mcp-skatteetaten

A comprehensive Model Context Protocol (MCP) server for Skatteetaten — the Norwegian Tax Administration.

Exposes 35+ tools covering all major Skatteetaten APIs so that LLM agents and AI assistants can query tax data, submit reports, look up population register information, validate VAT returns, and more — all authenticated via Maskinporten.

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Covered APIs

API	Description
Inntekt	Employer-reported income (monthly/yearly)
Beregnet Skatt	Calculated tax: trinnskatt, trygdeavgift, fellesskatt
Summert Skattegrunnlag	Aggregated tax basis (income, assets, deductions)
Skattemelding	Tax return retrieval and validation
Restanse	Outstanding tax debts and arrears
Formuesobjekt Fast Eiendom	Property ownership and classification
Formuesgrunnlag Eiendomsskatt	Property value basis for property tax
Folkeregisteret	Population register: lookup, search, event feed
A-Melding	Wage/personnel reporting (replaces Altinn A02)
A-Melding Tilbakemelding	Feedback for submitted A-meldinger
MVA-Melding	VAT return validation
Skattekorttilarbeidsgiver	Tax deduction cards for employers
Krav og Betalinger	Claims and payment history (Fremtidens innkreving)
Tredjepartsopplysninger	Third-party data reporting (banks, brokers, etc.)

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Prerequisites

1. A Norwegian organisation with an organisation number
2. Access to Maskinporten with a registered client and private key
3. Rights packages (rettighetspakker) granted by Skatteetaten for the APIs you need
4. Node.js 20+

Getting Access

• Register your Maskinporten client at Samarbeidsportalen
• Request the relevant scopes from Skatteetaten at skatteetaten.no/deling
• For test environments, use Tenor test data to get synthetic identifiers

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Installation

npm install
npm run build

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Configuration

Copy .env.example to .env and fill in your credentials:

cp .env.example .env

Variable	Required	Description
MASKINPORTEN_CLIENT_ID	Yes	Your Maskinporten client ID
MASKINPORTEN_PRIVATE_KEY_PATH	Yes*	Path to your RSA private key PEM file
MASKINPORTEN_PRIVATE_KEY_JWK	Yes*	Or provide the JWK as a JSON string
SKATTEETATEN_ENV	No	test (default) or production
MASKINPORTEN_ISSUER	No	Override Maskinporten issuer URL
MASKINPORTEN_TOKEN_ENDPOINT	No	Override token endpoint URL
FOLKEREGISTERET_AUTH_PACKAGE	No	offentlig-med-hjemmel (default), offentlig-uten-hjemmel, or privat

*Either MASKINPORTEN_PRIVATE_KEY_PATH or MASKINPORTEN_PRIVATE_KEY_JWK is required.

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Usage

With Claude Desktop

Add to your claude_desktop_config.json:

{
  "mcpServers": {
    "skatteetaten": {
      "command": "node",
      "args": ["/path/to/mcp-skatteetaten/dist/index.js"],
      "env": {
        "MASKINPORTEN_CLIENT_ID": "your-client-id",
        "MASKINPORTEN_PRIVATE_KEY_PATH": "/path/to/private-key.pem",
        "SKATTEETATEN_ENV": "test"
      }
    }
  }
}

With Claude Code

claude mcp add skatteetaten -- node /path/to/mcp-skatteetaten/dist/index.js

Or run directly:

MASKINPORTEN_CLIENT_ID=... MASKINPORTEN_PRIVATE_KEY_PATH=... npm start

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Available Tools

Income (inntekt)

Tool	Description
get_inntekt	Income for a person in a specific month
get_inntekt_for_year	All income across 12 months for a year

Tax (skatt)

Tool	Description
get_beregnet_skatt	Calculated tax breakdown
get_summert_skattegrunnlag	Aggregated tax basis
get_skattemelding	Retrieve tax return document
validate_skattemelding	Validate a tax return XML
get_restanse	Outstanding tax debts

Property (eiendom)

Tool	Description
get_formuesobjekt_fast_eiendom	Property assets for a person
get_formuesgrunnlag_eiendomsskatt	Property value for tax purposes

Population Register (folkeregisteret)

Tool	Description
get_person_folkeregisteret	Full person record lookup
search_personer_folkeregisteret	Search by criteria
get_folkeregisteret_hendelser	Change event feed
get_folkeregisteret_current_sekvens	Current event feed position

Wage Reporting (amelding)

Tool	Description
submit_amelding	Submit monthly A-melding
get_amelding_status	Check submission status
get_amelding_tilbakemelding	Get feedback on submitted report
list_amelding_for_maaned	List submissions for a month

VAT (mva)

Tool	Description
validate_mva_melding_xml	Validate VAT return XML
validate_mva_melding_json	Validate VAT return JSON
get_mva_koder	List valid VAT codes

Tax Deduction Cards (skattekort)

Tool	Description
get_skattekort	Get deduction card for an employee
order_skattekort	Bulk order deduction cards
get_skattekort_ordre_status	Check order status
get_skattekort_resultat	Retrieve completed order results

Claims & Payments (krav-og-betalinger)

Tool	Description
get_krav	Outstanding claims
get_betalinger	Payment history

Third-Party Reporting (tredjepartsopplysninger)

Tool	Description
submit_tredjepartsopplysninger	Submit third-party data
get_tredjepartsopplysninger_status	Check submission status
get_tredjepartsopplysninger_oppgavetyper	List valid report types

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Authentication

All APIs use Maskinporten for server-to-server OAuth2 authentication with enterprise certificates.

The client automatically:

• Creates signed JWT grants using your RSA private key
• Exchanges them for Maskinporten access tokens
• Caches tokens until 30 seconds before expiry
• Fetches per-scope tokens (different scopes for different APIs)

Test environment: https://test.maskinporten.no/ Production: https://maskinporten.no/

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API Documentation

• Skatteetaten API Documentation
• Folkeregisteret API
• MVA-Meldingen
• Skattemeldingen
• Maskinporten Guide
• SwaggerHub — Skatteetaten

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Development

# Run in development mode
npm run dev

# Type check
npm run typecheck

# Build
npm run build

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License

MIT