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JSON Agent Toolkit

This example shows how to load and use an agent with a JSON toolkit.

npm install @langchain/openai
import * as fs from "fs";
import * as yaml from "js-yaml";
import { OpenAI } from "@langchain/openai";
import { JsonSpec, JsonObject } from "langchain/tools";
import { JsonToolkit, createJsonAgent } from "langchain/agents";

export const run = async () => {
let data: JsonObject;
try {
const yamlFile = fs.readFileSync("openai_openapi.yaml", "utf8");
data = yaml.load(yamlFile) as JsonObject;
if (!data) {
throw new Error("Failed to load OpenAPI spec");
} catch (e) {

const toolkit = new JsonToolkit(new JsonSpec(data));
const model = new OpenAI({ temperature: 0 });
const executor = createJsonAgent(model, toolkit);

const input = `What are the required parameters in the request body to the /completions endpoint?`;

console.log(`Executing with input "${input}"...`);

const result = await executor.invoke({ input });

console.log(`Got output ${result.output}`);

`Got intermediate steps ${JSON.stringify(

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