Revit API reference

Namespace → using directive table, pre-injected globals, and version-specific quirks for writing bim revit exec snippets across Revit 2022–2026.

Pre-injected globals

These variables are available in every snippet without any import:

Variable	Type	Available when
`uiApp`	`Autodesk.Revit.UI.UIApplication`	always
`app`	`Autodesk.Revit.ApplicationServices.Application`	always
`doc`	`Autodesk.Revit.DB.Document`	when a document is open
`uiDoc`	`Autodesk.Revit.UI.UIDocument`	when a document is open
`linkedDocs`	`IEnumerable<Document>`	when a document is open
`allDocs`	`IEnumerable<Document>`	when a document is open (active + linked)

doc and uiDoc are null when no document is open. Scripts that don't need a document can use app and uiApp directly.

Namespace → `using` directive

These namespaces are available in all supported Revit versions (2022–2026) unless noted otherwise.

Namespace	Add to snippet	What it covers
`Autodesk.Revit.DB`	`using Autodesk.Revit.DB;`	Elements, documents, parameters, geometry (XYZ, BoundingBoxXYZ, Solid), filtering (`FilteredElementCollector`), views, sheets, transactions, PDF export (`PDFExportOptions`), built-in categories and parameters (`BuiltInCategory`, `BuiltInParameter`)
`Autodesk.Revit.UI`	`using Autodesk.Revit.UI;`	UI interaction, task dialogs, selection, `UIDocument`, `UIApplication`, ribbon and external commands
`Autodesk.Revit.ApplicationServices`	`using Autodesk.Revit.ApplicationServices;`	`Application` services, language settings, version info, product type
`Autodesk.Revit.Creation`	`using Autodesk.Revit.Creation;`	Factory methods for creating elements: `Document.Create`, `Application.Create`. Required for `NewExtrusion()`, `NewFamilyInstance()` and similar creation APIs — family-document only for geometry creation methods.
`System.Linq`	`using System.Linq;`	LINQ queries — pre-injected, available without explicit import
`System.Collections.Generic`	`using System.Collections.Generic;`	`List<T>`, `Dictionary<K,V>`, etc. — pre-injected
`System.IO`	`using System.IO;`	File, Path, Directory — for export scripts writing to disk
`System.Text.Json`	`using System.Text.Json;`	JSON serialization for structured return values
`System.Text.RegularExpressions`	`using System.Text.RegularExpressions;`	Regex for name/parameter filtering

Use bim revit api search <term> to look up which namespace any type lives in against your locally installed Revit version.

Version-specific quirks (2022–2026)

ElementId — integer value access

Revit version	Access element ID as integer
2022, 2023	`element.Id.IntegerValue`
2024, 2025, 2026	`element.Id.Value` (returns `long`; `IntegerValue` removed in 2024)

For snippets that must run on both old and new versions: use bim revit api describe "P:Autodesk.Revit.DB.ElementId.Value" to check availability against your target.

ProjectPosition — latitude/longitude

Revit version	Notes
2022–2024	`doc.ActiveProjectLocation.GetProjectPosition(...).Latitude` works
2025, 2026	`Latitude` and `Longitude` removed from `ProjectPosition`. Use `doc.SiteLocation.Latitude` / `doc.SiteLocation.Longitude` instead.

Autodesk.Revit.Creation — NewExtrusion and geometry creation

Context	Notes
Family documents	`doc.FamilyCreate.NewExtrusion()` available in all 2022–2026 versions
Project documents	Geometry creation methods (`NewExtrusion`, `NewSweep`, etc.) are family-document only and throw `InvalidOperationException` in a project context. Use `DirectShape` for project-level geometry instead.

Transaction mode

Pattern	Notes
Auto-transaction (default)	`bim revit exec` wraps the snippet in a `Transaction` automatically. Safe for write operations in all 2022–2026 versions.
`--no-transaction`	Required when: setting `uidoc.ActiveView`, calling `doc.Regenerate()` standalone, or managing your own nested transactions.
`uidoc.ActiveView = view`	Throws `InvalidOperationException` inside the auto-transaction. Fix: pass `--no-transaction` to the exec call.

PDF export

Revit version	Notes
2022–2026	`doc.Export(folder, IList<ElementId> viewIds, PDFExportOptions)` available. `PDFExportOptions.Combine = false` = one PDF per view. Use `--no-transaction` for export calls.

.NET target and TCP port by Revit year

Revit	.NET target	TCP port	Notes
2022	net48 (.NET Framework 4.8)	14700	Use `ElementId.IntegerValue`
2023	net48	14701	Use `ElementId.IntegerValue`
2024	net48	14702	Use `ElementId.Value`; `IntegerValue` removed
2025	net8.0-windows	14703	`ProjectPosition.Latitude/Longitude` removed
2026	net8.0-windows	14704

A .NET target mismatch causes the TCP bridge to fail silently at startup. Run bim revit status --detailed to check the installed add-in version against your Revit year.

Diagnosing version issues

# check add-in version, port state, and installation
bim revit status --detailed

# verify a type or member exists for your installed version
bim revit api search "ProjectPosition"
bim revit api type "Autodesk.Revit.DB.ProjectPosition"
bim revit api describe "P:Autodesk.Revit.DB.ElementId.Value"