Obsidian Bases

by kepano3ccff5338ea7No licenseListed Oct 8, 2026Updated Oct 8, 2026

Create and edit Obsidian Bases (.base files) with views, filters, formulas, and summaries. Use when working with .base files, creating database-like views of notes, or when the user mentions Bases, table views, card views, filters, or formulas in Obsidian.

Instructions onlyDocuments & Office

AI-generated overview

Creates and edits Obsidian Bases (.base) YAML files with filters, formulas, summaries, and table, card, list, or map views.

What it does: This skill guides the agent through authoring Obsidian Bases files: valid YAML with global and per-view filters, formula properties, display-name settings, custom summaries, and one or more views. It documents filter operators, file and note properties, formula syntax, duration and date arithmetic, view types, and default summary formulas. It also covers embedding bases in Markdown and troubleshooting YAML quoting and formula errors. The deliverable is a working .base file, not a rendered document.
When to use it: Use it when creating or editing .base files, building database-like views over notes, or when the user mentions Obsidian Bases, table or card views, filters, or formulas. It also fits debugging YAML or formula errors in an existing base.
Requirements: No scripts; instructions only. Requires Obsidian to create and test .base files, and the Maps community plugin for map views. A bundled reference file documents the full function set.

Obsidian Bases Skill

Workflow

Create the file: Create a .base file in the vault with valid YAML content
Define scope: Add filters to select which notes appear (by tag, folder, property, or date)
Add formulas (optional): Define computed properties in the formulas section
Configure views: Add one or more views (table, cards, list, or map) with order specifying which properties to display
Validate: Verify the file is valid YAML with no syntax errors. Check that all referenced properties and formulas exist. Common issues: unquoted strings containing special YAML characters, mismatched quotes in formula expressions, referencing formula.X without defining X in formulas
Test in Obsidian: Open the .base file in Obsidian to confirm the view renders correctly. If it shows a YAML error, check quoting rules below

Schema

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

yaml

# Global filters apply to ALL views in the basefilters:  # Can be a single filter string  # OR a recursive filter object with exactly ONE key: and, or, or not  and:    - 'status == "active"'    - not:        - 'file.hasTag("archived")'
# Define formula properties that can be used across all viewsformulas:  formula_name: 'expression'
# Configure display names and settings for propertiesproperties:  property_name:    displayName: "Display Name"  formula.formula_name:    displayName: "Formula Display Name"  file.ext:    displayName: "Extension"
# Define custom summary formulassummaries:  custom_summary_name: 'values.mean().round(3)'
# Define one or more viewsviews:  - 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 follow the same rules      and:        - 'status == "active"'    order:                       # Properties to display in order      - file.name      - property_name      - formula.formula_name    summaries:                   # Map properties to summary formulas      property_name: Average

# Global filters apply to ALL views in the basefilters:  # Can be a single filter string  # OR a recursive filter object with exactly ONE key: and, or, or not  and:    - 'status == "active"'    - not:        - 'file.hasTag("archived")'
# Define formula properties that can be used across all viewsformulas:  formula_name: 'expression'
# Configure display names and settings for propertiesproperties:  property_name:    displayName: "Display Name"  formula.formula_name:    displayName: "Formula Display Name"  file.ext:    displayName: "Extension"
# Define custom summary formulassummaries:  custom_summary_name: 'values.mean().round(3)'
# Define one or more viewsviews:  - 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 follow the same rules      and:        - 'status == "active"'    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

yaml

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

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

Filter Operators

Properties

Three Types of Properties

Note properties - From frontmatter: note.author or just author
File properties - File metadata: file.name, file.mtime, etc.
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.

yaml

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")'
  # Calculate days since created (use .days for Duration)  days_old: '(now() - file.ctime).days'
  # Calculate days until due date  days_until_due: 'if(due_date, (date(due_date) - today()).days, "")'

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")'
  # Calculate days since created (use .days for Duration)  days_old: '(now() - file.ctime).days'
  # Calculate days until due date  days_until_due: 'if(due_date, (date(due_date) - today()).days, "")'

Key Functions

Most commonly used functions. For the complete reference of all types (Date, String, Number, List, File, Link, Object, RegExp), see FUNCTIONS_REFERENCE.md [blocked].

Function	Signature	Description
`date()`	`date(string): date`	Parse string to date (`YYYY-MM-DD HH:mm:ss`)
`now()`	`now(): date`	Current date and time
`today()`	`today(): date`	Current date (time = 00:00:00)
`if()`	`if(condition, trueResult, falseResult?)`	Conditional
`duration()`	`duration(string): duration`	Parse duration string
`file()`	`file(path): file`	Get file object
`link()`	`link(path, display?): Link`	Create a link

Duration Type

When subtracting two dates, the result is a Duration type (not a number).

Duration Fields: duration.days, duration.hours, duration.minutes, duration.seconds, duration.milliseconds

IMPORTANT: Duration does NOT support .round(), .floor(), .ceil() directly. Access a numeric field first (like .days), then apply number functions.

yaml

# CORRECT: Calculate days between dates"(date(due_date) - today()).days"                    # Returns number of days"(now() - file.ctime).days"                          # Days since created"(date(due_date) - today()).days.round(0)"           # Rounded days
# WRONG - will cause error:# "((date(due) - today()) / 86400000).round(0)"      # Duration doesn't support division then round

# CORRECT: Calculate days between dates"(date(due_date) - today()).days"                    # Returns number of days"(now() - file.ctime).days"                          # Days since created"(date(due_date) - today()).days.round(0)"           # Rounded days
# WRONG - will cause error:# "((date(due) - today()) / 86400000).round(0)"      # Duration doesn't support division then round

Date Arithmetic

yaml

# Duration units: y/year/years, M/month/months, d/day/days,#                 w/week/weeks, h/hour/hours, m/minute/minutes, s/second/seconds"now() + \"1 day\""       # Tomorrow"today() + \"7d\""        # A week from today"now() - file.ctime"      # Returns Duration"(now() - file.ctime).days"  # Get days as number

# Duration units: y/year/years, M/month/months, d/day/days,#                 w/week/weeks, h/hour/hours, m/minute/minutes, s/second/seconds"now() + \"1 day\""       # Tomorrow"today() + \"7d\""        # A week from today"now() - file.ctime"      # Returns Duration"(now() - file.ctime).days"  # Get days as number

View Types

Table View

yaml

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

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

Cards View

yaml

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

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

List View

Map View

Requires latitude/longitude properties and the Maps community plugin.

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
`Range`	Date	Latest - Earliest
`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

yaml

filters:  and:    - file.hasTag("task")    - 'file.ext == "md"'
formulas:  days_until_due: 'if(due, (date(due) - today()).days, "")'  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

filters:  and:    - file.hasTag("task")    - 'file.ext == "md"'
formulas:  days_until_due: 'if(due, (date(due) - today()).days, "")'  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

yaml

filters:  or:    - file.hasTag("book")    - file.hasTag("article")
formulas:  reading_time: 'if(pages, (pages * 2).toString() + " min", "")'  status_icon: 'if(status == "reading", "📖", if(status == "done", "✅", "📚"))'  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

filters:  or:    - file.hasTag("book")    - file.hasTag("article")
formulas:  reading_time: 'if(pages, (pages * 2).toString() + " min", "")'  status_icon: 'if(status == "reading", "📖", if(status == "done", "✅", "📚"))'  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

Daily Notes Index

yaml

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

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:

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

Troubleshooting

YAML Syntax Errors

Unquoted special characters: Strings containing :, {, }, [, ], ,, &, *, #, ?, |, -, <, >, =, !, %, @, ` must be quoted.

yaml

# WRONG - colon in unquoted stringdisplayName: Status: Active
# CORRECTdisplayName: "Status: Active"

# WRONG - colon in unquoted stringdisplayName: Status: Active
# CORRECTdisplayName: "Status: Active"

Mismatched quotes in formulas: When a formula contains double quotes, wrap the entire formula in single quotes.

yaml

# WRONG - double quotes inside double quotesformulas:  label: "if(done, "Yes", "No")"
# CORRECT - single quotes wrapping double quotesformulas:  label: 'if(done, "Yes", "No")'

# WRONG - double quotes inside double quotesformulas:  label: "if(done, "Yes", "No")"
# CORRECT - single quotes wrapping double quotesformulas:  label: 'if(done, "Yes", "No")'

Common Formula Errors

Duration math without field access: Subtracting dates returns a Duration, not a number. Always access .days, .hours, etc.

yaml

# WRONG - Duration is not a number"(now() - file.ctime).round(0)"
# CORRECT - access .days first, then round"(now() - file.ctime).days.round(0)"

# WRONG - Duration is not a number"(now() - file.ctime).round(0)"
# CORRECT - access .days first, then round"(now() - file.ctime).days.round(0)"

Missing null checks: Properties may not exist on all notes. Use if() to guard.

yaml

# WRONG - crashes if due_date is empty"(date(due_date) - today()).days"
# CORRECT - guard with if()'if(due_date, (date(due_date) - today()).days, "")'

# WRONG - crashes if due_date is empty"(date(due_date) - today()).days"
# CORRECT - guard with if()'if(due_date, (date(due_date) - today()).days, "")'

Referencing undefined formulas: Ensure every formula.X in order or properties has a matching entry in formulas.

yaml

# This will fail silently if 'total' is not defined in formulasorder:  - formula.total
# Fix: define itformulas:  total: "price * quantity"

# This will fail silently if 'total' is not defined in formulasorder:  - formula.total
# Fix: define itformulas:  total: "price * quantity"

References

Bases Syntax
Functions
Views
Formulas
Complete Functions Reference [blocked]

Source and attribution

Source:kepano/obsidian-skillsinskills/obsidian-basesat commit3ccff53

License: No license

Content belongs to its original authors. SourceWeft indexes it from a public repository.

Report or request removal

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

Obsidian Bases

Obsidian Bases Skill

Workflow

Schema

Filter Syntax

Filter Structure

Filter Operators

Properties

Three Types of Properties

File Properties Reference

The this Keyword

Formula Syntax

Key Functions

Duration Type

Date Arithmetic

View Types

Table View

Cards View

List View

Map View

Default Summary Formulas

Complete Examples

Task Tracker Base

Reading List Base

Daily Notes Index

Embedding Bases

YAML Quoting Rules

Troubleshooting

YAML Syntax Errors

Common Formula Errors

References

Source and attribution

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