Obsidian Bases

# Obsidian Bases ## Summary This reference documents the complete specification for Obsidian Bases, a feature that enables creation of dynamic, customizable views of notes in an Obsidian vault. It covers file structure, syntax rules, formulas, filters, view types, and practical implementation examples.

Overview

Obsidian Bases are YAML-based files that define dynamic views of notes in an Obsidian vault. A Base file can contain multiple views, global filters, formulas, property configurations, and custom summaries. This specification enables Claude Code to create and edit valid Obsidian Bases (.base files) including all related configurations.

File Format

Base files use the .base extension and contain valid YAML. They can also be embedded in Markdown code blocks.

Complete Schema

# Global filters apply to ALL views in the base
filters:
  # Can be a single filter string
  # OR a recursive filter object with and/or/not
  and: []
  or: []
  not: []
 
# Define formula properties that can be used across all views
formulas:
  formula_name: 'expression'
 
# Configure display names and settings for properties
properties:
  property_name:
    displayName: "Display Name"
  formula.formula_name:
    displayName: "Formula Display Name"
  file.ext:
    displayName: "Extension"
 
# Define custom summary formulas
summaries:
  custom_summary_name: 'values.mean().round(3)'
 
# Define one or more views
views:
  - type: table | cards | list | map
    name: "View Name"
    limit: 10                    # Optional: limit results
    groupBy:                     # Optional: group results
      property: property_name
      direction: ASC | DESC
    filters:                     # View-specific filters
      and: []
    order:                       # Properties to display in order
      - file.name
      - property_name
      - formula.formula_name
    summaries:                   # Map properties to summary formulas
      property_name: Average

Filter Syntax

Filters narrow down results. They can be applied globally or per-view.

Filter Structure

# Single filter
filters: 'status == "done"'
 
# AND - all conditions must be true
filters:
  and:
    - 'status == "done"'
    - 'priority > 3'
 
# OR - any condition can be true
filters:
  or:
    - 'file.hasTag("book")'
    - 'file.hasTag("article")'
 
# NOT - exclude matching items
filters:
  not:
    - 'file.hasTag("archived")'
 
# Nested filters
filters:
  or:
    - file.hasTag("tag")
    - and:
        - file.hasTag("book")
        - file.hasLink("Textbook")
    - not:
        - file.hasTag("book")
        - file.inFolder("Required Reading")

Filter Operators

Operator	Description
==	equals
!=	not equal
>	greater than
<	less than
>=	greater than or equal
<=	less than or equal
&&	logical and
||	logical or
!	logical not

Properties

Three Types of Properties

1. Note properties - From frontmatter: note.author or just author
2. File properties - File metadata: file.name, file.mtime, etc.
3. Formula properties - Computed values: formula.my_formula

File Properties Reference

Property	Type	Description
file.name	String	File name
file.basename	String	File name without extension
file.path	String	Full path to file
file.folder	String	Parent folder path
file.ext	String	File extension
file.size	Number	File size in bytes
file.ctime	Date	Created time
file.mtime	Date	Modified time
file.tags	List	All tags in file
file.links	List	Internal links in file
file.backlinks	List	Files linking to this file
file.embeds	List	Embeds in the note
file.properties	Object	All frontmatter properties

The this Keyword

• In main content area: refers to the base file itself
• When embedded: refers to the embedding file
• In sidebar: refers to the active file in main content

Formula Syntax

Formulas compute values from properties. Defined in the formulas section.

formulas:
  # Simple arithmetic
  total: "price * quantity"
  
  # Conditional logic
  status_icon: 'if(done, "✅", "⏳")'
  
  # String formatting
  formatted_price: 'if(price, price.toFixed(2) + " dollars")'
  
  # Date formatting
  created: 'file.ctime.format("YYYY-MM-DD")'
  
  # Complex expressions
  days_old: '((now() - file.ctime) / 86400000).round(0)'

Functions Reference

Global Functions

Function	Signature	Description
date()	date(string): date	Parse string to date. Format: YYYY-MM-DD HH:mm:ss
duration()	duration(string): duration	Parse duration string
now()	now(): date	Current date and time
today()	today(): date	Current date (time = 00:00:00)
if()	if(condition, trueResult, falseResult?)	Conditional
min()	min(n1, n2, ...): number	Smallest number
max()	max(n1, n2, ...): number	Largest number
number()	number(any): number	Convert to number
link()	link(path, display?): Link	Create a link
list()	list(element): List	Wrap in list if not already
file()	file(path): file	Get file object
image()	image(path): image	Create image for rendering
icon()	icon(name): icon	Lucide icon by name
html()	html(string): html	Render as HTML
escapeHTML()	escapeHTML(string): string	Escape HTML characters

Any Type Functions

Function	Signature	Description
isTruthy()	any.isTruthy(): boolean	Coerce to boolean
isType()	any.isType(type): boolean	Check type
toString()	any.toString(): string	Convert to string

Date Functions & Fields

Fields: date.year, date.month, date.day, date.hour, date.minute, date.second, date.millisecond

Function	Signature	Description
date()	date.date(): date	Remove time portion
format()	date.format(string): string	Format with Moment.js pattern
time()	date.time(): string	Get time as string
relative()	date.relative(): string	Human-readable relative time
isEmpty()	date.isEmpty(): boolean	Always false for dates

Date Arithmetic

# Duration units: y/year/years, M/month/months, d/day/days, 
#                 w/week/weeks, h/hour/hours, m/minute/minutes, s/second/seconds
 
# Add/subtract durations
"date + \"1M\""           # Add 1 month
"date - \"2h\""           # Subtract 2 hours
"now() + \"1 day\""       # Tomorrow
"today() + \"7d\""        # A week from today
 
# Subtract dates for millisecond difference
"now() - file.ctime"
 
# Complex duration arithmetic
"now() + (duration('1d') * 2)"

String Functions

Field: string.length

Function	Signature	Description
contains()	`string.contains(value): boolean