OpenAI-compatible API

One API key.
Every AI model.

Reach 248+ models from OpenAI, Anthropic, Google, DeepSeek and more through one endpoint. Use them in your code and agents, or chat right here. Pay only for what you use.

Models248
Ready to use
AI labs43
One catalog
Free118
No cost
Paid130
Pay per use
Get started

Start in three steps.

From sign-up to your first request in a few minutes.

1

Sign up

Create an account in under a minute. No credit card needed to start.

Continue with GitHub
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2

Top up or subscribe

Begin with the free models. Top up or pick a plan when you need paid ones. Pay-as-you-go credit never expires.

Free
$0
May 02
$50
Apr 18
$20
Apr 04
$10
3

Get your API key

Use it in your code, in Claude Code, or paste it into SillyTavern, RisuAI, or any OpenAI-compatible AI chat client.

LUMEN_API_KEY
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Fully OpenAI compatible
Why Lumen

Built for production.

Everything you need to ship AI features without juggling providers, keys and invoices.

Drop-in compatible

OpenAI, Anthropic and Gemini formats. Point your SDK at Lumen and keep your code.

Automatic failover

When a provider slows down or fails, requests move to a healthy one. No retry logic to write.

Pay as you go

Clear per-token prices, free models to start, and credit that never expires.

Keys with limits

Create a key per project and cap it with model allow-lists, spending limits and expiry dates.

Usage analytics

Spend, latency and success rate per model and per key, for any date range.

Private chat

The built-in chat keeps your conversations in your browser, not on our servers.

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Captain Elara Voss

Reporting in, recruit. Stow your gear, we jump in ten.

148 in / 297 out
Type a message...
Character chat
Characters
Personas
Lorebooks
Presets
Cards
Built-in Chat

Rather just chat?
It's built in.

Open the chat and start talking. Free models are ready with no sign-up and no setup. Bring characters, personas and lorebooks, and keep every conversation in your browser.

No Setup

Free models are ready to go. Open the page and start chatting, no account needed.

Characters

Personas, presets, prompt templates, and SillyTavern card import built in.

Private & BYOK

Conversations live in your browser, never on our server. Bring your own OpenAI-compatible endpoint and key too, fired straight from the browser.

Character chat

Lorebooks, group chats and swipes: a complete character chat engine.

Start building with Lumen

Create a free account, copy your key and make your first request in under a minute.