Create a new React application
AI agents invoke create-react-app to trigger actions in Https://github Com/Streen9/react. 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.
Creating a React app involves executing shell commands (e.g., npx create-react-app or similar), writing files, and modifying the filesystem. This goes beyond a simple Write because it triggers external tooling execution and spawns processes. The blast radius is high since it can write arbitrary files to the host system and execute npm/npx commands.
From the tool's definition "Create a new React application" — initializes a new project, runs scaffolding commands, creates files and directory structures on the host filesystem
Documented attack patterns abuse exactly the kind of access create-react-app gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Https://github Com/Streen9/react, and nothing reaches the server without passing your rules. This is the rule we recommend for create-react-app:
{
"version": "1",
"default": "deny",
"tools": {
"create-react-app": {
"limits": [
{
"counter": "create-react-app_rate",
"window": "minute",
"max": 10,
"scope": "grant"
}
]
}
}
}create-react-app 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.
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Create a new React application. It is categorised as a Execute tool in the Https://github Com/Streen9/react MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
Register the Https://github Com/Streen9/react MCP server in PolicyLayer and add a rule for create-react-app: 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 Https://github Com/Streen9/react. Nothing to install.
create-react-app 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 create-react-app 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 create-react-app. 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.
create-react-app is provided by the Https://github Com/Streen9/react MCP server (kalivaraprasad-gonapa/react-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Https://github Com/Streen9/react, 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.
9 Https://github Com/Streen9/react tools catalogued and risk-classified — across an index of 43,000+ MCP servers.