patch_line · TermPipe MCP: Risk & Policy

WHAT IT DOES

What patch_line does on TermPipe MCP

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

WHY IT NEEDS A POLICY

Why patch_line needs a policy

The name 'patch_line' most naturally refers to modifying a specific line in a file, which is a reversible write operation. However, without explicit documentation, there is some uncertainty whether this modifies, replaces, or conditionally updates lines.

From the tool's definition Tool name 'patch_line' suggests modification of file contents. Server description confirms 'manage files' capability. Sibling tools include 'append_file' (Write) and 'analyze_file_structure' (Read), indicating a file management context.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

patch_line Rate-limited

patch_line 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": {
    "patch_line": {
      "limits": [
        {
          "counter": "patch_line_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches TermPipe MCP, so you can run agents against it safely.

FAQ

Questions about patch_line

What does the patch_line tool do? +

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

How do I enforce a policy on patch_line? +

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

What risk level is patch_line? +

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

Can I rate-limit patch_line? +

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

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

patch_line is provided by the TermPipe MCP server (wbind-core/termpipe-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.