build_cook_run
Full BuildCookRun pipeline — build, cook, stage, package, and optionally deploy/run. This is the primary command for packaging a project.
This record as markdown: /tools/jjpxdev-unreal-mcp/build-cook-run.md
What build_cook_run does on Unreal
AI agents invoke build_cook_run to trigger actions in Unreal. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call: builds kicked off, notifications sent, workflows started.
| Parameter | Type | Required | Description |
|---|---|---|---|
run | boolean | — | Run after packaging |
cook | boolean | — | Cook content for target platform |
build | boolean | — | Compile C++ code |
stage | boolean | — | Stage files for packaging |
deploy | boolean | — | Deploy to device |
archive | boolean | — | Archive the build |
iterate | boolean | — | Iterative cook (faster rebuilds) |
package | boolean | — | Create distributable package |
platform | string | — | Target platform |
compressed | boolean | — | Compress pak files |
configuration | object | — | Build configuration |
additional_args | array | — | Additional UAT arguments |
Parameters from the server's own tool schema.
Why build_cook_run is rated High
This tool triggers a complete build-cook-run pipeline in Unreal Engine, which compiles code, processes assets, stages files, packages the project, and can deploy/run the result. While not destructive (data remains intact), it executes external operations whose effects depend on configuration arguments and can modify the local filesystem and potentially remote systems if deployment is triggered.
From the tool's definition Tool performs 'Full BuildCookRun pipeline — build, cook, stage, package, and optionally deploy/run' which executes a complex multi-stage compilation and deployment process with external effects.
Risk signalsHigh parameter count (12 properties)
Attacks that exploit this kind of access
The rule that runs build_cook_run safely
PolicyLayer is an MCP gateway: it sits between your AI agents and Unreal, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For build_cook_run, this is the rule to start with:
build_cook_run stays usable, but rate-capped: a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.
The button opens the PolicyLayer dashboard: create your workspace, connect Unreal, apply this rule, and every build_cook_run call is checked against it from then on.
Questions about build_cook_run
Full BuildCookRun pipeline — build, cook, stage, package, and optionally deploy/run. This is the primary command for packaging a project. It is categorised as a Execute tool in the Unreal MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
build_cook_run accepts 12 parameters: run, cook, build, stage, deploy, archive, iterate, package, platform, compressed, configuration, additional_args. The full parameter table on this page comes from the server's own tool schema.
Register the Unreal MCP server in PolicyLayer and add a rule for build_cook_run: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Unreal. Nothing to install.
build_cook_run is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.
Yes. Add a rate_limit block to the build_cook_run rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for build_cook_run. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
build_cook_run is provided by the Unreal MCP server (@jjpxdev/unreal-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
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