> ## Documentation Index
> Fetch the complete documentation index at: https://mintlify.com/obsidianmd/obsidian-help/llms.txt
> Use this file to discover all available pages before exploring further.

# Bases syntax

> Reference for the .base file format. Learn the structure of filters, formulas, properties, summaries, and views in a base configuration file.

When you create a base in Obsidian, it is saved as a `.base` file. Bases are typically edited through the app interface, but you can also edit the underlying syntax directly or write it in a `base` code block embedded in a Markdown note.

Bases syntax is YAML-based. Filters and formulas share the same expression language.

## Complete example

Here is a fully configured `.base` file:

```yaml theme={null}
filters:
  or:
    - file.hasTag("tag")
    - and:
        - file.hasTag("book")
        - file.hasLink("Textbook")
    - not:
        - file.hasTag("book")
        - file.inFolder("Required Reading")
formulas:
  formatted_price: 'if(price, price.toFixed(2) + " dollars")'
  ppu: "(price / age).toFixed(2)"
properties:
  status:
    displayName: Status
  formula.formatted_price:
    displayName: "Price"
  file.ext:
    displayName: Extension
summaries:
  customAverage: 'values.mean().round(3)'
views:
  - type: table
    name: "My table"
    limit: 10
    groupBy:
      property: note.age
      direction: DESC
    filters:
      and:
        - 'status != "done"'
        - or:
            - "formula.ppu > 5"
            - "price > 2.1"
    order:
      - file.name
      - file.ext
      - note.age
      - formula.ppu
      - formula.formatted_price
    summaries:
      formula.ppu: Average
```

## Sections

### `filters`

The `filters` section narrows which files the base includes. Without filters, a base shows every file in your vault.

Filters can be applied at two levels:

1. **Global** — under the top-level `filters` key. Applies to all views.
2. **Per-view** — inside an individual view's `filters` key. Applies only to that view.

Both levels are combined with `AND` when evaluating a view.

```yaml theme={null}
# Simple filter
filters:
  and:
    - file.hasTag("tag")

# Complex filter with nested logic
filters:
  or:
    - file.hasTag("tag")
    - and:
        - file.hasTag("book")
        - file.hasLink("Textbook")
    - not:
        - file.hasTag("book")
        - file.inFolder("Required Reading")
```

A filter statement is any expression that evaluates to truthy or falsey for a given file. This includes comparisons and function calls.

### `formulas`

The `formulas` section defines computed properties available across all views:

```yaml theme={null}
formulas:
  formatted_price: 'if(price, price.toFixed(2) + " dollars")'
  ppu: "(price / age).toFixed(2)"
```

Formulas are stored as strings in YAML. Use nested quotes for text literals. A formula's output type is determined by the data and functions used — formulas are not constrained to strings at runtime.

Reference property types in formulas:

| Type            | Syntax                        | Example       |
| --------------- | ----------------------------- | ------------- |
| Note property   | `property` or `note.property` | `price`       |
| File property   | `file.name`, `file.size`      | `file.mtime`  |
| Another formula | `formula.name`                | `formula.ppu` |

### `properties`

The `properties` section stores display configuration for properties:

```yaml theme={null}
properties:
  status:
    displayName: Status
  formula.formatted_price:
    displayName: "Price"
  file.ext:
    displayName: Extension
```

Display names are used in column headers and UI labels. They are not used in filters or formulas.

### `summaries`

The `summaries` section defines custom summary formulas. In the `values` expression, `values` is a list of all values for that property across every row in the result set:

```yaml theme={null}
summaries:
  customAverage: 'values.mean().round(3)'
```

Default summary formulas are also available without defining them here:

| Name      | Input type | Description                            |
| --------- | ---------- | -------------------------------------- |
| Average   | Number     | Mean of all values                     |
| Min       | Number     | Smallest value                         |
| Max       | Number     | Largest value                          |
| Sum       | Number     | Total of all values                    |
| Range     | Number     | Difference between max and min         |
| Median    | Number     | Median value                           |
| Stddev    | Number     | Standard deviation                     |
| Earliest  | Date       | Oldest date                            |
| Latest    | Date       | Most recent date                       |
| Range     | Date       | Difference between earliest and latest |
| 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 distinct values               |

### `views`

The `views` section is a list of view configurations:

```yaml theme={null}
views:
  - type: table
    name: "My table"
    limit: 10
    groupBy:
      property: note.age
      direction: DESC
    filters:
      and:
        - 'status != "done"'
    order:
      - file.name
      - note.age
    summaries:
      formula.ppu: Average
```

| Key         | Description                                                              |
| ----------- | ------------------------------------------------------------------------ |
| `type`      | Layout type: `table`, `list`, `cards`, `map`                             |
| `name`      | Display name for the view. Used to select a default view when embedding. |
| `limit`     | Maximum number of rows to display.                                       |
| `filters`   | View-specific filters (same syntax as global `filters`).                 |
| `groupBy`   | Property and direction to group results.                                 |
| `order`     | List of property names defining column order.                            |
| `summaries` | Map of property names to summary formula names.                          |

## Properties in bases

Bases work with three types of properties:

### Note properties

Stored in the YAML frontmatter of Markdown files. Access with `property_name` or `note.property_name`:

```yaml theme={null}
author == "Ursula Le Guin"
note.status == "Done"
```

### File properties

Built-in properties available for all file types:

| Property          | Type   | Description                      |
| ----------------- | ------ | -------------------------------- |
| `file.name`       | String | File name including extension    |
| `file.basename`   | String | File name without extension      |
| `file.path`       | String | Full path relative to vault root |
| `file.folder`     | String | Path to the parent folder        |
| `file.ext`        | String | File extension                   |
| `file.size`       | Number | File size in bytes               |
| `file.tags`       | List   | Tags including inline tags       |
| `file.links`      | List   | Internal links within the file   |
| `file.ctime`      | Date   | Creation timestamp               |
| `file.mtime`      | Date   | Last-modified timestamp          |
| `file.properties` | Object | All frontmatter properties       |

### `this` — context-aware file reference

Use `this` to reference the file where the base is displayed:

* **Opened as a file**: `this` refers to the `.base` file itself.
* **Embedded in a note**: `this` refers to the embedding note.
* **In a sidebar**: `this` refers to the active file in the main content area.

Example — replicate the backlinks panel:

```yaml theme={null}
filters:
  and:
    - file.hasLink(this.file)
```

## Operators

### Arithmetic

| Operator | Description            |
| -------- | ---------------------- |
| `+`      | Add                    |
| `-`      | Subtract               |
| `*`      | Multiply               |
| `/`      | Divide                 |
| `%`      | Modulo                 |
| `( )`    | Parentheses (grouping) |

### Comparison

| Operator | Description              |
| -------- | ------------------------ |
| `==`     | Equals                   |
| `!=`     | Not equal                |
| `>`      | Greater than             |
| `<`      | Less than                |
| `>=`     | Greater than or equal to |
| `<=`     | Less than or equal to    |

### Boolean

| Operator | Description |
| -------- | ----------- |
| `!`      | Logical not |
| `&&`     | Logical and |
| `\|\|`   | Logical or  |

### Date arithmetic

Add or subtract durations from dates using string suffixes:

```js theme={null}
now() + "1 day"
file.mtime > now() - "1 week"
date("2024-12-01") + "1M" + "4h" + "3m"
```

| Unit   | Accepted formats         |
| ------ | ------------------------ |
| Year   | `y`, `year`, `years`     |
| Month  | `M`, `month`, `months`   |
| Day    | `d`, `day`, `days`       |
| Week   | `w`, `week`, `weeks`     |
| Hour   | `h`, `hour`, `hours`     |
| Minute | `m`, `minute`, `minutes` |
| Second | `s`, `second`, `seconds` |

Subtracting two dates returns the difference in milliseconds.

## Types

| Type    | Notes                                                                                |
| ------- | ------------------------------------------------------------------------------------ |
| String  | Enclosed in single or double quotes: `"hello"`, `'world'`                            |
| Number  | Written as digits, optionally in parentheses: `1`, `(2.5)`                           |
| Boolean | `true` or `false` (no quotes)                                                        |
| Date    | Created with `date()`, `today()`, or `now()`                                         |
| List    | Access elements with `property[0]` (0-based index)                                   |
| Object  | Access values with `property.key` or `property["key"]`                               |
| Link    | Wikilinks in frontmatter are automatically recognized; construct with `link("path")` |