Documentation

Everything you need to integrate ApexApi into your application.

Quickstart

Get up and running in under 2 minutes. ApexApi is fully compatible with the OpenAI SDK.

1. Create an account and get your API key

2. Install the OpenAI SDK

ApexApi is compatible with the official OpenAI SDK. No custom SDK needed.

Terminal

npm install openai

3. Make your first API call

Point the OpenAI client to ApexApi and specify any supported model using the provider/model format.

example.ts

import OpenAI from "openai";

const client = new OpenAI({
  apiKey: "ak-your-api-key",
  baseURL: "https://api.apexapi.dev/v1",
});

const completion = await client.chat.completions.create({
  model: "openai/gpt-4o",
  messages: [{ role: "user", content: "Hello, world!" }],
});

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

4. Stream responses

Enable streaming by setting stream: true. Works with all chat completion models.

streaming.ts

const stream = await client.chat.completions.create({
  model: "anthropic/claude-sonnet-4-20250514",
  messages: [{ role: "user", content: "Write a haiku about APIs." }],
  stream: true,
});

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

Browse Documentation

API Reference

Chat completions, image generation, and model listing endpoints.

Models

Browse all supported models across 14+ providers.

Error Handling

Error codes, retry strategies, and troubleshooting.

Rate Limits

Understand rate limit tiers, headers, and best practices.

Billing & Credits

Credits system, pricing, usage tracking, and auto top-up.