Quickstart

This guide gets you from zero to a working API call. By the end you’ll have:

• A RouterLink account and API key
• A successful chat completion against any supported model
• A budget set on your key so you can’t overspend

1. Create an API key

Sign in

Visit routerlink.ai and sign in with email or Google.

Top up credits

Open Settings → Billing and add credits.

Generate a key

Go to API Keys → Create key. Copy the key (it starts with sk- and is shown only once).

2. Make your first request (OpenAI-compatible)

Replace <ROUTERLINK_API_KEY> with your RouterLink Key.

For available model options, please check the Model Gallery. Simply copy and paste the model name to use it.

Curl

curl https://router-link.world3.ai/api/v1/chat/completions \
  -H "Authorization: Bearer <ROUTERLINK_API_KEY>" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "world3-router-north-america/openai/gpt-5.3-codex",
    "messages": [
      {"role": "user", "content": "Say hello in one short sentence."}
    ]
  }'

Python

from openai import OpenAI

client = OpenAI(
    base_url="https://router-link.world3.ai/api/v1",
    api_key="<ROUTERLINK_API_KEY>",
)

resp = client.chat.completions.create(
    model="world3-router-north-america/openai/gpt-5.3-codex",
    messages=[{"role": "user", "content": "Say hello in one short sentence."}],
)
print(resp.choices[0].message.content)

Node.js

import OpenAI from "openai";

const client = new OpenAI({
  baseURL: "https://router-link.world3.ai/api/v1",
  apiKey: process.env.ROUTERLINK_API_KEY,
});

const resp = await client.chat.completions.create({
  model: "world3-router-north-america/openai/gpt-5.3-codex",
  messages: [{ role: "user", content: "Say hello in one short sentence." }],
});
console.log(resp.choices[0].message.content);

3. Use the native Anthropic SDK

RouterLink exposes an Anthropic-compatible Messages endpoint, so any official Anthropic client SDK works by overriding base_url (and pointing api_key at your RouterLink key).

Base URL: https://router-link.world3.ai/api — the SDK appends /v1/messages automatically. Make sure to replace <ROUTERLINK_API_KEY> with your API key from RouterLink.

Curl

curl https://router-link.world3.ai/api/v1/messages \
  -H "x-api-key: <ROUTERLINK_API_KEY>" \
  -H "Content-Type: application/json" \
  -H "anthropic-version: 2023-06-01" \
  -d '{
    "model": "anthropic/claude-opus-4-6",
    "max_tokens": 1024,
    "messages": [
      {"role": "user", "content": "Say hello in one short sentence."}
    ]
  }'

Python

pip install anthropic

import anthropic

client = anthropic.Anthropic(
    base_url="https://router-link.world3.ai/api",
    api_key="<ROUTERLINK_API_KEY>",
)

message = client.messages.create(
    model="anthropic/claude-opus-4-6",
    max_tokens=1024,
    messages=[{"role": "user", "content": "Say hello in one short sentence."}],
)
print(message.content[0].text)

Node.js

npm install @anthropic-ai/sdk

import Anthropic from "@anthropic-ai/sdk";

const client = new Anthropic({
  baseURL: "https://router-link.world3.ai/api",
  apiKey: process.env.ROUTERLINK_API_KEY,
});

const message = await client.messages.create({
  model: "anthropic/claude-opus-4-6",
  max_tokens: 1024,
  messages: [{ role: "user", content: "Say hello in one short sentence." }],
});
console.log(message.content);

Other official SDKs (Java, Go, Ruby, C#, PHP) work the same way — set the SDK’s base URL to https://router-link.world3.ai/api and pass your RouterLink key.

4. Watch your spend

Open Settings → Logs and Settings → Usage to see request volume, latency, and cost broken down by model and key.

Initiate requests through a third-party client

Already using Claude Code, Codex, or another tool that speaks the Anthropic or OpenAI API? Point it at RouterLink and bring your own key — see the Integration Guides for end-to-end setup.