4SAPI brings integration, model switching, failover and compliance into one gateway. No more separate integrations, bills and quotas for every vendor.

380msFirst token / EDGE ROUTING

99.98%Success rate / FAILOVER

200+Models / LIVE CATALOG

1 KEYAll models / ONE GATEWAY

OpenAIAnthropicGoogleDeepSeekKimiQwenNew models added

01 / 4S ARCHITECTURE

Four S’s in the name,
four non-negotiables.

Speed, Stability, Security, Scalability. Each stands on its own, and without any one of them, no enterprise will trust you with its core traffic.

01 / SPEED

Fast by default

Global edge nodes route to the nearest region over dedicated links, with millisecond scheduling your app never notices.

02 / STABILITY

Built to stay up

Official enterprise channels with multi-channel failover. If the primary falters, traffic switches to a backup and retries.

03 / SECURITY

Secure and compliant

End-to-end encryption, fine-grained permissions and per-call logs you can export for review.

04 / SCALABILITY

Elastic scale

Scales horizontally with your business, with smart load balancing and no throttling at high concurrency.

02 / ZERO REFACTOR

Change the base_url.
Keep your SDK.

Fully compatible with the OpenAI SDK and API protocol. Switch models in one line without touching business code, and adopt new models without another integration cycle.

01Zero-refactor integration

02Unified billing

03New models added

// Existing code, just a new endpoint

const client = new OpenAI({

baseURL: "https://4sapi.com/v1",

apiKey: process.env.API_KEY

});

await client.chat.completions.create({

model: "gpt-4o",

messages

});

ONE KEY / MULTIPLE MODELS / SAME BUSINESS CODE

03 / WHY GATEWAY

Integrate every vendor,
or build it all yourself.

Both paths work. The cost just lands in different places: one up front in integration, the other in years of maintenance.

Integration cost

A separate SDK, auth and quota per vendor, each integrated and billed on its own.

An in-house adapter layer you maintain long after launch.

Zero-refactor integrationChange one base_url. Full OpenAI protocol compatibility.

Switching models

New vendor, new integration.

Patch the adapter, ship another release.

One-line model switchSwitch models in one line. Business code stays untouched.

Upstream outages

Any upstream hiccup hits your product directly.

Retries, circuit breakers and fallbacks are all on you.

Automatic multi-channel failoverMulti-channel failover switches to backup when the primary fails.

Access and audit

Every vendor console is separate, so nothing lines up.

Sub-accounts, roles and audit trails built by hand.

Traceable usage and accessBroken down by member, key and model, with exportable usage logs.

04 / ENTERPRISE READY

Private deployment, audit and access,
built in from day one.

Listed companies trust us with core traffic not because of promises, but because of what ships by default.

DEPLOY / 01

Private deployment

Deploy the full stack on your own servers, private cloud or hybrid cloud. Accounts, logs and model access stay in your hands.

AUDIT / 02

Audit-grade logs

Who called which model, when, and at what cost. Every call is logged and exportable for audits.

ACCESS / 03

Team controls

Sub-accounts, groups and role-based access, with quotas and bills split by person and team so costs stay visible.

SCALE / 04

Elastic scale

Scales horizontally with smart load balancing and no throttling, so you never pre-provision for peaks.

05 / FAQ

Before you start,
get the answers you need.

From zero-refactor integration and model switching to data boundaries, 4SAPI answers the questions that shape your decision.

We use the official OpenAI SDK. How much code has to change?−

Just the base_url. 4SAPI is fully compatible with the OpenAI SDK and API protocol, so your calls, parameters and response handling stay the same.

Does switching models mean integrating all over again?+

No. Switch models in one line: change the model name and the same code calls a different vendor. New models need no new integration work.

If an upstream vendor goes down, does my product go down too?+

No. Multi-channel failover switches to a backup channel and retries when the primary fails, so a single shaky route won't take you down.

Will our data stay on your servers?+

It doesn't have to. Deploy on your own servers, private cloud or hybrid cloud, and keep accounts, logs and model access in your hands.

How do I get started? Do I need a card?+

Sign up free for trial credits, no card required. Once you are up and running, you pay per call. For private deployment, talk to our sales team.

NEXT BUILD / NEXT MODEL

Put AI into
your product today.

Change one base_url and you are live. Sign up free for trial credits, no card required.

Start with one clear business task and connect OpenAI, Claude, Gemini, DeepSeek, Kimi, Qwen and more.

Get started with 4SAPI ↗

One API,every top LLM

Fully OpenAI-compatible

Automatic channel failover

Access and audit

Elastic scale

Four S’s in the name,four non-negotiables.

Fast by default

Built to stay up

Secure and compliant

Elastic scale

Change the base_url.Keep your SDK.

Integrate every vendor,or build it all yourself.

Private deployment, audit and access,built in from day one.

Private deployment

Audit-grade logs

Team controls

Elastic scale

Before you start,get the answers you need.

Put AI intoyour product today.

Four S’s in the name,
four non-negotiables.

Change the base_url.
Keep your SDK.

Integrate every vendor,
or build it all yourself.

Private deployment, audit and access,
built in from day one.

Before you start,
get the answers you need.

Put AI into
your product today.