Copy a Bazel-built macOS .app into /Applications or a custom directory.
AI agents use bazel_macos_install to create or update resources in XcodeBazelMCP — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your XcodeBazelMCP environment.
This tool creates or modifies files on disk by copying applications into /Applications or custom directories. While not destructive (files can be uninstalled), it irreversibly changes system state by installing software that may affect other applications, security posture, or system behavior.
From the tool's definition Tool description states it will 'Copy a Bazel-built macOS .app into /Applications or a custom directory' — this modifies the filesystem by creating or updating application files in system-managed locations.
Documented attack patterns abuse exactly the kind of access bazel_macos_install gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and XcodeBazelMCP, and nothing reaches the server without passing your rules. This is the rule we recommend for bazel_macos_install:
{
"version": "1",
"default": "deny",
"tools": {
"bazel_macos_install": {
"limits": [
{
"counter": "bazel_macos_install_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}bazel_macos_install stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.
Free to start. No card required.
Copy a Bazel-built macOS .app into /Applications or a custom directory. It is categorised as a Write tool in the XcodeBazelMCP MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the XcodeBazel MCP server in PolicyLayer and add a rule for bazel_macos_install: 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 XcodeBazelMCP. Nothing to install.
bazel_macos_install is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the bazel_macos_install 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 bazel_macos_install. 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.
bazel_macos_install is provided by the XcodeBazel MCP server (xcodebazelmcp/xcodebazelmcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from XcodeBazelMCP, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
117 XcodeBazelMCP tools catalogued and risk-classified — across an index of 43,000+ MCP servers.