C# Omnisharp Roslyn Configuration

The details below describe how to install and configure the C# Omnisharp Roslyn language server found here.

Installing the Language Server

To install the language server download the latest omnisharp-win-x64.zip binaries found here.
NOTE: This testing described below was done using the v1.32.9 release.
Extract the contents of the zip file taking note of that folder location.
In this case the zip file was extracted to the folder location shown below with that folder containing the language server executable: 
C:\Project\omnisharp\

 Directory of C:\Project\omnisharp

22/01/2019  07:02 PM             8,192 OmniSharp.exe
Check the language server binary by running the following command: 
C:\Project\omnisharp\OmniSharp.exe -?
That command should result in the following output: 
Usage:  [options]

Options:
  -? | -h | --help           Show help information
  -s | --source              Solution or directory for OmniSharp to point at (defaults to current directory).
  -l | --loglevel            Level of logging (defaults to 'Information').
  -v | --verbose             Explicitly set 'Debug' log level.
  -hpid | --hostPID          Host process ID.
  -z | --zero-based-indices  Use zero based indices in request/responses (defaults to 'false').
  -pl | --plugin             Plugin name(s).
  -d | --debug               Wait for debugger to attach
  -lsp | --languageserver    Use Language Server Protocol.
  -e | --encoding            Input / output encoding for STDIO protocol.

Configuration

Start Zeus and use the Options, Document Types menu to edit the C# document type and in the Language Server panel apply the following configuration settings: 
Program Type: Executable
     Program: C:\Project\omnisharp\OmniSharp.exe
   Directory: $wdd
   Arguments: -lsp
              -z
NOTE: The fully qualified executable name can omitted the directory details if the executable folder is found in the system PATH environment variable.
The $wdd value used for the directory is a Zeus tag that will evaluate to the workspace drive and directory. This means the language server will start in that workspace folder if a workspace is open.

Using the Language Server

To test the configuration create a simple test.cs file and fire off an auto-complete request:
lsp d


Latest Version: Zeus 3.99c
Released: 3rd January 2025
What's New