> ## Documentation Index
> Fetch the complete documentation index at: https://docs.paywalls.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# AI SDKs

**Client‑agnostic by design.** If your client can call an OpenAI‑style HTTP API, it works with Paywalls. In most cases you only change the **baseURL** and the **API key** — no new SDK integration or code changes required.

**Works with:** official OpenAI SDK, Vercel AI SDK, OpenRouter SDK, community clients, and plain HTTP requests. Edge/serverless runtimes are supported.

**Compatibility:** Chat Completions (including streaming), tools/function‑calling, JSON/structured outputs.

## OpenAI SDK

<Tabs>
  <Tab title="Typescript">
    ```ts theme={null}
    import OpenAI from "openai";

    const user = "user_123"; // Stable, pseudonymous user ID

    const client = new OpenAI({
      apiKey: process.env.PAYWALLS_API_KEY, // Set your Paywalls API key here
      baseURL: "https://api.paywalls.ai/v1", // Change baseURL to Paywalls
      headers: {
        "X-Paywall-User": user // Identify the end user
      }
    });

    const stream = await client.chat.completions.create({
      model: "gpt-5",
      user: "user_123",
      stream: true,
      messages: [
        { role: "user", content: "Explain usage-based pricing in 2 lines." },
      ],
    });

    for await (const chunk of stream) {
      const delta = chunk.choices?.[0]?.delta?.content;
      if (delta) process.stdout.write(delta);
    }
    ```
  </Tab>

  <Tab title="Python">
    ```python theme={null}
    from openai import OpenAI
    import os

    client = OpenAI(api_key=os.environ["PAYWALLS_API_KEY"], base_url="https://api.paywalls.ai/v1")

    with client.chat.completions.create(
        model="openai/gpt-4o-mini",
        user="user_123",
        stream=True,
        messages=[{"role": "user", "content": "Explain usage-based pricing in 2 lines."}],
    ) as stream:
        for event in stream:
            delta = event.choices[0].delta.content if event.choices and event.choices[0].delta else None
            if delta:
                print(delta, end="")
    ```
  </Tab>
</Tabs>

## Vercel AI SDK with Next.js

<Tabs>
  <Tab title="Next.js API route">
    ```ts theme={null}
    import { streamText } from 'ai'
    import { createOpenAI } from '@ai-sdk/openai'

    export async function POST(request: Request) {
      const { messages } = await request.json()

      const user = "user_123" // Stable, pseudonymous user ID

      const monetizedAI = createOpenAI({
        apiKey: process.env.PAYWALLS_API_KEY, // Your Paywalls API key
        baseURL: 'https://api.paywalls.ai/v1', // Change baseURL to Paywalls
        headers: {
          "X-Paywall-User": user // Identify the end user
        }
      })

      const result = await streamText({
        model: monetizedAI('gpt-5'),
        messages
      })

      return result.toAIStreamResponse()
    }
    ```
  </Tab>

  <Tab title="Client component">
    ```tsx theme={null}
    'use client'

    import { useChat } from 'ai/react'

    export default function PersonalAssistant() {
      const { messages, input, handleInputChange, handleSubmit } = useChat()

      return (
        <div className="flex flex-col h-screen max-w-2xl mx-auto p-4">
          <div className="flex-1 overflow-y-auto space-y-4">
            {messages.map((message) => (
              <div
                key={message.id}
                className={`p-4 rounded-lg ${
                  message.role === 'user' ? 'bg-blue-100 ml-auto' : 'bg-gray-100'
                }`}
              >
                <p>{message.content}</p>
              </div>
            ))}
          </div>

          <form onSubmit={handleSubmit} className="mt-4">
            <input
              value={input}
              onChange={handleInputChange}
              placeholder="Tell me about yourself or ask me anything..."
              className="w-full p-2 border rounded"
            />
          </form>
        </div>
      )
    }
    ```
  </Tab>
</Tabs>

## OpenRouter

```ts theme={null}
import { createOpenRouter } from "@openrouter/ai-sdk-provider";
import { streamText } from "ai";

const openrouter = createOpenRouter({
  apiKey: process.env.PAYWALLS_API_KEY, // Your Paywalls API key
  baseURL: "https://api.paywalls.ai/v1", // Change baseURL to Paywalls
  headers: {
    "X-Paywall-User": "user_123", // Stable, pseudonymous user ID
  },
});
const model = openrouter("anthropic/claude-3.7-sonnet:thinking");
await streamText({
  model,
  messages: [{ role: "user", content: "Hello" }],
});
```

## Together AI

```ts theme={null}
import Together from "together-ai";

const client = new Together({
  apiKey: process.env.PAYWALLS_API_KEY, // Your Paywalls API key
  baseURL: "https://api.paywalls.ai/v1", // Change baseURL to Paywalls
  headers: {
    "X-Paywall-User": "user_123", // Stable, pseudonymous user ID
  },
});

const chatCompletion = await client.chat.completions.create({
  messages: [
    { role: "user", content: "Explain usage-based pricing in 2 lines." },
  ],
  model: "mistralai/Mixtral-8x7B-Instruct-v0.1",
});

console.log(chatCompletion.choices);
```

## Environment Setup

Ensure you have your Paywalls API key set in your environment variables:

```bash theme={null}
PAYWALLS_API_KEY="your_paywalls_api_key_here"
```

<Note>
  Always send a stable, pseudonymous `user` id. For browser-only apps, do not expose your paywall key — use a server or edge function.
</Note>