---
updatedAt: 2026-10-01T17:11:41.000Z
agentTools:
projectIndex: https://docs.sensible.so/llms.txt
---
# Anchor object
How the Anchor object works in Sensible, including its parameters, simple and complex syntax, and how it locates data.
An *anchor* is a string, [Match](https://docs.sensible.so/docs/match) object, or array of Match objects.
An anchor's behavior depends on its field's method:
| Category | Required? | Notes |
| -------------------- | --------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| Layout-based methods | required | An anchor is a computationally quick way to narrow down the rough location of the data you want to extract in a document. After locating the anchor, Sensible uses a layout-based ["method"](https://docs.sensible.so/docs/method) to spatially expand out from the anchor and extract the data you want. |
| LLM-based methods | optional | An anchor is a test for running a field or skipping it:
- If the anchor is present in the document, Sensible searches the whole document for the target data.
- If the anchor is missing, Sensible returns null for the field.
You can use this behavior to define backup, or "[fallback](https://docs.sensible.so/docs/fallbacks)", fields.
For an exception to this behavior, see the [Multimodal Engine](https://docs.sensible.so/docs/query-group#parameters) parameter. |
[**Parameters**](https://docs.sensible.so/docs/anchor#parameters)\
[**Examples**](https://docs.sensible.so/docs/anchor#examples)\
[**Notes**](https://docs.sensible.so/docs/anchor#notes)
Define anchors using simple or complex syntax. The following example shows simple syntax:
```json
{
"fields": [
{
"id": "simple_label",
"anchor": "this is a string to anchor on",
"method": {
"id": "label",
"position": "below"
}
}
]
}
```
Behind the scenes, Sensible expands string anchors to case-insensitive `includes` matches. For example, Sensible automatically expands the preceding example as:
```json
"anchor": {
"match": {
"type": "includes",
"text": "this is a string to anchor on",
}
},
```
## Parameters
An Anchor object has the following top-level parameters:
| key | value | description |
| ----------------------------------------------- | ------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| match (**required**, except for string anchors) | Match object or array of Match objects | See [Match object](https://docs.sensible.so/docs/match). |
| start | string, Match object, or Match object array | Starts the search for the anchor's Match parameter and for its End parameter at a line of text in the document, and ignores all the text that precedes the start line.
The terms "preceding" and "succeeding" primarily mean *above* and *below* the Start line, respectively. For more information, see [Line sorting](https://docs.sensible.so/docs/lines#line-sorting).
You can extract anchor output with the [Passthrough method](https://docs.sensible.so/docs/passthrough). |
| end | string, Match, or Match array | Stops the search for the anchor's Match parameter before a line of text in the document. Ignores the End line and all the text that succeeds the End line.
The terms "preceding" and "succeeding" primarily mean *above* and *below* the End line, respectively. For more information, see [Line sorting](https://docs.sensible.so/docs/lines#line-sorting).
If unspecified, the anchor searches for matches to the end of the document.
If you specify a Start line, Sensible searches for the End line starting at the Start line instead of at the start of the document. |
| includeEnd | boolean. default: false | Whether to include or ignore the End line in the search for the anchor's Match parameter. |
## Examples
Here's an example of an Anchor object that uses all these parameters:
```json
{
"fields": [
{
"id": "simple_label",
"anchor": { /* required for layout methods. for LLM methods, acts as an optional run/skip check */
"start": "My section heading. Start matching at the start of this line", /* optional. ignore everything before this line */
"end": "My footer text. Stop matching before it", /* optional. stop searching at this line */
"includeEnd": true, /* default: false. if true, include the end line in the match search */
"match": /* locates the anchor line. accepts a single Match object or an array of Match objects */
[
{
"type": "includes", /* equals | startsWith | endsWith | includes | regex | first | any | all | not */
"text": "Only finds anchor if you match this string in a line that is between the start and end lines",
"isCaseSensitive": false, /* default: false */
},
]
},
"method": {
"id": "label",
"position": "below"
}
}
]
}
```
# Notes
For information about complex anchor syntax, see [Anchor variables](https://docs.sensible.so/docs/anchor-nuances) and .[Match arrays](https://docs.sensible.so/docs/match-arrays).