Threads, REST: Message.List

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Updated at April 24, 2025

HTTP request
Query parameters
Response
Author
MessageContent
ContentPart
Text
Citation
Source
FileChunk
SearchIndex
ExpirationConfig
TextSearchIndex
ChunkingStrategy
StaticChunkingStrategy
NgramTokenizer
VectorSearchIndex
HybridSearchIndex
CombinationStrategy
MeanCombinationStrategy
ReciprocalRankFusionCombinationStrategy
File
ChunkContent

List messages in a specific thread.
By default, messages are listed in reverse chronological order, i.e., from the newest to the oldest.

HTTP request

GET https://rest-assistant.api.cloud.yandex.net/assistants/v1/messages

Query parameters

Request message for listing messages in a specific thread.

Field

Description

threadId

string

Required field. ID of the thread whose messages will be listed.

Response

HTTP Code: 200 - OK

{
  "id": "string",
  "threadId": "string",
  "createdBy": "string",
  "createdAt": "string",
  "author": {
    "id": "string",
    "role": "string"
  },
  "labels": "object",
  "content": {
    "content": [
      {
        // Includes only one of the fields `text`
        "text": {
          "content": "string"
        }
        // end of the list of possible fields
      }
    ]
  },
  "status": "string",
  "citations": [
    {
      "sources": [
        {
          // Includes only one of the fields `chunk`
          "chunk": {
            "searchIndex": {
              "id": "string",
              "folderId": "string",
              "name": "string",
              "description": "string",
              "createdBy": "string",
              "createdAt": "string",
              "updatedBy": "string",
              "updatedAt": "string",
              "expirationConfig": {
                "expirationPolicy": "string",
                "ttlDays": "string"
              },
              "expiresAt": "string",
              "labels": "object",
              // Includes only one of the fields `textSearchIndex`, `vectorSearchIndex`, `hybridSearchIndex`
              "textSearchIndex": {
                "chunkingStrategy": {
                  // Includes only one of the fields `staticStrategy`
                  "staticStrategy": {
                    "maxChunkSizeTokens": "string",
                    "chunkOverlapTokens": "string"
                  }
                  // end of the list of possible fields
                },
                // Includes only one of the fields `ngramTokenizer`, `standardTokenizer`
                "ngramTokenizer": {
                  "minGram": "string",
                  "maxGram": "string"
                },
                "standardTokenizer": "object",
                // end of the list of possible fields
                // Includes only one of the fields `standardAnalyzer`, `yandexLemmerAnalyzer`
                "standardAnalyzer": "object",
                "yandexLemmerAnalyzer": "object"
                // end of the list of possible fields
              },
              "vectorSearchIndex": {
                "docEmbedderUri": "string",
                "queryEmbedderUri": "string",
                "chunkingStrategy": {
                  // Includes only one of the fields `staticStrategy`
                  "staticStrategy": {
                    "maxChunkSizeTokens": "string",
                    "chunkOverlapTokens": "string"
                  }
                  // end of the list of possible fields
                }
              },
              "hybridSearchIndex": {
                "textSearchIndex": {
                  "chunkingStrategy": {
                    // Includes only one of the fields `staticStrategy`
                    "staticStrategy": {
                      "maxChunkSizeTokens": "string",
                      "chunkOverlapTokens": "string"
                    }
                    // end of the list of possible fields
                  },
                  // Includes only one of the fields `ngramTokenizer`, `standardTokenizer`
                  "ngramTokenizer": {
                    "minGram": "string",
                    "maxGram": "string"
                  },
                  "standardTokenizer": "object",
                  // end of the list of possible fields
                  // Includes only one of the fields `standardAnalyzer`, `yandexLemmerAnalyzer`
                  "standardAnalyzer": "object",
                  "yandexLemmerAnalyzer": "object"
                  // end of the list of possible fields
                },
                "vectorSearchIndex": {
                  "docEmbedderUri": "string",
                  "queryEmbedderUri": "string",
                  "chunkingStrategy": {
                    // Includes only one of the fields `staticStrategy`
                    "staticStrategy": {
                      "maxChunkSizeTokens": "string",
                      "chunkOverlapTokens": "string"
                    }
                    // end of the list of possible fields
                  }
                },
                "chunkingStrategy": {
                  // Includes only one of the fields `staticStrategy`
                  "staticStrategy": {
                    "maxChunkSizeTokens": "string",
                    "chunkOverlapTokens": "string"
                  }
                  // end of the list of possible fields
                },
                "normalizationStrategy": "string",
                "combinationStrategy": {
                  // Includes only one of the fields `meanCombination`, `rrfCombination`
                  "meanCombination": {
                    "meanEvaluationTechnique": "string",
                    "weights": [
                      "string"
                    ]
                  },
                  "rrfCombination": {
                    "k": "string"
                  }
                  // end of the list of possible fields
                }
              }
              // end of the list of possible fields
            },
            "sourceFile": {
              "id": "string",
              "folderId": "string",
              "name": "string",
              "description": "string",
              "mimeType": "string",
              "createdBy": "string",
              "createdAt": "string",
              "updatedBy": "string",
              "updatedAt": "string",
              "expirationConfig": {
                "expirationPolicy": "string",
                "ttlDays": "string"
              },
              "expiresAt": "string",
              "labels": "object"
            },
            "content": {
              "content": [
                {
                  // Includes only one of the fields `text`
                  "text": {
                    "content": "string"
                  }
                  // end of the list of possible fields
                }
              ]
            }
          }
          // end of the list of possible fields
        }
      ]
    }
  ]
}

Field	Description
id	string Unique identifier of the message.
threadId	string ID of the thread that this message belongs to.
createdBy	string Identifier of the subject who created this message.
createdAt	string (date-time) Timestamp representing when the message was created. String in RFC3339 text format. The range of possible values is from `0001-01-01T00:00:00Z` to `9999-12-31T23:59:59.999999999Z`, i.e. from 0 to 9 digits for fractions of a second. To work with values in this field, use the APIs described in the Protocol Buffers reference. In some languages, built-in datetime utilities do not support nanosecond precision (9 digits).
author	Author Author of the message, containing details about the message's creator.
labels	object (map<string, string>) Set of key-value pairs that can be used to organize and categorize the message.
content	MessageContent Content of the message.
status	enum (MessageStatus) Status of the message. `MESSAGE_STATUS_UNSPECIFIED`: Unspecified message status. `COMPLETED`: Message was successfully created by a user or generated by an assistant. `TRUNCATED`: Message generation was truncated due to reaching the maximum allowed number of tokens. `FILTERED_CONTENT`: Message generation was stopped because potentially sensitive content was detected either in the prompt or in the generated response.
citations[]	Citation List of citations used to generate the message.

Author

Author of the message, containing details about the message's creator.

Field

Description

string

Unique identifier of the author. This could be either the user's ID or the assistant's ID, depending on the role.

role

string

Role of the author, indicating whether the message was created by a "user" or an "assistant".

MessageContent

Represents the content of a message, which can consist of multiple parts.

Field

Description

content[]

ContentPart

A list of content parts that make up the message.

ContentPart

ContentPart represents an individual part of the message content, which can be of various types.

Field

Description

text

Text

Text content of the message part.

Includes only one of the fields text.

Specifies the type of content that the part contains.

Text

Text represents a textual content part of a message.

Field

Description

content

string

Text content of the message.

Citation

Represents a citation used for generating a message.

Field

Description

sources[]

Source

List of sources for citation.

Source

Represents a source used for generating a message citation.

Field

Description

chunk

FileChunk

File chunk source.

Includes only one of the fields chunk.

Specifies the type of source type.

FileChunk

FileChunk represents a chunk of a file used as a source.

Field	Description
searchIndex	SearchIndex Search index associated with the file chunk.
sourceFile	File The original file from which the chunk is derived.
content	ChunkContent Content of the file chunk.

SearchIndex

Represents a search index used to store and query data, either using traditional keyword-based text search or vector-based search mechanisms.

Field	Description
id	string Unique identifier of the search index.
folderId	string ID of the folder that the search index belongs to.
name	string Name of the search index.
description	string Description of the search index.
createdBy	string Identifier of the subject who created this search index.
createdAt	string (date-time) Timestamp representing when the search index was created. String in RFC3339 text format. The range of possible values is from `0001-01-01T00:00:00Z` to `9999-12-31T23:59:59.999999999Z`, i.e. from 0 to 9 digits for fractions of a second. To work with values in this field, use the APIs described in the Protocol Buffers reference. In some languages, built-in datetime utilities do not support nanosecond precision (9 digits).
updatedBy	string Identifier of the subject who last updated this search index.
updatedAt	string (date-time) Timestamp representing the last time this search index was updated. String in RFC3339 text format. The range of possible values is from `0001-01-01T00:00:00Z` to `9999-12-31T23:59:59.999999999Z`, i.e. from 0 to 9 digits for fractions of a second. To work with values in this field, use the APIs described in the Protocol Buffers reference. In some languages, built-in datetime utilities do not support nanosecond precision (9 digits).
expirationConfig	ExpirationConfig Configuration for the expiration of the search index, defining when and how the search index will expire.
expiresAt	string (date-time) Timestamp representing when the search index will expire. String in RFC3339 text format. The range of possible values is from `0001-01-01T00:00:00Z` to `9999-12-31T23:59:59.999999999Z`, i.e. from 0 to 9 digits for fractions of a second. To work with values in this field, use the APIs described in the Protocol Buffers reference. In some languages, built-in datetime utilities do not support nanosecond precision (9 digits).
labels	object (map<string, string>) Set of key-value pairs that can be used to organize and categorize the search index.
textSearchIndex	TextSearchIndex Keyword-based text search index configuration. This type of index is used for traditional text search, where documents are indexed based on their keywords. Includes only one of the fields `textSearchIndex`, `vectorSearchIndex`, `hybridSearchIndex`. Type of the search index. It can be either a traditional keyword-based text search or a vector-based search.
vectorSearchIndex	VectorSearchIndex Vector-based search index configuration. This type is used for vector search, where documents are indexed using vector embeddings. Includes only one of the fields `textSearchIndex`, `vectorSearchIndex`, `hybridSearchIndex`. Type of the search index. It can be either a traditional keyword-based text search or a vector-based search.
hybridSearchIndex	HybridSearchIndex Hybrid (vector-based + keyword-based) search index configuration This type is used for hybrid search, where documents are indexed using both keyword-based and vector-based search mechanisms. Includes only one of the fields `textSearchIndex`, `vectorSearchIndex`, `hybridSearchIndex`. Type of the search index. It can be either a traditional keyword-based text search or a vector-based search.

ExpirationConfig

Field

Description

expirationPolicy

enum (ExpirationPolicy)

EXPIRATION_POLICY_UNSPECIFIED
STATIC
SINCE_LAST_ACTIVE

ttlDays

string (int64)

TextSearchIndex

Defines the configuration for a traditional keyword-based text search index.

Field	Description
chunkingStrategy	ChunkingStrategy Chunking strategy used to split text into smaller chunks before indexing. In the case of text search, tokens are individual text characters.
ngramTokenizer	NgramTokenizer Tokenizer that generates n-grams. Includes only one of the fields `ngramTokenizer`, `standardTokenizer`. Tokenizer type used for text search. The tokenizer determines how the input text is broken down into tokens before indexing. If not specified, the default tokenizer configuration is applied.
standardTokenizer	object Tokenizer that generates words. Includes only one of the fields `ngramTokenizer`, `standardTokenizer`. Tokenizer type used for text search. The tokenizer determines how the input text is broken down into tokens before indexing. If not specified, the default tokenizer configuration is applied.
standardAnalyzer	object Standard analyzer that performs common text processing operations to normalize text. Includes only one of the fields `standardAnalyzer`, `yandexLemmerAnalyzer`. Analyzer type used for text search. The analyzer determines how the tokenized text is further processed before indexing. If not specified, the default analyzer configuration is applied.
yandexLemmerAnalyzer	object Specialized analyzer that uses Yandex's lemmatization technology, particularly effective for Russian and other Slavic languages. Includes only one of the fields `standardAnalyzer`, `yandexLemmerAnalyzer`. Analyzer type used for text search. The analyzer determines how the tokenized text is further processed before indexing. If not specified, the default analyzer configuration is applied.

ChunkingStrategy

Defines a general strategy for chunking text into smaller segments.
Currently, only StaticChunkingStrategy is supported.

Field

Description

staticStrategy

StaticChunkingStrategy

Includes only one of the fields staticStrategy.

StaticChunkingStrategy

Defines a chunking strategy where chunks are created with a fixed maximum chunk size and an overlap between consecutive chunks.

Field

Description

maxChunkSizeTokens

string (int64)

The maximum number of tokens allowed in a single chunk.
Constraints: must be within the range [100, 2048].
Default value: 800

chunkOverlapTokens

string (int64)

The number of tokens that should overlap between consecutive chunks.
This allows for some context from the previous chunk to be included in the next chunk.
Constraints: must be less than or equal to half of max_chunk_size_tokens.
Default value: 400

NgramTokenizer

Configuration for the NgramTokenizer, which splits text into overlapping character sequences (n-grams) of specified lengths.

Example:
Input text: hello
min_gram = 2, max_gram = 3

Generated tokens:

For n = 2 (2-character n-grams): he, el, ll, lo
For n = 3 (3-character n-grams): hel, ell, llo

Final tokens: [he, el, ll, lo, hel, ell, llo]

Field

Description

minGram

string (int64)

Minimum length of characters in a gram. Defaults to 3

maxGram

string (int64)

Maximum length of characters in a gram. Defaults to 4

VectorSearchIndex

Defines the configuration for a vector-based search index. This type uses embeddings to represent documents and queries.

Field	Description
docEmbedderUri	string The ID of the model to be used for obtaining document text embeddings.
queryEmbedderUri	string The ID of the model to be used for obtaining query text embeddings.
chunkingStrategy	ChunkingStrategy Chunking strategy used to split text into smaller chunks before indexing. In the case of vector search, tokens are produced by the tokenizer from the embedding model.

HybridSearchIndex

Defines the configuration for a hybrid (vector-based + keyword-based) search index. This type uses both embeddings and keyword-based search to represent documents and queries.

Field	Description
textSearchIndex	TextSearchIndex Configuration for a traditional keyword-based text search index.
vectorSearchIndex	VectorSearchIndex Configuration for a vector-based search index.
chunkingStrategy	ChunkingStrategy Common chunking strategy that applies to both text and vector search indexes. If provided, it overrides the individual chunking strategies in both `text_search_index` and `vector_search_index`. In this case, both text and vector search will use token-based chunking, where tokens are produced by the tokenizer of the embedding model.
normalizationStrategy	enum (NormalizationStrategy) Normalization strategy for relevance scores from different indices. Default is MIN_MAX_STRATEGY `NORMALIZATION_STRATEGY_UNSPECIFIED` `MIN_MAX`: https://en.wikipedia.org/wiki/Feature_scaling#Rescaling_(min-max_normalization) `L2`: https://en.wikipedia.org/wiki/Cosine_similarity#L2-normalized_Euclidean_distance
combinationStrategy	CombinationStrategy Combination strategy for merging rankings from different indices. Default is arithmetic mean

CombinationStrategy

Combination strategy for merging rankings from different indices

Field

Description

meanCombination

MeanCombinationStrategy

Includes only one of the fields meanCombination, rrfCombination.

rrfCombination

ReciprocalRankFusionCombinationStrategy

Includes only one of the fields meanCombination, rrfCombination.

MeanCombinationStrategy

Field

Description

meanEvaluationTechnique

enum (MeanEvaluationTechnique)

Technique for averaging relevance scores from different indices. Default is ARITHMETIC

MEAN_EVALUATION_TECHNIQUE_UNSPECIFIED
ARITHMETIC: https://en.wikipedia.org/wiki/Arithmetic_mean
GEOMETRIC: https://en.wikipedia.org/wiki/Geometric_mean
HARMONIC: https://en.wikipedia.org/wiki/Harmonic_mean

weights[]

string

Weights used for evaluating the weighted mean of relevance scores. The sum of the values must equal 1.0
If not provided, all scores are given equal weight

ReciprocalRankFusionCombinationStrategy

https://plg.uwaterloo.ca/~gvcormac/cormacksigir09-rrf.pdf

Field

Description

string (int64)

The parameter k for RRFscore. Default is 60

File

Field	Description
id	string Unique identifier of the file.
folderId	string ID of the folder that the file belongs to.
name	string Name of the file.
description	string Description of the file.
mimeType	string MIME type of the file, indicating the file's format (e.g., "application/pdf")
createdBy	string Identifier of the subject who created this file.
createdAt	string (date-time) Timestamp representing when the file was created. String in RFC3339 text format. The range of possible values is from `0001-01-01T00:00:00Z` to `9999-12-31T23:59:59.999999999Z`, i.e. from 0 to 9 digits for fractions of a second. To work with values in this field, use the APIs described in the Protocol Buffers reference. In some languages, built-in datetime utilities do not support nanosecond precision (9 digits).
updatedBy	string Identifier of the subject who last updated this file.
updatedAt	string (date-time) Timestamp representing the last time this file was updated. String in RFC3339 text format. The range of possible values is from `0001-01-01T00:00:00Z` to `9999-12-31T23:59:59.999999999Z`, i.e. from 0 to 9 digits for fractions of a second. To work with values in this field, use the APIs described in the Protocol Buffers reference. In some languages, built-in datetime utilities do not support nanosecond precision (9 digits).
expirationConfig	ExpirationConfig Configuration for the expiration of the file, defining when and how the file will expire.
expiresAt	string (date-time) Timestamp representing when the file will expire. String in RFC3339 text format. The range of possible values is from `0001-01-01T00:00:00Z` to `9999-12-31T23:59:59.999999999Z`, i.e. from 0 to 9 digits for fractions of a second. To work with values in this field, use the APIs described in the Protocol Buffers reference. In some languages, built-in datetime utilities do not support nanosecond precision (9 digits).
labels	object (map<string, string>) Set of key-value pairs that can be used to organize and categorize the file.

ChunkContent

Represents the content of a file chunk.

Field

Description

content[]

ContentPart

A list of content parts that make up the chunk.

Threads, REST: Message.List

HTTP requestHTTP request

Query parametersQuery parameters

ResponseResponse

AuthorAuthor

MessageContentMessageContent

ContentPartContentPart

TextText

CitationCitation

SourceSource

FileChunkFileChunk

SearchIndexSearchIndex

ExpirationConfigExpirationConfig

TextSearchIndexTextSearchIndex

ChunkingStrategyChunkingStrategy

StaticChunkingStrategyStaticChunkingStrategy

NgramTokenizerNgramTokenizer

VectorSearchIndexVectorSearchIndex

HybridSearchIndexHybridSearchIndex

CombinationStrategyCombinationStrategy

MeanCombinationStrategyMeanCombinationStrategy

ReciprocalRankFusionCombinationStrategyReciprocalRankFusionCombinationStrategy

FileFile

ChunkContentChunkContent

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HTTP request

Query parameters

Response

Author

MessageContent

ContentPart

Text

Citation

Source

FileChunk

SearchIndex

ExpirationConfig

TextSearchIndex

ChunkingStrategy

StaticChunkingStrategy

NgramTokenizer

VectorSearchIndex

HybridSearchIndex

CombinationStrategy

MeanCombinationStrategy

ReciprocalRankFusionCombinationStrategy

File

ChunkContent