Obsidian Bases

This skill enables Claude Code to create and edit valid Obsidian Bases (.base files) including views, filters, formulas, and all related configurations.

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.

When to Use This Skill

• Creating database-like views of notes in Obsidian
• Building task trackers, reading lists, or project dashboards
• Filtering and organizing notes by properties or tags
• Creating calculated/formula fields
• Setting up table, card, list, or map views
• Working with .base files in an Obsidian vault

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, "check", "pending")'

  # 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
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

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	Description
contains(value)	Check substring
containsAll(...values)	All substrings present
containsAny(...values)	Any substring present
startsWith(query)	Starts with query
endsWith(query)	Ends with query
isEmpty()	Empty or not present
lower()	To lowercase
title()	To Title Case
trim()	Remove whitespace
replace(pattern, replacement)	Replace pattern
repeat(count)	Repeat string
reverse()	Reverse string
slice(start, end?)	Substring
split(separator, n?)	Split to list

Number Functions

Function	Description
abs()	Absolute value
ceil()	Round up
floor()	Round down
round(digits?)	Round to digits
toFixed(precision)	Fixed-point notation
isEmpty()	Not present

List Functions

Field: list.length

Function	Description
contains(value)	Element exists
containsAll(...values)	All elements exist
containsAny(...values)	Any element exists
filter(expression)	Filter by condition (uses value, index)
map(expression)	Transform elements (uses value, index)
reduce(expression, initial)	Reduce to single value (uses value, index, acc)
flat()	Flatten nested lists
join(separator)	Join to string
reverse()	Reverse order
slice(start, end?)	Sublist
sort()	Sort ascending
unique()	Remove duplicates
isEmpty()	No elements

File Functions

Function	Description
asLink(display?)	Convert to link
hasLink(otherFile)	Has link to file
hasTag(...tags)	Has any of the tags
hasProperty(name)	Has property
inFolder(folder)	In folder or subfolder

View Types

Table View

views:
  - type: table
    name: "My Table"
    order:
      - file.name
      - status
      - due_date
    summaries:
      price: Sum
      count: Average

Cards View

views:
  - type: cards
    name: "Gallery"
    order:
      - file.name
      - cover_image
      - description

List View

views:
  - type: list
    name: "Simple List"
    order:
      - file.name
      - status

Map View

Requires latitude/longitude properties and the Maps plugin.

views:
  - type: map
    name: "Locations"

Default Summary Formulas

Name	Input Type	Description
Average	Number	Mathematical mean
Min	Number	Smallest number
Max	Number	Largest number
Sum	Number	Sum of all numbers
Range	Number	Max - Min
Median	Number	Mathematical median
Stddev	Number	Standard deviation
Earliest	Date	Earliest date
Latest	Date	Latest date
Checked	Boolean	Count of true values
Unchecked	Boolean	Count of false values
Empty	Any	Count of empty values
Filled	Any	Count of non-empty values
Unique	Any	Count of unique values

Complete Examples

Task Tracker Base

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

formulas:
  days_until_due: 'if(due, ((date(due) - today()) / 86400000).round(0), "")'
  is_overdue: 'if(due, date(due) < today() && status != "done", false)'
  priority_label: 'if(priority == 1, "High", if(priority == 2, "Medium", "Low"))'

properties:
  status:
    displayName: Status
  formula.days_until_due:
    displayName: "Days Until Due"
  formula.priority_label:
    displayName: Priority

views:
  - type: table
    name: "Active Tasks"
    filters:
      and:
        - 'status != "done"'
    order:
      - file.name
      - status
      - formula.priority_label
      - due
      - formula.days_until_due
    groupBy:
      property: status
      direction: ASC
    summaries:
      formula.days_until_due: Average

  - type: table
    name: "Completed"
    filters:
      and:
        - 'status == "done"'
    order:
      - file.name
      - completed_date

Reading List Base

filters:
  or:
    - file.hasTag("book")
    - file.hasTag("article")

formulas:
  reading_time: 'if(pages, (pages * 2).toString() + " min", "")'
  status_icon: 'if(status == "reading", "reading", if(status == "done", "done", "to-read"))'
  year_read: 'if(finished_date, date(finished_date).year, "")'

properties:
  author:
    displayName: Author
  formula.status_icon:
    displayName: ""
  formula.reading_time:
    displayName: "Est. Time"

views:
  - type: cards
    name: "Library"
    order:
      - cover
      - file.name
      - author
      - formula.status_icon
    filters:
      not:
        - 'status == "dropped"'

  - type: table
    name: "Reading List"
    filters:
      and:
        - 'status == "to-read"'
    order:
      - file.name
      - author
      - pages
      - formula.reading_time

Project Notes Base

filters:
  and:
    - file.inFolder("Projects")
    - 'file.ext == "md"'

formulas:
  last_updated: 'file.mtime.relative()'
  link_count: 'file.links.length'

summaries:
  avgLinks: 'values.filter(value.isType("number")).mean().round(1)'

properties:
  formula.last_updated:
    displayName: "Updated"
  formula.link_count:
    displayName: "Links"

views:
  - type: table
    name: "All Projects"
    order:
      - file.name
      - status
      - formula.last_updated
      - formula.link_count
    summaries:
      formula.link_count: avgLinks
    groupBy:
      property: status
      direction: ASC

  - type: list
    name: "Quick List"
    order:
      - file.name
      - status

Daily Notes Index

filters:
  and:
    - file.inFolder("Daily Notes")
    - '/^\d{4}-\d{2}-\d{2}$/.matches(file.basename)'

formulas:
  word_estimate: '(file.size / 5).round(0)'
  day_of_week: 'date(file.basename).format("dddd")'

properties:
  formula.day_of_week:
    displayName: "Day"
  formula.word_estimate:
    displayName: "~Words"

views:
  - type: table
    name: "Recent Notes"
    limit: 30
    order:
      - file.name
      - formula.day_of_week
      - formula.word_estimate
      - file.mtime

Embedding Bases

Embed in Markdown files:

![[MyBase.base]]

<!-- Specific view -->
![[MyBase.base#View Name]]

YAML Quoting Rules

• Use single quotes for formulas containing double quotes: 'if(done, "Yes", "No")'
• Use double quotes for simple strings: "My View Name"
• Escape nested quotes properly in complex expressions

Common Patterns

Filter by Tag

filters:
  and:
    - file.hasTag("project")

Filter by Folder

filters:
  and:
    - file.inFolder("Notes")

Filter by Date Range

filters:
  and:
    - 'file.mtime > now() - "7d"'

Filter by Property Value

filters:
  and:
    - 'status == "active"'
    - 'priority >= 3'

Combine Multiple Conditions

filters:
  or:
    - and:
        - file.hasTag("important")
        - 'status != "done"'
    - and:
        - 'priority == 1'
        - 'due != ""'

References

• Bases Syntax
• Functions
• Views
• Formulas