Change paths

A change path is the syntax used in the keys of a change object to name a place in a document or in search settings.

Supported endpoints

The following endpoints use change paths:

Endpoint	What a path names
PATCH /v1alpha1/indexes/{name}/documents/{key}	A place in one document.
POST /v1alpha1/indexes/{name}/documents/actions/update	A place in each document of a batch.
PATCH /v1alpha1/admin/indexes/{name}/settings	A place in the search settings.

For more information on these endpoints, see the Documents API and the Admin API. For a task-based guide, see Updating parts of documents.

Change object behavior

Change objects apply their properties in the order they are written:

• A path with a value replaces what the path names.
• A path set to null clears what the path names.
• A path that is omitted leaves what it names unchanged.
• If two paths name the same place, the later path replaces the value set by the earlier path.

Syntax

A path consists of names joined by .. A name can carry an optional selector in brackets.

Path	Names
price	The place itself.
dimensions.width	A place inside it.
tags[]	A value added to the ones the place holds.
title[sv]	The value identified by one word.
variants[sku=V-2]	The values whose sku reads as V-2.
variants[sku=V-2].price	One name inside those values.
fields.variants\.colour	A name holding a . of its own.

Selector forms

Selectors match values by what they hold rather than by their position in a list. Reordering a list does not change which value a selector targets.

The syntax supports three selector forms:

• Empty brackets ([]): Adds a value. The operation matches nothing, replaces no values, and places the added value last.
• Key-value match ([field=value]): Names values whose field reads as value. Values are compared as text, so a value stored as the number 2 matches the selector [field=2]. Only the first unescaped = splits the selector, so [sku=a=b] matches a sku of a=b.
• Single word ([word]): Names a value by one word, such as [sv] or [V-2]. The meaning of the word depends on the target.

Escaping

A backslash (\) escapes the character immediately following it in both names and selectors.

Escape the following characters:

• In a name: ., [, and \.
• In a selector: ], \, and an = in single-word form.

An = in the [field=value] form requires no backslash after the first unescaped =, because the first = splits the selector.

All other characters represent themselves. Hyphens and locale tags such as en-GB require no escaping.

Because JSON strings use backslashes as escape characters, write each backslash twice in a JSON request body: "fields.variants\\.colour" or "variants[sku=a\\]b]".

Single-word selectors

The target endpoint determines what a single word in brackets means:

Target	Meaning of a single word
A document	A BCP 47 language tag on a locale-specific field, or the declared key on an object field. A field is never both.
Search settings	The key the list declares: field on ranking.signals and ranking.tieBreakers, and value on fields.<name>.values. Every other list declares none, and a word on one returns settings:patch:key_unsupported.

In document fields, a BCP 47 tag resolves against the variants declared on the field. For example, title[nb-NO] changes a field that declares no. If the field declares no variant for the tag, the endpoint returns document:locale_unknown. For more details on fields, see Field types.

Target depth and creation

A path replaces what it names based on how deeply it reaches:

• variants replaces every value in the field.
• variants[sku=V-2] replaces values whose sku matches V-2, leaving other values unchanged.
• variants[sku=V-2].price replaces only the price field inside matching values, leaving the rest of the object unchanged.

A value replaced in place retains its position in the list.

Paths follow these creation rules:

• Paths automatically create missing objects that they reach through.
• A path ending in [] with a value creates a list if none exists.
• A selector never creates the value it names. If a selector matches no stored value, the endpoint returns no_match.

Target differences

Document paths and search settings paths differ in the following ways:

• Selector count: A path into a document supports one selector. A path into search settings supports a selector at each name.
• Name resolution: A document resolves names before and after a selector as a dotted path through object values against the index definition. Because declared field names contain no ., escaping a dot reaches the same place as writing it without an escape.
• How many values a key names: A key of a document names at most one value, because a document holding two values under one key is refused when it is indexed. A key of ranking.signals names every signal reading that field, because two signals may read one field with different shapes. A key of ranking.tieBreakers and of fields.<name>.values names at most one.
• Which lists declare a key: An index definition declares one per object field, with "key": "sku". The search settings have a shape no client defines, so the lists that carry a key are fixed, and are listed above.

Error codes

Endpoints return errors in two prefix families: document:patch:* for documents, and settings:patch:* for search settings. Both families return 400 Bad Request and share the same error arguments and last segments.

For general error handling, see Errors.

Error suffix	Cause
path_invalid	The key cannot be parsed as a change path.
field_unknown	The path reaches a name that is not declared.
not_an_object	The path reaches inside a value that holds no fields.
selector_required	The path reaches into a list without specifying which value.
selector_unsupported	The path specifies a selector on a place that holds no list.
match_not_an_object	The path matches on a field inside values that are not objects.
key_unsupported	The path names a value by a single word on a field that declares no key.
add_unsupported	The path adds a value using [] to a place that holds a single value.
add_reaches_inside	The path attempts to reach inside a value that the same change adds.
no_match	The selector names no stored value.

Target-specific error codes

The following error codes occur on specific targets:

Code	Cause
settings:patch:value_invalid	The path names a settings location that cannot accept the provided value. Documents report field validation errors per type, such as document:number:value_invalid.
document:locale_unknown	The document field holds no variant matching the specified locale tag.