store_credential

THE RISK

Medium Risk

Why store_credential needs a policy

This tool writes sensitive credential data (usernames, passwords) into an encrypted vault. It is a Write operation because it creates or stores new records reversibly (credentials can be deleted or updated).

From the tool's definition 'Securely store login credentials' — creates/writes new credential data; 'encrypted at rest and wiped from memory after use' confirms persistent storage write operation

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

POLICY

How to control store_credential

PolicyLayer is an MCP gateway — it sits between your AI agents and Chrome MCP Server (Security Hardened), and nothing reaches the server without passing your rules. This is the rule we recommend for store_credential:

policy.json

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

store_credential 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 Chrome MCP Server (Security Hardened) — 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 Chrome MCP Server (Security Hardened) tools

Destructive delete_credential Permanently delete a stored credential. Execute secure_login Perform a secure login using stored credentials. Automatically fills in username/email and Write update_credential Update an existing credential. Only provided fields will be updated. Read get_credential Get a specific credential by ID. Returns metadata only - use secure_login for authenticati Read get_vault_status Get the status of the credential vault including encryption configuration. Read list_credentials List all stored credentials. Returns metadata only - no passwords or API keys are exposed.

All 7 Chrome MCP Server (Security Hardened) 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 store_credential

What does the store_credential tool do? +

Securely store login credentials with post-quantum encryption. Credentials are encrypted at rest and wiped from memory after use. It is categorised as a Write tool in the Chrome MCP Server (Security Hardened) MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on store_credential? +

Register the Chrome MCP Server (Security Hardened) MCP server in PolicyLayer and add a rule for store_credential: 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 Chrome MCP Server (Security Hardened). Nothing to install.

What risk level is store_credential? +

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

Can I rate-limit store_credential? +

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

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

store_credential is provided by the Chrome MCP Server (Security Hardened) MCP server (pantheon-security/chrome-mcp-secure). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every Chrome MCP Server (Security Hardened) tool call.

Start from Chrome MCP Server (Security Hardened), add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

CHECK YOUR STACK →