The hands
The hands, the budget and the silence
What stops a hand? Its slot when the pool is full, its budget when the work is bigger than it said, and its silence clock always.
A hand is a live run
A hand is the live form of a run: the process doing the work now. A run is one execution of one step by one hand, opened when the step is claimed and closed with an outcome and an end cause — so "why did this stop" is a row, not a guess.
The pool, and the two lanes
The pool is the hands the engine spawns, and it is counted per lane: an external lane for work on the machine, an internal lane for work inside the hub, and the conversations' own slots so a chat never waits behind the work. A queue that holds a place keeps it until it closes; the arrival waits.
The free hand
Not every hand is in the pool. A free hand is an external agent the engine did not spawn: it takes a work order from the free list, holds it for a deadline that defends itself, and hands it in. It holds no lane and no slot, it opens no queue, and the engine's own takes leave it alone — whoever it is and wherever it runs, it cannot occupy a place the pool counts.
The budget
A worker estimates the work when it accepts it, and the step is carried with a
declared budget. Raising it is +N, and +N is
a new acceptance: a step does not quietly spend more than it was given. At the
threshold the queue closes and returns to the operator with what it did, what is
missing and why.
The silence
A step that says nothing for its silence limit is stopped by the engine; every announcement puts the clock back to the full limit. A step that needs longer declares a budget for itself, and there is a ceiling over the whole of it that nothing renews — only the operator can give it longer. A step that goes quiet is not killed in silence: it is stopped, and what it had written stays where it was written.
What is left behind
The trace is the product, not a side effect. When a hand ends, the record answers four questions and is readable while the hub runs.
- What happened, in order — the events, read from a cursor, never from zero.
- Who worked, for how long, how it ended — one row per run.
- The account — the report a delivery leaves, with the evidence for every artifact it declares.
- What the gate checked and refused — the verdict, in its own words.
Beside them are the documents — plan, roadmap, progress — because a chain says the order and the documents say why.