Get started

Quickstart

Create a key and send a first request in a few minutes.

Create a key

Open API keys and select Create key. Name it after what will use it, and copy the key when it appears: it is shown once.

New accounts get up to $2.50 of free credit for open-weight text models, like the one below. For any other model, add credit with USDC or INFERENCE.

Set the key

export DEFERENCE_API_KEY="sk-df-..."

$env:DEFERENCE_API_KEY = "sk-df-..."

Send a request

curl https://deference.si/v1/chat/completions \
  -H "Authorization: Bearer $DEFERENCE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "deepseek/deepseek-v3.2",
    "messages": [{ "role": "user", "content": "Say hello in one sentence." }],
    "max_tokens": 100
  }'

import os
from openai import OpenAI

client = OpenAI(
    base_url="https://deference.si/v1",
    api_key=os.environ["DEFERENCE_API_KEY"],
)

response = client.chat.completions.create(
    model="deepseek/deepseek-v3.2",
    messages=[{"role": "user", "content": "Say hello in one sentence."}],
    max_tokens=100,
)
print(response.choices[0].message.content)

import OpenAI from "openai";

const client = new OpenAI({
  baseURL: "https://deference.si/v1",
  apiKey: process.env.DEFERENCE_API_KEY,
});

const response = await client.chat.completions.create({
  model: "deepseek/deepseek-v3.2",
  messages: [{ role: "user", content: "Say hello in one sentence." }],
  max_tokens: 100,
});
console.log(response.choices[0].message.content);

Swap model for any id from Models. Models that are not open-weight need credit.

Check it in Activity

Open Activity. The request is the top row, with its model, tokens and cost. The cost reads "estimating" for a few seconds, then shows the final amount. A request rejected with a 401, 402, 404 or 429 does not appear there.

If it fails

You see	Cause	Fix
`401 missing_api_key`	The variable is empty, so no key was sent	Set the variable in the shell that runs the code
`401 invalid_api_key`	The key is mistyped	Set the variable again from your saved key, or create a replacement. Keep the value out of logs
`402 insufficient_credit`	The account has no available credit	Add credit
`402 free_credit_not_eligible`	The account has only free credit, and this model or request does not qualify	Use an open-weight text model, or set a lower `max_tokens`
`404 model_not_found`	The model id is not in the catalog	Copy an id from the Models page
`429 rate_limited`	Too many requests in a minute	Wait for the `retry-after` seconds

Set up a tool

Point your coding tool at Deference next. Every guide is in Coding tools.

Writing code instead? See what your key can do.