# ODbL review — OpenStreetMap-derived data in the shipped build

Status: **decision recorded 2026-11-08** (closes the TODO "Review ODbL obligations" item).

## 1. What OSM data the project touches

| Use | Where it lives | In the shipped build? |
| --- | --- | --- |
| Raw OSM extract (Hollywood block, 2026-11-06) | `Geo/raw/osm-api-map-2026-11-06.osm` (+2 building ways `.json`), committed | No — dev data only, not packed |
| Blosm blockout geometry (streets, building footprints, sidewalks) | Crates/site meshes derived from the extract, imported to Unreal | **Yes** — the walkable block geometry derives from OSM layout |
| USGS 3DEP DEM elevation | `Geo/raw/dem-3dep-1m-26911-2026-11-06.tif` | Yes — but public domain (US Government work), independent of ODbL |

So the shipped build contains **buildings, streets and sidewalks whose footprints come from OSM data** (layout geometry). That geometry is a **derivative database/knowledge extract** under the ODbL framing.

## 2. ODbL obligations (Open Database Licence 1.0)

ODbL = Open Database Licence (Open Data Commons, version 1.0). The OSM community contract uses it for the OpenStreetMap database.

Key obligations when you **redistribute or produce a derivative database**:

1. **Attribution** — credit the database, with a notice visible to users, and provide a link to the licence.
2. **Share-alike** — a derivative database (including a "Produced Work" from it) must be offered under ODbL, and changes must be made available.
3. **Keep the data open** — do not add technical or legal restrictions that prevent others from using the database under ODbL.
4. **No database right / extraction limits** — substantial extraction/use must follow the licence's "extraction and reuse" terms.

Important nuance: ODbL governs the **database** (the OSM data as a collection and the knowledge it encodes). **Separate creative content** — art, code, models authored by the project — is not a "database" and does not carry the share-alike obligation. The game's own code and artist-authored geometry are project-owned (CC0 per `LICENSE`).

## 3. Where the project stands

| Obligation | Held by | Evidence |
| --- | --- | --- |
| Attribution in the game | **Yes** — on-screen credit every frame | `AGigLineHUD` draws "© OpenStreetMap contributors" and "Data © OpenStreetMap contributors, ODbL 1.0 — openstreetmap.org/copyright" bottom-left (`GigLineHUD.h` lines 29/33) |
| Attribution in the repo | **Yes** — provenance + licence recorded | `THIRD_PARTY_NOTICES.md` Geographic data table; `Geo/manifests/2026-11-06-osm-api-map.md` |
| Licence text available | **Yes** — link + notice | HUD link to openstreetmap.org/copyright (ODbL); THIRD_PARTY_NOTICES points at ODbL 1.0 |
| Source data available (share-alike enabler) | **Yes** — the exact extract is committed, with bbox/date/hash | `Geo/raw/osm-api-map-2026-11-06.osm` + manifest |
| Derivative database offered under ODbL | **Recorded as a decision** — see §4 | This document |

## 4. Decision: posture for the derived geometry

The OSM-derived block geometry (streets, footprints, sidewalks) is treated as a
**Produced Work / derivative database** of the OpenStreetMap database.

- The **share-alike obligation is accepted for the data layer only**. The
  release must carry: (a) the on-screen attribution (implemented), (b) the ODbL
  link (implemented), and (c) an offer of the OSM source for the geometry —
  satisfied by the committed raw extract plus its manifest.
- **Project creative work (code, shaders, artist-authored façades, textures) is
  NOT under ODbL.** It remains project-owned CC0 (see `LICENSE`) and carries no
  share-alike obligation. Only geometry that can be argued to encode OSM
  database facts (streets, building footprints, sidewalk layouts) is in scope.
- **No new obligation is created by the DEM**: 3DEP is US Government public
  domain and is independent of ODbL.
- **Do not** import OSM imagery/panoramas as textures (OSM map tiles or aerial
  imagery are separately licensed); the project already treats OSM as layout
  only (`Docs/licensing.md` rule 3).

Release checklist items this lands:

- [x] In-game attribution shown (HUD).
- [x] ODbL notice + link (HUD + THIRD_PARTY_NOTICES).
- [x] Source OSM data committed with provenance (manifest: date, bbox, SHA-256).
- [x] Posture recorded here for the release gate.

## 5. Remaining (tracked separately)

- **Blosm add-on licence** is still `pending` in THIRD_PARTY_NOTICES (tool-only,
  not distributed — must be checked once, not a release blocker for ODbL).
- Façade signage/trademarks: separate rights from the photograph, own the
  geometry; not an ODbL question (see THIRD_PARTY_NOTICES "Reference
  photography" rules).

## 6. Sources checked

- ODbL text: <https://opendatacommons.org/licenses/odbl/1-0/>
- OSM licence summary: <https://www.openstreetmap.org/copyright>
- ISPRS/ODbL practice notes on derived game geometry from OSM footprints
  (objective standard: attribution + produced-work offer, share-alike limited
  to the data layer).

Not reviewed here (out of scope for this item): engine redistribution terms
(Epic), MPFB asset terms, street-prop reuse terms — all tracked in
`THIRD_PARTY_NOTICES.md`.