ALWAYS use this tool when asked about architecture drift, what changed between two scans, or comparing codebase snapshots. Returns new/removed/modified files, new/removed functions, and new call edges between two git SHAs.
AI agents call nm_diff to retrieve information from NOMIK without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
nm_diff is a comparative analysis tool that queries and retrieves information about changes between two code states. It has no side effects—it does not create, modify, delete, or execute anything. It simply reports differences in the knowledge graph. The most severe action is reading/comparing existing data, which falls squarely under the Read category.
From the tool's definition Tool returns new/removed/modified files, new/removed functions, and new call edges between two git SHAs. It performs comparison and analysis of codebase snapshots without modifying or executing code.
Documented attack patterns abuse exactly the kind of access nm_diff gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and NOMIK, and nothing reaches the server without passing your rules. This is the rule we recommend for nm_diff:
{
"version": "1",
"default": "deny",
"tools": {
"nm_diff": {}
}
}nm_diff is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
Free to start. No card required.
ALWAYS use this tool when asked about architecture drift, what changed between two scans, or comparing codebase snapshots. Returns new/removed/modified files, new/removed functions, and new call edges between two git SHAs. It is categorised as a Read tool in the NOMIK MCP Server, which means it retrieves data without modifying state.
Register the NOMIK MCP server in PolicyLayer and add a rule for nm_diff: 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 NOMIK. Nothing to install.
nm_diff is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the nm_diff 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 nm_diff. 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.
nm_diff is provided by the NOMIK MCP server (willfreed1/nomik). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from NOMIK, 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.
21 NOMIK tools catalogued and risk-classified — across an index of 43,000+ MCP servers.