parsing, image handling, and more.

Full reference

# Content settings
content:
  dir: "content"                  # content directory (relative to site root)
  markdown:
    extra: true                   # extended markdown features
    auto_links: true              # auto-link URLs in text
    auto_url_links: true          # auto-link bare URLs

# Cache settings
cache:
  enabled: true
  driver: "filesystem"            # "memory", "filesystem", or "kv"
  lifetime: 3600                  # seconds
  check: "file"                   # "file" (mtime), "hash", or "none"

# Image processing
images:
  default_quality: 80             # JPEG/WebP quality (1-100)
  cache_dir: ".dune/cache/images"
  allowed_sizes: [320, 640, 768, 1024, 1280, 1536, 1920]   # prevent resize attacks

# Language support
languages:
  supported: ["en"]
  default: "en"
  include_default_in_url: false   # if true: /en/page, if false: /page

# Typography
typography:
  orphan_protection: true         # prevent single-word last lines in paragraphs

# Debug mode
debug: false

# Timezone
timezone: "UTC"

Cache drivers

Driver	Storage	Best for
`filesystem`	`.dune/cache/` directory	Local development, traditional servers
`memory`	In-process memory	Development, small sites
`kv`	Deno KV store	Deno Deploy, edge deployment

Cache invalidation

The check field determines how Dune detects stale content:

Strategy	How it works	Trade-off
`file`	Compare file modification time	Fast, misses renames
`hash`	Hash file content	Accurate, slightly slower
`none`	Never invalidate	Fastest, manual rebuild needed

Environment-specific overrides

Development and production often need different settings. Put overrides in config/env/{name}/:

config/env/development/system.yaml:

debug: true
cache:
  enabled: false

config/env/production/system.yaml:

debug: false
cache:
  enabled: true
  driver: "kv"
  check: "hash"

Environment detection

Dune detects the current environment in this order:

DUNE_ENV environment variable (explicit)
DENO_DEPLOYMENT_ID exists → "production" (Deno Deploy auto-detection)
Default: "development"

Set DUNE_ENV in your deploy script:

DUNE_ENV=production dune serve

Typography

`orphan_protection`

Default: true

When enabled, Dune inserts a non-breaking space ( ) before the last word of every rendered paragraph. This prevents typographic orphans — single words stranded alone on the last line.

Disable if you're post-processing HTML output yourself or if your theme handles orphan prevention:

typography:
  orphan_protection: false