yapy_set_agent_key · Yapy MCP Server MCP: Risk & Policy

WHAT IT DOES

What yapy_set_agent_key does on Yapy MCP Server

AI agents use yapy_set_agent_key to create or update resources in Yapy MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Yapy MCP Server environment.

WHY IT NEEDS A POLICY

Why yapy_set_agent_key needs a policy

This tool modifies session-level configuration by storing/setting an API key credential. While it doesn't create or delete persistent data in the platform itself, it does mutate the runtime state of the MCP session in a reversible manner. It is Write rather than Execute because it does not trigger external operations or run code—it simply stores a credential.

From the tool's definition Tool description states 'Set the YAPY_AGENT_KEY in the current MCP server session', which modifies configuration state. This is a reversible state change (the key can be updated or replaced in subsequent calls).

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

yapy_set_agent_key Rate-limited

yapy_set_agent_key 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.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "yapy_set_agent_key": {
      "limits": [
        {
          "counter": "yapy_set_agent_key_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Yapy MCP Server, so you can run agents against it safely.

FAQ

Questions about yapy_set_agent_key

What does the yapy_set_agent_key tool do? +

Set the YAPY_AGENT_KEY in the current MCP server session. Call this immediately after you receive your API key so you can start using other tools without needing to restart your environment. It is categorised as a Write tool in the Yapy MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on yapy_set_agent_key? +

Register the Yapy MCP Server MCP server in PolicyLayer and add a rule for yapy_set_agent_key: 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 Yapy MCP Server. Nothing to install.

What risk level is yapy_set_agent_key? +

yapy_set_agent_key is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit yapy_set_agent_key? +

Yes. Add a rate_limit block to the yapy_set_agent_key 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.

How do I block yapy_set_agent_key completely? +

Set action: deny in the PolicyLayer policy for yapy_set_agent_key. 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.

What MCP server provides yapy_set_agent_key? +

yapy_set_agent_key is provided by the Yapy MCP Server MCP server (lnicolaie/yapybot-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.