List all knowledge bases accessible via Open WebUI API
AI agents call list_knowledge_bases to retrieve information from Open Webui Knowledge without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool performs a data retrieval operation (listing) with no side effects. It queries the Open WebUI API to enumerate available knowledge bases, making it a straightforward Read category tool. The severity is low because listing knowledge bases reveals only structural information about available resources, not sensitive data content itself, and causes no changes to the system.
From the tool's definition Tool name: list_knowledge_bases. Description: "List all knowledge bases accessible via Open WebUI API". The verb 'list' is a read operation that retrieves metadata about available knowledge bases without modifying, executing, or deleting anything.
Documented attack patterns abuse exactly the kind of access list_knowledge_bases gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Open Webui Knowledge, and nothing reaches the server without passing your rules. This is the rule we recommend for list_knowledge_bases:
{
"version": "1",
"default": "deny",
"tools": {
"list_knowledge_bases": {}
}
}list_knowledge_bases is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
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List all knowledge bases accessible via Open WebUI API. It is categorised as a Read tool in the Open Webui Knowledge MCP Server, which means it retrieves data without modifying state.
Register the Open Webui Knowledge MCP server in PolicyLayer and add a rule for list_knowledge_bases: 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 Open Webui Knowledge. Nothing to install.
list_knowledge_bases is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the list_knowledge_bases 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 list_knowledge_bases. 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.
list_knowledge_bases is provided by the Open Webui Knowledge MCP server (ronasit/open-webui-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Open Webui Knowledge, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
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3 Open Webui Knowledge tools catalogued and risk-classified — across an index of 43,000+ MCP servers.