index_transactions · Marqeta DiVA API MCP Server MCP

WHAT IT DOES

What index_transactions does on Marqeta DiVA API MCP Server

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

WHY IT NEEDS A POLICY

Why index_transactions needs a policy

This tool reads transactions from the DiVA API and writes/indexes them into local storage systems (SQLite database and ChromaDB vector store). It creates or updates data in local storage, making it a Write operation. It is reversible in that data can be cleared (the sibling 'clear_index' tool suggests this).

From the tool's definition Sync transactions from DiVA to local storage (SQLite + ChromaDB)

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

index_transactions Rate-limited

index_transactions 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": {
    "index_transactions": {
      "limits": [
        {
          "counter": "index_transactions_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 Marqeta DiVA API MCP Server, so you can run agents against it safely.

FAQ

Questions about index_transactions

What does the index_transactions tool do? +

Sync transactions from DiVA to local storage (SQLite + ChromaDB). It is categorised as a Write tool in the Marqeta DiVA API MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on index_transactions? +

Register the Marqeta DiVA API MCP Server MCP server in PolicyLayer and add a rule for index_transactions: 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 Marqeta DiVA API MCP Server. Nothing to install.

What risk level is index_transactions? +

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

Can I rate-limit index_transactions? +

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

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

index_transactions is provided by the Marqeta DiVA API MCP Server MCP server (zvika-finally/marqeta-diva-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.