kv_set

THE RISK

Medium Risk

Why kv_set needs a policy

This tool creates or modifies key-value pairs reversibly. It does not execute arbitrary code, delete data irreversibly, or move money. The 'optional TTL' feature means data can expire automatically, but this is still a reversible write operation.

From the tool's definition Tool name 'kv_set' and description 'Set key-value pair in a space with optional TTL and keyspace' indicate creation or modification of data in key-value storage.

Documented attack patterns abuse exactly the kind of access kv_set gives an agent:

POLICY

How to control kv_set

PolicyLayer is an MCP gateway — it sits between your AI agents and Codehooks Io MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for kv_set:

policy.json

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

kv_set 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.

Create a free account and register Codehooks Io MCP Server — nothing to install.
Add this policy — paste it, or build it visually.
Point your MCP client (Claude, Cursor, anything) at your gateway URL.

LIMIT THIS TOOL →

Free to start. No card required.

EXPLORE

Related tools and policies

More Codehooks Io MCP Server tools

Destructive drop_collection Delete a collection Destructive drop_index Remove field(s) from a query index Destructive file_delete Delete a file from server Destructive kv_del Delete key-value pair in a space. Destructive remove_schema Remove JSON schema from a collection Write uncap_collection Remove cap from a collection Write add_schema Add a JSON schema to a collection. Provide the schema content as a JSON string. Write cap_collection Cap a collection

All 20 Codehooks Io MCP Server tools →

Write tools on other servers

M-Team MCP Server download_torrent YouTube MCP Server generate_video_title Android Forensics ADB MCP Server combine_reports 0xarchive web3_signup

Go deeper

The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Argument validation → Checking tool call arguments against schema and policy before they run.
Scoped token → Per-person credentials that grant a defined subset of servers and tools.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

Questions about kv_set

What does the kv_set tool do? +

Set key-value pair in a space with optional TTL and keyspace. It is categorised as a Write tool in the Codehooks Io 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 kv_set? +

Register the Codehooks Io MCP Server MCP server in PolicyLayer and add a rule for kv_set: 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 Codehooks Io MCP Server. Nothing to install.

What risk level is kv_set? +

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

Can I rate-limit kv_set? +

Yes. Add a rate_limit block to the kv_set 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 kv_set completely? +

Set action: deny in the PolicyLayer policy for kv_set. 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 kv_set? +

kv_set is provided by the Codehooks Io MCP Server MCP server (restdb/codehooks-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every Codehooks Io MCP Server tool call.

Start from Codehooks Io MCP Server, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

CHECK YOUR STACK →