obsidian-bases

name	obsidian-bases
description	Authors Obsidian Bases .base YAML: global filters, formulas, summaries, and table/cards/list/map views over note properties. Use when creating database-like views of notes, embedding ![[MyBase.base]], or editing Bases filters/formulas. Not for ordinary Markdown note CRUD (obsidian) or Dataview JS queries.
version	1.0.1
risk	unknown
source	https://github.com/kepano/obsidian-skills
date_added	2026-03-21

When to Use

• Use when creating or editing .base files in an Obsidian vault.
• Use for database-like note views with filters, formulas, summaries, or cards/tables.
• Use when the user asks about Obsidian Bases specifically, or mentions .base files, table views, card views, list views, map views, filters, or formulas.
• Use when the user wants to embed a Base in a Markdown note (![[MyBase.base]]).

Prerequisites

• Obsidian installed with Bases support (Obsidian 1.9+ or a build that includes the Bases feature).
• The target vault must be open and accessible on the Windows host (PowerShell).
• For map views, the Maps community plugin must be installed and latitude/longitude properties must exist on the target notes.

Procedure

1. Create the .base file

Create a .base file in the vault using valid YAML. On Windows (PowerShell):

New-Item -Path "C:\path\to\vault\MyBase.base" -ItemType File -Force

Then write YAML content into the file. The entire file must be valid YAML.

2. Define global filters

Add a top-level filters key to select which notes appear across ALL views. Filters can be a single string or a recursive object with and / or / not.

# Single filter string
filters: 'status == "done"'

# Recursive object
filters:
  and:
    - 'status == "done"'
    - 'priority > 3'
  or:
    - 'file.hasTag("book")'
    - 'file.hasTag("article")'
  not:
    - 'file.hasTag("archived")'

3. Define formulas (optional)

Add a formulas section to compute values from properties. Formula expressions are strings.

formulas:
  total: "price * quantity"
  status_icon: 'if(done, "✅", "⏳")'
  days_until_due: 'if(due_date, (date(due_date) - today()).days, "")'

4. Configure property display names (optional)

Use the properties section to set displayName for note properties, file properties, or formula properties.

properties:
  status:
    displayName: "Status"
  formula.days_until_due:
    displayName: "Days Until Due"
  file.ext:
    displayName: "Extension"

5. Define custom summaries (optional)

summaries:
  custom_summary_name: 'values.mean().round(3)'

6. Configure views

Add one or more views under views. Each view has a type (table, cards, list, or map), a name, and an order list specifying which properties to display.

views:
  - type: table
    name: "My Table"
    limit: 10
    groupBy:
      property: status
      direction: ASC
    filters:
      and:
        - 'status != "done"'
    order:
      - file.name
      - status
      - due_date
      - formula.days_until_due
    summaries:
      price: Sum
      formula.days_until_due: Average

7. Validate the YAML

Verify the file is valid YAML with no syntax errors. Check that:

• All referenced formula.X entries in order or properties have a matching definition in formulas.
• All strings containing special YAML characters (:, {, }, [, ], ,, &, *, #, ?, |, -, <, >, =, !, %, @, `) are quoted.
• Formulas containing double quotes are wrapped in single quotes.

On Windows (PowerShell), you can do a quick YAML lint if Python is available:

python -c "import yaml,sys; yaml.safe_load(open(r'C:\path\to\vault\MyBase.base',encoding='utf-8')); print('YAML OK')"

8. Test in Obsidian

Open the .base file in Obsidian to confirm the view renders correctly. If Obsidian shows a YAML error, re-check quoting rules and formula syntax.

Schema Reference

filters:
  and: []
  or: []
  not: []

formulas:
  formula_name: 'expression'

properties:
  property_name:
    displayName: "Display Name"
  formula.formula_name:
    displayName: "Formula Display Name"
  file.ext:
    displayName: "Extension"

summaries:
  custom_summary_name: 'values.mean().round(3)'

views:
  - type: table | cards | list | map
    name: "View Name"
    limit: 10
    groupBy:
      property: property_name
      direction: ASC | DESC
    filters:
      and: []
    order:
      - file.name
      - property_name
      - formula.formula_name
    summaries:
      property_name: Average

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

Property Types

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

Key Functions

Most commonly used functions. Load references/FUNCTIONS_REFERENCE.md when you need the complete reference for all types (Date, String, Number, List, File, Link, Object, RegExp).

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

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

# CORRECT
"(date(due_date) - today()).days"
"(now() - file.ctime).days"
"(date(due_date) - today()).days.round(0)"

# WRONG — will cause error
# "((date(due) - today()) / 86400000).round(0)"
# "(now() - file.ctime).round(0)"

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.

"now() + \"1 day\""
"today() + \"7d\""
"now() - file.ctime"
"(now() - file.ctime).days"

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

Examples

Task Tracker Base

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

    
     
    
      
         
    
       
       

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", "📖", 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:
      - 
       
       
       

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 in Markdown

![[MyBase.base]]

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

Pitfalls

YAML Syntax Errors

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

# WRONG — colon in unquoted string
displayName: Status: Active

# CORRECT
displayName: "Status: Active"

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

# WRONG — double quotes inside double quotes
formulas:
  label: "if(done, "Yes", "No")"

# CORRECT — single quotes wrapping double quotes
formulas:
  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. before calling number functions.

# 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.

# 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. Undefined formula references fail silently.

# This will fail silently if 'total' is not defined in formulas
order:
  - formula.total

# Fix: define it
formulas:
  total: "price * quantity"

Verification

1. YAML validity — Run a YAML parse check (if Python is available):

python -c "import yaml; yaml.safe_load(open(r'C:\path\to\vault\MyBase.base',encoding='utf-8')); print('YAML OK')"

Expected output: YAML OK

2. Formula references — Confirm every formula.X referenced in order, properties, or summaries has a matching key in the formulas section.

3. Render check — Open the .base file in Obsidian. The view should render without a YAML error banner. If an error appears, check quoting rules and formula syntax.

4. Embed check — Embed the base in a Markdown note with ![[MyBase.base]] and confirm the view appears inline.

References

• Bases Syntax
• Functions
• Views
• Formulas
• Load references/FUNCTIONS_REFERENCE.md when you need the complete function reference for all types (Date, String, Number, List, File, Link, Object, RegExp).

Limitations

• Use this skill only when the task clearly matches the scope described above.
• Do not treat the output as a substitute for environment-specific validation, testing, or expert review.
• Stop and ask for clarification if required inputs, permissions, safety boundaries, or success criteria are missing.