Overview
AI Gateway lets each customer connect the AI provider account your application uses for them.
your backend
│ OpenAI or Anthropic request
│ customer ID: org_123
▼
AI Gateway
│
└── provider connected by org_123
AWS Bedrock · Vertex AI · Azure AI Foundry
OpenAI · Anthropic · DatabricksYour backend keeps one API integration. The customer’s provider credentials stay in their connection; your application receives an Alien API key instead.
Add it to an OpenAI client
Change the base URL, add the customer ID, and use the model ID shown by Alien:
import OpenAI from "openai"
const ai = new OpenAI({
baseURL: "https://ai.alien.dev/v1",
apiKey: process.env.ALIEN_AI_API_KEY,
defaultHeaders: {
"X-Alien-External-ID": customer.id,
},
})
const response = await ai.chat.completions.create({
model: "byo/claude-opus-5",
messages: [{ role: "user", content: "Hello" }],
})The three values that choose the route are visible in the example:
| Value | Chooses |
|---|---|
| Alien API key | Your project |
X-Alien-External-ID | The customer connection |
model | A model available through that connection |
AI Gateway supports OpenAI Chat Completions, OpenAI Responses, Anthropic Messages, and model discovery.