One thesis: assign is the push, claim is the pull — a pull is not management, and that difference is what puts the two verbs on opposite sides of the free/paid line. They look like one operation from the outside. They are two acts by two different parties, and an append-only record has to know which one happened.
Two ways a task reaches a hand
A pallet of lettuce lands at dock 12, and a receiving task exists for it. There are two ways that task ends up with a receiver.
Somebody pushes it. A dispatcher, a routing rule, a supervisor's queue projection decides that this task goes to this person or this role. That is assign: task plus performer, human or agent, the door does not care which. It is a management act — somebody maintained the queue, somebody made the routing decision, and the decision is recorded with the task.
Somebody pulls it. The receiver finishes the previous pallet, looks at the station pool, and takes the next one. That is claim: a pooled task plus the caller, held by the caller. Nobody routed anything. A performer reached for work.
The record shows both as appended acts. assign writes an assignment; claim writes a hold. The fold treats them differently, and it has to.
The fold distinguishes them
An assigned act folds to pending — waiting, available to claim — not to claimed. That is not a quirk. If a push folded to claimed, a task anyone had assigned would vanish from the worklist predicate status = pending, and every assigned task would be invisible to the person it was assigned to. A claimed act folds to claimed: locked by the holder, unavailable to others.
Reassignment is not a third verb. Assigning an already-assigned task is reassignment, and the record shows both assignments in order. A separate verb for it would add nothing and hide the history. Likewise unassign returns the task to the pool with the prior assignment retained — the resource survives the act, so it is a transition, not a delete.
What claim refuses
Two refusals define the verb as much as what it does.
There is no claim-on-behalf-of. claim takes the task and the caller. A claim that could name another performer would be assign at the free price, and the line would be a fiction. The caller is resolved by the auth rail; it is not a parameter.
A failed claim does not name the holder. When a task is already held, the refusal says held. It does not say by whom. Answering who has it for the price of a failed claim is performer-to-objects disclosure, one task at a time, and it is refused for the same reason any per-person query is refused on this door.
A double claim is one of the poison fixtures in the package's test suite, alongside the second settle and the early alarm.
Why the line is where it is
The free/paid line on this door does not come from a task being state or not. It comes from a simpler question: are you recording what you did, or paying to have work organized for you?
- complete, block, escalate emit. Emitting is never paywalled; witness is never behind a paywall. Free, permanently.
- query and trace are stateless reads. Free.
- claim is a performer taking the next thing. A pull is not management. Free.
- dispatch, assign, unassign, start are the management of work — queues, routing, projections, scheduling at org scale. Paid.
Without claim on the free side, the free tier could say you always can record what you did and could not say you can take the next thing. That is not a tier; it is a defect, and it is why the verb was added when the model was ruled rather than left for later.
For the station pool
If you are modeling a dock with six receivers and a pool of receiving tasks, the device calls claim, not assign. The station-pool view renders ref, do, at — and has no assignee column, because a pooled item has no assignee, which is exactly what makes that view safe to render and a per-person queue unsafe.
claim is one of the five verbs that answer in the package today, with query, trace, complete and timeout. assign is declared in the portfolio and the fold reads its acts; no verb in the package writes one. Get started by writing a pool, claiming from it twice with two callers, and reading the second refusal. It tells you the task is held, and nothing else.