redis_publish · RedisNexus MCP: Risk & Policy

WHAT IT DOES

What redis_publish does on RedisNexus

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

WHY IT NEEDS A POLICY

Why redis_publish needs a policy

Publishing a message to a Pub/Sub channel modifies system state (enqueues a message) but is reversible and does not permanently delete or corrupt data. It does not execute arbitrary code or move financial resources. The severity is medium rather than low because publishing to a Pub/Sub channel could trigger downstream subscribers to perform unintended actions if an AI agent misuses it, creating moderate blast radius.

From the tool's definition Tool name 'redis_publish' and description 'Publish a message to a Redis Pub/Sub channel' indicate the tool creates/sends data to a message queue, which is a reversible write operation.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

redis_publish Rate-limited

redis_publish 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": {
    "redis_publish": {
      "limits": [
        {
          "counter": "redis_publish_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 RedisNexus, so you can run agents against it safely.

FAQ

Questions about redis_publish

What does the redis_publish tool do? +

Publish a message to a Redis Pub/Sub channel. Subscribers listening on. It is categorised as a Write tool in the RedisNexus MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on redis_publish? +

Register the RedisNexus MCP server in PolicyLayer and add a rule for redis_publish: 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 RedisNexus. Nothing to install.

What risk level is redis_publish? +

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

Can I rate-limit redis_publish? +

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

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

redis_publish is provided by the RedisNexus MCP server (rajkumar-madhu/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.