write_secret

Write secret to Vault

SERVERNcp SOURCE@portel/ncp

Medium RISK CLASS

Category Write

Parameters 00 required

Recommended Rate-limitedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/io-github-portel-dev-ncp/write-secret.md

WHAT IT DOES

What write_secret does on Ncp

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

RISK

Why write_secret is rated Medium

This tool creates or modifies secrets in a vault system. While not destructive (secrets can be updated/overwritten), it is a Write operation that stores sensitive authentication credentials. Severity is high because misuse could compromise security credentials that provide access to other systems, representing significant blast radius despite being reversible.

From the tool's definition Tool name is 'write_secret' and description states 'Write secret to Vault'. The verb 'Write' combined with 'secret' and 'Vault' indicates creation or modification of sensitive credential data.

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs write_secret safely

PolicyLayer is an MCP gateway: it sits between your AI agents and Ncp, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For write_secret, this is the rule to start with:

write_secret Rate-limited

write_secret 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": {
    "write_secret": {
      "limits": [
        {
          "counter": "write_secret_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect Ncp, apply this rule, and every write_secret call is checked against it from then on.

FAQ

Questions about write_secret

What does the write_secret tool do? +

Write secret to Vault. It is categorised as a Write tool in the Ncp MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on write_secret? +

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

What risk level is write_secret? +

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

Can I rate-limit write_secret? +

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

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

write_secret is provided by the Ncp MCP server (@portel/ncp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

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