// lexi

Lower
AI costs.

Change one URL.
Pay less per request.

$10 free · No card required
Your configuration
api.openai.com/v1
+ api.lexisaas.com/v1
Why Lexi
01

Works with the AI you already pay for

OpenAI, Anthropic, Google, Mistral, Groq, xAI — and more. Your provider keys go directly to them. Lexi never holds them.

28 models
02

Up and running in two minutes

One URL change in your configuration. Streaming, tool calls, structured output — all supported. Nothing else in your stack changes.

One change
03

Pay only when you save

Lexi earns a share of what it reduces on each request. When there's no saving, there's no Lexi fee. You cannot pay more than going direct.

Share of savings
04

Conversations that go further

Long AI sessions hit a wall — the context fills up and the model loses track of earlier decisions. Lexi keeps context bounded so sessions stay coherent for much longer. Context is restructured, not truncated — facts and decisions survive.

Stay sharp
Under the hood

Powered by STONE

Semantic Token Optimization and Natural Encoding. A purpose-built engine that restructures context into a bounded representation — the amount sent to your provider stays constant regardless of conversation length.

Context Bounded What's sent stays constant whether you're on turn 5 or turn 50
Resources O(1) 14.4 KB per session. Constant memory and CPU regardless of history
Recall Fact pinning Numbers, dates, decisions survive across turns
Guarantee Zero-negative If restructuring doesn't help, the original is sent instead
How STONE works →
Measured, not promised

Live end-to-end tests, GPT-4o-mini, March 2026. Results vary by content and conversation pattern.

78% less sent at turn 2
84% less sent at turn 5
90% less sent at turn 10

As conversations grow, the amount sent to your provider stays bounded. A 9,000-token conversation was reduced to under 900 — and stayed there.

Full visibility

Every cent. In the response headers.

No estimates, no opaque bills. Every response carries the exact cost breakdown — savings, margin, balance — in HTTP headers you can log, alert on, or display to your users.

X-Lexi-Request-Cost-Cents
X-Lexi-Savings-Cents
X-Lexi-Balance-Remaining
X-Lexi-Tokens-Original
X-Lexi-Tokens-Compressed
X-Lexi-Compression-Ratio
X-Lexi-Margin-Cents
For developers
const openai = new OpenAI({
  baseURL: 'https://api.lexisaas.com/v1',
  apiKey:  'lx_live_yourkey:sk-your-openai-key',
});

// Anthropic:
const anthropic = new Anthropic({
  baseURL: 'https://api.lexisaas.com',
  apiKey:  'lx_live_yourkey:sk-ant-your-key',
});
Full API documentation →

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