mypy

Runs mypy and returns structured type-check diagnostics (file, line, severity, message, code).

SERVERPython SOURCEDave-London/Pare

High RISK CLASS

Category Execute

Parameters 120 required

Recommended Rate-limitedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/io-github-dave-london-pare-python/mypy.md

WHAT IT DOES

What mypy does on Python

AI agents invoke mypy to trigger actions in Python. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call: builds kicked off, notifications sent, workflows started.

Parameter	Type	Required	Description
`path`	string	—	Project root path
`module`	string	—	Specific module to type-check (-m MODULE)
`strict`	boolean	—	Enable strict mode for thorough type checking (--strict)
`compact`	boolean	—	Prefer compact output
`exclude`	string	—	Regular expression to exclude files/directories
`package`	string	—	Specific package to type-check (-p PACKAGE)
`targets`	array	—	Files or directories to check (default: ['.'])
`configFile`	string	—	Path to mypy config file (--config-file)
`pythonPath`	string	—	Python interpreter path to use (overrides executable/PATH fallback)
`installTypes`	boolean	—	Auto-install missing type stubs (--install-types --non-interactive)
`followImports`	string	—	How to handle imports (normal/silent/skip/error)
`noIncremental`	boolean	—	Disable incremental mode (--no-incremental)

Parameters from the server's own tool schema.

RISK

Why mypy is rated High

The tool executes the mypy type-checker as an external process. While it is read-like in intent (reporting diagnostics), it actively runs a command/process whose effects depend on arguments. Misuse could trigger analysis of arbitrary files or paths, but blast radius is moderate since mypy itself is a read-only analysis tool with no write side effects.

From the tool's definition Runs mypy and returns structured type-check diagnostics

Risk signalsAccepts file system path (path) · High parameter count (22 properties)

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs mypy safely

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

mypy Rate-limited

mypy stays usable, but rate-capped: a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "mypy": {
      "limits": [
        {
          "counter": "mypy_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL → Instant setup, no code required.

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

FAQ

Questions about mypy

What does the mypy tool do? +

Runs mypy and returns structured type-check diagnostics (file, line, severity, message, code). It is categorised as a Execute tool in the Python MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

What parameters does mypy accept? +

mypy accepts 12 parameters: path, module, strict, compact, exclude, package, targets, configFile, pythonPath, installTypes, followImports, noIncremental. The full parameter table on this page comes from the server's own tool schema.

How do I enforce a policy on mypy? +

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

What risk level is mypy? +

mypy is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit mypy? +

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

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

mypy is provided by the Python MCP server (Dave-London/Pare). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

KEEP EXPLORING

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