# Emap developer documentation

> Emap is a browser map rendering and editing engine. This index points to the authored guides and generated API for the current source tree. It is not a release or device-validation claim.

## Integration contracts

- Create a map after its sized DOM container mounts, using await Emap.create(). A string container is an element ID, without #.
- WebGL2 is the default backend. Canvas2D and WebGPU are explicit choices with different environment requirements. GPU initialization failure rejects creation rather than silently changing backend.
- Sources own vector datasets; render layers reference source IDs and data-layer IDs. FeatureRef IDs are indexes, not durable business keys.
- project/unproject transform project coordinates and canvas pixels. reproject changes the CRS. Do not confuse degrees, projected units, and pixels.
- Use public editing and attribute APIs for mutations. Readonly datasets are live views; feature properties are shallow-frozen snapshots.
- Check OpResult.ok. Also catch rejected Promises from initialization, import, and independent tools. Diagnostic events do not replace either check.
- JavaScript-style processing expressions are disabled by default. trusted is only for application-controlled expressions, not an input sandbox.
- Optional Arrow, DuckDB, MapLibre, GeoPackage, and GeoTIFF capabilities use separate entry points. Check the plugins and resources required by each workflow.
- GeoTIFF uses file/window reads and raster services rather than vector topology. Raster project references do not embed image pixels.
- Await map.dispose(). The application owns a supplied shared workerRuntime.

## Documentation

- [Source layout](https://mapseekai.github.io/mapseekai/emap/en/concepts/architecture)
- [Coordinates and CRS](https://mapseekai.github.io/mapseekai/emap/en/concepts/coordinates-crs)
- [Emap map instance](https://mapseekai.github.io/mapseekai/emap/en/concepts/emap)
- [Map and data model](https://mapseekai.github.io/mapseekai/emap/en/concepts/overview)
- [Runtime composition](https://mapseekai.github.io/mapseekai/emap/en/concepts/runtime)
- [Sources and layers](https://mapseekai.github.io/mapseekai/emap/en/concepts/source-layer)
- [Topology model](https://mapseekai.github.io/mapseekai/emap/en/concepts/topology)
- [Attributes](https://mapseekai.github.io/mapseekai/emap/en/data/attributes)
- [DuckDB Processing Toolbox](https://mapseekai.github.io/mapseekai/emap/en/data/duckdb)
- [Data formats](https://mapseekai.github.io/mapseekai/emap/en/data/formats)
- [Direct GeoPackage vector import](https://mapseekai.github.io/mapseekai/emap/en/data/geopackage)
- [Local GeoTIFF rasters](https://mapseekai.github.io/mapseekai/emap/en/data/geotiff)
- [Data operations](https://mapseekai.github.io/mapseekai/emap/en/data/operations)
- [Installation](https://mapseekai.github.io/mapseekai/emap/en/getting-started/installation)
- [Your first map](https://mapseekai.github.io/mapseekai/emap/en/getting-started/quick-start)
- [Camera](https://mapseekai.github.io/mapseekai/emap/en/guides/camera)
- [Controls](https://mapseekai.github.io/mapseekai/emap/en/guides/controls)
- [Editing](https://mapseekai.github.io/mapseekai/emap/en/guides/editing)
- [Events](https://mapseekai.github.io/mapseekai/emap/en/guides/events)
- [How-to guides](https://mapseekai.github.io/mapseekai/emap/en/guides/)
- [Native Cordis plugins and AI capabilities](https://mapseekai.github.io/mapseekai/emap/en/guides/plugins)
- [Selection](https://mapseekai.github.io/mapseekai/emap/en/guides/selection)
- [Styling layers](https://mapseekai.github.io/mapseekai/emap/en/guides/styling)
- [Web Worker](https://mapseekai.github.io/mapseekai/emap/en/guides/worker)
- [Emap documentation](https://mapseekai.github.io/mapseekai/emap/en/)
- [Error handling](https://mapseekai.github.io/mapseekai/emap/en/recipes/error-handling)
- [File import](https://mapseekai.github.io/mapseekai/emap/en/recipes/file-upload)
- [Fit bounds](https://mapseekai.github.io/mapseekai/emap/en/recipes/fit-bounds)
- [Performance](https://mapseekai.github.io/mapseekai/emap/en/recipes/performance)
- [Status control](https://mapseekai.github.io/mapseekai/emap/en/recipes/status-control)
- [Undo and redo](https://mapseekai.github.io/mapseekai/emap/en/recipes/undo-redo)
- [Compatibility](https://mapseekai.github.io/mapseekai/emap/en/reference/compatibility)
- [Errors reference](https://mapseekai.github.io/mapseekai/emap/en/reference/errors)
- [Events reference](https://mapseekai.github.io/mapseekai/emap/en/reference/events)
- [FAQ](https://mapseekai.github.io/mapseekai/emap/en/reference/faq)
- [Reference](https://mapseekai.github.io/mapseekai/emap/en/reference/)

## Generated resources

- [API signatures](https://mapseekai.github.io/mapseekai/emap/api/)
- [Runnable examples](https://mapseekai.github.io/mapseekai/emap/examples/)

Check the installed package declarations and matching Worker/WASM assets when using a published release. Authored pages link to owning implementation files.