MCP Server

Russian tax calculators (VAT, USN, NDFL) and FNS fiscal-status checks via MCP.

Remote serverstreamable-http

What is the MCP MCP server?

MCP MCP server exists for a simple reason — assistants are far more useful when they can act on MCP directly instead of describing what you should do. Russian tax calculators (VAT, USN, NDFL) and FNS fiscal-status checks via MCP.

What you get

MCP-сервер (Model Context Protocol) для бухгалтеров, ИП и малого бизнеса. 6 калькуляторов работают локально и офлайн, без ключа, с формулой и ссылкой на статью НК РФ: calc_vat (НДС 20/10/0 и спец-ставки 5/7), calc_usn (доходы 6% и доходы-минус-расходы 15% с минимальным налогом и вычетом взносов), calc_insurance_ip (фиксвзносы ИП + 1% с дохода свыше 300 000 ₽, неполный год), calc_ndfl (прогрессивная шкала 2025+ 13/15/18/20/22% с разбивкой по ступеням), calc_patent (ПСН), calc_penalty (пени по ключевой ставке ЦБ, 1/300 и 1/150). Плюс get_rates — актуальные ставки и лимиты.

What the assistant can call

Once MCP is connected, these are the calls the assistant has available:

  • MCP_FNS_CALC_TOKEN — API-ключ (тариф Pro) для live-проверок статусов и свежих ставок
  • MCP_FNS_CALC_API_BASE — Базовый URL hosted-бэкенда
  • MCP_FNS_CALC_TIMEOUT — Таймаут HTTP, сек (default 30)
  • calc_vat — офлайн
  • calc_usn — офлайн
  • calc_insurance_ip — офлайн
  • calc_ndfl — офлайн
  • calc_patent — офлайн
  • calc_penalty — офлайн
  • get_rates — офлайн/hosted
  • check_selfemployed — hosted (Pro)
  • check_ip_status — hosted (Pro)

Configuration and credentials

You will need one environment variable: MCP_FNS_CALC_TOKEN. The server will not start without them, which is usually why the tools fail to appear on a first run. Keep credentials in your client's env block or a secrets manager rather than in a file you might commit.

Setting it up

Being a remote server, there is no local install. You register the endpoint with your client, authorise it once, and the tools appear.

Choosing this one

Plenty of developer tooling servers cover similar ground. The differences that matter in practice are scope of access and how much setup stands between you and a working tool call. MCP's toolset — MCP_FNS_CALC_TOKEN, MCP_FNS_CALC_API_BASE, MCP_FNS_CALC_TIMEOUT and 11 more — is a fair guide to whether it matches your workflow. It is maintained by atomno-mcp; worth a glance at recent repository activity before you build anything load-bearing on it.

We check each listing at SyncDev against the project's documentation before it goes live — if something here drifts out of date, it is a bug worth reporting.

Before you rely on it

  • Your data travels to the provider's service, so the usual questions apply about what you send and what they retain.
  • With 14 tools registered it takes up a noticeable share of the context window; turn it off in projects that never touch MCP.
  • Missing credentials fail quietly in some clients — if no tools show up, check the environment block first.
  • MCP clients confirm each tool call by default. Leave that on until you have watched what the mcp mcp server does with a few real requests.

Available tools

ToolWhat it does
MCP_FNS_CALC_TOKENAPI-ключ (тариф Pro) для live-проверок статусов и свежих ставок
MCP_FNS_CALC_API_BASEБазовый URL hosted-бэкенда
MCP_FNS_CALC_TIMEOUTТаймаут HTTP, сек (default 30)
calc_vatофлайн
calc_usnофлайн
calc_insurance_ipофлайн
calc_ndflофлайн
calc_patentофлайн
calc_penaltyофлайн
get_ratesофлайн/hosted
check_selfemployedhosted (Pro)
check_ip_statushosted (Pro)
check_disqualifiedhosted (Pro)
check_account_blockhosted (Pro)

How to install the MCP MCP server

{
  "mcpServers": {
    "fns-calc": {
      "command": "uvx",
      "args": ["atomno-mcp-fns-calc"],
      "env": {
        "MCP_FNS_CALC_TOKEN": "your-value"
      }
    }
  }
}

Add to claude_desktop_config.json, then restart Claude Desktop.

Configuration

VariableDescriptionRequired
MCP_FNS_CALC_TOKENCredential the server authenticates with.Yes

Example prompts to try

  • Use MCP to MCP FNS CALC TOKEN.
  • Use MCP to MCP FNS CALC API BASE.
  • Use MCP to MCP FNS CALC TIMEOUT.

Frequently asked questions

It connects MCP to MCP-compatible AI assistants such as Claude and Cursor, exposing 14 tools (MCP_FNS_CALC_TOKEN, MCP_FNS_CALC_API_BASE, MCP_FNS_CALC_TIMEOUT, and more) that the assistant can call on your behalf. Instead of copying data back and forth by hand, the assistant works with MCP directly.