Receipt spectrum
A receipt says what the crossing was. The signature says who signed that claim. Those are two different things.
The session receipt is free. You ask for it when a run is finished. The other crossings are charged when they happen. The signature is how the charge is counted. It is not a second fee.
The seat price is on the card. The session receipt is free on both seats.
Below, each crossing is named for what it does, and for when you would meet it.
Kinds
| Kind | Unit | Rate | Signature |
|---|---|---|---|
| Session | GET /v1/sessions/{id} | included · 0p | Ed25519 |
| Cache HIT | per 1,000 tokens, rounded up | 0.45p | Ed25519 |
| Cache MISS | per 1,000 tokens of the fill, rounded up | 0.1125p | Ed25519 |
| API call | per completed GET | 0.45p | Ed25519 |
| Custody | per minted JWS | 0.75p | Ed25519 |
| Statement | per UTC-month close, once | 7.5p | Ed25519 |
| Fetch | per URL | 2p | Ledgered, no signature |
A part-thousand counts as one thousand. 27 tokens on a HIT bills one thousand: 0.45p.
What a receipt can prove.
One row per kind. The kind says what the receipt proves.
| Kind | What it proves |
|---|---|
| Sessionsession | A tagged run closed into one checkable object, pulled with GET /v1/sessions/{id}, with the id itself never inside. Inspecting it does not bill. |
| Cache HITcache_hit | Proof of an exact replay served by the pipe: the model, the tokens not bought again, the pipe cost, the serving plane, and the request digest. |
| Cache MISScache_miss | Proof of the fill that followed: zero tokens replayed, the miss rate as pipe cost, the same request digest a later hit will share. |
| Web fetchweb_fetch | A governed, ledgered crossing per URL. Robots, PII and SSRF checks run before anything reaches the model. No fetch-kind JWS exists. |
| API callapi_call | Proof of one completed third-party GET through the pipe, 200 or 500. The request digest covers service, path and query, never the raw path. |
| Custodycustody | A signed, chained note that this system retained, accessed, amended, or deleted something. Digests only; deletion is a tombstone. |
| Statementstatement | The UTC month, closed for the whole org: totals, pipe rent and an explicitly estimated-avoided figure. The blob you keep after the hot copy ages out. |
How it is signed.
Ed25519 is the signature on every live receipt, and anyone can check it against the published key.
| Signature | Status | What that means |
|---|---|---|
| Ed25519 | Live | The signature on every receipt today. It checks against the published key. The name has to match, and the signature has to be intact. |
| A shared secret | Out | A stranger could not check it, so it is not a receipt. |
Directory + kid
The public forever-link is the directory and the kid. Session, statement and custody stay seated.
https://api.metrecept.co.uk/.well-known/http-message-signatures-directory