# What MCP means for your money

> The Model Context Protocol in plain words, how Claude and ChatGPT use it to reach your data, and what a good financial MCP server should and shouldn't let an agent do.

Canonical: https://usetruenote.com/guides/what-is-mcp-for-your-money

MCP, the Model Context Protocol, is how AI assistants reach outside their chat: a server offers *tools* (named functions with typed arguments), and the assistant calls them when a question needs them. Claude's connectors and ChatGPT's apps are MCP clients. Truenote is an MCP server.

## What that looks like

You ask Claude "how is this month going against the plan?" Claude sees it has a tool called `plan_vs_actual` on a server called Truenote, calls it, gets a compact answer (bills paid, set aside, everyday spending by category against the trailing average, what's left of take-home), and writes you a reply. If you then say "charge the vet visit to Pets and make it a rule", it calls `resolve_review_item` and `create_bucket_rule`, which need write access, so Truenote asks you to allow that first.

## What a financial MCP server should do

- **Authenticate properly.** OAuth 2.1 with PKCE and a consent screen that shows what the client will see. Truenote's discovers everything from the URL; no keys to paste.
- **Scope narrowly.** Separate scopes for accounts, transactions, investments, liabilities, context and documents, plus the ability to hide specific accounts or a business from one agent. Read-only by default.
- **Give agent-shaped answers.** Summaries first (the overview, the plan, the tax projection), raw rows on request, so the assistant doesn't spend its context on five thousand transactions.
- **Never move money.** The server should have no way to, not merely a policy against it.
- **Leave receipts.** Every call in a log the person can read, with revoke one click away.

## What it shouldn't

Hold a bank login (Plaid Link exists so it doesn't have to), hand out long-lived tokens, let an agent change its own permissions, or hide what it did.

## Try it

Truenote's server is `https://app.usetruenote.com/mcp`. [Connect Claude](/connect/claude), [ChatGPT](/connect/chatgpt) or [Claude Code](/connect/claude-code); the [tool reference](/docs/mcp-tools) lists every tool with its scopes and arguments.