@gatelit/sdk

TypeScript client for the Gatelit AI gateway — chat, streaming, tool calling, and structured output across any LLM provider through a single API.

import { GatelitClient } from "@gatelit/sdk"

const client = new GatelitClient({
  gatewayUrl: "https://gateway.gatelit.dev",
  getToken: async () => ({ token: "glk_...", scheme: "GatelitKey" }),
})

const response = await client.chat({
  model: "openai/gpt-4o",
  messages: [{ role: "user", content: "Hello" }],
})
console.log(response.content)

Features

• Universal client — one API for OpenAI, Anthropic, Google, Mistral, and more
• Streaming — async generator-based token-by-token output
• Tool calling — send tools/toolChoice, receive toolCalls in responses
• Structured output — typed JSON responses with chatJson<T>()
• Multi-turn conversations — automatic history management with Conversation
• Retry — configurable exponential backoff for transient failures
• Zero dependencies — only the Web Crypto API (Node 18+, browser, edge)
• Dual CJS/ESM — works everywhere: Node.js, Deno, Bun, Cloudflare Workers, browsers
• Lightweight sign subpath — import @gatelit/sdk/sign for exchangeToken() without the client

Install

npm install @gatelit/sdk
# or
pnpm add @gatelit/sdk
# or
yarn add @gatelit/sdk

Quick start

import { GatelitClient } from "@gatelit/sdk"

const client = new GatelitClient({
  gatewayUrl: "https://gateway.gatelit.dev",
  getToken: async () => {
    // Option A: long-lived service key (backend only)
    return { token: process.env.GATELIT_SERVICE_KEY!, scheme: "GatelitKey" }

    // Option B: short-lived signed token (browser apps)
    // const res = await fetch("/api/ai-token")
    // const { token } = await res.json()
    // return { token, scheme: "GatelitSigned" }
  },
})

// Chat
const res = await client.chat({
  model: "openai/gpt-4o",
  messages: [{ role: "user", content: "What is the capital of France?" }],
})
console.log(res.content, res.usage)

// Streaming
for await (const chunk of client.stream({
  model: "anthropic/claude-3-5-sonnet-20241022",
  messages: [{ role: "user", content: "Tell me a story" }],
})) {
  process.stdout.write(chunk.delta)
}

// Tool calling
const toolRes = await client.chat({
  model: "openai/gpt-4o",
  messages: [{ role: "user", content: "What's the weather in Boston?" }],
  tools: [{
    type: "function",
    function: {
      name: "get_weather",
      description: "Get current weather",
      parameters: {
        type: "object",
        properties: { location: { type: "string" } },
      },
    },
  }],
})
if (toolRes.toolCalls) {
  console.log(toolRes.toolCalls[0].function.name) // "get_weather"
}

// Typed JSON
const data = await client.chatJson<{ name: string; age: number }>({
  model: "openai/gpt-4o",
  messages: [{ role: "user", content: "Alice is 30" }],
  outputSchema: { mode: "json_object" },
})
console.log(data.name, data.age)

// Retry on transient failures
const resilient = new GatelitClient({
  gatewayUrl: "https://gateway.gatelit.dev",
  getToken: async () => ({ token: "glk_...", scheme: "GatelitKey" }),
  maxRetries: 3,
  retryDelay: 1000,
})

Documentation

Full docs at docs.gatelit.dev/sdk/typescript/overview.

License

MIT