genai-toolbox/docs/en/samples/pre_post_processing/js.md

title, type, weight, description

title	type	weight	description
Javascript	docs	2	How to add pre- and post- processing to your Agents using JS.

Prerequisites

This tutorial assumes that you have set up Toolbox with a basic agent as described in the local quickstart.

This guide demonstrates how to implement these patterns in your Toolbox applications.

Implementation

{{< tabpane persist=header >}} {{% tab header="ADK" text=true %}} Coming soon. {{% /tab %}} {{% tab header="Langchain" text=true %}} The following example demonstrates how to use ToolboxClient with LangChain's middleware to implement pre- and post- processing for tool calls.

{{< include "js/langchain/agent.js" >}}

For more information, see the LangChain Middleware documentation. {{% /tab %}} {{< /tabpane >}}

Results

The output should look similar to the following. Note that exact responses may vary due to the non-deterministic nature of LLMs and differences between orchestration frameworks.

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