PDC

Production and Distribution Coordination — software for organising resources and labour by need, in physical units, without a currency.

Post-capitalist resource coordination: model what a community needs, what a region can produce, and what any proposed allocation costs whom — then show that to everyone and let people decide. It is a calculator and a shared picture, not an allocator.

Named for the Odonian institution in Ursula K. Le Guin's The Dispossessed. Early, and pre-alpha: there is a design, and it is being built.

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The idea

A town of 25,000 needs a certain number of calories, and a certain amount of iron and protein and water. Producing that requires particular farms, and those farms require phosphorus and labour and land, and the phosphorus and the labour come from somewhere too. All of that is calculable from public data.

What is not calculable is who should get the wheat when there is not enough wheat. PDC does the first part and refuses the second.

So the output is not a plan. It is an argument-grade picture:

If we direct all the phosphorus to farm A, farm B will not produce the alfalfa that ranches C and D need the year after, which costs the system 50% of its calories. If we split the phosphorus, the loss is 15%.

Everyone can see that, everyone can check the arithmetic against their own copy of the data, and then people decide — by whatever process they use, outside the software.

What makes it different

Nearly every adjacent project — Valueflows' own rollup, Basis, Cockshott's labour-time accounting, participatory economics, and obviously conventional ERP — eventually converts everything into one unit so that options can be ranked. Money, or hours, or credits, or shadow prices.

PDC does not. Costs and needs are carried as vectors of physically distinct quantities — labour-hours by skill, kg of phosphorus, m³ of water, kcal, hectare-seasons — and are never collapsed:

Aggregate freely within a dimension. Never reduce across dimensions.

Summing calories across a region is arithmetic. Converting phosphorus into labour-hours is a value judgement, and it belongs to people rather than to a solver. This is Otto Neurath's calculation in kind, expressed as a data structure.

The cost of that choice is that the software cannot choose between options. That is the point, not a limitation.

Design commitments

• The software proposes, explains, and records. It never allocates. No objective function ships.
• No currency, credits, labour-time accounting, or priority scores. No universal equivalent of any kind.
• Need is derived from cited standards, not from requests. A standard with no citation and no author is a validation error. There is no built-in ladder of tiers and no privileged standard.
• Standards are a total expression language, not code — so that anyone can re-derive them in another language, in a spreadsheet, or on paper. Cheap independent verification is the whole auditability model.
• Simulation-first. Reality is simply the branch whose events people authored. Scenarios are reproducible byte-for-byte on any mirror.
• Recursive agents. Households nest in communes nest in valleys. Federation is aggregation at a different depth, not a separate system.
• No blockchain. A 51% attack means capital aggregation can overrule community consensus, which is the failure this project exists to avoid. Mirrorable, forkable, independently recomputable databases are strictly better here.

Full reasoning, including what each decision forecloses, is in DECISIONS.md.

Built on

Valueflows v1.0.0 — the REA-derived vocabulary for economic networks, stable since February 2026 — adopted as the ontology, with its value-rollup algorithm replaced by a dimensional one. See docs/ontology.md for the exact mapping and the three concepts PDC adds.

Documentation

DECISIONS.md	What was decided, why, and what it forecloses
docs/ontology.md	Valueflows mapping; NeedStandard, ResponseModel, CostVector
docs/architecture.md	Layering, simulation kernel, propagation engine
docs/prior-art.md	What exists, what to take, where each stops
docs/roadmap.md	Milestones, defined by what becomes answerable
docs/model-gaps.md	What the model does not represent, and what that does to its answers

Status

Early, but the kernel works. v1 is complete: the reference region runs the phosphorus comparison three years forward, reports per community against each community's declared standards, and exports byte-reproducibly — so anyone can re-run a scenario and be told whether they disagree, and about what.

pdc compare              both allocations, side by side, no verdict line
pdc explain chakar       the causal chain, down to the cited coefficient
pdc export out.json      a self-contained, reproducible scenario document
pdc verify theirs.json   re-run someone else's and find where you differ

Next is a web interface, because the audit right is only real if checking the work does not require a terminal. See docs/roadmap.md.

Known limits are tracked openly in docs/model-gaps.md — most notably that there is no nitrogen yet, so legume rotation has no benefit and forage looks worse than it is.

Uses

Coordination for real communes; scenario planning; simulation; and a backend for simulation games. These are the same system because reality is just the branch with human-authored events.

Licence

AGPL-3.0. Network copyleft is the operative clause: it prevents a proprietary hosted fork of a community's own allocation data.