OpenAI-Compatible API

One OpenAI-Compatible API for Multiple AI Models

VoyageAge is an OpenAI-compatible API provider for developers who want to keep their existing OpenAI SDK workflow. Change the endpoint to access supported OpenAI and Claude models through one multi-model AI API, with pay-as-you-go billing and lower-cost API access.

Get Started View API Docs

One endpointOpenAI SDK workflowGPT + ClaudePay as you go

pythonOpenAI SDK

from openai import OpenAI

client = OpenAI(
    api_key="YOUR_VOYAGEAGE_API_KEY",
    base_url="https://api.voyageage.com/v1",
)

response = client.chat.completions.create(
    model="gpt-5.6-sol",
    messages=[
        {"role": "user", "content": "Hello"}
    ],
)

Compatible endpointapi.voyageage.com/v1

Change the connection, not the client

Keep Your Existing OpenAI SDK

If your application already uses a standard OpenAI client, connect it to VoyageAge by updating the API key and base URL. Choose a model identifier from /v1/models when your current name does not match the VoyageAge catalog.

Open the quick start

No SDK rewrite required

Continue using the official OpenAI Python client and its familiar chat-completions method.

OpenAI-compatible request format

Keep the standard messages structure while selecting a supported model through one gateway.

Streaming and tool calls

Use streaming and tool or function calls on compatible models and endpoints; validate model-specific behavior before production.

A unified AI API workflow

One API, Multiple Leading Models

Use one API key, one billing system, and one compatible request format across the supported model families in the shared VoyageAge catalog.

GET /v1/models

ClientOpenAI SDKExisting workflow

HTTPS

VoyageAge endpointhttps://api.voyageage.com/v1One key · one wallet · one usage view

OpenAI3 shown

GPT-5.6 Solgpt-5.6-sol
GPT-5.6 Terragpt-5.6-terra
GPT-5.6 Lunagpt-5.6-luna

Anthropic3 shown

Claude Opus 5claude-opus-5
Claude Fable 5claude-fable-5
Claude Opus 4.8claude-opus-4-8

The displayed model list is derived from the same build-time pricing snapshot used elsewhere on VoyageAge. Current availability can depend on your API key and the live /v1/models response.

Compatibility as infrastructure

Why Use an OpenAI-Compatible API?

An OpenAI-compatible LLM API lets teams preserve a familiar integration boundary while changing where supported requests are served.

Less Integration Work

Keep a familiar OpenAI client and request shape instead of maintaining a separate SDK integration for every model provider.

Easier Model Switching

Select another supported model ID while keeping authentication, billing, and the surrounding API workflow in one place.

Existing Tool Compatibility

Connect tools and agents that support a custom OpenAI-compatible endpoint. Always validate the specific client and model you plan to use.

Simpler Infrastructure

Use one API key, one usage view, one wallet, and one compatible request format across supported model families.

Shared model pricing

Compare Model Pricing

Compare VoyageAge input and output prices with the official reference prices in the shared model-pricing source. Prices are shown per one million tokens.

ModelProviderOfficial inputVoyageAge inputOfficial outputVoyageAge outputSave vs. official API

✦GPT-5.6 Solgpt-5.6-solOpenAI$5.0000$0.6050$30.0000$3.6300Save 88%

✦Claude Opus 5claude-opus-5Anthropic$5.0000$1.5000$25.0000$7.5000Save 70%

GPT-5.6 Terragpt-5.6-terraOpenAI$2.0000$0.2280$12.0000$1.3680Save 89%

Claude Sonnet 5claude-sonnet-5Anthropic$2.0000$0.4000$10.0000$2.0000Save 80%

Understand the distinction

OpenAI API vs. an OpenAI-Compatible API

OpenAI-compatible describes the request workflow; it does not mean a provider is the official OpenAI service. VoyageAge is an independent third-party API provider and gateway.

Use the official OpenAI API when you specifically need a direct OpenAI-operated service. Use VoyageAge when a compatible multi-model gateway better fits your application.

CapabilityOpenAI APIVoyageAge

API formatOpenAI nativeOpenAI-compatible

OpenAI modelsYesYes

Claude modelsNoYes

Multiple providersNoYes

Existing OpenAI SDK workflowNativeCompatible

Pay-as-you-goYesYes

Practical workloads

Built for Developers Using AI APIs

VoyageAge fits server-side and tool-based workflows that benefit from a compatible endpoint and access to more than one model family.

AI Applications

Backend services, SaaS products, and customer-facing AI features that call model APIs.

Coding Agents

Coding tools that accept a custom OpenAI-compatible endpoint and supported model ID.

Automation

Agents, workflows, and scheduled processes built around API requests.

Startups

Teams managing integration complexity and model spend as products evolve.

Multi-model Applications

Applications that need access to both GPT and Claude model families.

A controlled provider change

Switch to VoyageAge with Minimal Code Changes

Move from the official OpenAI API or another compatible provider by changing connection settings first, then testing your actual model and feature requirements.

Before · OpenAI defaultclient = OpenAI(api_key="OPENAI_API_KEY")

After · VoyageAgeclient = OpenAI( api_key="YOUR_VOYAGEAGE_API_KEY", base_url="https://api.voyageage.com/v1" )

1Create a VoyageAge account
2Generate an API key
3Update the API key in your server environment
4Set the base URL to https://api.voyageage.com/v1
5Select a model returned by /v1/models
6Test the request before moving production traffic

Read the API Docs

Implementation questions

OpenAI-Compatible API FAQ

Clear answers about SDK compatibility, Claude access, migration, streaming, tool calls, and billing.

What is an OpenAI-compatible API?

An OpenAI-compatible API follows familiar OpenAI request conventions so existing clients can usually connect through a custom base URL and API key. Compatibility does not mean the service is operated by OpenAI, and model-specific behavior can still vary.

Is VoyageAge an OpenAI-compatible API?

Yes. VoyageAge provides an OpenAI-compatible endpoint at https://api.voyageage.com/v1 for supported models and workflows. VoyageAge is an independent third-party API provider, not an OpenAI service.

Can I use the OpenAI Python SDK with VoyageAge?

Yes. Configure the OpenAI client with your VoyageAge API key and the VoyageAge base URL, then choose a supported model ID returned by /v1/models.

Can I access Claude through an OpenAI-compatible API?

Yes. VoyageAge exposes supported Claude models through its unified model catalog. It also provides an Anthropic-compatible gateway for clients that require Anthropic-specific behavior.

Do I need to rewrite my existing OpenAI integration?

Usually not. Most integrations can keep the OpenAI SDK and request format while changing the API key, base URL, and model identifier when required. Test the exact features your application depends on before switching production traffic.

Can I use streaming and tool calls?

VoyageAge supports streaming responses and tool or function calls on compatible models and endpoints. Support can vary by model, so validate the selected model and client workflow.

How is VoyageAge different from the official OpenAI API?

The official OpenAI API is operated by OpenAI and serves OpenAI models. VoyageAge is an independent third-party gateway that uses an OpenAI-compatible workflow to provide supported OpenAI and Claude models through one account and billing system.

Is VoyageAge pay-as-you-go?

Yes. Add balance to your wallet and pay for the API usage you consume. A recurring subscription is not required to start using the API.

Start with one test request

Use Your Existing OpenAI Workflow with VoyageAge

Create an account, generate an API key, update your endpoint, and start testing multiple AI models through one OpenAI-compatible API.

Get Started Read the Docs

Looking for an OpenRouter alternative?Looking specifically for a Claude API alternative?Contact Privacy Status

Need help?Chat on Discord