Method: projects.locations.collections.engines.servingConfigs.searchLite

Performs a search. Similar to the SearchService.Search method, but a lite version that allows API key for authentication, where OAuth and IAM checks are not required.

Only public website search is supported by this method. If data stores and engines not associated with public website search are specified, a FAILED_PRECONDITION error is returned.

This method can be used for easy onboarding without having to implement an authentication backend. However, it is strongly recommended to use SearchService.Search instead with required OAuth and IAM checks to provide better data security.

HTTP request

POST https://discoveryengine.googleapis.com/v1alpha/{servingConfig=projects/*/locations/*/collections/*/engines/*/servingConfigs/*}:searchLite

The URL uses gRPC Transcoding syntax.

Path parameters

Parameters
servingConfig

string

Required. The resource name of the servingConfigs.search serving config, such as projects/*/locations/global/collections/default_collection/engines/*/servingConfigs/default_serving_config, or projects/*/locations/global/collections/default_collection/dataStores/default_data_store/servingConfigs/default_serving_config. This field is used to identify the serving configuration name, set of models used to make the search.

Request body

The request body contains data with the following structure:

JSON representation 
{
  "branch": string,
  "query": string,
  "imageQuery": {
    object (ImageQuery)
  },
  "pageSize": integer,
  "pageToken": string,
  "offset": integer,
  "oneBoxPageSize": integer,
  "dataStoreSpecs": [
    {
      object (DataStoreSpec)
    }
  ],
  "filter": string,
  "canonicalFilter": string,
  "orderBy": string,
  "userInfo": {
    object (UserInfo)
  },
  "languageCode": string,
  "regionCode": string,
  "facetSpecs": [
    {
      object (FacetSpec)
    }
  ],
  "boostSpec": {
    object (BoostSpec)
  },
  "params": {
    string: value,
    ...
  },
  "queryExpansionSpec": {
    object (QueryExpansionSpec)
  },
  "spellCorrectionSpec": {
    object (SpellCorrectionSpec)
  },
  "userPseudoId": string,
  "contentSearchSpec": {
    object (ContentSearchSpec)
  },
  "embeddingSpec": {
    object (EmbeddingSpec)
  },
  "rankingExpression": string,
  "safeSearch": boolean,
  "userLabels": {
    string: string,
    ...
  },
  "naturalLanguageQueryUnderstandingSpec": {
    object (NaturalLanguageQueryUnderstandingSpec)
  },
  "searchAsYouTypeSpec": {
    object (SearchAsYouTypeSpec)
  },
  "customFineTuningSpec": {
    object (CustomFineTuningSpec)
  },
  "session": string,
  "sessionSpec": {
    object (SessionSpec)
  },
  "relevanceThreshold": enum (RelevanceThreshold),
  "personalizationSpec": {
    object (PersonalizationSpec)
  }
}
Fields
branch

string

The branch resource name, such as projects/*/locations/global/collections/default_collection/dataStores/default_data_store/branches/0.

Use default_branch as the branch ID or leave this field empty, to search documents under the default branch.
query

string

Raw search query.
imageQuery

object (ImageQuery)

Raw image query.
pageSize

integer

Maximum number of Documents to return. The maximum allowed value depends on the data type. Values above the maximum value are coerced to the maximum value.

  • Websites with basic indexing: Default 10, Maximum 25.
  • Websites with advanced indexing: Default 25, Maximum 50.
  • Other: Default 50, Maximum 100.

If this field is negative, an INVALID_ARGUMENT is returned.
pageToken

string

A page token received from a previous SearchService.Search call. Provide this to retrieve the subsequent page.

When paginating, all other parameters provided to SearchService.Search must match the call that provided the page token. Otherwise, an INVALID_ARGUMENT error is returned.
offset

integer

A 0-indexed integer that specifies the current offset (that is, starting result location, amongst the Documents deemed by the API as relevant) in search results. This field is only considered if pageToken is unset.

If this field is negative, an INVALID_ARGUMENT is returned.
oneBoxPageSize

integer

The maximum number of results to return for OneBox. This applies to each OneBox type individually. Default number is 10.
dataStoreSpecs[]

object (DataStoreSpec)

Specs defining DataStores to filter on in a search call and configurations for those data stores. This is only considered for Engines with multiple data stores. For engines with a single data store, the specs directly under SearchRequest should be used.
filter

string

The filter syntax consists of an expression language for constructing a predicate from one or more fields of the documents being filtered. Filter expression is case-sensitive.

If this field is unrecognizable, an INVALID_ARGUMENT is returned.

Filtering in Vertex AI servingConfigs.search is done by mapping the LHS filter key to a key property defined in the Vertex AI servingConfigs.search backend -- this mapping is defined by the customer in their schema. For example a media customer might have a field 'name' in their schema. In this case the filter would look like this: filter --> name:'ANY("king kong")'

For more information about filtering including syntax and filter operators, see Filter
canonicalFilter

string

The default filter that is applied when a user performs a search without checking any filters on the search page.

The filter applied to every search request when quality improvement such as query expansion is needed. In the case a query does not have a sufficient amount of results this filter will be used to determine whether or not to enable the query expansion flow. The original filter will still be used for the query expanded search. This field is strongly recommended to achieve high search quality.

For more information about filter syntax, see SearchRequest.filter.
orderBy

string

The order in which documents are returned. Documents can be ordered by a field in an Document object. Leave it unset if ordered by relevance. orderBy expression is case-sensitive.

For more information on ordering the website search results, see Order web search results. For more information on ordering the healthcare search results, see Order healthcare search results. If this field is unrecognizable, an INVALID_ARGUMENT is returned.
userInfo

object (UserInfo)

Information about the end user. Highly recommended for analytics. UserInfo.user_agent is used to deduce deviceType for analytics.
languageCode

string

The BCP-47 language code, such as "en-US" or "sr-Latn". For more information, see Standard fields. This field helps to better interpret the query. If a value isn't specified, the query language code is automatically detected, which may not be accurate.
regionCode

string

The Unicode country/region code (CLDR) of a location, such as "US" and "419". For more information, see Standard fields. If set, then results will be boosted based on the regionCode provided.
facetSpecs[]

object (FacetSpec)

Facet specifications for faceted search. If empty, no facets are returned.

A maximum of 100 values are allowed. Otherwise, an INVALID_ARGUMENT error is returned.
boostSpec

object (BoostSpec)

Boost specification to boost certain documents. For more information on boosting, see Boosting
params

map (key: string, value: value (Value format))

Additional search parameters.

For public website search only, supported values are:

  • user_country_code: string. Default empty. If set to non-empty, results are restricted or boosted based on the location provided. For example, user_country_code: "au"

For available codes see Country Codes

  • searchType: double. Default empty. Enables non-webpage searching depending on the value. The only valid non-default value is 1, which enables image searching. For example, searchType: 1
queryExpansionSpec

object (QueryExpansionSpec)

The query expansion specification that specifies the conditions under which query expansion occurs.
spellCorrectionSpec

object (SpellCorrectionSpec)

The spell correction specification that specifies the mode under which spell correction takes effect.
userPseudoId

string

A unique identifier for tracking visitors. For example, this could be implemented with an HTTP cookie, which should be able to uniquely identify a visitor on a single device. This unique identifier should not change if the visitor logs in or out of the website.

This field should NOT have a fixed value such as unknown_visitor.

This should be the same identifier as UserEvent.user_pseudo_id and CompleteQueryRequest.user_pseudo_id

The field must be a UTF-8 encoded string with a length limit of 128 characters. Otherwise, an INVALID_ARGUMENT error is returned.
contentSearchSpec

object (ContentSearchSpec)

A specification for configuring the behavior of content search.
embeddingSpec

object (EmbeddingSpec)

Uses the provided embedding to do additional semantic document retrieval. The retrieval is based on the dot product of SearchRequest.EmbeddingSpec.EmbeddingVector.vector and the document embedding that is provided in SearchRequest.EmbeddingSpec.EmbeddingVector.field_path.

If SearchRequest.EmbeddingSpec.EmbeddingVector.field_path is not provided, it will use ServingConfig.EmbeddingConfig.field_path.
rankingExpression

string

The ranking expression controls the customized ranking on retrieval documents. This overrides ServingConfig.ranking_expression. The ranking expression is a single function or multiple functions that are joined by "+".

  • rankingExpression = function, { " + ", function };

Supported functions:

  • double * relevanceScore
  • double * dotProduct(embedding_field_path)

Function variables:

  • relevanceScore: pre-defined keywords, used for measure relevance between query and document.
  • embedding_field_path: the document embedding field used with query embedding vector.
  • dotProduct: embedding function between embedding_field_path and query embedding vector.

Example ranking expression:

If document has an embedding field doc_embedding, the ranking expression could be 0.5 * relevanceScore + 0.3 * dotProduct(doc_embedding).
userLabels

map (key: string, value: string)

The user labels applied to a resource must meet the following requirements:

  • Each resource can have multiple labels, up to a maximum of 64.
  • Each label must be a key-value pair.
  • Keys have a minimum length of 1 character and a maximum length of 63 characters and cannot be empty. Values can be empty and have a maximum length of 63 characters.
  • Keys and values can contain only lowercase letters, numeric characters, underscores, and dashes. All characters must use UTF-8 encoding, and international characters are allowed.
  • The key portion of a label must be unique. However, you can use the same key with multiple resources.
  • Keys must start with a lowercase letter or international character.

See Google Cloud Document for more details.
naturalLanguageQueryUnderstandingSpec

object (NaturalLanguageQueryUnderstandingSpec)

If naturalLanguageQueryUnderstandingSpec is not specified, no additional natural language query understanding will be done.
searchAsYouTypeSpec

object (SearchAsYouTypeSpec)

servingConfigs.search as you type configuration. Only supported for the IndustryVertical.MEDIA vertical.
customFineTuningSpec

object (CustomFineTuningSpec)

Custom fine tuning configs. If set, it has higher priority than the configs set in ServingConfig.custom_fine_tuning_spec.
session

string

The session resource name. Optional.

Session allows users to do multi-turn /search API calls or coordination between /search API calls and /answer API calls.

Example #1 (multi-turn /search API calls): 1. Call /search API with the auto-session mode (see below). 2. Call /search API with the session ID generated in the first call. Here, the previous search query gets considered in query standing. I.e., if the first query is "How did Alphabet do in 2022?" and the current query is "How about 2023?", the current query will be interpreted as "How did Alphabet do in 2023?".

Example #2 (coordination between /search API calls and /answer API calls): 1. Call /search API with the auto-session mode (see below). 2. Call /answer API with the session ID generated in the first call. Here, the answer generation happens in the context of the search results from the first search call.

Auto-session mode: when projects/.../sessions/- is used, a new session gets automatically created. Otherwise, users can use the create-session API to create a session manually.

Multi-turn servingConfigs.search feature is currently at private GA stage. Please use v1alpha or v1beta version instead before we launch this feature to public GA. Or ask for allowlisting through Google Support team.
sessionSpec

object (SessionSpec)

Session specification.

Can be used only when session is set.
relevanceThreshold

enum (RelevanceThreshold)

The relevance threshold of the search results.

Default to Google defined threshold, leveraging a balance of precision and recall to deliver both highly accurate results and comprehensive coverage of relevant information.
personalizationSpec

object (PersonalizationSpec)

The specification for personalization.

Notice that if both ServingConfig.personalization_spec and SearchRequest.personalization_spec are set, SearchRequest.personalization_spec overrides ServingConfig.personalization_spec.

Response body

If successful, the response body contains an instance of SearchResponse.

Authorization scopes

Requires the following OAuth scope:

  • https://www.googleapis.com/auth/cloud-platform

For more information, see the Authentication Overview.