# add_blueprint_variable Add a variable to a Blueprint. Agent View of the PolicyLayer registry record for `add_blueprint_variable`. HTML page: https://policylayer.com/tools/jjpxdev-unreal-mcp/add-blueprint-variable ## Facts - Tool: `add_blueprint_variable` - Server: Unreal (`@jjpxdev/unreal-mcp`) — https://policylayer.com/tools/jjpxdev-unreal-mcp.md - Install: `npx -y @jjpxdev/unreal-mcp` - Homepage: https://www.npmjs.com/package/@jjpxdev/unreal-mcp - Risk category: Write (Medium risk) - Registry record: grade F, identity unverified - Server rate-limited: no - Parameters: 4 (3 required) - Recommended policy verdict: Rate-limited ## Parameters | Parameter | Type | Required | Description | | --- | --- | --- | --- | | `default_value` | string | no | Default value as string | | `variable_name` | string | yes | Variable name | | `variable_type` | string | yes | Variable type | | `blueprint_path` | string | yes | Blueprint asset path | Parameters from the server's own tool schema. ## Example call (MCP tools/call, JSON-RPC 2.0) ```json { "jsonrpc": "2.0", "id": 1, "method": "tools/call", "params": { "name": "add_blueprint_variable", "arguments": { "variable_name": "", "variable_type": "", "blueprint_path": "" } } } ``` ## Why add_blueprint_variable is rated Medium Adding a Blueprint variable is a reversible write operation that modifies game project source code. It creates new data in the Blueprint system but can be undone (removed). The severity is medium because while it modifies project assets, the impact is scoped to a single Blueprint and the modification is non-destructive and reversible. From the tool's own definition: "Tool is named 'add_blueprint_variable' and described as 'Add a variable to a Blueprint.' This creates a new variable definition in Blueprint source code, modifying the Blueprint structure." ## Use case AI agents use add_blueprint_variable to create or update resources in Unreal, usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Unreal environment. ## Recommended policy (PolicyLayer) Verdict: **Rate-limited**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches Unreal: ```json { "version": "1", "default": "deny", "tools": { "add_blueprint_variable": { "limits": [ { "counter": "add_blueprint_variable_rate", "window": "minute", "max": 30, "scope": "grant" } ] } } } ``` ## Other tools on Unreal (126) - `delete_actor` — Destructive — https://policylayer.com/tools/jjpxdev-unreal-mcp/delete-actor.md - `delete_asset` — Destructive — https://policylayer.com/tools/jjpxdev-unreal-mcp/delete-asset.md - `delete_material_expression` — Destructive — https://policylayer.com/tools/jjpxdev-unreal-mcp/delete-material-expression.md - `remove_graph_node` — Destructive — https://policylayer.com/tools/jjpxdev-unreal-mcp/remove-graph-node.md - `build_cook_run` — Execute — https://policylayer.com/tools/jjpxdev-unreal-mcp/build-cook-run.md - `build_graph` — Execute — https://policylayer.com/tools/jjpxdev-unreal-mcp/build-graph.md - `build_plugin` — Execute — https://policylayer.com/tools/jjpxdev-unreal-mcp/build-plugin.md - `build_target` — Execute — https://policylayer.com/tools/jjpxdev-unreal-mcp/build-target.md - `call_preset_function` — Execute — https://policylayer.com/tools/jjpxdev-unreal-mcp/call-preset-function.md - `clean_project` — Execute — https://policylayer.com/tools/jjpxdev-unreal-mcp/clean-project.md - `compile_blueprint` — Execute — https://policylayer.com/tools/jjpxdev-unreal-mcp/compile-blueprint.md - `content_audit` — Execute — https://policylayer.com/tools/jjpxdev-unreal-mcp/content-audit.md - `cook_content` — Execute — https://policylayer.com/tools/jjpxdev-unreal-mcp/cook-content.md - `execute_console_command` — Execute — https://policylayer.com/tools/jjpxdev-unreal-mcp/execute-console-command.md - `execute_python` — Execute — https://policylayer.com/tools/jjpxdev-unreal-mcp/execute-python.md - `generate_lods` — Execute — https://policylayer.com/tools/jjpxdev-unreal-mcp/generate-lods.md - `package_project` — Execute — https://policylayer.com/tools/jjpxdev-unreal-mcp/package-project.md - `recompile_material` — Execute — https://policylayer.com/tools/jjpxdev-unreal-mcp/recompile-material.md - `reinit_niagara_system` — Execute — https://policylayer.com/tools/jjpxdev-unreal-mcp/reinit-niagara-system.md - `render_sequence` — Execute — https://policylayer.com/tools/jjpxdev-unreal-mcp/render-sequence.md - `reset_niagara_system` — Execute — https://policylayer.com/tools/jjpxdev-unreal-mcp/reset-niagara-system.md - `run_all_automation_tests` — Execute — https://policylayer.com/tools/jjpxdev-unreal-mcp/run-all-automation-tests.md - `run_automation_test` — Execute — https://policylayer.com/tools/jjpxdev-unreal-mcp/run-automation-test.md - `run_automation_tests_by_category` — Execute — https://policylayer.com/tools/jjpxdev-unreal-mcp/run-automation-tests-by-category.md - `run_editor_utility_blueprint` — Execute — https://policylayer.com/tools/jjpxdev-unreal-mcp/run-editor-utility-blueprint.md - `run_editor_utility_widget` — Execute — https://policylayer.com/tools/jjpxdev-unreal-mcp/run-editor-utility-widget.md - `run_gauntlet` — Execute — https://policylayer.com/tools/jjpxdev-unreal-mcp/run-gauntlet.md - `run_map_check` — Execute — https://policylayer.com/tools/jjpxdev-unreal-mcp/run-map-check.md - `run_stat_command` — Execute — https://policylayer.com/tools/jjpxdev-unreal-mcp/run-stat-command.md - `spawn_niagara_at_location` — Execute — https://policylayer.com/tools/jjpxdev-unreal-mcp/spawn-niagara-at-location.md - …and 96 more: https://policylayer.com/tools/jjpxdev-unreal-mcp.md ## For agents This record is a snapshot. Live verdicts and the full registry: - Check every server in your MCP config at once: `npx -y policylayer stack` - Vet a server before you add it: install the mcp-precheck skill — `npx skills add https://policylayer.com` (skill text: https://policylayer.com/skill.md) - Query the registry over MCP: endpoint `https://api.policylayer.com/mcp` — tools `check_mcp_server`, `check_mcp_stack`, `check_tool`, `search_registry`, `get_change_events` --- Source: the PolicyLayer MCP registry — one continuously verified record per MCP server. Full record: https://policylayer.com/registry?q=jjpxdev-unreal-mcp · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/jjpxdev-unreal-mcp