Scrapbook: MCP Tooling & Security Design

MCP Server Interface

1. `search_events(query: string) -> list<EventSummary>`

• Free‑text search over event payloads (simple LIKE or future vector). Returns matching events with id, type, timestamp, entity, snippet.

• Returns the pre‑computed natural‑language summary for that date, or generates on‑the‑fly if missing.

• Returns flagged anomalies in date range, with explanations.

• Full timeline for given entity.

• Generate ad‑hoc reports; e.g., export all sales for a date range.

Security, Compliance, Politics Checklist

IT approval concerns for on‑prem software:

• Minimum privileges:


• DB: read‑only replica account for MySQL; `REPLICATION SLAVE` + `SELECT` on captured tables. If using native CDC for SQL Server, need `db_owner` to enable CDC initially, then a read‑only account for the poller. We’ll document that enabling CDC is a one‑time DBA task; afterwards the poller uses `SELECT` on CDC tables.


• Network layout:


• All components communicate over localhost or a dedicated Docker bridge network. No inbound ports from outside the host, except optionally a UI port (HTTPS) behind corporate firewall.


• Encryption:


• In‑transit: DB connection uses TLS if available (MySQL can use `REQUIRE SSL`). Overlay services can use HTTPS internally if desired, but localhost plain is acceptable.


• At rest: SQLite database file stored with restricted permissions (0600). Optional disk encryption at host level (customer’s responsibility).


• Audit logging of the overlay itself:


• The overlay’s own operations (ingest requests, errors, admin actions) are logged to a local rotating file with size limit. Logs are not sent to external parties.


• Data minimization:


• Before any data leaves the host (optional cloud LLM), we strip columns marked as PII (e.g., `users.username`, `customers.*`). This is configurable via `mask_columns` list per table.


• If using on‑prem LLM (Ollama), no data leaves; but we still mask to avoid accidental exposure in logs.


• On‑prem vs cloud LLM:


• Default: on‑prem Ollama (e.g., `llama3.2:3b` or Mistral 7B). Requires CPU or modest GPU.


• Optional: cloud LLM (OpenRouter, Anthropic) for higher quality summaries if customer allowlists outbound traffic and signs data processing agreement.


• Recommendation for pilot: start with on‑prem to simplify compliance; switch to cloud only if quality unacceptable and customer agrees.

• The overlay is read‑only from the DB’s perspective (except optional offset storage in source for Maxwell; avoid that). IT likes that it doesn’t modify production data.


• Installation should be a single command (Docker Compose) and should not require changes to the application. That’s the main selling point.

Pilot Proposal Outline (Low‑Risk)

Scope:

• MySQL instance with a copy of the customer’s schema (minus PII) and synthetic realistic data.


• Overlay runs in a VM or Docker host inside the customer’s network.


• No changes to existing applications.

• Daily summary generated without errors.


• At least 3 anomaly alerts per week that are verified as true positives by customer staff.


• Entity traceability queries return results < 2 seconds.


• Auditor feedback: >7/10 on usefulness.

MCP Tool Definitions (Detailed)

search_events

{

  "jsonrpc": "2.0",

  "method": "audit.search_events",

  "params": { "query": "inventory theft" },

  "id": 1

}

{

  "jsonrpc": "2.0",

  "result": {

    "events": [

      {

        "event_id": "...",

        "type": "inventory.adjustment",

        "timestamp": "2026-02-15T22:30:00Z",

        "entity_type": "product",

        "entity_id": "123",

        "snippet": "adjustment reason=THEFT, qty -50"

      }

    ]

  },

  "id": 1

}

get_daily_summary

get_anomalies

trace_entity

export_report