Generate a Web3 backend using NestJS or Express with viem integration for Arbitrum. Includes contract interaction services, API endpoints, and TypeScript configuration.
AI agents use generate_backend to create or update resources in ARBuilder — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your ARBuilder environment.
This tool generates code artifacts (backend service code, configuration files, API endpoints). It creates new files/content but does not execute code, delete data, or move money. The primary action is code generation/writing. Severity is medium because generated backend code with contract interaction services could be deployed and interact with live contracts if misused, but the tool itself only produces code.
From the tool's definition Generate a Web3 backend using NestJS or Express with viem integration for Arbitrum. Includes contract interaction services, API endpoints, and TypeScript configuration.
Documented attack patterns abuse exactly the kind of access generate_backend gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and ARBuilder, and nothing reaches the server without passing your rules. This is the rule we recommend for generate_backend:
{
"version": "1",
"default": "deny",
"tools": {
"generate_backend": {
"limits": [
{
"counter": "generate_backend_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}generate_backend 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.
Generate a Web3 backend using NestJS or Express with viem integration for Arbitrum. Includes contract interaction services, API endpoints, and TypeScript configuration. It is categorised as a Write tool in the ARBuilder MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the ARBuilder MCP server in PolicyLayer and add a rule for generate_backend: 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 ARBuilder. Nothing to install.
generate_backend 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 generate_backend 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 generate_backend. 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.
generate_backend is provided by the ARBuilder MCP server (quantum3-labs/arbuilder). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from ARBuilder, 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.
18 ARBuilder tools catalogued and risk-classified — across an index of 43,000+ MCP servers.