Data sources, attribution & method

What GnextD creates

GnextD uses official data as input to an independent analysis: it validates files and responses, normalises identifiers, reprojects geometry, applies documented filters, compares a point or parcel and presents a bounded conclusion with sources and next steps.

The product is the organisation, checking, interpretation and presentation of that evidence. GnextD does not sell ownership of public data, offer the national source files, expose private tables or provide a bulk download as its own data product.

Method and changes made

• Acquire from the official URL or a validated snapshot identified by version/hash.
• Validate format, geometry, counts, classes and known coverage; rejected items are not treated as absence.
• Normalise and reproject to the analysis coordinate system; remove properties not needed by the product.
• Deterministically intersect the point or transient parcel geometry with applicable layers.
• Retain internal audit states — found, clear, unknown, unavailable or not_covered — and coverage metadata without returning the provider’s raw payload.
• Project those details into four visible states: Match when there is an occurrence; No match only when the source is technically available, the query and coverage are complete and there are no occurrences; Snapshot checked · coverage unproven when the local query completed without an occurrence but complete coverage has not been proven; Source unavailable when no usable Match or No match result is available for the check. The technical evidence separately retains whether this was caused by unavailability, an incomplete query or explicit non-coverage.
• Simplify and generate tiles only for technically active visual representations; a visual map never creates analytical evidence.

Licensing and source conditions are provenance

There is no global licence for “official data”. Each dataset keeps its own source, version, attribution and conditions; a CC BY 4.0 reference never removes additional dataset-, catalogue-, service- or legal-act-specific conditions.

GnextD records those facts without treating runtime availability as permission. Each release decision is explicit: SGIFR APPS has its own control and defaults to inactive without disabling the separate DGT wildfire-hazard source. SOURCE_CONTROL_<FAMILY>_ALLOW=false excludes a family from new runs without changing recorded provenance.

Technical availability is a separate dimension

Each run records separately whether a source was available, partial, stale under a source-specific rule or unavailable. A completed local query may be technically available even when snapshot coverage is unproven; that case remains an inconclusive warning. Likewise, the visible Source unavailable label does not turn an out-of-coverage conclusion into a technical outage. A timeout, partial response, stale snapshot, unproven coverage or missing layer is never silently converted into a favourable result.

Coverage and result meaning

A local source is not automatically newer or more complete than a remote source. Errors, missing layers, unproven coverage and other limits remain recorded in the internal audit details. The four-state presentation keeps a completed local query with unproven coverage separate from No match and Source unavailable. These states describe only the result returned by the integrated data; the legal consequence of a match depends on the applicable regime and competent authority.

Maps, geocoding and municipal context

The OpenFreeMap basemap and DGT OrtoSat imagery are orientation surfaces, not result evidence, and retain independent controls. Photon remains limited to non-public environments. The OSMF policy for the public service at nominatim.openstreetmap.org strictly prohibits client-side autocomplete, so that service is never used as a Production autocomplete fallback.

Geoapify search is the separate primary technical integration when its server-only key is present. Geoapify publicly permits commercial Free-plan use within its published conditions and provides an Article 28 DPA; individual permission is not required for that use. The plan currently advertises 3,000 daily credits with a soft limit. Before each upstream request, GnextD enforces a shared, durable 2,850-attempt rolling-24-hour ceiling. When the ceiling is exhausted or unavailable, new upstream address lookups stop until capacity returns; existing valid five-minute cache hits may still be served without a reservation or provider call. There is no automatic paid or public-Nominatim fallback. Followed attribution links to Geoapify, OpenStreetMap and OpenAddresses remain visible. Without the key, Production fails closed. Location search is not part of the evidence Source Control snapshot used by screening.

Municipality profiles organise confirmed Câmara, DGAL, Diário da República and other official contacts and links. Each profile and guide keeps its own references. That organisation creates no affiliation and does not turn municipal context into a parcel decision.

Operations, measurement and feedback are not evidence sources

Cloudflare provides the proxy, TLS, WAF and abuse-protection layer. The optional Zaraz/Google Analytics 4 choice and aggregate “Helpful/Not helpful” counts serve only operations and content quality. They never enter a screening, alter a result or report, or appear as an official source. The manual audience event is limited to public pages and excludes searches, coordinates, property, account and private routes.

Corrections and updates

Provenance is versioned and reviewed when a source, term, version or method changes. To report incorrect attribution, an outdated link or an additional condition, include the source_id and affected page or report.

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