The background ceiling applied only when the operator funded the chain, so on a
chain the operator does not pay for the automatic generators and the chat shared
one undivided ceiling and the first could still take all of it. That is the
configuration the recommended remedy for the original lockout produces — put the
personal Codex account first — so the guarantee was missing on exactly the setup
it was written for.
The ceiling is now expressed as what it is meant to protect. Background work may
run until the day's spend would leave less than a fixed reserve for whoever is
waiting on an answer, on both cost owners. A reserve and a quota look alike at
the boundary and mean opposite things in the middle: a quota stops useful
generation on a day nobody was ever going to interrupt, while a reserve costs it
nothing until the moment it would take the last of the day. An account
generating 1.45 million tokens of insights on its own plan keeps every one of
them and the chat still holds 400 000.
INTERACTIVE_RESERVE_SHARE replaces JOB_SURFACE_SHARE. The old name described a
quota over the jobs rather than a floor under the person waiting, and a name
that states the opposite of the intent is what put the wrong comparison in this
ledger twice already.
The fraction is a default an operator will want to change. The setting and its
documentation are separate work.
CLAUDE.md forbids planning shorthand in committed artefacts, and this branch
introduced 74 lines of it across source, tests, a schema field and two
migrations. Someone reading the migration SQL in a year has no way to resolve a
wave letter or a round number, and a comment that points at something outside
the repository names no reason at all.
Three passes. A version followed by a parenthetical keeps the version and loses
the parenthetical, because the version says since when something holds. A
sentence that leaned on the vocabulary to carry its meaning is rewritten to
state the reason directly: the arrival reservation now says it was refused over
money the operator never spent, rather than naming the defect a wave existed to
remove. Three test titles carried the marker in the name itself and are renamed
to what they pin.
Comments only. No behaviour, no renames beyond those three titles.
The owner split left an operator-funded chain with no ceiling at all. Its arm
compared operator_tokens, and that counter returns to roughly zero on every
reconcile the user's own plan settled: on the 2026-09-11 evidence the shared
key answered 500 and codex served, so the counter never grew, every job
reservation was admitted forever, and a runaway client loop could write an
unbounded row. A pre-existing concurrency contract caught it from the other
side, two reservations that must not both pass one cap both passing.
reserveBudget now refuses when the owner's counter is over its cap OR the day's
mixed total is over the abuse ceiling, and a background surface gets its share
of that ceiling too, so background spend is bounded on the total and not only
under a counter the operator's key never fills. The surface is a required
argument, so the type checker enumerated every reservation site.
The hop guard learns the same lesson: an operator-funded fallback hop is now
rationed at the calling surface's ceiling rather than the full operator cap. A
job admitted under the job share could previously spend the whole 200 000 once
its chain fell back onto the shared key, which is the original defect reached
by the fallback path.
The job share applies only where the operator pays for the chain. Multiplying
whichever ceiling the chain resolved halved background generation for a
self-hoster on a local model, who costs the operator nothing.
Refusals now name the ceiling they hit and whose it was. A refusal used to emit
the day's mixed total and nothing else, which on an operator refusal is not the
counter that tripped.
The reservation compared the day's TOTAL against whichever ceiling the
chain resolved, and the chain walker's hop guard did the same. On an
account whose background jobs run on the user's own ChatGPT plan, both
saw a total the operator had not paid for: the chat refused at 06:42Z
with 513 539 tokens against the 200 000 operator ceiling, and the
fallback hop to the shared key was closed on the same arithmetic.
An operator-funded chain is now measured against `operator_tokens` and a
user-plan chain keeps its abuse ceiling on the total; the hop guard reads
the operator share too. A day of turns the user's own plan paid for can
no longer lock anyone out of the operator's ceiling.
`coach_usage` counted one number per (user, day). A turn served by the
user's own ChatGPT plan after the operator's shared key answered 500 was
therefore charged to the operator-cost cap, and the operator's chat was
locked out every morning by background work he pays for himself.
The ledger gains `operator_tokens`: the share of `total_tokens` served by
an operator-funded provider. `reserveBudget` books a reservation to the
owner of the chain's primary and `reconcileSpend` settles it against the
provider that actually served, both inside the same statements as the
total so concurrent requests can never see one counter without the other.
Every call site names its cost owner and its serving hop; the argument is
required, so a new surface cannot inherit the old blind accounting.
Marc-André Bombeck