Speaks every GIS server's language. Then becomes one.

VoltGrid works both sides of the wire: it consumes ArcGIS Portal, Server, and Online, GeoServer, QGIS Server, and MapServer as layer sources — and it emulates Esri endpoints locally from an embedded Kestrel server, so QGIS, ArcGIS Pro, and any ArcGIS SDK client can consume your desktop as if it were enterprise GIS infrastructure.

FeatureServerImageServerStreamServer I3S SceneServerTile servicesHub / Living AtlasConnect-to-GIS

One desktop, an Esri REST surface

Enterprise endpoints without the enterprise

The in-process server exposes ESRI-compatible REST APIs over your local data — GeoPackages become FeatureServers, COGs become ImageServers, SLPKs become SceneServers, live sources become a StreamServer — with no ArcGIS license and no external process.

Standard clients just work — ArcGIS Maps SDK FeatureLayer, StreamLayer, and SceneLayer point at localhost URLs and load like any hosted service.
Transactional editing — the FeatureServer implements query, addFeatures, updateFeatures, deleteFeatures, and batch applyEdits with rollback-on-failure.
Cache-smart serving — tile and I3S responses carry ETags and immutable Cache-Control, answering repeat requests with 304s.
Discoverable — the Connect-to-GIS REST catalog lists everything the server exposes, ready to paste into QGIS or ArcGIS Pro.

http://localhost:5059

// local data, Esri dialects
GET  /api/featureserver/{ds}/{layer}/query   → FeatureServer
POST /api/featureserver/{ds}/{layer}/applyEdits
GET  /ImageServer/exportImage?renderingRule= → ImageServer
GET  /api/slpk/packages/{id}/SceneServer
     /layers/0                               → I3S SceneServer
WS   /api/streamserver/subscribe             → StreamServer
GET  /api/tiles/{layerId}/{z}/{x}/{y}        → converted TPKX/VTPK
GET  /api/connect                            → Connect-to-GIS catalog

● serving  clients QGIS · ArcGIS Pro · JS SDK  · in-process

Emulated locally

Five Esri service types, served from your workstation

Each emulation is a native .NET implementation inside the embedded server — no Python runtime, no cloud dependency.

📝

FeatureServer (GPKG)

ESRI FeatureServer REST over GeoPackage with full CRUD, offline edit queuing and sync, conflict-resolution strategies, change tracking, and geometry conversion across ESRI JSON, GeoJSON, WKT, WKB, and GPKG blobs. Drives the native Editor and Sketch widgets directly.

🛰️

ImageServer / ElevationServer

ESRI ImageServer REST over COG GeoTIFF: exportImage with renderingRule raster functions, 20+ spectral indices (NDVI, NDWI, EVI, NBR), auto sensor detection for Sentinel-2 and Landsat, and VRT mosaics/time-series from multiple COGs. An ElevationServer facade serves registered DEMs to ArcGIS elevation sources.

📶

StreamServer

ESRI-compatible streaming matching ArcGIS Velocity/GeoEvent conventions: WebSocket and SSE transports, temporal queries and playback, real-time analytics, and multi-source aggregation over Meshtastic, TAK, RTK/GNSS, and radio feeds — consumable by a stock StreamLayer.

🏙️

I3S SceneServer (SLPK)

Upload a .slpk and the embedded server answers standard I3S REST — node pages, geometries, textures, attributes — straight from the archive. I3S 1.6 / 1.7 / 1.8 supported; IntegratedMesh, 3DObject, and Point layer types render in the SceneView.

🗂️

Tile services (TPKX / VTPK)

ESRI Tile Packages convert to MBTiles or GeoPackage via a native Compact Cache V2 bundle reader, then serve as XYZ tiles with extracted vector styles — a verified 417-tile raster package converts in about 160 ms.

🖼️

COG range serving

Cloud Optimized GeoTIFFs stream to ImageryTileLayer over HTTP range requests (206 / Content-Range) — reference multi-GB rasters in place on disk, no conversion, no copy.

Consuming the outside world

Every server you already run, one client

🔌

Connect to enterprise GIS servers

ArcGIS Portal / Server / ArcGIS Online — browse and load hosted services directly.
GeoServer, QGIS Server, MapServer — the open-source stack is a first-class layer source.
30+ layer types land on the 3D scene, from feature and imagery services to WMS/WMTS/WFS.

🌎

ArcGIS Hub & Living Atlas

Browse curated Living Atlas and open Hub content without leaving the app.
Search across the catalog to find authoritative layers for your AOI.
Download datasets for disconnected use.
Load-to-map in one action — from discovery to the 3D scene.

Server emulation reflects the implemented endpoint surface documented for each facade; "100% ESRI compatible" refers to the documented FeatureServer/StreamServer request contracts consumed by native ArcGIS SDK widgets, not certification by Esri.