ksef_add_source_document · KSeF MCP: Risk & Policy

WHAT IT DOES

What ksef_add_source_document does on KSeF MCP

AI agents use ksef_add_source_document to create or update resources in KSeF MCP — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your KSeF MCP environment.

WHY IT NEEDS A POLICY

Why ksef_add_source_document needs a policy

This tool creates a new index entry and persists a document in the KSeF system. It is reversible (documents can typically be removed or re-indexed), so it does not qualify as Destructive. The action modifies the invoice/document management state by storing and indexing, making it a Write operation.

From the tool's definition Tool description states 'Store a local source document and index it' — 'store' and 'index' are write operations that create or modify data in the system.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

ksef_add_source_document Rate-limited

ksef_add_source_document 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.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "ksef_add_source_document": {
      "limits": [
        {
          "counter": "ksef_add_source_document_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL →

Instant setup, no code required.

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

FAQ

Questions about ksef_add_source_document

What does the ksef_add_source_document tool do? +

Store a local source document and index it for advisory retrieval. It is categorised as a Write tool in the KSeF MCP MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on ksef_add_source_document? +

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

What risk level is ksef_add_source_document? +

ksef_add_source_document is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit ksef_add_source_document? +

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

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

ksef_add_source_document is provided by the KSeF MCP server (olegtyshcneko/ksef-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.