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JavaScriptlangchainbrowserBaseMessage
Classā—Since v1.2

BaseMessage

Base class for all types of messages in a conversation. It includes properties like content, name, and additional_kwargs. It also includes methods like toDict() and _getType().

Copy
class BaseMessage

Bases

Serializable

Used in Docs

  • Branching Chat
  • Graph Execution
  • Human-in-the-Loop
  • Join & Rejoin Streams
  • Markdown Messages

Constructors

constructor
constructor

Properties

property
additional_kwargs: __type
property
content: $InferMessageContent<TStructure, TRole>

Array of content blocks that make up the message content

property
id: string

Content block identifier, which can be either

  • generated by the provider (e.g., a provider-specific ID)
  • generated by LangChain upon creation (a uuid prefixed with 'lc-')
property
lc_kwargs: SerializedFields
property
lc_namespace: string[]

A path to the module that contains the class, eg. ["langchain", "llms"] Usually should be the same as the entrypoint the class is exported from.

property
lc_serializable: boolean
property
name: string

The name of the tool being called

property
response_metadata: NonNullable<BaseMessageFields<TStructure, TRole>["response_metadata"]>

Metadata about the message

property
type: TRole

Type of the content block

property
_printableFields: Record<string, unknown>
property
[toStringTag]: any
property
contentBlocks: Standard[]
property
lc_aliases: Record<string, string>
property
lc_attributes: SerializedFields | undefined
property
lc_id: string[]
property
lc_secrets: __type | undefined
property
lc_serializable_keys: string[] | undefined
property
text: string

Methods

method
_updateId
method
toDict→ StoredMessage
method
toFormattedString→ string
method
toJSON→ Serialized
method
toJSONNotImplemented→ SerializedNotImplemented
method
isInstance→ obj is BaseMessage<T, MessageType> & AIMessage<T>

Type guard to check if an object is an AIMessage. Preserves the MessageStructure type parameter when called with a typed BaseMessage. When called with a typed BaseMessage, preserves the TStructure type

method
lc_name→ string

The name of the serializable. Override to provide an alias or to preserve the serialized module name in minified environments.

Implemented as a static method to support loading logic.

deprecatedmethod
_getType→ MessageType
deprecatedmethod
getType→ MessageType

Inherited fromSerializable

Properties

Plc_kwargs: SerializedFieldsPlc_namespace: string[]
—

A path to the module that contains the class, eg. ["langchain", "llms"]

Plc_serializable: booleanPlc_aliases: Record<string, string>Plc_attributes: SerializedFields | undefinedPlc_id: string[]Plc_secrets: __type | undefinedPlc_serializable_keys: string[] | undefined

Methods

MtoJSON→ SerializedMtoJSONNotImplemented→ SerializedNotImplementedMlc_name→ string
—

The name of the serializable. Override to provide an alias or

View source on GitHub