Seven Families, One Ledger — how a house gets a grammar

A developer at ML Systems described a shared seven-family code grammar that lets seven AI agents — each owning a phase such as finance, deconstruction, design, build, market, verification, and an equity loop — write to a single JSON ledger for a home without separate databases or schema migrations. The system tags every fact with a SECTION:task code, treats entries as claims with attributed evidence rather than plain values, and closes the value chain with a backward LUP → FIN edge so the homeowner's decision drives another cycle. The developer noted that finance, deconstruction, market, and loop families shipped with only one to four slots each, a gap attributed to a single line of code rather than deliberate prioritization.

To an assessor a house is a valuation. To a lender it is collateral. To a deconstruction crew it is tonnage. To an architect it is a plan set. To a robot, eventually, it is a sequence of manipulable members. Every one of those descriptions is correct, and every one of them uses different words for the same rafter. ML Systems runs a value chain — Loan Origination → Deconstruction → Construction, closed into an equity loop when the homeowner chooses to keep building — and seven software minds https://dev.to/salparvez/my-ai-agents-dont-talk-to-each-other-166e work it. If each of them kept its own vocabulary, the company would have seven databases that could not talk. So there is one grammar. This is what it looks like, what it got wrong until this week, and how it is being fixed. Every fact the system holds about a home is tagged with a code of the form SECTION:task — an uppercase phase, a colon, a lowercase task token: DES:footprint BLD:load-path VER:code-compliance FIN:budget DEC:sequence LUP:decision The prefix is the phase. That one convention does a surprising amount of work. The whole ledger for a home is a single JSON document; a new fact is a new key in that document, never a new table. Labels title-case themselves from the task token. Units infer from the measure name. The question the orchestrator asks the homeowner falls back to the slot's meaning. A new code costs no schema, no migration, and no label. The ontology grows by extending its codes, not its storage. Until now the public documentation named three families: DES design , BLD build and VER verification . The engine has always shipped seven. | Code | Family | Owning mind | The question it answers | |---|---|---|---| | FIN | Finance | PIT LORD | What can this homeowner afford, and what will lenders compete to fund? | | DEC | Deconstruction | REAPER | What is already here, and in what order does it come apart so every layer survives? | | DES | Design | CDA | What is the best thing we can build on what is here? | | BLD | Build | MURPHY | What is the critical path to completion? | | MKT | Market | MIA | What does the market say — about this home, and about what comes out of it? | | VER | Verify | VERA | What is true about this house, and how sure are we? | | LUP | Equity Loop | PI · PIT LORD · REAPER | What did this cycle create — and does the homeowner want to go again? | They form a small directed graph — FIN → DEC → DES → BLD → VER → LUP , with MKT hanging off deconstruction — and one edge points backward: LUP → FIN . That edge is the only reason this is a loop and not a line. LUP is not an acronym; it is loop . It is where the homeowner's choice lives as a code — LUP:decision : expand this home again, open another value-chain home, or hold. The system never assumes the answer. It asks. Here is the honest part. Count the slots each family actually had in the shipped template: | Family | Shipped slots | |---|---| | DES | 18 | | VER | 10 | | BLD | 7 | | DEC | 4 | | LUP | 4 | | FIN | 1 | | MKT | 1 | Design and verification were rich. Finance, deconstruction, market and the loop itself were nearly empty. That is not a prioritisation choice. It is a structural consequence of one line of code. On the ledger, a fact is not a value. It is a claim — a value, plus who made it, plus the grade of evidence behind it. Several claims sit on the same entry, and the ledger decides which one stands, shows every one that dissented, and refuses to present a contested number as fact. The reconciliation model is written up in Claims, Not Facts https://dev.to/salparvez/claims-not-facts-building-an-auditable-multi-author-record-for-a-house-33d6 ; this post is about who gets to make one. The type that says who may make a claim looks like this: type VcClaimant = "custodian" | "homeowner" | "vera" | "cda" | "pi" | "record"; Six names. Look at who is missing. REAPER, PIT LORD, MURPHY and MIA — the minds that own deconstruction, finance, construction and market — cannot put their name on a claim. The phases they own had nowhere to speak. Of course FIN had one slot. The fix was already sitting in that list. cda is there — the design mind can claim — but CDA holds no seat on the ledger's party strip. That is deliberate. The five seats that can ground an entry are the homeowner, the public record, VERA, PI and the Custodian. CDA is the model being grounded; a design claim is the thing being checked, never a check. That standing extends cleanly to the other four. A V2 mind may claim; it may never ground. Its claim enters as modeled , the lowest grade on the evidence ladder. It can be confirmed only if an independent party agrees. It can never win a standoff against a tape measure. And its name never lights a seat — because lit means input, not agreement , and a seat that lit for its own model would be the ledger agreeing with itself. Every mind claims. Five seats ground. VERA gates. Only the Custodian stamps. The ledger does not rank claimants globally. It ranks them per kind of fact — what it calls a domain. Four ship today: | Domain | Meaning | Who leads, after the Custodian | |---|---|---| | interior | what the homeowner can see and touch inside | the homeowner | | legal-record | recorded facts — stories, year, recorded square footage | the record | | exterior-geo | exterior geometry measured by instrument | VERA | | derived | computed from other facts; nobody observes it | VERA | The Custodian leads every domain — a stamp is the review. Below that, a tape measure inside the house outranks a satellite; the assessor's card outranks memory on the year it was built; the instrument outranks everyone on the roof pitch. Now put a finance code through it. Nothing routes FIN: anywhere in particular, so it falls to derived — and in derived , VERA outranks the homeowner. Which means that on the question what is the most you want to spend , a model would outrank the person whose money it is. So two domains are proposed alongside the new claimants. intent — a choice or a constraint only the homeowner can set: budget, timeline, the loop decision — where the homeowner leads. market — a price or a velocity observed in a market: comparable sales, a lender's bid, absorption — where the record and MIA lead. Twenty-nine proposed slots, each with its domain, who may claim it, who verifies it, and which minds consume it. A sample: FIN:budget DEC:contamination DEC:assembly-stack MKT:comps LUP:equity-delta LUP:decision The full table, with every slot marked shipped or proposed , is in the repository's ontology/families.json https://github.com/MLSystemsRI/ml-systems-public/blob/main/ontology/families.json , and the diagram that goes with it is master-ledger-workflow.html https://github.com/MLSystemsRI/ml-systems-public/blob/main/ontology/master-ledger-workflow.html . Reality labels, because this company labels everything: SECTION:task grammar, the claim model, the four domains, the five seats, the two-key stamp — The ontology is the connective tissue that lets a fact discovered on a job site inform a financing decision without losing its meaning. For four of its seven families, that tissue was there but the nerve was not connected. The fix is small. The reason it matters is not. ML Systems LLC · Rhode Island · NAICS 236115 · mlsystemsri.com https://mlsystemsri.com · github.com/MLSystemsRI/ml-systems-public https://github.com/MLSystemsRI/ml-systems-public