Honest Mbank Parser

Local MCP server that parses mBank CSV operation exports — the exact file you can download from the mBank web app under "Historia" → "Eksportuj do CSV". Runs entirely offline. Nothing leaves your machine.

Part of the honest-mcp family of small, auditable, local-first MCP servers.

Why

Anyone using mBank in Poland — private, JDG, sp. z o.o. — does the same monthly ritual:

1. Log into mBank, download the CSV.
2. Open in Excel, squint at Polish-locale amounts (space-thousands, comma-decimals, PLN suffix).
3. Filter by date, sum by category for VAT / income tax reconciliation.

This server automates step 2 and 3 through your AI. You keep your bank data on disk; the AI just calls a tool that reads and filters it locally.

Zero network calls. The requirements.txt is one line — the MCP SDK. No dependency footprint to audit.

Features

Three tools:

• read_statement_header — quick preview of a file: client name, date range, listed accounts, inflow/outflow totals, operation count. No operation rows loaded.
• list_operations — parse + filter operations. Combine any of: date_from, date_to, category, account, contains (description substring), min_amount, max_amount, limit.
• summarize_operations — aggregate by category, account, or month. Returns count, inflow, outflow, net per bucket plus grand totals.

Amounts come back as signed floats (negative = expense), currency separate. Polish-locale numbers (-3 283,33 PLN) and non-breaking-space thousand separators are handled.

Supported files

• ✅ CSV export from mBank web banking ("Historia operacji" → "Eksportuj do CSV")
• ❌ PDF statements — mBank's layout varies too much per statement type for reliable parsing. Skipped intentionally.

Requirements

• Python 3.10+

Setup

git clone https://github.com/bartosz-kuc/honest-mbank-parser-mcp.git
cd honest-mbank-parser-mcp
python3 -m venv venv
./venv/bin/pip install -r requirements.txt

On Windows use python instead of python3, and venv\Scripts\pip and venv\Scripts\python instead of venv/bin/pip and venv/bin/python (here and in the configs below).

Register with Claude Code:

claude mcp add mbank /absolute/path/to/venv/bin/python /absolute/path/to/server.py

Claude Desktop claude_desktop_config.json:

{
  "mcpServers": {
    "mbank": {
      "command": "/absolute/path/to/venv/bin/python",
      "args": ["/absolute/path/to/server.py"]
    }
  }
}

Example usage

"How much did I spend on 'Ubezpieczenia' in Q2?"

summarize_operations(file_path=".../lista_operacji.csv", group_by="category", date_from="2026-04-01", date_to="2026-06-30") → totals per category, including "Ubezpieczenia".

"List all incoming transfers over 10 000 PLN this year."

list_operations(file_path=".../lista_operacji.csv", min_amount=10000, date_from="2026-01-01")

"Show me every card purchase mentioning Anthropic."

list_operations(file_path=".../lista_operacji.csv", contains="ANTHROPIC")

Data flow

Your AI client
     ↕  MCP stdio
This server (Python, on your machine)
     ↕  local filesystem
Your mBank CSV

No HTTP, no external service — the server has no requests or httpx dependency at all.

Author

Bartosz Kuć — Warsaw-based developer, JDG owner running skanfirmy.pl.

• GitHub: https://github.com/bartosz-kuc

• Email: [email protected]

Consulting

Available for consulting on Polish tax and business integrations (KSeF, GUS/NFZ/GIOŚ APIs, mBank data), MCP server design, and AI-assisted tooling for JDGs and small teams. See skanfirmy.pl/uslugi for productized packages (audit 3k PLN, setup 8-15k PLN, retainer 2-4k PLN/mo), or reach out via email.

License

MIT — see LICENSE.

Related

• Part of the honest-mcp family — see the family index.