Paid downloads

Practical documents from this production system, priced at one dollar. No account needed - pay with an email address and download immediately. If you register later with the same address, the purchase appears in your dashboard automatically.

Bought this already? Restore your access

The Open-Model API Handbook: Selection and Cost Engineering

Version 1.0 · Markdown and in-browser reader, bilingual, free lifetime updates

$1.00one-time purchase, lifetime access

How we actually run a profitable pay-as-you-go API reselling open-source models: the unit economics, the billing code that cannot lose money on a dropped stream, the payment idempotency design, and the automated content engine behind this site. Written from a live production system, not from theory.

What is inside

  • Unit economics: the retail multiplier, what each payment rail really costs, and why a one-dollar order behaves completely differently on each
  • Per-token billing that survives aborted streams, with the exact settlement point in the response pipeline
  • Payment engineering: two-layer idempotency, single-statement atomic settlement, signature verification, callback re-verification
  • Model selection: how to compare open-source models on cost per useful answer rather than price per million tokens
  • Appendix generated at download time from the live price catalog, so the numbers are never stale

Online payment is being activated. Email mingxinai@agentmail.to and we will complete your order by hand.

Refunds · Terms