RunnablePassthrough<RunInput extends Object> constructor
const
RunnablePassthrough<RunInput extends Object> ()
A RunnablePassthrough takes the input it receives and passes it through as output.
You can create a RunnablePassthrough using the Runnable.passthrough static method.
When you call invoke on a RunnablePassthrough, it will return the input it receives.
Example:
final openaiApiKey = Platform.environment['OPENAI_API_KEY'];
final model = ChatOpenAI(apiKey: openaiApiKey);
final promptTemplate = ChatPromptTemplate.fromTemplate(
'Tell me a joke about {foo}',
);
final map = Runnable.fromMap({
'foo': Runnable.passthrough(),
});
final chain = map | promptTemplate | model | StringOutputParser();
final res = await chain.invoke('bears');
print(res);
// Why don't bears wear shoes? Because they have bear feet!
Implementation
const RunnablePassthrough() : super(defaultOptions: const RunnableOptions());