Overview

A .base file is a YAML Base Definition. Opening it shows one of its views — a read-only List View, Table View, Cards View, or Graph View; use the Edit/View toggle to edit its YAML source.

formulas:
  ppu: (price / count).toFixed(2)

summaries:
  roundedAverage: values.mean().round(2)

filters:
  and:
    - 'file.inFolder("Projects")'
    - 'status != "archived"'
    - 'file.mtime > now() - "1 week"'

properties:
  file.name:
    displayName: Note
  file.mtime:
    displayName: Updated

views:
  - type: table
    name: Recently updated
    limit: 25
    order:
      - file.name
      - status
      - formula.ppu
      - file.mtime
    sort:
      - property: file.mtime
        direction: DESC
    groupBy:
      property: status
      direction: ASC
  - type: graph
    name: Link map

This page covers everything shared by all view types. Each view type documents its particular settings on its own page:

• List
• Table
• Cards
• Graph

Views

Every Base must declare one or more named views under views. The first view is selected by default; use the view switcher to change views without editing the file.

The supported view types are list, table, cards, and graph. View names must be non-empty and unique.

Global filters and per-view filters are combined with AND.

Settings that belong to another view type are silently ignored, so a stray rowHeight: on a list view is harmless. Unknown keys still fail validation, so typos are never swallowed.

Properties

order controls displayed property order. When it is omitted, the view shows file.name.

The optional properties mapping configures display labels:

properties:
  file.name:
    displayName: Note

A display name is used at every label site: table headers, indented list property labels, summary labels, and card property labels. Without one, the label falls back to the property path’s last segment.

Formula properties

The formulas mapping declares named formulas usable anywhere a property can appear — in order, sort, groupBy, summaries, filters, and even inside other formulas (circular references are rejected):

formulas:
  ppu: (price / count).toFixed(2)

Formula names are referenced with formula.<name> or the shorthand shown above.

Supported file properties are:

• file.name: file name without its extension. It is rendered as a link to the file.
• file.path: normalized relative path.
• file.ext: file extension.
• file.folder: normalized relative folder.
• file.size: file size, displayed as a readable byte value.
• file.mtime: modified time, displayed as an ISO-8601 UTC date and time.
• file.ctime: created time, same display as file.mtime.
• file.links: all resolved outgoing links from the file. Each link is interactive.
• file.embeds: resolved embed targets (![[...]]) from the file.
• file.backlinks: files whose resolved links point here.
• file.tags: tags from YAML frontmatter.
• file.properties: the complete frontmatter object.

Note properties are read from Markdown frontmatter. Scalar values, lists, and nested objects can be displayed. Missing and null values are empty. Explicit wikilink values such as [[Other Note]] are interactive.

Expressions

Filters, formulas, custom summaries, class filters, and date arithmetic share one expression language. Expressions support arithmetic (+, -, *, /, %, parentheses), inline boolean operators (!, &&, ||), comparisons (==, !=, >, >=, <, <=), string/number/boolean/null literals, and function calls.

Property paths may use shorthand, dot notation, or bracket notation:

filters:
  and:
    - 'status == "active"'
    - 'note.project.owner == "Romain"'
    - 'note["project status"] != null'
    - 'price > 5 && !archived'
    - 'tags.contains("reading")'
    - 'name.startsWith("Read")'
    - 'file.hasTag("reading")'
    - 'file.hasLink("Index")'
    - '(price / age) > 5'
    - 'if(done, file.size, 0) > 1024'

Structured filter objects are also accepted: {and: [...]}, {or: [...]}, and {not: ...} wrap expression strings.

Supported functions include if, min, max, abs, round, length, lower, upper, trim, ltrim, rtrim, replace, substr, instr, and the date functions date(), datetime(), time(), and julianday(). Supported methods include .contains(), .startsWith(), .endsWith(), .toFixed(n), .round(n), .lower(), .upper(), .trim(), .date(), and moment-style .format("YYYY-MM-DD").

Functions outside this whitelist fail Base validation with a precise error rather than being approximated.

Dates And Durations

Dates are canonical ISO-8601 UTC values; file.mtime and file.ctime compare chronologically against them. Duration literals combine with dates using + and -:

filters:
  - 'file.mtime > now() - "1 week"'
  - 'file.ctime + "1M" < today()'

Duration units are y, M (months), w, d, h, m (minutes), and s. Subtracting two dates yields milliseconds. now() and today() are frozen once per refresh so results stay internally consistent. All date handling is UTC.

Grouping

A list, table, or cards view may group rows by one property:

groupBy:
  property: status
  direction: ASC

Groups are ordered by their key value using groupBy.direction; rows within each group follow sort. Each view type renders a non-interactive header showing the key value and row count. Missing or empty keys form an “Empty” group rendered last. limit counts rows only — headers never consume it.

Graph views do not use groupBy; they classify nodes with classes instead.

Summaries

Default summaries are selected by name in a view’s summaries mapping: Average, Min, Max, Sum, Range, Median, Stddev, Earliest, Latest, Checked, Unchecked, Empty, Filled, and Unique. Range uses days for date-typed sources like file.mtime.

Custom summaries are declared globally from the values keyword and must reduce to one aggregate (values.mean(), .min(), .max(), .sum(), or .count()) followed by optional .round(n) and .abs() calls in any order:

summaries:
  roundedAverage: values.mean().round(2)
views:
  - type: table
    name: T
    summaries:
      price: Average
      score: roundedAverage

Summaries aggregate every matching row, before limit. Each view places them differently:

• Table: a footer under the summarized columns, plus a per-group strip in each group header.
• List: a Summary entry at the top of the list, or one inside each group when grouped; each entry reads Pages Sum: 350.
• Cards: a header above the grid for the whole set, plus a per-group line under each group title.
• Graph: a box under the legend, one entry per line.

Whole-set summaries aggregate every matching row; grouped views additionally show one summary per group, computed over that group’s rows only.

Sorting And Limits

sort controls row order and accepts multiple property/direction entries:

sort:
  - property: status
    direction: ASC
  - property: file.mtime
    direction: DESC

Rows are filtered, sorted, tie-broken by normalized path, and then limited. limit must be between 1 and 50,000. A view without an explicit limit is still bounded by the 50,000-row safety ceiling, and the view reports how many matching files were omitted.

Deferred Syntax

The following Bases features cause a validation error rather than being silently ignored:

• Embedded Base blocks in Markdown.
• Map layouts and plugin-provided view types.
• Dynamic durations stored in properties (duration literals work).
• Custom summaries beyond aggregate-plus-rounding chains.
• Fan-out of list-valued group keys into multiple groups.
• The this context for bases opened from another file or sidebar.
• View-local search, inline property editing, copy/export actions, and creating files from a view.