upload_file
Upload a file to Huly storage. Provide ONE of: filePath (local file - preferred), fileUrl (fetch from URL), or data (base64 - for small files only). Returns blob ID and URL for referencing the file.
This record as markdown: /tools/dugynoo-huly-mcp/upload-file.md
What upload_file does on Huly
AI agents use upload_file to create or update resources in Huly, usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Huly environment.
Why upload_file is rated Medium
Uploading a file is a write operation that creates new data (file storage) in a reversible manner. While files could theoretically be deleted later, the upload itself is a write action.
From the tool's definition Tool description states 'Upload a file to Huly storage' and 'Returns blob ID and URL for referencing the file' — this creates and stores new data in the system.
Attacks that exploit this kind of access
The rule that runs upload_file safely
PolicyLayer is an MCP gateway: it sits between your AI agents and Huly, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For upload_file, this is the rule to start with:
upload_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.
The button opens the PolicyLayer dashboard: create your workspace, connect Huly, apply this rule, and every upload_file call is checked against it from then on.
Questions about upload_file
Upload a file to Huly storage. Provide ONE of: filePath (local file - preferred), fileUrl (fetch from URL), or data (base64 - for small files only). Returns blob ID and URL for referencing the file. It is categorised as a Write tool in the Huly MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Huly MCP server in PolicyLayer and add a rule for upload_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 Huly. Nothing to install.
upload_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_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_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_file is provided by the Huly MCP server (dugynoo/huly-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
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