ht_create_session · HT MCP Server MCP: Risk & Policy

WHAT IT DOES

What ht_create_session does on HT MCP Server

AI agents invoke ht_create_session to trigger actions in HT MCP Server. 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.

WHY IT NEEDS A POLICY

Why ht_create_session needs a policy

Creating a headless terminal session instantiates an execution environment capable of running arbitrary commands and shell operations. Combined with sibling tools like ht_execute_command and ht_send_keys, this session is a gateway to arbitrary code execution. Enabling a web server further expands the attack surface. The blast radius is high as it bootstraps a persistent execution context.

From the tool's definition Create a new HT (headless terminal) session... Optionally enable web server for live terminal preview

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

ht_create_session Rate-limited

ht_create_session 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": {
    "ht_create_session": {
      "limits": [
        {
          "counter": "ht_create_session_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL →

Instant setup, no code required.

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

FAQ

Questions about ht_create_session

What does the ht_create_session tool do? +

Create a new HT (headless terminal) session. Returns a session ID that can be used with other HT tools. Optionally enable web server for live terminal preview. It is categorised as a Execute tool in the HT MCP Server MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on ht_create_session? +

Register the HT MCP Server MCP server in PolicyLayer and add a rule for ht_create_session: 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 HT MCP Server. Nothing to install.

What risk level is ht_create_session? +

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

Can I rate-limit ht_create_session? +

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

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

ht_create_session is provided by the HT MCP Server MCP server (memextech/headless-terminal-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.