GitlabMCPSharp

A standalone C# MCP (Model Context Protocol) server for GitLab (gitlab.com and self-hosted) over Streamable HTTP.

Features

• HTTP MCP server using the Streamable HTTP transport.
• Read-only mode by default — write/delete tools stay disabled until explicitly enabled.
• Project / group allow/deny lists and per-feature toggles (issues / merge requests / repository / pipelines / releases / groups / snippets).
• Configuration via GitlabMCPSharp.json, environment variables, or command line.
• Serilog logging to console and rolling files (daily + 50 MB rollover, 14-file retention).
• Runs as a console app or as a Windows Service.

Configuration

Configure via GitlabMCPSharp.json or environment variables. Environment variables win over JSON; in Docker, use the GITLABMCP_ prefix and __ for nested keys.

Setting	Default	Description
Gitlab:ApiBaseUrl	https://gitlab.com	Override for self-hosted GitLab (https://gitlab.example.com)
Gitlab:PersonalAccessToken	(none)	PAT with scope read_api (or api for writes)
Gitlab:OAuth2Token	(none)	Optional OAuth2 token used in place of a PAT
Gitlab:DefaultNamespace	(none)	Default group used when tools omit one
Gitlab:DefaultProject	(none)	Default project (group/project) used when tools omit one
Gitlab:UserAgent	GitlabMCPSharp	UA header sent to GitLab
Gitlab:ReadOnly	true	When true, all write/delete tools are disabled
Gitlab:DefaultPageSize	30	Page size for list operations (max 100)
Gitlab:MaxPages	5	Max pages traversed when paginating
Gitlab:RequestTimeoutSeconds	100	HTTP timeout
Gitlab:AllowedProjects	[]	Allow-list of group/project. Empty = no restriction
Gitlab:BlockedProjects	[]	Deny-list of group/project
Gitlab:AllowedGroups	[]	Allow-list of group full paths
Gitlab:EnableIssues / EnableMergeRequests / EnableRepository / EnablePipelines / EnableReleases / EnableGroups / EnableSnippets	true	Per-feature tool toggles
Gitlab:AcceptInvalidCertificates	false	Accept self-signed TLS certs (self-hosted only)
Server:Host	localhost	Host to bind
Server:Port	5702	HTTP port
Server:Path	/mcp	MCP endpoint path
Server:WindowsServiceName	GitlabMCPSharp	Service name when running under SCM
Server:Password	blank	Optional MCP endpoint password; blank disables password auth

When Server:Password is set, MCP requests must provide the password as Authorization: Bearer <password>, the Basic auth password, or X-MCP-Password.

Arrays use numeric indexes, for example GITLABMCP_Gitlab__AllowedProjects__0=group/project. Booleans use true or false.

Running

dotnet run

Then point your MCP client at http://localhost:5702/mcp.

Docker

Tagged releases publish a multi-architecture image for linux/amd64 and linux/arm64 to GitHub Container Registry:

docker run --rm -p 5702:5702 \
  -e GITLABMCP_Gitlab__ApiBaseUrl=https://gitlab.example.com \
  -e GITLABMCP_Gitlab__PersonalAccessToken=your-token \
  -e GITLABMCP_Gitlab__AllowedProjects__0=group/project \
  -e GITLABMCP_Server__Password=change-me \
  ghcr.io/wixely/gitlabmcpsharp:latest

Version tags such as v1.2.3 also publish image tags like v1.2.3, 1.2.3, and 1.2. Read-only mode is on by default; set GITLABMCP_Gitlab__ReadOnly=false only when you want write tools available.

Running as a Windows Service

The host detects when it's launched by the Service Control Manager and switches to service mode automatically (config and logs resolve from the executable directory, not the SCM's C:\Windows\System32 working directory).

Publish, then register with sc.exe (run as Administrator):

dotnet publish -c Release -r win-x64 --self-contained false -o C:\Services\GitlabMCPSharp

sc.exe create GitlabMCPSharp `
    binPath= "C:\Services\GitlabMCPSharp\GitlabMCPSharp.exe" `
    start= auto `
    DisplayName= "GitLab MCP (C#)"
sc.exe description GitlabMCPSharp "MCP server for GitLab."
sc.exe start GitlabMCPSharp

Put credentials in C:\Services\GitlabMCPSharp\GitlabMCPSharp.Local.json (or set GITLABMCP_Gitlab__PersonalAccessToken as a machine-level env var) — never in GitlabMCPSharp.json, which is checked in.

To remove:

sc.exe stop GitlabMCPSharp
sc.exe delete GitlabMCPSharp

Logs land in <install-dir>\logs\gitlabmcp-*.log.

Read-only mode

Read-only is on by default. To enable write tools (e.g. create_issue, trigger_pipeline), set Gitlab:ReadOnly=false.