SAP AI SDK for JavaScript - v2.8.0
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    Class AzureOpenAiChatClient

    LangChain chat client for Azure OpenAI consumption on SAP BTP.

    Hierarchy

    Index

    Constructors

    • Parameters

      • fields: AzureOpenAiChatModelParams
      • Optionaldestination:
            | never
            | Without<HttpDestination> & DestinationFetchOptions & {
                serviceBindingTransformFn?: ServiceBindingTransformFunction;
            } & { destinationName: string; service?: undefined }
            | Without<
                DestinationFetchOptions & {
                    serviceBindingTransformFn?: ServiceBindingTransformFunction;
                } & { destinationName: string; service?: undefined },
            > & Destination & { url: string }
        • never
        • Without<HttpDestination> & DestinationFetchOptions & {
              serviceBindingTransformFn?: ServiceBindingTransformFunction;
          } & { destinationName: string; service?: undefined }
          • OptionalserviceBindingTransformFn?: ServiceBindingTransformFunction

            Custom transformation function to control how a Destination is built from the given Service.

          • destinationName: string

            The name of the destination to retrieve from service bindings.

          • Optionalservice?: undefined
        • Without<
              DestinationFetchOptions & {
                  serviceBindingTransformFn?: ServiceBindingTransformFunction;
              } & { destinationName: string; service?: undefined },
          > & Destination & { url: string }

      Returns AzureOpenAiChatClient

    Properties

    cache?: BaseCache<Generation[]>
    callbacks?: Callbacks
    caller: AsyncCaller

    The async caller should be used by subclasses to make any async calls, which will thus benefit from the concurrency and retry logic.

    disableStreaming: boolean
    frequency_penalty?: number
    lc_kwargs: SerializedFields
    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.

    lc_runnable: boolean
    lc_serializable: boolean
    logit_bias?: Record<string, any> | null
    max_tokens?: number
    metadata?: Record<string, unknown>
    modelName: string
    name?: string
    outputVersion?: MessageOutputVersion
    ParsedCallOptions: Omit<
        CallOptions,
        Exclude<keyof RunnableConfig, "signal" | "timeout" | "maxConcurrency">,
    >
    presence_penalty?: number
    stop?: string | string[]
    streaming: boolean
    supportsStrictToolCalling?: boolean
    tags?: string[]
    temperature?: number | null
    top_p?: number | null
    user?: string
    verbose: boolean

    Whether to print out response text.

    Accessors

    • get callKeys(): string[]

      Keys that the language model accepts as call options.

      Returns string[]

    • get lc_aliases(): { [key: string]: string } | undefined

      A map of aliases for constructor args. Keys are the attribute names, e.g. "foo". Values are the alias that will replace the key in serialization. This is used to eg. make argument names match Python.

      Returns { [key: string]: string } | undefined

    • get lc_attributes(): { [key: string]: undefined } | undefined

      A map of additional attributes to merge with constructor args. Keys are the attribute names, e.g. "foo". Values are the attribute values, which will be serialized. These attributes need to be accepted by the constructor as arguments.

      Returns { [key: string]: undefined } | undefined

    • get lc_id(): string[]

      The final serialized identifier for the module.

      Returns string[]

    • get lc_secrets(): { [key: string]: string } | undefined

      A map of secrets, which will be omitted from serialization. Keys are paths to the secret in constructor args, e.g. "foo.bar.baz". Values are the secret ids, which will be used when deserializing.

      Returns { [key: string]: string } | undefined

    • get lc_serializable_keys(): string[] | undefined

      A manual list of keys that should be serialized. If not overridden, all fields passed into the constructor will be serialized.

      Returns string[] | undefined

    • get profile(): ModelProfile

      Return profiling information for the model.

      Returns ModelProfile

      An object describing the model's capabilities and constraints

    Methods

    • Parameters

      • pkg: string
      • version: string

      Returns void

    • Internal method that handles batching and configuration for a runnable It takes a function, input values, and optional configuration, and returns a promise that resolves to the output values.

      Type Parameters

      • T extends BaseLanguageModelInput

      Parameters

      • func: (
            inputs: T[],
            options?: Partial<AzureOpenAiChatCallOptions>[],
            runManagers?: (CallbackManagerForChainRun | undefined)[],
            batchOptions?: RunnableBatchOptions,
        ) => Promise<(AIMessageChunk<MessageStructure<MessageToolSet>> | Error)[]>

        The function to be executed for each input value.

      • inputs: T[]
      • Optionaloptions:
            | Partial<
                BaseLanguageModelCallOptions & {
                    outputVersion?: MessageOutputVersion;
                    tool_choice?: ToolChoice;
                } & Pick<
                    AzureOpenAiCreateChatCompletionRequest,
                    | "function_call"
                    | "data_sources"
                    | "n"
                    | "seed"
                    | "logprobs"
                    | "top_logprobs"
                    | "response_format"
                    | "tool_choice"
                    | "functions",
                > & {
                    promptIndex?: number;
                    requestConfig?: CustomRequestConfig;
                    strict?: boolean;
                    tools?: ChatAzureOpenAIToolType[];
                } & { runType?: string },
            >
            | Partial<
                BaseLanguageModelCallOptions & {
                    outputVersion?: MessageOutputVersion;
                    tool_choice?: ToolChoice;
                } & Pick<
                    AzureOpenAiCreateChatCompletionRequest,
                    | "function_call"
                    | "data_sources"
                    | "n"
                    | "seed"
                    | "logprobs"
                    | "top_logprobs"
                    | "response_format"
                    | "tool_choice"
                    | "functions",
                > & {
                    promptIndex?: number;
                    requestConfig?: CustomRequestConfig;
                    strict?: boolean;
                    tools?: ChatAzureOpenAIToolType[];
                } & { runType?: string },
            >[]
      • OptionalbatchOptions: RunnableBatchOptions

      Returns Promise<(AIMessageChunk<MessageStructure<MessageToolSet>> | Error)[]>

      A promise that resolves to the output values.

    • Type Parameters

      • T extends BaseLanguageModelInput

      Parameters

      • func:
            | (
                (input: T) => Promise<AIMessageChunk<MessageStructure<MessageToolSet>>>
            )
            | (
                (
                    input: T,
                    config?: Partial<AzureOpenAiChatCallOptions>,
                    runManager?: CallbackManagerForChainRun,
                ) => Promise<AIMessageChunk<MessageStructure<MessageToolSet>>>
            )
      • input: T
      • Optionaloptions: Partial<AzureOpenAiChatCallOptions> & { runType?: string }

      Returns Promise<AIMessageChunk<MessageStructure<MessageToolSet>>>

    • Parameters

      • ...llmOutputs: (Record<string, any> | undefined)[]

      Returns Record<string, any> | undefined

    • Internal

      Type Parameters

      • O

      Parameters

      • first: O
      • second: O

      Returns O

    • Parameters

      • messages: BaseMessage<MessageStructure<MessageToolSet>, MessageType>[]
      • options: Omit<
            AzureOpenAiChatCallOptions,
            | "tags"
            | "configurable"
            | "recursionLimit"
            | "runName"
            | "metadata"
            | "callbacks"
            | "runId",
        >
      • OptionalrunManager: CallbackManagerForLLMRun

      Returns Promise<ChatResult>

    • Parameters

      • __namedParameters: {
            cache: BaseCache<Generation[]>;
            handledOptions: RunnableConfig;
            llmStringKey: string;
            messages: BaseMessageLike[][];
            parsedOptions: any;
        }

      Returns Promise<
          LLMResult & {
              missingPromptIndices: number[];
              startedRunManagers?: CallbackManagerForLLMRun[];
          },
      >

    • Type Parameters

      • O extends BaseLanguageModelCallOptions & {
            outputVersion?: MessageOutputVersion;
            tool_choice?: ToolChoice;
        } & Pick<
            AzureOpenAiCreateChatCompletionRequest,
            | "function_call"
            | "data_sources"
            | "n"
            | "seed"
            | "logprobs"
            | "top_logprobs"
            | "response_format"
            | "tool_choice"
            | "functions",
        > & {
            promptIndex?: number;
            requestConfig?: CustomRequestConfig;
            strict?: boolean;
            tools?: ChatAzureOpenAIToolType[];
        } & { runType?: string }

      Parameters

      • options: Partial<O> | Partial<O>[]
      • Optionallength: number

      Returns Partial<O>[]

    • Create a unique cache key for a specific call to a specific language model.

      Parameters

      • callOptions: BaseLanguageModelCallOptions & {
            outputVersion?: MessageOutputVersion;
            tool_choice?: ToolChoice;
        } & Pick<
            AzureOpenAiCreateChatCompletionRequest,
            | "function_call"
            | "data_sources"
            | "n"
            | "seed"
            | "logprobs"
            | "top_logprobs"
            | "response_format"
            | "tool_choice"
            | "functions",
        > & {
            promptIndex?: number;
            requestConfig?: CustomRequestConfig;
            strict?: boolean;
            tools?: ChatAzureOpenAIToolType[];
        } & { config?: RunnableConfig<Record<string, any>> }

        Call options for the model

        • OptionaloutputVersion?: MessageOutputVersion

          Version of AIMessage output format to store in message content.

          AIMessage.contentBlocks will lazily parse the contents of content into a standard format. This flag can be used to additionally store the standard format as the message content, e.g., for serialization purposes.

          • "v0": provider-specific format in content (can lazily parse with .contentBlocks)
          • "v1": standardized format in content (consistent with .contentBlocks)

          You can also set LC_OUTPUT_VERSION as an environment variable to "v1" to enable this by default.

          "v0"
          
        • Optionaltool_choice?: ToolChoice

          Specifies how the chat model should use tools.

          undefined

          Possible values:
          - "auto": The model may choose to use any of the provided tools, or none.
          - "any": The model must use one of the provided tools.
          - "none": The model must not use any tools.
          - A string (not "auto", "any", or "none"): The name of a specific tool the model must use.
          - An object: A custom schema specifying tool choice parameters. Specific to the provider.

          Note: Not all providers support tool_choice. An error will be thrown
          if used with an unsupported model.
        • Optionalconfig?: RunnableConfig<Record<string, any>>

      Returns string

      A unique cache key.

    • Get the identifying parameters of the LLM.

      Returns Record<string, any>

    • Returns string

    • Returns string

    • Parameters

      Returns [
          RunnableConfig<Record<string, any>>,
          Omit<
              Partial<AzureOpenAiChatCallOptions>,
              keyof RunnableConfig<Record<string, any>>,
          >,
      ]

    • Parameters

      Returns [
          RunnableConfig<Record<string, any>>,
          Omit<
              AzureOpenAiChatCallOptions,
              | "tags"
              | "configurable"
              | "recursionLimit"
              | "runName"
              | "metadata"
              | "callbacks"
              | "runId",
          >,
      ]

    • Default streaming implementation. Subclasses should override this method if they support streaming output.

      Parameters

      Returns AsyncGenerator<AIMessageChunk<MessageStructure<MessageToolSet>>>

    • Parameters

      • input: BaseLanguageModelInput
      • logStreamCallbackHandler: LogStreamCallbackHandler
      • config: Partial<CallOptions>

      Returns AsyncGenerator<RunLogPatch>

    • Stream response chunks from the Azure OpenAI client.

      Parameters

      • messages: BaseMessage<MessageStructure<MessageToolSet>, MessageType>[]

        The messages to send to the model.

      • options: Omit<
            AzureOpenAiChatCallOptions,
            | "tags"
            | "configurable"
            | "recursionLimit"
            | "runName"
            | "metadata"
            | "callbacks"
            | "runId",
        >

        The call options.

      • OptionalrunManager: CallbackManagerForLLMRun

        The callback manager for the run.

      Returns AsyncGenerator<ChatGenerationChunk>

      An async generator of chat generation chunks.

    • Helper method to transform an Iterator of Input values into an Iterator of Output values, with callbacks. Use this to implement stream() or transform() in Runnable subclasses.

      Type Parameters

      • I extends BaseLanguageModelInput
      • O extends AIMessageChunk<MessageStructure<MessageToolSet>>

      Parameters

      • inputGenerator: AsyncGenerator<I>
      • transformer: (
            generator: AsyncGenerator<I>,
            runManager?: CallbackManagerForChainRun,
            options?: Partial<AzureOpenAiChatCallOptions>,
        ) => AsyncGenerator<O>
      • Optionaloptions: Partial<AzureOpenAiChatCallOptions> & { runType?: string }

      Returns AsyncGenerator<O>

    • Assigns new fields to the dict output of this runnable. Returns a new runnable.

      Parameters

      • mapping: RunnableMapLike<Record<string, unknown>, Record<string, unknown>>

      Returns Runnable

    • Convert a runnable to a tool. Return a new instance of RunnableToolLike which contains the runnable, name, description and schema.

      Type Parameters

      • T extends BaseLanguageModelInput = BaseLanguageModelInput

      Parameters

      • fields: { description?: string; name?: string; schema: InteropZodType<T> }
        • Optionaldescription?: string

          The description of the tool. Falls back to the description on the Zod schema if not provided, or undefined if neither are provided.

        • Optionalname?: string

          The name of the tool. If not provided, it will default to the name of the runnable.

        • schema: InteropZodType<T>

          The Zod schema for the input of the tool. Infers the Zod type from the input type of the runnable.

      Returns RunnableToolLike<
          InteropZodType<T | ToolCall<string, Record<string, any>>>,
          AIMessageChunk<MessageStructure<MessageToolSet>>,
      >

      An instance of RunnableToolLike which is a runnable that can be used as a tool.

    • Default implementation of batch, which calls invoke N times. Subclasses should override this method if they can batch more efficiently.

      Parameters

      • inputs: BaseLanguageModelInput[]

        Array of inputs to each batch call.

      • Optionaloptions: Partial<AzureOpenAiChatCallOptions> | Partial<AzureOpenAiChatCallOptions>[]

        Either a single call options object to apply to each batch call or an array for each call.

      • OptionalbatchOptions: RunnableBatchOptions & { returnExceptions?: false }
        • returnExceptions

          Whether to return errors rather than throwing on the first one

        • OptionalreturnExceptions?: false

          Whether to return errors rather than throwing on the first one

      Returns Promise<AIMessageChunk<MessageStructure<MessageToolSet>>[]>

      An array of RunOutputs, or mixed RunOutputs and errors if batchOptions.returnExceptions is set

    • Default implementation of batch, which calls invoke N times. Subclasses should override this method if they can batch more efficiently.

      Parameters

      • inputs: BaseLanguageModelInput[]

        Array of inputs to each batch call.

      • Optionaloptions: Partial<AzureOpenAiChatCallOptions> | Partial<AzureOpenAiChatCallOptions>[]

        Either a single call options object to apply to each batch call or an array for each call.

      • OptionalbatchOptions: RunnableBatchOptions & { returnExceptions: true }
        • returnExceptions

          Whether to return errors rather than throwing on the first one

        • returnExceptions: true

          Whether to return errors rather than throwing on the first one

      Returns Promise<(AIMessageChunk<MessageStructure<MessageToolSet>> | Error)[]>

      An array of RunOutputs, or mixed RunOutputs and errors if batchOptions.returnExceptions is set

    • Default implementation of batch, which calls invoke N times. Subclasses should override this method if they can batch more efficiently.

      Parameters

      • inputs: BaseLanguageModelInput[]

        Array of inputs to each batch call.

      • Optionaloptions: Partial<AzureOpenAiChatCallOptions> | Partial<AzureOpenAiChatCallOptions>[]

        Either a single call options object to apply to each batch call or an array for each call.

      • OptionalbatchOptions: RunnableBatchOptions
        • returnExceptions

          Whether to return errors rather than throwing on the first one

      Returns Promise<(AIMessageChunk<MessageStructure<MessageToolSet>> | Error)[]>

      An array of RunOutputs, or mixed RunOutputs and errors if batchOptions.returnExceptions is set

    • Bind tool-like objects to this chat model.

      Parameters

      • tools: ChatAzureOpenAIToolType[]

        A list of tool definitions to bind to this chat model. Can be a structured tool, an OpenAI formatted tool, or an object matching the provider's specific tool schema.

      • Optionalkwargs: Partial<AzureOpenAiChatCallOptions>

        Any additional parameters to bind.

      Returns Runnable<
          BaseLanguageModelInput,
          AIMessageChunk<MessageStructure<MessageToolSet>>,
          AzureOpenAiChatCallOptions,
      >

    • Generates chat based on the input messages.

      Parameters

      • messages: BaseMessageLike[][]

        An array of arrays of BaseMessage instances.

      • Optionaloptions: string[] | Partial<AzureOpenAiChatCallOptions>

        The call options or an array of stop sequences.

      • Optionalcallbacks: Callbacks

        The callbacks for the language model.

      Returns Promise<LLMResult>

      A Promise that resolves to an LLMResult.

    • Generates a prompt based on the input prompt values.

      Parameters

      • promptValues: BasePromptValueInterface[]

        An array of BasePromptValue instances.

      • Optionaloptions: string[] | Partial<AzureOpenAiChatCallOptions>

        The call options or an array of stop sequences.

      • Optionalcallbacks: Callbacks

        The callbacks for the language model.

      Returns Promise<LLMResult>

      A Promise that resolves to an LLMResult.

    • Parameters

      • Optional_: RunnableConfig<Record<string, any>>

      Returns Graph

    • Parameters

      • options: Omit<
            AzureOpenAiChatCallOptions,
            | "tags"
            | "configurable"
            | "recursionLimit"
            | "runName"
            | "metadata"
            | "callbacks"
            | "runId",
        >

      Returns LangSmithParams

    • Parameters

      • Optionalsuffix: string

      Returns string

    • Get the number of tokens in the content.

      Parameters

      • content: MessageContent

        The content to get the number of tokens for.

      Returns Promise<number>

      The number of tokens in the content.

    • Get the parameters used to invoke the model

      Parameters

      • Optional_options: Omit<
            AzureOpenAiChatCallOptions,
            | "tags"
            | "configurable"
            | "recursionLimit"
            | "runName"
            | "metadata"
            | "callbacks"
            | "runId",
        >

      Returns any

    • Invokes the chat model with a single input.

      Parameters

      • input: BaseLanguageModelInput

        The input for the language model.

      • Optionaloptions: Partial<AzureOpenAiChatCallOptions>

        The call options.

      Returns Promise<AIMessageChunk<MessageStructure<MessageToolSet>>>

      A Promise that resolves to a BaseMessageChunk.

    • Pick keys from the dict output of this runnable. Returns a new runnable.

      Parameters

      • keys: string | string[]

      Returns Runnable

    • Create a new runnable sequence that runs each individual runnable in series, piping the output of one runnable into another runnable or runnable-like.

      Type Parameters

      • NewRunOutput

      Parameters

      • coerceable: RunnableLike<AIMessageChunk<MessageStructure<MessageToolSet>>, NewRunOutput>

        A runnable, function, or object whose values are functions or runnables.

      Returns Runnable<BaseLanguageModelInput, Exclude<NewRunOutput, Error>>

      A new runnable sequence.

    • Returns SerializedLLM

      Return a json-like object representing this LLM.

    • Stream output in chunks.

      Parameters

      Returns Promise<
          IterableReadableStream<AIMessageChunk<MessageStructure<MessageToolSet>>>,
      >

      A readable stream that is also an iterable.

    • Generate a stream of events emitted by the internal steps of the runnable.

      Use to create an iterator over StreamEvents that provide real-time information about the progress of the runnable, including StreamEvents from intermediate results.

      A StreamEvent is a dictionary with the following schema:

      • event: string - Event names are of the format: on_[runnable_type]_(start|stream|end).
      • name: string - The name of the runnable that generated the event.
      • run_id: string - Randomly generated ID associated with the given execution of the runnable that emitted the event. A child runnable that gets invoked as part of the execution of a parent runnable is assigned its own unique ID.
      • tags: string[] - The tags of the runnable that generated the event.
      • metadata: Record<string, any> - The metadata of the runnable that generated the event.
      • data: Record<string, any>

      Below is a table that illustrates some events that might be emitted by various chains. Metadata fields have been omitted from the table for brevity. Chain definitions have been included after the table.

      ATTENTION This reference table is for the V2 version of the schema.

      +----------------------+-----------------------------+------------------------------------------+
      | event                | input                       | output/chunk                             |
      +======================+=============================+==========================================+
      | on_chat_model_start  | {"messages": BaseMessage[]} |                                          |
      +----------------------+-----------------------------+------------------------------------------+
      | on_chat_model_stream |                             | AIMessageChunk("hello")                  |
      +----------------------+-----------------------------+------------------------------------------+
      | on_chat_model_end    | {"messages": BaseMessage[]} | AIMessageChunk("hello world")            |
      +----------------------+-----------------------------+------------------------------------------+
      | on_llm_start         | {'input': 'hello'}          |                                          |
      +----------------------+-----------------------------+------------------------------------------+
      | on_llm_stream        |                             | 'Hello'                                  |
      +----------------------+-----------------------------+------------------------------------------+
      | on_llm_end           | 'Hello human!'              |                                          |
      +----------------------+-----------------------------+------------------------------------------+
      | on_chain_start       |                             |                                          |
      +----------------------+-----------------------------+------------------------------------------+
      | on_chain_stream      |                             | "hello world!"                           |
      +----------------------+-----------------------------+------------------------------------------+
      | on_chain_end         | [Document(...)]             | "hello world!, goodbye world!"           |
      +----------------------+-----------------------------+------------------------------------------+
      | on_tool_start        | {"x": 1, "y": "2"}          |                                          |
      +----------------------+-----------------------------+------------------------------------------+
      | on_tool_end          |                             | {"x": 1, "y": "2"}                       |
      +----------------------+-----------------------------+------------------------------------------+
      | on_retriever_start   | {"query": "hello"}          |                                          |
      +----------------------+-----------------------------+------------------------------------------+
      | on_retriever_end     | {"query": "hello"}          | [Document(...), ..]                      |
      +----------------------+-----------------------------+------------------------------------------+
      | on_prompt_start      | {"question": "hello"}       |                                          |
      +----------------------+-----------------------------+------------------------------------------+
      | on_prompt_end        | {"question": "hello"}       | ChatPromptValue(messages: BaseMessage[]) |
      +----------------------+-----------------------------+------------------------------------------+
      

      The "on_chain_*" events are the default for Runnables that don't fit one of the above categories.

      In addition to the standard events above, users can also dispatch custom events.

      Custom events will be only be surfaced with in the v2 version of the API!

      A custom event has following format:

      +-----------+------+------------------------------------------------------------+
      | Attribute | Type | Description                                                |
      +===========+======+============================================================+
      | name      | str  | A user defined name for the event.                         |
      +-----------+------+------------------------------------------------------------+
      | data      | Any  | The data associated with the event. This can be anything.  |
      +-----------+------+------------------------------------------------------------+
      

      Here's an example:

      import { RunnableLambda } from "@langchain/core/runnables";
      import { dispatchCustomEvent } from "@langchain/core/callbacks/dispatch";
      // Use this import for web environments that don't support "async_hooks"
      // and manually pass config to child runs.
      // import { dispatchCustomEvent } from "@langchain/core/callbacks/dispatch/web";

      const slowThing = RunnableLambda.from(async (someInput: string) => {
      // Placeholder for some slow operation
      await new Promise((resolve) => setTimeout(resolve, 100));
      await dispatchCustomEvent("progress_event", {
      message: "Finished step 1 of 2",
      });
      await new Promise((resolve) => setTimeout(resolve, 100));
      return "Done";
      });

      const eventStream = await slowThing.streamEvents("hello world", {
      version: "v2",
      });

      for await (const event of eventStream) {
      if (event.event === "on_custom_event") {
      console.log(event);
      }
      }

      Parameters

      • input: BaseLanguageModelInput
      • options: Partial<AzureOpenAiChatCallOptions> & { version: "v1" | "v2" }
      • OptionalstreamOptions: Omit<EventStreamCallbackHandlerInput, "autoClose">

      Returns IterableReadableStream<StreamEvent>

    • Generate a stream of events emitted by the internal steps of the runnable.

      Use to create an iterator over StreamEvents that provide real-time information about the progress of the runnable, including StreamEvents from intermediate results.

      A StreamEvent is a dictionary with the following schema:

      • event: string - Event names are of the format: on_[runnable_type]_(start|stream|end).
      • name: string - The name of the runnable that generated the event.
      • run_id: string - Randomly generated ID associated with the given execution of the runnable that emitted the event. A child runnable that gets invoked as part of the execution of a parent runnable is assigned its own unique ID.
      • tags: string[] - The tags of the runnable that generated the event.
      • metadata: Record<string, any> - The metadata of the runnable that generated the event.
      • data: Record<string, any>

      Below is a table that illustrates some events that might be emitted by various chains. Metadata fields have been omitted from the table for brevity. Chain definitions have been included after the table.

      ATTENTION This reference table is for the V2 version of the schema.

      +----------------------+-----------------------------+------------------------------------------+
      | event                | input                       | output/chunk                             |
      +======================+=============================+==========================================+
      | on_chat_model_start  | {"messages": BaseMessage[]} |                                          |
      +----------------------+-----------------------------+------------------------------------------+
      | on_chat_model_stream |                             | AIMessageChunk("hello")                  |
      +----------------------+-----------------------------+------------------------------------------+
      | on_chat_model_end    | {"messages": BaseMessage[]} | AIMessageChunk("hello world")            |
      +----------------------+-----------------------------+------------------------------------------+
      | on_llm_start         | {'input': 'hello'}          |                                          |
      +----------------------+-----------------------------+------------------------------------------+
      | on_llm_stream        |                             | 'Hello'                                  |
      +----------------------+-----------------------------+------------------------------------------+
      | on_llm_end           | 'Hello human!'              |                                          |
      +----------------------+-----------------------------+------------------------------------------+
      | on_chain_start       |                             |                                          |
      +----------------------+-----------------------------+------------------------------------------+
      | on_chain_stream      |                             | "hello world!"                           |
      +----------------------+-----------------------------+------------------------------------------+
      | on_chain_end         | [Document(...)]             | "hello world!, goodbye world!"           |
      +----------------------+-----------------------------+------------------------------------------+
      | on_tool_start        | {"x": 1, "y": "2"}          |                                          |
      +----------------------+-----------------------------+------------------------------------------+
      | on_tool_end          |                             | {"x": 1, "y": "2"}                       |
      +----------------------+-----------------------------+------------------------------------------+
      | on_retriever_start   | {"query": "hello"}          |                                          |
      +----------------------+-----------------------------+------------------------------------------+
      | on_retriever_end     | {"query": "hello"}          | [Document(...), ..]                      |
      +----------------------+-----------------------------+------------------------------------------+
      | on_prompt_start      | {"question": "hello"}       |                                          |
      +----------------------+-----------------------------+------------------------------------------+
      | on_prompt_end        | {"question": "hello"}       | ChatPromptValue(messages: BaseMessage[]) |
      +----------------------+-----------------------------+------------------------------------------+
      

      The "on_chain_*" events are the default for Runnables that don't fit one of the above categories.

      In addition to the standard events above, users can also dispatch custom events.

      Custom events will be only be surfaced with in the v2 version of the API!

      A custom event has following format:

      +-----------+------+------------------------------------------------------------+
      | Attribute | Type | Description                                                |
      +===========+======+============================================================+
      | name      | str  | A user defined name for the event.                         |
      +-----------+------+------------------------------------------------------------+
      | data      | Any  | The data associated with the event. This can be anything.  |
      +-----------+------+------------------------------------------------------------+
      

      Here's an example:

      import { RunnableLambda } from "@langchain/core/runnables";
      import { dispatchCustomEvent } from "@langchain/core/callbacks/dispatch";
      // Use this import for web environments that don't support "async_hooks"
      // and manually pass config to child runs.
      // import { dispatchCustomEvent } from "@langchain/core/callbacks/dispatch/web";

      const slowThing = RunnableLambda.from(async (someInput: string) => {
      // Placeholder for some slow operation
      await new Promise((resolve) => setTimeout(resolve, 100));
      await dispatchCustomEvent("progress_event", {
      message: "Finished step 1 of 2",
      });
      await new Promise((resolve) => setTimeout(resolve, 100));
      return "Done";
      });

      const eventStream = await slowThing.streamEvents("hello world", {
      version: "v2",
      });

      for await (const event of eventStream) {
      if (event.event === "on_custom_event") {
      console.log(event);
      }
      }

      Parameters

      • input: BaseLanguageModelInput
      • options: Partial<AzureOpenAiChatCallOptions> & {
            encoding: "text/event-stream";
            version: "v1" | "v2";
        }
      • OptionalstreamOptions: Omit<EventStreamCallbackHandlerInput, "autoClose">

      Returns IterableReadableStream<Uint8Array<ArrayBufferLike>>

    • Stream all output from a runnable, as reported to the callback system. This includes all inner runs of LLMs, Retrievers, Tools, etc. Output is streamed as Log objects, which include a list of jsonpatch ops that describe how the state of the run has changed in each step, and the final state of the run. The jsonpatch ops can be applied in order to construct state.

      Parameters

      • input: BaseLanguageModelInput
      • Optionaloptions: Partial<AzureOpenAiChatCallOptions>
      • OptionalstreamOptions: Omit<LogStreamCallbackHandlerInput, "autoClose">

      Returns AsyncGenerator<RunLogPatch>

    • Returns Serialized

    • Returns SerializedNotImplemented

    • Default implementation of transform, which buffers input and then calls stream. Subclasses should override this method if they can start producing output while input is still being generated.

      Parameters

      • generator: AsyncGenerator<BaseLanguageModelInput>
      • options: Partial<CallOptions>

      Returns AsyncGenerator<AIMessageChunk<MessageStructure<MessageToolSet>>>

    • Bind config to a Runnable, returning a new Runnable.

      Parameters

      • config: Partial<CallOptions>

        New configuration parameters to attach to the new runnable.

      Returns Runnable<
          BaseLanguageModelInput,
          AIMessageChunk<MessageStructure<MessageToolSet>>,
          AzureOpenAiChatCallOptions,
      >

      A new RunnableBinding with a config matching what's passed.

    • Create a new runnable from the current one that will try invoking other passed fallback runnables if the initial invocation fails.

      Parameters

      • fields:
            | {
                fallbacks: Runnable<
                    BaseLanguageModelInput,
                    AIMessageChunk<MessageStructure<MessageToolSet>>,
                    RunnableConfig<Record<string, any>>,
                >[];
            }
            | Runnable<
                BaseLanguageModelInput,
                AIMessageChunk<MessageStructure<MessageToolSet>>,
                RunnableConfig<Record<string, any>>,
            >[]
        • {
              fallbacks: Runnable<
                  BaseLanguageModelInput,
                  AIMessageChunk<MessageStructure<MessageToolSet>>,
                  RunnableConfig<Record<string, any>>,
              >[];
          }
          • fallbacks: Runnable<
                BaseLanguageModelInput,
                AIMessageChunk<MessageStructure<MessageToolSet>>,
                RunnableConfig<Record<string, any>>,
            >[]

            Other runnables to call if the runnable errors.

        • Runnable<
              BaseLanguageModelInput,
              AIMessageChunk<MessageStructure<MessageToolSet>>,
              RunnableConfig<Record<string, any>>,
          >[]

      Returns RunnableWithFallbacks<
          BaseLanguageModelInput,
          AIMessageChunk<MessageStructure<MessageToolSet>>,
      >

      A new RunnableWithFallbacks.

    • Bind lifecycle listeners to a Runnable, returning a new Runnable. The Run object contains information about the run, including its id, type, input, output, error, startTime, endTime, and any tags or metadata added to the run.

      Parameters

      • params: {
            onEnd?: (
                run: Run,
                config?: RunnableConfig<Record<string, any>>,
            ) => void | Promise<void>;
            onError?: (
                run: Run,
                config?: RunnableConfig<Record<string, any>>,
            ) => void | Promise<void>;
            onStart?: (
                run: Run,
                config?: RunnableConfig<Record<string, any>>,
            ) => void | Promise<void>;
        }

        The object containing the callback functions.

        • OptionalonEnd?: (run: Run, config?: RunnableConfig<Record<string, any>>) => void | Promise<void>

          Called after the runnable finishes running, with the Run object.

        • OptionalonError?: (run: Run, config?: RunnableConfig<Record<string, any>>) => void | Promise<void>

          Called if the runnable throws an error, with the Run object.

        • OptionalonStart?: (run: Run, config?: RunnableConfig<Record<string, any>>) => void | Promise<void>

          Called before the runnable starts running, with the Run object.

      Returns Runnable<
          BaseLanguageModelInput,
          AIMessageChunk<MessageStructure<MessageToolSet>>,
          AzureOpenAiChatCallOptions,
      >

    • Add retry logic to an existing runnable.

      Parameters

      • Optionalfields: {
            onFailedAttempt?: RunnableRetryFailedAttemptHandler;
            stopAfterAttempt?: number;
        }
        • OptionalonFailedAttempt?: RunnableRetryFailedAttemptHandler

          A function that is called when a retry fails.

        • OptionalstopAfterAttempt?: number

          The number of attempts to retry.

      Returns RunnableRetry<
          BaseLanguageModelInput,
          AIMessageChunk<MessageStructure<MessageToolSet>>,
          AzureOpenAiChatCallOptions,
      >

      A new RunnableRetry that, when invoked, will retry according to the parameters.

    • Type Parameters

      • RunOutput extends Record<string, any> = Record<string, any>

      Parameters

      • outputSchema: Record<string, any> | InteropZodType<RunOutput>
      • Optionalconfig: StructuredOutputMethodOptions<false>

      Returns Runnable<BaseLanguageModelInput, RunOutput>

    • Type Parameters

      • RunOutput extends Record<string, any> = Record<string, any>

      Parameters

      • outputSchema: Record<string, any> | InteropZodType<RunOutput>
      • Optionalconfig: StructuredOutputMethodOptions<true>

      Returns Runnable<BaseLanguageModelInput, { parsed: RunOutput; raw: BaseMessage }>

    • Type Parameters

      • RunOutput extends Record<string, any> = Record<string, any>

      Parameters

      • outputSchema: Record<string, any> | InteropZodType<RunOutput>
      • Optionalconfig: StructuredOutputMethodOptions<boolean>

      Returns
          | Runnable<
              BaseLanguageModelInput,
              RunOutput,
              RunnableConfig<Record<string, any>>,
          >
          | Runnable<
              BaseLanguageModelInput,
              { parsed: RunOutput; raw: BaseMessage },
              RunnableConfig<Record<string, any>>,
          >

    • Parameters

      • input: BaseLanguageModelInput

      Returns BasePromptValueInterface

    • Parameters

      • _data: SerializedLLM

      Returns Promise<BaseLanguageModel<any, BaseLanguageModelCallOptions>>

      Load an LLM from a json-like object describing it.

    • Parameters

      • thing: any

      Returns thing is Runnable<any, any, RunnableConfig<Record<string, any>>>

    • 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.

      Copyright Ⓒ 2026 SAP SE or an SAP affiliate company. All rights reserved.

      Returns string