# onUserMessage

open suspend fun onUserMessage(invocationContext: InvocationContext, userMessage: Content): Content

Callback executed when a user message is received before an invocation starts.

Helps log and modify/replace the user message before the runner starts the invocation.

#### Return

The potentially modified Content to propagate down the chain.

#### Parameters

invocationContext

The context for the entire invocation.

userMessage

The message content input by the user.