| name | unreal-mcphub-cli |
| description | Use when the user wants to operate UnrealMCPHub through its CLI: bind a project, manage configured MCPs, inspect status or health, launch or restart the editor, list tools, call tools, or sync the active MCP into bundled MCPHub. |
UnrealMCPHub CLI
Use this skill when the task should be completed by running UnrealMCPHub commands instead of editing code directly.
Quick Rules
- Prefer the built binary at
UnrealMCPHub\target\debug\unreal-mcphub.exe.
- If the binary is missing or stale after code changes, run
cargo build in UnrealMCPHub first.
- When the current working directory is already inside an Unreal project tree, rely on UnrealMCPHub's auto-bind behavior before adding extra selectors; it now reuses an existing saved binding and only refreshes it when the detected engine path or discovered MCP endpoints changed.
- For the common single-project, single-MCP flow, omit
--project and --mcp.
- When
call-tool is used, pass --arguments-json as a JSON object string.
- In Windows PowerShell, prefer building non-empty
--arguments-json values with ConvertTo-Json -Compress; this build also accepts the de-quoted object syntax PowerShell often forwards to native executables.
run_unreal_skill now honors optional defaults correctly; pass only the fields your current mode uses.
- Prefer
verify-ue --summary for interactive terminal checks, and verify-ue --output <file> when a full JSON report should be preserved.
--wait-seconds only controls how long UnrealMCPHub waits for the embedded MCP endpoint to become healthy; live verification steps can continue after that window.
- On Windows,
stop automatically falls back to a forced process-tree termination if a graceful stop leaves child processes behind.
- If the active Unreal plugin endpoint is discovered with
auto_start=false, treat launch or verify-ue failures to reach the endpoint as a likely plugin configuration issue first: the editor can start successfully while the embedded MCP stays offline until the plugin starts its server. Recommend enabling the plugin's MCP auto-start setting or starting the MCP manually inside Unreal.
- For PowerShell quoting, temp-script execution, and large-payload guidance, load
references/powershell_best_practices.md from this skill instead of duplicating those details here.
Primary Commands
- Bind or refresh the current project:
target\debug\unreal-mcphub.exe setup "<path-to.uproject>"
- Inspect overall state:
target\debug\unreal-mcphub.exe status
- Launch the editor and wait for MCP readiness:
target\debug\unreal-mcphub.exe launch --wait-seconds 180
- Run a full live UE verification pass with a concise terminal summary:
target\debug\unreal-mcphub.exe verify-ue --compile --wait-seconds 180 --summary
- Run a full live UE verification pass and save the full report:
target\debug\unreal-mcphub.exe verify-ue --compile --wait-seconds 180 --output verify-ue-report.json
- Discover configured Unreal instances:
target\debug\unreal-mcphub.exe discover
- Inspect the active instance or one explicit instance:
target\debug\unreal-mcphub.exe health
target\debug\unreal-mcphub.exe session --scope full --limit 20
- Explicit instance keys use the shape
<project>:<mcp-id>:<port> and are best copied from discover.
- Switch the active project or active MCP:
target\debug\unreal-mcphub.exe use-project <project-name>
target\debug\unreal-mcphub.exe use-mcp <mcp-id>
- Register another MCP under a project:
target\debug\unreal-mcphub.exe add-mcp <mcp-id> --host 127.0.0.1 --port 19841 --path /mcp --activate
- Forward generic MCP operations:
target\debug\unreal-mcphub.exe list-tools
target\debug\unreal-mcphub.exe call-tool <tool-name> --arguments-json "{}"
- Inspect the current tool surface with schema details:
target\debug\unreal-mcphub.exe list-tools --json
- Forward generic MCP operations with non-empty PowerShell arguments:
$args = @{ skill_name = "cpp_editor_api"; path = "docs/overview.md" } | ConvertTo-Json -Compress
target\debug\unreal-mcphub.exe call-tool read_unreal_skill --arguments-json "$args"
- Mirror the selected MCP into bundled MCPHub:
target\debug\unreal-mcphub.exe sync-mcphub
- After
sync-mcphub, inspect the full synced tool surface without exposing extra facade tools:
vendor\MCPHub\target\debug\mcphub.exe tool-info --all --json <mcp-id>
- To zoom in on one synced tool only:
vendor\MCPHub\target\debug\mcphub.exe tool-info <mcp-id>/<tool-name> --json
- Stop the active editor instance:
target\debug\unreal-mcphub.exe stop
Working Style
- Confirm whether the task is lifecycle management, MCP inspection, or tool forwarding.
- Choose the narrowest CLI command that solves it.
- If selectors are required, prefer
--project and --mcp; otherwise let the active defaults resolve them.
- For interactive verification, prefer concise terminal output first; only emit the full JSON when the user explicitly needs raw report details.
- Report the concrete project name, MCP id, instance key, URL, or tool name that was used so the result is easy to audit.