execute_in_glyphs

THE RISK

High Risk

Why execute_in_glyphs needs a policy

The tool name 'execute_in_glyphs' explicitly indicates execution of code or commands within GlyphsApp. While the description is empty (lowering confidence slightly), the server's stated purpose of providing direct programmatic control over font data in a live editor, combined with 'execute' in the tool name, indicates this triggers external operations whose effects depend on arguments.

From the tool's definition Tool name 'execute_in_glyphs' combined with server description stating the MCP bridge 'lets Claude, Cursor, or any MCP client read and write font data directly in GlyphsApp' and operates 'bidirectional, real-time, live in the editor.' The name…

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

POLICY

How to control execute_in_glyphs

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

policy.json

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

execute_in_glyphs 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.

Create a free account and register Glyphs — nothing to install.
Add this policy — paste it, or build it visually.
Point your MCP client (Claude, Cursor, anything) at your gateway URL.

RATE-LIMIT THIS TOOL →

Free to start. No card required.

EXPLORE

Related tools and policies

More Glyphs tools

Destructive delete_glyph Delete a glyph from the font. This cannot be undone via MCP. Destructive delete_kerning_pair Delete a kerning pair. Execute rmx_scale rmx_scale Write duplicate_glyph Duplicate a glyph (all layers and paths) under a new name. Write create_glyph create_glyph Write rename_glyph Rename a glyph. Fails if new_name already exists. Write set_feature_code Create or update an OpenType feature. Write set_glyph_color Set the color label of a glyph in the font view.

All 41 Glyphs tools →

Execute tools on other servers

Android Forensics ADB MCP Server adb_shell_command EMBA-MCP run_emba_scan Frida Game Hacking MCP remove_breakpoint Procmon request_elevation

Go deeper

High-risk tools in Glyphs → Every high-risk tool this server exposes, in one view.
All high-risk MCP tools → Every high-risk tool across the catalogue, and the policy pattern that contains them.
The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Agent sandbox → Bounding what an agent can execute and where the boundary should sit.
Least privilege for MCP → Granting agents the minimum tool surface the task needs.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

Questions about execute_in_glyphs

What does the execute_in_glyphs tool do? +

execute_in_glyphs. It is categorised as a Execute tool in the Glyphs MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on execute_in_glyphs? +

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

What risk level is execute_in_glyphs? +

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

Can I rate-limit execute_in_glyphs? +

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

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

execute_in_glyphs is provided by the Glyphs MCP server (nmassi/glyphs-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every Glyphs tool call.

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

CHECK YOUR STACK →