revit-api-references

# Revit API References The `Nice3point.Revit.Api.*` NuGet packages carry the Revit API assemblies; a project compiles for any Revit year without that year installed locally. A local file (`HintPath`) reference ties the build to one installed version at one path and breaks CI and teammates' machines. ## When to use - Adding a reference to `RevitAPI`, `RevitAPIUI`, or another Revit-targeting assembly. - Reviewing a project that references Revit DLLs by local path. ## Workflow ### Step 1: Reference the API package ```xml <PackageReference Include="Nice3point.Revit.Api.RevitAPI" Version="$(RevitVersion).*" /> <PackageReference Include="Nice3point.Revit.Api.RevitAPIUI" Version="$(RevitVersion).*" /> <PackageReference Include="Nice3point.Revit.Extensions" Version="2025.0.0" Condition="$(RevitVersion) == '2025'" /> <PackageReference Include="Nice3point.Revit.Extensions" Version="2026.0.0" Condition="$(RevitVersion) == '2026'" /> <PackageReference Include="Nice3point.Revit.Extensions" Version="2027.0.0" Condition="$(RevitVersion) == '2027'" /> ``` The `$(RevitVersion).*` wildcard resolves the assembly set for the active configuration. `$(RevitVersion)` is supplied by the `Nice3point.Revit.Sdk`, which derives it from the build configuration (for example `Release.R27` → `2027`) — see `revit-sdk-project-configuration`. The `$(RevitVersion).*` wildcard fits the built-in API dependencies; they almost never carry critical changes within a major version. Every other dependency takes an exact package version. A floating version on such a dependency breaks the build when the package is updated. With central package management, pin the version in `Directory.Packages.props`. ### Step 2: Never reference a local Revit DLL Do not add a local file reference — it requires that exact Revit version at that exact path on every build machine: ```xml <!-- BAD --> <Reference Include="RevitAPI"> <HintPath>C:\Program Files\Autodesk\Revit 2027\RevitAPI.dll</HintPath> </Reference> ``` ### Step 3: Find the right package Assemblies ship as `Nice3point.Revit.Api.*` with `RevitAPI`, `RevitAPIUI`, `RevitAPIIFC`, `AdWindows`, `UIFramework`, and more. Check the `Nice3point.Revit.Api.*` packages before adding any assembly reference; only request a new one if it does not exist. ### Step 4: Verify Restore and build on a machine (or CI) with no Revit installed. ## Validation - [ ] Revit API assemblies come from `Nice3point.Revit.Api.*` packages. - [ ] No `HintPath`/local-file reference to a Revit DLL remains. - [ ] The version uses the `$(RevitVersion).*` wildcard (or central package management). - [ ] The project restores and builds without Revit installed. ## Common Pitfalls | Pitfall | Correct approach | |------------------------------------------------------|--------------------------------------------------------| | `<HintPath>` to an installed Revit DLL | Use `Nice3point.Revit.Api.*` with `$(RevitVersion).*`. | | A fixed API version that breaks other years | Use the `$(RevitVersion).*` wildcard. | | An external NuGet package targets a floating version | Use the exact package version. | | Copying a Revit DLL into the repo | Reference the NuGet package. |