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.
• Display the authority data date separately from GnextD’s check or import date when each value exists, without estimating either value.
• 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 three visible results: Match when there is an occurrence; Nothing found in checked maps when the local source was available, the query completed and the integrated data returned no occurrence; Source unavailable when the check produced no usable result or a documented source-specific gap applies. Technical evidence separately retains coverage, unavailability, incomplete-query and scope states.
• 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 with no occurrence produces Nothing found in checked maps and continues to describe only the checked data. A timeout, partial response, stale snapshot, missing layer or documented source-specific gap produces Source unavailable and is never silently converted into Nothing found.

Coverage and result meaning

A local snapshot is not automatically current or complete. Errors, missing layers, known limits and coverage metadata remain recorded in internal audit details and the professional report. The three public results describe only what the integrated data returned in the query; they do not declare legal absence, buildability or permission. The 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.

PDM pages use published, immutable municipal revisions that link to the official documents; GnextD does not host those documents. Questions marked as user facts can adjust the document route, while administrative-confirmation questions go directly to the Câmara. Both remain bound to the revision and no user answer replaces an official source.

Municipal planning boundaries derived from an official map remain private, versioned and explicitly identified as derived. They compare the point and cadastral parcel; they are not a survey and do not state whether development is permitted. The Câmara confirms the applicable position, particularly near a boundary.

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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