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shellcheck

Runs ShellCheck (shell script linter) and returns structured diagnostics (file, line, column, rule, severity, message).

How to control shellcheck ↓

What shellcheck does on Http

AI agents invoke shellcheck to trigger actions in Http. 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.

High Risk

Why shellcheck needs a policy

The tool executes an external process (ShellCheck) against provided shell script content or files. While it is a read-only linter that doesn't modify data, it actively runs a program and its effects depend on the arguments supplied. This fits the Execute category.

From the tool's definition Runs ShellCheck (shell script linter) and returns structured diagnostics

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

How to control shellcheck

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

policy.json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "shellcheck": {
      "limits": [
        {
          "counter": "shellcheck_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

shellcheck 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.

  1. Create a free account and register Http — 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.
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Related tools and policies

Go deeper

Questions about shellcheck

What does the shellcheck tool do? +

Runs ShellCheck (shell script linter) and returns structured diagnostics (file, line, column, rule, severity, message). It is categorised as a Execute tool in the Http MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on shellcheck? +

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

What risk level is shellcheck? +

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

Can I rate-limit shellcheck? +

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

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

shellcheck is provided by the Http MCP server (@paretools/http). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every Http tool call.

Start from Http, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

Free to start. No card required.

202 Http tools catalogued and risk-classified — across an index of 43,000+ MCP servers.

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