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API Reference

Runnables​

Runnable<I, O>​

  • invoke(input: I): Promise<O>
  • pipe(next: Runnable<O, NextOutput>): Runnable<I, NextOutput>

RunnableLambda<I, O>​

Wraps a sync/async function as runnable.

RunnableSequence<I, O>​

Runs runnable steps in order.

RunnableParallel<I, TMap>​

Runs multiple runnable branches with same input and returns merged object.

RunnableMap<I, TMap>​

Builds named object output by mapping one input into multiple runnable fields.

RunnablePassthrough<T>​

Identity runnable that returns input as-is.

ModelRunnable​

Adapter from Model to runnable (string -> string).

Prompts​

PromptTemplate<TVars>​

  • input: object of template variables
  • output: formatted prompt string
  • throws: PromptTemplateError on missing variable values

Output Parsers​

StringOutputParser​

Pass-through parser for raw text output.

JsonOutputParser<T>​

Parses JSON string to typed object.

Throws OutputParserError on invalid JSON.

Agent Runtime​

Agent​

  • new Agent({ model, tools, passes?, hooks?, maxSteps? })
  • run(input: string): Promise<string>

Runtime behavior:

  • iterative model loop
  • tool execution when requested
  • memory context injection
  • max-step enforcement

Errors​

  • ToolNotFoundError
  • ToolValidationError
  • ModelError
  • MaxStepsExceededError
  • PromptTemplateError
  • OutputParserError