Cadastral & land-registry lookup

This project exposes a cadastral/land-registry MCP server. Its tools are the way to answer parcel and ownership questions - prefer them over guessing. If they are not already loaded, find them by searching available tools for cadastre, katastar, land registry, zemljišne knjige, or parcel.

Pick the right register (the #1 mistake to avoid)

Cadastre and land registry are different registers and often list different people. Choose deliberately:

• "vlasnik", "tko je vlasnik", "prema zemljišnim knjigama", "ZK", "gruntovnica", ownership shares -> land registry (vlastovnica / B-list).
• "posjednik", "posjedovni list", "kataster" -> cadastre (possessors).

Every returned person record carries a register field (cadastre | land_registry) - check it.

Tool playbook

Two tools do the work; both take a list of references (one for a single item, several for a portfolio) and return one entry per reference, in order.

• Owner of specific parcel(s), "prema ZK" -> get_lr_unit with {"parcel_number": ..., "municipality": ...} references. It resolves the land-registry unit even when the parcel has no direct unit (via parcel links; check lr_unit_derived_from_links) and returns B-list owners.
• Cadastre possessors / area / land use of parcel(s) -> get_parcel with source="cadastre" (find_parcel for a bare existence check + parcel_id).
• A portfolio -> one get_parcel call with all references (source="land_registry" if owners are wanted), then one get_lr_unit call with the parcel references or the returned data.lr_unit references. Units shared by several parcels are fetched once (status: "duplicate", same_unit_as).
• By unit number directly -> get_lr_unit with {"lr_unit_number": "769", "main_book_id": 21277}, or with "main_book_name": "SAVAR" when only the main book (glavna knjiga) name is known; find_main_book lists the books.
• Building parcels ("35/1 ZGR", "zgr. 35/1", "*35/1") -> any spelling works; they have no land-registry unit of their own (the building is registered on its land parcel), so their get_lr_unit entry is an error saying so.
• Is the possessor the owner (posjednik vs vlasnik) -> compare_registers with the parcel references: relationship per parcel (same, overlapping, disjoint, cadastre_only), matched pairs (fuzzy when the match rests on the name without "POK./UD."), who is in one register only, party_type_inferred (always an inference), distinct people across the set. Read both registers through it instead of comparing by hand.
• Assembling land, due diligence over a set -> build_assembly with up to 50 parcel references: matrix of persons x parcels, persons ranked by controlled area (grouped by surname), parcels ranked by ease of acquisition with the weights and per-parcel factors shown (a factor not evaluated is left out, never counted against the parcel); include_zoning for the building-area factor; export for CSV/GeoJSON text. Quote the caveats in notes (inferred party types, cadastre areas).
• Possession sheet by number (its possessors and its parcels) -> get_possession_sheet with the exact number. A harmonized sheet has no cadastre possessors (possessors_in_land_registry); its registered owners come back under owners. find_possession_sheet lists the sheets whose number begins with a text, at most 50, from an index that lags: an empty answer is not proof the sheet does not exist. KPU books -> find_book_of_dc.
• What a pending plomba is -> get_lr_unit with include_plombe_detail, or get_file_status for one file number and the unit's institution_id.
• Municipalities of an office -> list_municipalities with the office_id from list_cadastral_offices.
• Map / boundaries -> get_parcel_geometry.
• Parcels in an area, or around a parcel -> find_parcels_in_area (bbox, polygon or centre + radius, EPSG:3765 metres as get_parcel_geometry returns them) and find_parcel_neighbours (shared boundary, corner touch). Both read the cached cadastral map and give numbers and graphical areas only; follow with get_parcel / get_lr_unit for the registers.

Response shaping

get_lr_unit takes detail = summary | ownership (default) | shares | parcels | encumbrances | full:

• Default ownership returns B-list owners + structured shares (share = {num, den, decimal}) + a summary - it already fits in context.
• shares is raw list B (shares with sub-shares, entries, status), parcels is list A and encumbrances is list C, each on its own; reach for full only when every sheet and the geometry are needed at once.
• For large units, pass limit and page with offset: every level carries a page block (total, returned, truncated, next_offset). A response too large to return comes back as that unit's error with the smaller options named; use a per-sheet level with a limit instead of retrying full.
• historical_overview=true adds deleted entries and non-active shares.
• Every entry has a status (success, error, duplicate); read the error and error_type of a failed reference instead of retrying blindly: *_not_found means no such record, access_denied that the server refused, rate_limit that it throttled, response_too_large that the entry must be paged (limit, offset), invalid_request that the reference was wrong. Tool-level errors end with [error_type=...] for the same reason.

Notes

• Every successful entry carries provenance (register, source_url, retrieved_at): quote it with any fact you forward, so the answer is never taken for an official extract. get_parcel entries also carry area_check (cadastre area against the cadastral map's graphical area and, when known, the land register's; mismatch above 5 %). get_lr_unit entries carry distinct_owners next to total_owners (one person on two shares is two records, one owner) for judging fragmentation.
• A parcel with in_land_registry: false (or the parcel_not_in_land_registry error) is cadastre-only - report it as such rather than inventing an owner.
• Names come with a name_normalized companion; the raw name preserves source quirks (use it for fidelity, the normalized form for matching/display).
• Each owner row carries entry (the registration entry: order number, receipt date, diary number, action type); share_entries are notes registered on single shares. Cite them when asked how or when someone became owner.