How to choose an AI API relay service

TL;DR An API relay forwards model API calls for you, so one key reaches several providers. Check three things first: per-token prices published in USD, a record of every call with what it cost, and no charge for failed calls. Then test with a small top-up instead of prepaying a large balance.

An API relay (also called an AI proxy or API reseller) is a third-party service that forwards large-model API calls through its own upstream channels. You get one key and one OpenAI-compatible base URL and can call GPT, Claude, Gemini, DeepSeek and others without opening an account with each provider. apimodels.app is one of these: a multi-model API gateway.

Relays differ widely. Two services can both list "GPT" and "Claude" while one forwards to the official API and the other runs reverse-engineered web accounts or quietly substitutes a lower-tier model. Below are the common traps, then a checklist you can go through before paying.

Common traps

Swapped models: you ask for a premium model and the answer comes from a lower-tier one. Be wary when a price is far below the provider’s own list.

Reverse-engineered web accounts: consumer chat accounts wrapped as an API. They break without notice and violate the providers’ terms.

Opaque billing: "multipliers", "groups" or quota units instead of a USD price per token, which makes the real cost of a call hard to work out.

Prepaid balances that vanish: a service pushes large up-front top-ups, and the balance cannot be recovered if it shuts down.

Unclear data handling: no statement on whether prompts are stored, for how long, or who can see them.

Seven things to check before you pay

What to check	How to check it
Transparent price	A USD price per 1M tokens for every model, with peak / off-peak and long-context rules written out
Per-call records	Every call has a record with tokens, cost and status that you can look up by id
No charge on failure	Errors, timeouts and refusals are not billed
Stability	A backup channel takes over when the main one errors, rate-limits or times out
Documented limits	Context, output caps and supported parameters are stated, and unsupported options fail with an error
Data retention	The privacy policy says what is stored and for how long
Small top-ups	You can test with a small amount instead of prepaying a large balance

How apimodels.app measures up

Price: every model page lists a USD price per 1M tokens, and some are below the official list — GPT-6 Sol at half OpenAI’s price, Claude Opus 5.5 40% below Anthropic’s, DeepSeek V4.1 Flash 10% below DeepSeek’s at every hour. Check each model page for the current price.

Records and billing: every call shows up in the console and can be fetched with GET /v1/records/{id}, including tokens and cost. Failed calls are not charged.

Stability: mainstream models have several upstream channels, and a call fails over to a backup when the main channel errors, rate-limits or times out. Long jobs run asynchronously with webhook callbacks. Not every call succeeds, and the failure reason is written to the record.

Data: API call records, including prompts, are kept with your account. The full request and response of LLM calls is also kept in private storage for 30 days, to check billing and investigate issues you report, and then deleted. Generated results and uploaded files are deleted after 30 days. The privacy policy has the details.

Payment: Stripe, PayPal, Alipay and USDT. You can start with a small top-up.

Access from mainland China: apimodels.app is served through Cloudflare, and most networks there can reach it directly; test with a small top-up first.

When a relay, ours included, is the wrong choice

Teams that need an enterprise contract, an official SLA or a data processing agreement directly with OpenAI, Anthropic or Google should go to the provider.

Workloads whose data must not leave your own environment, or where no third party may keep call records, should not go through any relay.

If you only use one provider and already have a working account and payment method with it, calling the provider directly is simpler.

Quick start

cURL

curl https://api.apimodels.app/v1/chat/completions \
  -H "Authorization: Bearer $APIMODELS_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "gpt-6-sol",
    "messages": [{"role": "user", "content": "Say hello in one word."}]
  }'

Python

from openai import OpenAI

client = OpenAI(api_key="YOUR_APIMODELS_KEY", base_url="https://api.apimodels.app/v1")

# One key, several providers: only the model string changes.
for model in ["gpt-6-sol", "claude-sonnet-5-5", "deepseek-v4.1-flash"]:
    r = client.chat.completions.create(
        model=model,
        messages=[{"role": "user", "content": "Say hello in one word."}],
    )
    print(model, r.choices[0].message.content)

FAQ

What is an API relay service?

A third-party service that forwards your large-model API calls through its own upstream channels, so one key and one OpenAI-compatible base URL reach several providers. apimodels.app is one example: a multi-model API gateway with a USD price per token on every model page.

Is it safe to use an API relay?

It depends on the service. Read its privacy policy for what it stores and for how long, check that every call has a record with its cost, and start with a small top-up. Do not send data through any relay if it may not leave your own environment.

How can I tell whether a relay is swapping models?

The model field in a response can be faked, so do not rely on it alone. Run a few prompts whose answers you know from the official model, check that long-context and tool-calling behaviour matches the provider’s documentation, and treat prices far below the provider’s own list as a warning sign.

Which API relay should I choose?

Go through the seven checks on this page — transparent prices, per-call records, no charge on failure, failover, documented limits, data retention and small top-ups — and test with a small amount. apimodels.app publishes all of these; whether it fits depends on your models and your data requirements.

Does apimodels.app work from mainland China?

It is served through Cloudflare, and most networks in mainland China can reach it directly. Alipay is supported for top-ups. Test with a small amount first.

Does apimodels.app store my prompts?

Yes. API call records, including prompts, are kept with your account, and the full request and response of LLM calls is kept in private storage for 30 days to check billing and investigate issues, then deleted automatically. You can ask for account deletion at support@apimodels.app.

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