Obsidian Bases Skill

Workflow

1. Create or open the target .base file and keep it valid YAML.
2. Define scope with the smallest useful filters.
3. Prefer existing file metadata and note properties before inventing new schema.
4. Add formulas only when the requested view cannot be expressed with raw properties.
5. Add one or more views with a clear order and optional grouping or summaries.
6. Validate YAML syntax, formula references, and quoted strings before finishing.

Property Discipline

Prefer Obsidian-native file properties and existing note properties before introducing new frontmatter fields.

• Use file.name, file.basename, file.folder, file.path, file.ext, file.ctime, file.mtime, file.tags, file.links, file.backlinks, file.embeds, and file.properties when they satisfy the request.
• Prefer file.hasTag(...), file.inFolder(...), and file.hasLink(...) for scope filters instead of adding duplicate custom metadata.
• Do not add custom properties such as status, priority, due, category, type, author, pages, or cover unless the user asks for them, the vault already uses them, or the requested view cannot be built from native metadata.
• When custom note properties are needed, keep them minimal and make the Base consume the existing schema rather than inventing extra fields.

Minimal Schema

Base files use the .base extension and contain valid YAML.

filters:
  and: []

formulas:
  age_days: '(now() - file.ctime).days'

properties:
  formula.age_days:
    displayName: "Age (days)"

views:
  - type: table
    name: "All Notes"
    order:
      - file.name
      - formula.age_days

Filters

Use string expressions for simple cases and nested and / or / not objects when the logic needs structure.

filters:
  and:
    - 'file.ext == "md"'
    - file.hasTag("project")

filters:
  or:
    - file.hasTag("book")
    - and:
        - file.inFolder("Reading")
        - 'status != "done"'

Prefer global filters for the overall dataset and per-view filters only when one view needs a narrower slice.

Formulas

Formulas are shared computed properties. Keep them null-safe and easy to read.

formulas:
  days_until_due: 'if(due_date, (date(due_date) - today()).days, "")'
  day_of_week: 'date(file.basename).format("dddd")'

Common rules:

• Date subtraction returns a Duration, so access .days, .hours, or another numeric field before rounding.
• Guard optional properties with if() instead of assuming every note has the field.
• Every formula.X used in properties, order, or summaries must exist in formulas.

Views

Supported view types are table, cards, list, and map.

• Use table for sortable indexes and status views.
• Use cards for gallery-style browsing with cover or summary fields.
• Use list for compact navigation.
• Use map only when the vault already has latitude and longitude style properties and the Maps plugin is relevant.

Example:

views:
  - type: table
    name: "Active Tasks"
    filters:
      and:
        - 'status != "done"'
    order:
      - file.name
      - status
      - due_date
    groupBy:
      property: status
      direction: ASC
    summaries:
      due_date: Latest

Common Pitfalls

• Quote strings that contain YAML-special characters such as :, #, [, ], {, }, or ,.
• Wrap formulas containing double quotes in single quotes.
• Do not reference formula.X unless X is defined in formulas.
• Reuse existing note properties when possible instead of creating a new tracking schema for every view.

References

• Bases Syntax
• Functions
• Views
• Formulas
• Complete Functions Reference