Migration from OpenAI - OpenModex

Overview

OpenModex is fully compatible with the OpenAI API. Migration typically requires changing just two lines of code: the base URL and the API key.

Option 1: Use the OpenAI SDK (Fastest)

If you’re already using the OpenAI SDK, just change the configuration:

import OpenAI from 'openai';

const client = new OpenAI({
  apiKey: 'omx_sk_YOUR_KEY',                   // ← OpenModex key
  baseURL: 'https://api.openmodex.com/v1',     // ← OpenModex URL
});

// All existing code works unchanged
const response = await client.chat.completions.create({
  model: 'gpt-4o',
  messages: [{ role: 'user', content: 'Hello!' }],
});

from openai import OpenAI

client = OpenAI(
    api_key="omx_sk_YOUR_KEY",                   # ← OpenModex key
    base_url="https://api.openmodex.com/v1",     # ← OpenModex URL
)

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

Option 2: Use the OpenModex SDK

For access to routing, caching, fallbacks, and model comparison:

// Before (OpenAI)
import OpenAI from 'openai';
const client = new OpenAI({ apiKey: 'sk-...' });

// After (OpenModex)
import OpenModex from '@openmodex/sdk';
const client = new OpenModex({ apiKey: 'omx_sk_...' });

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

# Before (OpenAI)
from openai import OpenAI
client = OpenAI(api_key="sk-...")

# After (OpenModex)
from openmodex import OpenModex
client = OpenModex(api_key="omx_sk_...")

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

Option 3: Environment Variable

For zero-code migration, just set environment variables:

# Replace
export OPENAI_API_KEY=sk-...
export OPENAI_BASE_URL=https://api.openai.com/v1

# With
export OPENAI_API_KEY=omx_sk_...
export OPENAI_BASE_URL=https://api.openmodex.com/v1

What You Gain

After migrating, you get access to:

Feature	OpenAI Direct	OpenModex
OpenAI models	✅	✅
Anthropic, Google, etc.	❌	✅
Automatic fallbacks	❌	✅
Smart routing	❌	✅
Prompt caching	❌	✅
Model comparison	❌	✅
Unified billing	❌	✅
Usage analytics	Basic	✅

Compatibility Notes

All OpenAI chat completion parameters are supported
Streaming works identically (SSE format)
Function calling / tool use is fully supported
Response format is identical — your parsing code stays the same
The openmodex metadata field is additive and won’t break existing code