# C# workspace builder API Source: https://libtmux.org/en/csharp/latest/workspace/reference/ > Internal reference for the C# workspace builder and configuration APIs. The [`LibTmux.Workspace`]() namespace provides configuration objects and a builder that uses a caller-supplied LibTmux [`Server`](). ## Configuration [`WorkspaceFile`](https://libtmux.org/en/csharp/latest/workspace/reference/libtmux-workspace-workspacefile/) parses YAML and holds the session description. [`WorkspaceWindow`]() and [`WorkspacePane`]() hold nested configuration. [`WorkspaceFormatException`]() identifies unsupported or invalid configuration. ## Builder options [`WorkspaceBuilder`](https://libtmux.org/en/csharp/latest/workspace/reference/libtmux-workspace-workspacebuilder/) accepts the server to use. [`PlanAsync`]() validates the declaration and observes that endpoint; its returned [`WorkspacePlan`](https://libtmux.org/en/csharp/latest/workspace/reference/libtmux-workspace-workspaceplan/) lists the actions to review before [`ApplyAsync`]() executes them. Enumerating those actions performs no I/O. Application rechecks the observed daemon and session. [`WorkspacePlanOptions`](https://libtmux.org/en/csharp/latest/workspace/reference/libtmux-workspace-workspaceplanoptions/) controls existing-session conflicts, readiness, host scripts, and cleanup. The defaults refuse an existing session and send pane input immediately. [`BuildAsync`]() combines planning and application with those defaults. Choose [`WorkspaceReadiness.Cooperative`](https://libtmux.org/en/csharp/latest/workspace/reference/libtmux-workspace-workspacereadiness/) when pane startup can signal its assigned channel. Configure a positive `ReadinessTimeout`; a timeout prevents command delivery to that pane. [Topics](https://libtmux.org/en/csharp/latest/workspace/topics/) explains the startup contract and its limits. ## Results and failures [`WorkspaceResult`](https://libtmux.org/en/csharp/latest/workspace/reference/libtmux-workspace-workspaceresult/) contains the session, created windows, rejected final layouts, and action journals. Reusing an existing session creates no windows. A rejected final layout does not discard its window. [`WorkspaceBuildException`](https://libtmux.org/en/csharp/latest/workspace/reference/libtmux-workspace-workspacebuildexception/) keeps a `PartialResult` when state could be materialized before failure. It can be null when no such result could be read. `Journal` records action outcomes; `CompensationJournal` records attempted cleanup. Inspect live tmux state before retrying; a missing result does not prove that no command reached tmux. Cancellation during application raises [`WorkspaceOperationCanceledException`](https://libtmux.org/en/csharp/latest/workspace/reference/libtmux-workspace-workspaceoperationcanceledexception/) with the caller's token, partial state, and journals. Cancellation does not imply rollback. `CompensateOnFailure` requests bounded cleanup only of resources proven to belong to that application. [Result contract](https://github.com/libtmux/libtmux-dotnet/blob/ec8b6ab2a4f65e23664f43fba538ba200d4ae8bc/src/LibTmux.Workspace/WorkspaceResult.cs); [Failure contract](https://github.com/libtmux/libtmux-dotnet/blob/ec8b6ab2a4f65e23664f43fba538ba200d4ae8bc/src/LibTmux.Workspace/WorkspaceBuildException.cs). ## API declarations - [LibTmux.Workspace.WorkspaceAction](https://libtmux.org/en/csharp/latest/workspace/reference/libtmux-workspace-workspaceaction/) - [LibTmux.Workspace.WorkspaceActionKind](https://libtmux.org/en/csharp/latest/workspace/reference/libtmux-workspace-workspaceactionkind/) - [LibTmux.Workspace.WorkspaceActionOutcome](https://libtmux.org/en/csharp/latest/workspace/reference/libtmux-workspace-workspaceactionoutcome/) - [LibTmux.Workspace.WorkspaceActionState](https://libtmux.org/en/csharp/latest/workspace/reference/libtmux-workspace-workspaceactionstate/) - [LibTmux.Workspace.WorkspaceBuilder](https://libtmux.org/en/csharp/latest/workspace/reference/libtmux-workspace-workspacebuilder/) - [LibTmux.Workspace.WorkspaceBuildException](https://libtmux.org/en/csharp/latest/workspace/reference/libtmux-workspace-workspacebuildexception/) - [LibTmux.Workspace.WorkspaceCommand](https://libtmux.org/en/csharp/latest/workspace/reference/libtmux-workspace-workspacecommand/) - [LibTmux.Workspace.WorkspaceExistingSession](https://libtmux.org/en/csharp/latest/workspace/reference/libtmux-workspace-workspaceexistingsession/) - [LibTmux.Workspace.WorkspaceFile](https://libtmux.org/en/csharp/latest/workspace/reference/libtmux-workspace-workspacefile/) - [LibTmux.Workspace.WorkspaceFormatException](https://libtmux.org/en/csharp/latest/workspace/reference/libtmux-workspace-workspaceformatexception/) - [LibTmux.Workspace.WorkspaceHostCommand](https://libtmux.org/en/csharp/latest/workspace/reference/libtmux-workspace-workspacehostcommand/) - [LibTmux.Workspace.WorkspaceHostResult](https://libtmux.org/en/csharp/latest/workspace/reference/libtmux-workspace-workspacehostresult/) - [LibTmux.Workspace.WorkspaceOperationCanceledException](https://libtmux.org/en/csharp/latest/workspace/reference/libtmux-workspace-workspaceoperationcanceledexception/) - [LibTmux.Workspace.WorkspacePane](https://libtmux.org/en/csharp/latest/workspace/reference/libtmux-workspace-workspacepane/) - [LibTmux.Workspace.WorkspacePlan](https://libtmux.org/en/csharp/latest/workspace/reference/libtmux-workspace-workspaceplan/) - [LibTmux.Workspace.WorkspacePlanOptions](https://libtmux.org/en/csharp/latest/workspace/reference/libtmux-workspace-workspaceplanoptions/) - [LibTmux.Workspace.WorkspaceReadiness](https://libtmux.org/en/csharp/latest/workspace/reference/libtmux-workspace-workspacereadiness/) - [LibTmux.Workspace.WorkspaceResult](https://libtmux.org/en/csharp/latest/workspace/reference/libtmux-workspace-workspaceresult/) - [LibTmux.Workspace.WorkspaceServerStartup](https://libtmux.org/en/csharp/latest/workspace/reference/libtmux-workspace-workspaceserverstartup/) - [LibTmux.Workspace.WorkspaceWindow](https://libtmux.org/en/csharp/latest/workspace/reference/libtmux-workspace-workspacewindow/)