Migrate from OpenAI

NoMask supports the OpenAI Chat Completions request and response format. Keep your existing SDK and message history, configure the NoMask connection, and choose a model from the catalog.

Change your connection

Setting	NoMask value
Base URL	`https://nomask.ai/api/v1`
API key	Your NoMask key from API Keys
Model	An exact model ID from the NoMask catalog
Text API	Chat Completions: `client.chat.completions.create(...)`

Leave /chat/completions off the base URL; the SDK adds it. An OpenAI model name is not automatically mapped to a NoMask model. Set NOMASK_API_KEY and NOMASK_MODEL in your server environment, then run one of these examples. Replace your-model-id with a current text model ID.

export NOMASK_API_KEY="nmk_live_..."
export NOMASK_MODEL="your-model-id"

Python
JavaScript

Install the SDK with pip install openai.

import os
from openai import OpenAI

client = OpenAI(
    base_url="https://nomask.ai/api/v1",
    api_key=os.environ["NOMASK_API_KEY"],
)

response = client.chat.completions.create(
    model=os.environ["NOMASK_MODEL"],
    messages=[{"role": "user", "content": "Explain a database index in one sentence."}],
)
print(response.choices[0].message.content)

Install the SDK with npm install openai. Save this example as main.mjs and run node main.mjs.

import OpenAI from "openai";

const client = new OpenAI({
  baseURL: "https://nomask.ai/api/v1",
  apiKey: process.env.NOMASK_API_KEY,
});

const response = await client.chat.completions.create({
  model: process.env.NOMASK_MODEL,
  messages: [{ role: "user", content: "Explain a database index in one sentence." }],
});
console.log(response.choices[0].message.content);

Choose OpenAI Compatible and Chat Completions when your tool offers multiple API modes. NoMask does not expose /responses or Anthropic’s /messages endpoint. Tools that require those formats need an adapter; see Codex or Claude Code.

Connect a framework

Use the same environment variables as above. Select Chat Completions explicitly when a framework also supports Responses.

Vercel AI SDK
LangChain

Install ai and @ai-sdk/openai.

import { createOpenAI } from "@ai-sdk/openai";
import { generateText } from "ai";

const nomask = createOpenAI({
  baseURL: "https://nomask.ai/api/v1",
  apiKey: process.env.NOMASK_API_KEY,
});

const { text } = await generateText({
  model: nomask.chat(process.env.NOMASK_MODEL),
  prompt: "Explain a database index in one sentence.",
});
console.log(text);

Use nomask.chat(...); the default model factory uses the Responses API. See the AI SDK OpenAI provider documentation.

Install langchain-openai.

import os
from langchain_openai import ChatOpenAI

model = ChatOpenAI(
    model=os.environ["NOMASK_MODEL"],
    base_url="https://nomask.ai/api/v1",
    api_key=os.environ["NOMASK_API_KEY"],
    use_responses_api=False,
)
print(model.invoke("Explain a database index in one sentence.").content)

Use standard chat and function tools, within the selected model’s capabilities. See the LangChain ChatOpenAI documentation.

For another SDK or client, configure its custom base URL, Bearer key, model ID, and Chat Completions mode. Check which optional fields it sends against the supported parameters below.

What carries over

Capability	NoMask behavior
Messages	`system`, `user`, `assistant`, and `tool` roles
Responses	`chat.completion` objects with `choices`, `finish_reason`, and `usage`
Streaming	`chat.completion.chunk` events over SSE; see Streaming
Tool calls	`tools`, `tool_choice`, and `parallel_tool_calls` on models with function calling
Image input	Image content parts on vision-capable models
Sampling	`temperature`, `top_p`, `frequency_penalty`, and `presence_penalty`, subject to model support
Output limits	`max_tokens` or `max_completion_tokens`; `stop` accepts one string or up to four strings
Errors	OpenAI-style `error` objects with `message`, `type`, `code`, and `param`

Model capabilities and limits are available through GET /models. For all fields, see Chat Completions. Video input uses NoMask’s supported video message format.

Images

NoMask also provides POST /images/generations and POST /images/edits. Select an image model, request one image (n: 1), and use response_format: "b64_json". Images are returned inline rather than as hosted URLs. Supported dimensions, formats, and reference-image counts depend on the model. The Image Generation reference covers generation, multipart edits, JSON references, and response decoding.

Add NoMask options

Keep your own instructions in a system message. Use nomask_system_prompt to prepend NoMask’s persona, and reasoning options to control supported models. With Python, put NoMask-specific fields in extra_body; with JavaScript, add them to the request body.

Python
JavaScript

response = client.chat.completions.create(
    model=os.environ["NOMASK_MODEL"],
    messages=[{"role": "user", "content": "Explain how binary search works."}],
    extra_body={
        "reasoning": {"enabled": True, "effort": "high"},
        "nomask_system_prompt": True,
    },
)

const response = await client.chat.completions.create({
  model: process.env.NOMASK_MODEL,
  messages: [{ role: "user", content: "Explain how binary search works." }],
  reasoning: { enabled: true, effort: "high" },
  nomask_system_prompt: true,
});

Parameter	Purpose
`reasoning`	An object with `enabled` and `effort`; supported levels depend on the model.
`reasoning_effort`	Shorthand for effort: `none`, `minimal`, `low`, `medium`, `high`, `xhigh`, or `max`. `none` requests Off.
`nomask_system_prompt`	Enables NoMask’s persona before your own messages; defaults to off.

See Reasoning for model-specific adjustments and System Prompt for persona behavior.

Account for the differences

Choose a NoMask model ID. IDs and capabilities come from the NoMask catalog. Unknown IDs return 404 model_not_found.
Use a NoMask balance. Paid requests draw from your prepaid USD balance. Completed responses add nomask.cost_usd; see Billing & Funding.
Read extensions when needed. Responses can include reasoning_content, warnings, and the nomask metadata object. A framework may not preserve every extra field.
Keep tools in your application. Function calls describe work for your code to execute. The developer API does not provide built-in web search or browsing tools.
Use supported endpoints. Responses, legacy Completions, Embeddings, Audio, Files, Assistants, and Moderations APIs are not provided. Use Chat Completions for text and the documented image endpoints for images.
Send file text as text. Extract document contents in your application; file uploads and file content parts are not supported by the chat endpoint.

Unsupported request options

These options return 400 unsupported_parameter, with the field identified in error.param:

Option	How to adapt
`functions`, `function_call`	Use `tools` and `tool_choice`.
`logprobs`, `top_logprobs`	Remove probability-output options.
`audio`, `modalities`, `prediction`	Remove these unsupported chat options.
`n` other than `1`	Send one completion per request.
`response_format` with `json_object` or `json_schema`	Use text output; JSON mode and structured-output enforcement are not supported.
Web-search or browsing parameters	Run your own tools and send their results as messages.

Start with the minimal SDK request, then add streaming, tools, or multimodal inputs supported by your selected model. Errors explains failure codes; Rate Limits covers retry behavior.

Chat Completions

Check request fields and the response format.

Coding tools

Connect an OpenAI-compatible coding assistant.

Docs

Getting Started

Text & Chat

Image

Production

Coding Tools

Chat API

Image API

Model API

Account & Usage

Errors & Limits

Migrate from OpenAI

Change your connection

Connect a framework

What carries over

Images

Add NoMask options

Account for the differences

Unsupported request options

Chat Completions

Coding tools

​Change your connection

​Connect a framework

​What carries over

​Images

​Add NoMask options

​Account for the differences

​Unsupported request options

Chat Completions

Coding tools

Change your connection

Connect a framework

What carries over

Images

Add NoMask options

Account for the differences

Unsupported request options