krs-poland-mcp-server: Instructions file for Claude Code

CLAUDE.md

krs-poland-mcp-server CLAUDE.md is an instructions file for Claude Code from pkolawa/krs-poland-mcp-server. It costs 415 tokens per session, scanned A, original, MIT.

Project instructions for a TypeScript MCP server that retrieves company records from Poland's public National Court Register (KRS) API. MCP is a standard way for an application to expose tools that an AI assistant can call.

In plain words
What is it for?
Use it when developing or maintaining this KRS server. It helps work with current and full company records, validate KRS numbers, build the TypeScript project, and run unit or integration tests.
Why use it?
It gives the codebase consistent rules for validation, API requests, retries, responses, building, testing, and linting. This makes changes easier to check against the server's existing structure.

Instructions file for Claude Code

Written for Claude Code: the file is CLAUDE.md.

This is pkolawa/krs-poland-mcp-server's own configuration. It tells Claude Code how to work on krs-poland-mcp-server itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything krs-poland-mcp-server configures →

Reuse

Borrowing it

Nothing to install: this file belongs to pkolawa/krs-poland-mcp-server. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/pkolawa/krs-poland-mcp-server/main/CLAUDE.md
Clone the repo
git clone --depth 1 https://github.com/pkolawa/krs-poland-mcp-server

Made for: Claude Code.

Wrote this? Show the measurements

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README.md
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Per session 415 This file is loaded in full into every session.
When invoked 415 The same file — it is already loaded in full.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00415 $0.00415
Opus 5 $0.00208 $0.00208
Sonnet 5 $0.00083 $0.00083
Haiku 4.5 $0.00042 $0.00042

Measured 10d ago against content hash 7af563902089, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

krs-poland-mcp-server CLAUDE.md scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 10d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

CLAUDE.md · 39 lines

What it actually says

KRS Poland MCP Server

Serwer MCP udostępniający dane z publicznego API Krajowego Rejestru Sądowego (KRS) Ministerstwa Sprawiedliwości.

Architektura

  • TypeScript + @modelcontextprotocol/sdk, transport stdio
  • Dwa narzędzia MCP: odpis aktualny (Get_Current_KRS_Record) i pełny (Get_Full_KRS_Record)
  • HTTP client z retry (30s/60s backoff) i dual URL fallback (path params + query params)
  • Build: esbuild do jednego pliku ESM (build/index.mjs)

Komendy

  • npm run build — lint + unit tests + esbuild bundle
  • npm run test:unit — testy unit (mockowany fetch)
  • npm run test:integration — testy z prawdziwym API KRS
  • npm run lint — ESLint
  • npm run typecheck — TypeScript strict mode

Konwencje

  • Walidacja inputów przez Zod ze schematem inline w tool definitions
  • Odpowiedzi MCP zawierają type: "text" z JSON w treści
  • API KRS: https://api-krs.ms.gov.pl/api/krs/{typ}/{rejestr}/{krs}?format=json
  • Numer KRS: 10 cyfr zaczynających się od 0, rejestr: P (przedsiębiorców) lub S (stowarzyszeń)

Struktura plików

src/index.ts        — entrypoint
src/server.ts       — rejestracja narzędzi
src/tools/          — handlery narzędzi MCP
src/types/krs.ts    — interfejs KrsExtract
src/utils/api.ts    — HTTP client
src/utils/format.ts — formatowanie nagłówka

@TODO.md

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 10d ago First seen · 39 lines · 415 tokens per session scan A 7af563902089

Subscribe to this mod's changes

krs-poland-mcp-server CLAUDE.md is an instructions file published in the GitHub repository pkolawa/krs-poland-mcp-server (4 stars, last pushed 18d ago), licensed MIT. It adds 415 tokens to every session, about $0.0021 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

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