OpenKit SDK

The library for agent interface.

Installation

npm install @opkt/openkit

Quick Start

Creating an App with a Route

Every app in OpenKit must have at least one route:

import { z } from "zod";
import openkit from "@opkt/openkit";

// Create an app
const timeApp = openkit.app({
  name: "Time",
  description: "An app that returns the current time",
});

// Add a route to the app
timeApp
  .route({
    name: "Get Time",
    description: "Get the current time",
    path: "get-time",
  })
  .input(
    z.object({
      timezone: z
        .string()
        .optional()
        .describe("Optional timezone (defaults to UTC)"),
    }),
  )
  .handler(async ({ input }) => {
    const now = new Date();
    let timeString;

    if (input.timezone) {
      try {
        timeString = now.toLocaleString("en-US", { timeZone: input.timezone });
      } catch (e) {
        timeString = now.toISOString();
      }
    } else {
      timeString = now.toISOString();
    }

    return {
      currentTime: timeString,
      timestamp: now.getTime(),
    };
  });

// Execute the route
const result = await timeApp.run("/get-time").handler({
  input: { timezone: "America/New_York" },
});

console.log(result);
// Output: { currentTime: "5/16/2024, 10:30:45 AM", timestamp: 1716024645000 }

Multi-Route App

Create an app with multiple routes:

import { z } from "zod";
import openkit from "@opkt/openkit";
import axios from "axios";

// Define the Pokemon app with multiple routes
const pokemonApp = openkit
  .app({
    name: "Pokemon",
    description: "App for working with Pokemon data from PokeAPI",
  })
  .context({
    apiBaseUrl: "https://pokeapi.co/api/v2",
  })
  // Capture route
  .route({
    name: "Capture",
    description: "Capture a random Pokemon",
    path: "capture",
  })
  .input(
    z.object({
      id: z
        .number()
        .int()
        .min(1)
        .max(1025)
        .optional()
        .describe("Optional Pokemon ID to capture"),
    }),
  )
  .handler(async ({ input, context }) => {
    const pokemonId = input.id || Math.floor(Math.random() * 1025) + 1;
    const response = await axios.get(
      `${context.apiBaseUrl}/pokemon/${pokemonId}`,
    );
    return response.data;
  })
  // Location route
  .route({
    name: "Location",
    description: "Get information about Pokemon locations",
    path: "location",
  })
  .input(
    z.object({
      region: z.string().describe("The region to get location information for"),
    }),
  )
  .handler(async ({ input, context }) => {
    const response = await axios.get(
      `${context.apiBaseUrl}/location/${input.region}`,
    );
    return response.data;
  });

// Execute routes
const captureResult = await pokemonApp.run("/capture").handler({
  input: { id: 25 }, // Pikachu
});

const locationResult = await pokemonApp.run("/location").handler({
  input: { region: "kanto" },
});

Using with OpenAI

OpenKit apps can be easily used with the OpenAI API:

import { OpenAI } from "openai";
import openkit from "@opkt/openkit";
import myApp from "./my-app";

const openai = new OpenAI({ apiKey: process.env.OPENAI_API_KEY });

// Create an OpenAI adapter with your app
const oai = openkit.openai({ apps: [myApp] });

// Use the tools in your OpenAI call
const response = await openai.chat.completions.create({
  model: "gpt-4-turbo",
  messages: [{ role: "user", content: "Can you help me use this tool?" }],
  tools: oai.tools(),
});

// Handle any tool calls
if (response.choices[0].message.tool_calls) {
  const toolResults = await oai.handler({ chatCompletion: response });

  // Send the results back to continue the conversation
  const continuedResponse = await openai.chat.completions.create({
    model: "gpt-4-turbo",
    messages: [
      { role: "user", content: "Can you help me use this tool?" },
      response.choices[0].message,
      ...toolResults,
    ],
  });

  console.log(continuedResponse.choices[0].message.content);
}

LLM Response Formatting

You can customize how your app formats responses for LLMs:

const weatherApp = openkit
  .app({
    name: "Weather",
    description: "Get weather information",
  })
  .route({
    name: "Forecast",
    description: "Get weather forecast",
    path: "forecast",
  })
  .input(
    z.object({
      location: z.string().describe("Location for forecast"),
      days: z.number().optional().describe("Number of days to forecast"),
    }),
  )
  .handler(async ({ input }) => {
    return {
      location: input.location,
      forecast: "Sunny",
      temperature: 72,
    };
  })
  .llm({
    success: (result) => {
      return `Weather in ${result.location}: ${result.forecast}, ${result.temperature}°F`;
    },
    error: (error) => {
      return `Error getting weather forecast: ${error.message}`;
    },
  });

Input and Output Validation

OpenKit uses Zod for input and output validation:

const validatedApp = openkit
  .app({
    name: "Validated",
    description: "An app with validation",
  })
  .route({
    name: "Validate",
    description: "Validates input and output",
    path: "validate",
  })
  .input(
    z.object({
      email: z.string().email(),
      age: z.number().min(18),
    }),
  )
  .output(
    z.object({
      verified: z.boolean(),
      data: z.object({
        id: z.string().uuid(),
        timestamp: z.number(),
      }),
    }),
  )
  .handler(async ({ input }) => {
    return {
      verified: true,
      data: {
        id: "123e4567-e89b-12d3-a456-426614174000",
        timestamp: Date.now(),
      },
    };
  });

Debugging

Enable debug mode to see detailed logs during development:

const app = openkit
  .app({
    name: "MyApp",
    description: "My test app",
  })
  .debug() // Enable debug mode for the app
  .route({
    name: "MyRoute",
    description: "Test route",
    path: "/test",
  })
  .handler(async () => {
    return { status: "ok" };
  })
  .debug(); // Enable debug mode for this specific route

Key Concepts

• App: The top-level container for your functionality.
• Routes: Every app contains at least one route, which represents a specific function.
• Context: Shared data and dependencies for your routes.
• Middleware: Functions that can modify the input, output, or execution flow.
• Input/Output Validation: Define and validate your input and output shapes with Zod.
• LLM Formatting: Customize how your app formats responses for LLMs.
• Debug: Enable detailed logging for development and troubleshooting.

For more information

Visit openkit.fun to learn more about OpenKit and discover other apps built by the community.

Type Inference

OpenKit provides excellent TypeScript support with automatic type inference for your routes, inputs, and outputs. This helps catch errors at compile time and provides better editor auto-completion.

Automatic Type Inference

When you define routes with Zod schemas, OpenKit automatically infers the correct types without requiring explicit type annotations:

import { openkit } from "@opkt/openkit";
import { z } from "zod";

// Define input and output schemas
const userInputSchema = z.object({
  name: z.string(),
  age: z.number().optional(),
  email: z.string().email(),
});

const userOutputSchema = z.object({
  id: z.string(),
  name: z.string(),
  createdAt: z.date(),
});

// Create your app
const app = openkit.app({ name: "UserService" });

// Create a route with auto-inferred types
const createUserRoute = app
  .route({
    name: "Create User",
    path: "/users",
  })
  .input(userInputSchema) // Types are inferred from here
  .output(userOutputSchema) // Types are inferred from here
  .handler(async ({ input, context }) => {
    // input is fully typed: { name: string, age?: number, email: string }
    console.log(`Creating user: ${input.name}`);

    // Return a typed response
    return {
      id: "user-123",
      name: input.name,
      createdAt: new Date(),
    };
  });

// Run the handler with correct input types
const result = await app.run("Create User").handler({
  input: {
    name: "John Doe",
    email: "[email protected]",
  },
});
// result is typed as { id: string, name: string, createdAt: Date }

Type Utilities

OpenKit also provides utility types if you need to extract types from your routes:

import { RouteInput, RouteOutput, AppContext } from "@opkt/openkit";

// Get the input type from a route
type UserInput = RouteInput<typeof createUserRoute>;

// Get the output type from a route
type UserOutput = RouteOutput<typeof createUserRoute>;

// Get the context type from an app
type AppCtx = AppContext<typeof app>;

This makes it easy to reuse types throughout your application.