Tutorials
Practical material on AI API relay services: how rates are calculated, how to verify a model has not been downgraded, what enterprises should check before buying, and the pitfalls we ran into while measuring these services ourselves.
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Tutorials (57 articles)
Prepaid, subscription or pay-as-you-go: where each billing model wins
The three billing models on offer look like a price question. They are really a cash-flow and risk question, and the rig…
Why reasoning models cost more than you expected: how thinking tokens are billed
Reasoning models produce tokens you never see, and those tokens are billed. This is why an estimate based on visible out…
Prompt caching on a relay service: does it actually work, and what is it worth
Cache discounts are the largest single lever on API cost for a lot of workloads. Whether a relay service passes them thr…
From list price to your invoice: a worked cost conversion
Rate, cache discounts, output weighting, tokenisers — by the time the bill arrives, the number is the product of four or…
A relay service starts erroring or slowing down: how to tell whose problem it is
"When it breaks, everyone blames the relay." Usually the truth is more specific: it could be your client, the relay, the…
What a relay service's "rate" actually means: 1.0, 0.3 and 0.05 explained
The rate is the only common language in relay pricing, and the number most easily dressed up in sales talk. This piece n…
Three ways to reach Claude from mainland China: official, relay, mirror
There are really three paths to using Claude with Claude Code from mainland China: a direct official connection, a third…
One key, many models: how to choose an aggregating relay service
If your product uses Claude, GPT and Gemini at once, talking to three vendors directly means three sets of keys and thre…
Corporate procurement of a relay service: invoices, contracts, compliance and risk control
If you are buying for yourself, rates and stability are enough. Corporate procurement has to clear three more gates: inv…
Supporting data & tools
The articles explain the method; the pages below give you measured data and prices to check it against. Reading them together is easier — once you know how to tell whether a rate is real, you can look the official price up in the price list.