Medium Risk

storage

Manage browser localStorage and sessionStorage.

How to control storage ↓

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

Medium Risk

This tool can create, update, and delete data in browser storage systems, making it a Write action. It is not Read-only (data retrieval), Execute (running code/commands), Destructive (irreversible deletion is possible but not the primary function), or Financial.

From the tool's definition Tool description states "Manage browser localStorage and sessionStorage" — these are storage mechanisms that tools can create, modify, or delete data in. The verb 'manage' encompasses write operations.

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

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

policy.json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "storage": {
      "limits": [
        {
          "counter": "storage_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

storage 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.

  1. Create a free account and register OpenChrome — nothing to install.
  2. Add this policy — paste it, or build it visually.
  3. Point your MCP client (Claude, Cursor, anything) at your gateway URL.
LIMIT THIS TOOL →

Free to start. No card required.

Go deeper

What does the storage tool do? +

Manage browser localStorage and sessionStorage. It is categorised as a Write tool in the OpenChrome MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on storage? +

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

What risk level is storage? +

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

Can I rate-limit storage? +

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

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

storage is provided by the OpenChrome MCP server (shaun0927/openchrome). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every OpenChrome tool call.

Deterministic rules across all 106 OpenChrome tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.

Free to start. No card required.

106 OpenChrome tools catalogued and risk-classified — across an index of 42,500+ MCP servers.

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