Service organisations have many technicians who use a tool occasionally and a few who use it constantly; dealers come and go; the senior engineer looks at escalations, not sessions. Per-seat pricing fits none of that. Field Triage meters diagnostic sessions.
The unit
One Case is one diagnostic session for one machine: any number of turns within 24 hours, up to three photos, parts and procedure lookups inside it, and the work-order summary at the end. Additional photos are a tenth of a case each. Pay as you go is USD 1.50 a case; annual plans include a monthly pool and bill overage lower.
Indexing is free
Uploading and indexing manuals, bulletins, catalogues and schematics costs nothing, and re-indexing after a revision costs nothing. If indexing were metered, organisations would ration what they upload, and a knowledge base with gaps is worse than none — the agent would escalate things it should have answered. The one exception is the one-off structuring of historical work orders, metered per hundred, because it is a genuinely large batch job.
Vision costs more, and we say so
Reading a photo consumes more model tokens than reading text. Rather than average it into the case price, model tokens are a separate meter at the provider's list price — model_access_usd — and the usage ledger shows tokens per case, so a service manager can see that photo-heavy cases cost more and decide whether three photos or one is the norm. With your own key the meter is zero.
On the Google Cloud invoice
Annual plans bill once at purchase through Marketplace; included cases are netted in the workspace and only overage is reported hourly as cases. Both meters appear as separate line items on your existing Google Cloud invoice and count toward commitment. Every case carries a request id.
Dealers
Dealer workspaces either roll up to the OEM's plan or are billed directly; the ledger is per workspace regardless. OEMs who subsidise dealer usage can see exactly what they are subsidising.
Caps
A monthly case cap and a model-spend cap per workspace. At the cap, new cases queue and the owner is told. Nothing bills past it.