AI agents use upload_form_file to create or update resources in GoHighLevel MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your GoHighLevel MCP Server environment.
This tool creates or modifies form data by uploading a file attachment to a custom field. It is reversible (files can typically be deleted or replaced), so it falls under Write rather than Destructive.
From the tool's definition Tool name 'upload_form_file' and description 'Upload a file to a form's custom field' indicate creating/modifying data by attaching a file to a form record.
Documented attack patterns abuse exactly the kind of access upload_form_file gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and GoHighLevel MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for upload_form_file:
{
"version": "1",
"default": "deny",
"tools": {
"upload_form_file": {
"limits": [
{
"counter": "upload_form_file_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}upload_form_file 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.
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Upload a file to a form's custom field. It is categorised as a Write tool in the GoHighLevel MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the GoHighLevel MCP Server MCP server in PolicyLayer and add a rule for upload_form_file: 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 GoHighLevel MCP Server. Nothing to install.
upload_form_file is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the upload_form_file 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.
Set action: deny in the PolicyLayer policy for upload_form_file. 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.
upload_form_file is provided by the GoHighLevel MCP Server MCP server (basicmachines-co/open-ghl-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from GoHighLevel MCP Server, 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.
64 GoHighLevel MCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.