Assigns value, not just count
Each span carries purpose, phase, and a reading. A total without attribution is still ore.
Token-value accounting
Assay the spend, not the count
Providers report totals. Assay records what the tokens were for, what a result cost, and what it cannot measure.
How the instrument holds
Local first. Conversations stay on your machine. One verb reaches the network — it fetches a public rate card.
Corrected, not rewritten. A wrong figure stays visible. The correction sits beside it, versioned.
Unknown is named. $0.00 is a claim. Unpriced is a fact.
Ore
Every token arrives as a count.
No purpose. No residual. A total with nothing assayed.
Bind
Assay binds each span to a purpose.
What it cannot price, it leaves unpriced — it will not invent the gap.
Metal
$0.00 is a claim. Unpriced is a fact.
Ore in. Metal out. The open cells stay open on purpose.
The register
A ledger you can bill from.
Written once. Corrected in the open. Joined to the conversation that caused the spend. Not a dashboard of totals.
Names what it cannot measure
If the rate card will not vouch for a model, the span records tokens and no cost. The residual stays on every total.
Runs on your machine
Assay is not in the request path. It cannot slow a turn. It reads what already happened.
Invariants
The limits sit next to the claims.
Your prompts do not leave
One verb reaches the network. It fetches public rate cards. It never opens the database.
Deletion that can refuse
assay shred destroys a principal's key. On a partial erasure it exits non-zero rather than report a completion it did not achieve.
Not a value oracle
Assay validates provenance, never truth. A team that labels everything "feature work" will get a clean, useless aggregate — and Assay will report it faithfully.
The substrate is MIT
The log, the stores, the rate card, and the capture path are free. The value layer is the product. The boundary is a lint rule, not a promise.