Quickstart - Corti API Documentation

Already using the OpenAI SDK, Azure OpenAI, or any OpenAI-compatible provider? This guide shows you how to point that existing client at Corti Models, then make your first request. No new SDK, rewrite, or migration. Looking to use Corti Models with your coding agent? Read Code with Corti.

Corti Models is available only for Corti projects hosted in the EU region (https://ai.eu.corti.app). Credentials from a US-hosted project can’t access Corti Models. See Environments & Tenants.

Get your API key

Grab a Corti Models Service API Key from the Corti Console. It’s a single value you pass straight to the SDK as your API key.

Open API Clients in the Corti Console

Swap your provider

If your code looks like this today:

from openai import OpenAI

client = OpenAI(
    api_key=os.environ["OPENAI_API_KEY"],
)

response = client.chat.completions.create(
    model="gpt-4o",
    messages=[{"role": "user", "content": "Hello!"}],
)

import OpenAI from "openai";

const client = new OpenAI({
  apiKey: process.env.OPENAI_API_KEY,
});

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

Change the base URL and API key, and you’re running on Corti:

from openai import OpenAI

# corti-s1 | corti-s1-instant | corti-s1-mini | corti-s1-mini-instant
MODEL = "corti-s1"

client = OpenAI(
    base_url="https://ai.eu.corti.app/v1",
    api_key="<your-api-key>",
)

response = client.chat.completions.create(
    model=MODEL,
    messages=[{"role": "user", "content": "Hello!"}],
)

print(response.choices[0].message.content)

import OpenAI from "openai";

// corti-s1 | corti-s1-instant | corti-s1-mini | corti-s1-mini-instant
const MODEL = "corti-s1";

const client = new OpenAI({
  baseURL: "https://ai.eu.corti.app/v1",
  apiKey: "<your-api-key>",
});

const response = await client.chat.completions.create({
  model: MODEL,
  messages: [{ role: "user", content: "Hello!" }],
});

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

API_KEY="<your-api-key>"
# corti-s1 | corti-s1-instant | corti-s1-mini | corti-s1-mini-instant
MODEL="corti-s1"

curl https://ai.eu.corti.app/v1/chat/completions \
  -H "Authorization: Bearer ${API_KEY}" \
  -H "Content-Type: application/json" \
  -d "{
    \"model\": \"${MODEL}\",
    \"messages\": [{\"role\": \"user\", \"content\": \"Hello!\"}]
  }"

Everything else in your code — streaming, tool calling, JSON mode, multi-turn conversations, the Responses API — works unchanged. Corti Models is a drop-in replacement.

corti-s1-mini and corti-s1-mini-instant also accept image inputs for OCR, image descriptions, and UI analysis. See Image input on the Models page, or the example below.

OAuth 2.0 access tokens will be supported soon. For now, use your Corti API key as the apiKey / Bearer credential.

Send an image

corti-s1-mini and corti-s1-mini-instant accept image inputs via the standard OpenAI multimodal content format. Encode your image as a base64 data URI and pass it in the messages array:

import OpenAI from "openai";
import { readFileSync } from "fs";

// corti-s1-mini | corti-s1-mini-instant
const MODEL = "corti-s1-mini";

// Replace with your values
const API_KEY = "<your-api-key>";
const IMAGE_PATH = "<path-to-your-image>";

const b64 = readFileSync(IMAGE_PATH).toString("base64");

const client = new OpenAI({
  baseURL: "https://ai.eu.corti.app/v1",
  apiKey: API_KEY,
});

const response = await client.chat.completions.create({
  model: MODEL,
  messages: [{
    role: "user",
    content: [
      { type: "text", text: "Describe this image." },
      { type: "image_url", image_url: { url: `data:image/jpeg;base64,${b64}` } },
    ],
  }],
});

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

import base64

from openai import OpenAI

# corti-s1-mini | corti-s1-mini-instant
MODEL = "corti-s1-mini"

# Replace with your values
API_KEY = "<your-api-key>"
IMAGE_PATH = "<path-to-your-image>"

with open(IMAGE_PATH, "rb") as f:
    b64 = base64.b64encode(f.read()).decode("ascii")

client = OpenAI(
    base_url="https://ai.eu.corti.app/v1",
    api_key=API_KEY,
)

response = client.chat.completions.create(
    model=MODEL,
    messages=[{
        "role": "user",
        "content": [
            {"type": "text", "text": "Describe this image."},
            {"type": "image_url", "image_url": {"url": f"data:image/jpeg;base64,{b64}"}},
        ],
    }],
)

print(response.choices[0].message.content)

# corti-s1-mini | corti-s1-mini-instant
MODEL="corti-s1-mini"

# Replace with your values
API_KEY="<your-api-key>"
IMAGE_PATH="<path-to-your-image>"

B64=$(base64 < "$IMAGE_PATH" | tr -d '\n')

curl https://ai.eu.corti.app/v1/chat/completions \
  -H "Authorization: Bearer ${API_KEY}" \
  -H "Content-Type: application/json" \
  -d "{
    \"model\": \"${MODEL}\",
    \"messages\": [{
      \"role\": \"user\",
      \"content\": [
        {\"type\": \"text\", \"text\": \"Describe this image.\"},
        {\"type\": \"image_url\", \"image_url\": {\"url\": \"data:image/jpeg;base64,${B64}\"}}
      ]
    }]
  }"

See which models are available

List the models your credentials can access to confirm the model IDs you can pass:

cURL

API_KEY="<your-api-key>"

curl https://ai.eu.corti.app/v1/models \
  -H "Authorization: Bearer ${API_KEY}"

See the Models page for the full lineup and pricing.

Next steps

Models

Compare the four model variants by capability, reasoning, speed, and price.

Code with Corti

Connect OpenCode, ForgeCode, Crush, or Pi to Corti Models with the Corti CLI.

API Reference

Browse the full Corti Models API with interactive examples.

Authentication

How authentication works at Corti.

​Get your API key

Open API Clients in the Corti Console

​Swap your provider

​Send an image

​See which models are available

​Next steps

Models

Code with Corti

API Reference

Authentication

Get your API key

Swap your provider

Send an image

See which models are available

Next steps