gpt-oss-20b (free)

curl https://api.openai.com/v1/chat/completions \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer $OPENAI_API_KEY" \
  -d '{
    "model": "gpt-oss-20b-free",
    "messages": [{"role": "user", "content": "Hello!"}]
  }'

# pip install openai
from openai import OpenAI

client = OpenAI(
    base_url="https://api.openai.com/v1",
    api_key=os.environ["OPENAI_API_KEY"],
)

resp = client.chat.completions.create(
    model="gpt-oss-20b-free",
    messages=[{"role": "user", "content": "Hello!"}],
)
print(resp.choices[0].message.content)

// npm install openai
import OpenAI from "openai";

const client = new OpenAI({
  baseURL: "https://api.openai.com/v1",
  apiKey: process.env.OPENAI_API_KEY,
});

const resp = await client.chat.completions.create({
  model: "gpt-oss-20b-free",
  messages: [{ role: "user", content: "Hello!" }],
});
console.log(resp.choices[0].message.content);