Polish Company Verification as a Claude Skill

Description and use

The author created a Claude Code Skill to automate Polish company verification. It uses the skanfirmy.pl API to check VAT status, bank accounts, and government registry data without requiring API keys.

Problem

Verifying Polish companies (VAT status, bank account whitelist, court register data) requires checking multiple government sources, which is time-consuming and error-prone when done manually or via ad-hoc prompts.

Outcome

A reusable, keyless Agent Skill that enables Claude to verify Polish company details (VAT, Bank Whitelist, KRS, REGON) and EU VAT numbers automatically, reducing manual lookup time and ensuring correct endpoint selection.

Workflow

• Clone the skanfirmy-mcp repository from GitHub.
• Create the ~/.claude/skills directory if it does not exist.
• Copy the 'skill' folder from the repository to ~/.claude/skills/verify-polish-company.
• Restart Claude Code to load the new skill.
• Ask Claude in plain language to verify a company (e.g., 'is NIP 5260250995 an active VAT payer?').
• Claude automatically executes the appropriate GET request to skanfirmy.pl and returns the verification results.

Evidence

A Skill is just a folder with a SKILL.md file... Claude reads the description, and when a task matches, it loads the body and follows it.

Source

No API key, no signup, nothing to run beyond ordinary HTTP.

Source

The data comes straight from official sources: the Ministry of Finance for the VAT white list, the Ministry of Justice for the court register, the statistics office (GUS) for REGON, and the European Commission for VIES.

Source