The seat is older than the occupant.

A computer permits a finite set of acts. The agent is whoever selects from that set. Agency is conferred by the substrate, not the actor. The seat has had many occupants — human computers, operators, programmers, schedulers, daemons, services, and now language-model runtimes — and only one ceiling.

act = ⟨ A, σ, p, t ⟩

The act coordinate · actor, selection process, primitive, timestamp

Conferred above, paid below.

A computer is a math machine. Voltage transitions across transistors, organized into Boolean gates, composed into arithmetic units, memory hierarchy, and I/O. The substrate does math. Only does math. The total set of acts it permits is enumerable.

The substrate is the ceiling. No actor, biological or silicon, no matter how sophisticated the selector, can make the substrate perform an act outside its permitted set. The substrate is also the floor. Every act incurs a thermodynamic cost — at minimum kBT · ln 2 per erased bit. A syscall emitted by a human and a syscall emitted by a daemon dissipate the same heat through the same gates.

Agency is what fits between the ceiling and the floor. The substrate confers it. The actor exercises it. The substrate is neutral to selection.

CEILING · EXPRESSIVE LIMIT ENUMERABLE, FINITE FLOOR · THERMODYNAMIC MINIMUM kBT · ln 2 per erased bit syscalls writes reads packets interrupts the permitted-act set
Fig 1Agency is what fits between the ceiling and the floor.

Four axes locate every act.

Two are agent-native — who the actor is, and how the selection was made. Two are inherited — the primitive is a coordinate in compute, and the timestamp is universal. Every act in the system, by any agent, carries a value on each axis.

The 2 × 2 of agent configurations.

The classification of agents reduces to two values: who occupies the seat, and how they select. Every actor known to the framework lives in one of these four cells at any given moment, and many switch cells across acts.

⟨ H, D ⟩ durable artifact

Authoring a Z₁ artifact

A human writing code, a shell pipeline, a SQL query, a regex. The authoring act is paid once. Subsequent executions run at the substrate’s thermodynamic floor.

⟨ H, S ⟩ source of novelty

Deliberation

Wetware noise drives selection. Judgment, taste, design, prose. The selection cannot be reproduced — not even by the same agent under the same conditions.

⟨ S, D ⟩ durable artifact

Compile, don’t loop

A compiler, a code generator, a scheduler, a language-model runtime in author mode. One stochastic upstream selection produces a deterministic program. The program is then a software-daemon agent in its own right.

⟨ S, S ⟩ no persistent artifact

Sample per iteration

A runtime samples each next act from a learned distribution. Every iteration re-samples. No persistent artifact survives the iteration. Tool-use loops, reinforcement-learning policies at inference.

Same task. Four cells. Four bills.

Extract invoice numbers from 500 PDFs. The substrate accepts all four routes. The cumulative cost across batches diverges by orders of magnitude.

⟨H, D⟩

$37.50

flat forever

⟨S, D⟩

$0.02

flat forever

⟨H, S⟩

$208

per batch · climbs

⟨S, S⟩

$7.50

per batch · climbs

The first two cells charge once. The second two charge every time. After ten batches, ⟨S, D⟩ is 3,750× lower-cost than ⟨S, S⟩, and the gap widens with every batch.

“Computer” was a job title
before it was a machine.

Software daemons have occupied the agent seat alongside humans since the early Unix era. init is from 1971. cron from 1975. make from 1976. Every Unix system has had non-human agents selecting acts on its behalf for over fifty years.

The arrival of language-model runtimes is the addition of a new occupant to a seat with a long roster, not the invention of the seat.

Agency inherits.

This site classifies neither the substrate nor the agency itself — both are already classified by the family. It classifies the relationship: how acts are selected, by what kinds of occupants, at what cost, with what reproducibility, producing what durable artifacts.

One method, applied across fields.

Seven sibling sites plus the parent thesis. Each describes what systems do or what claims are. Agent describes what they all have in common: an actor selecting acts on the substrate, paying its bill in joules.