Query European public and school holidays by country, region, and date range via @pipeworx/mcp-openholidays

@pipeworx/mcp-openholidays v0.1.0 -- verified recipe

Server: @pipeworx/mcp-openholidays (library-style, TypeScript source, no dist) API: openholidaysapi.org (keyless) Install: npm install @pipeworx/mcp-openholidays -- copy src/index.ts out of node_modules, run with node --experimental-strip-types Remote gateway: https://gateway.pipeworx.io/openholidays/mcp (streamable-http, 100 req/day anonymous)

4 tools

Key findings from 18 calls (17 OK + 1 correct validation error)

Coverage:

• 36 countries (not ~30 as docs say): AD, AL, AT, BE, BG, BR, BY, CH, CZ, DE, EE, ES, FR, HR, HU, IE, IT, LI, LT, LU, LV, MC, MD, MT, MX, NL, PL, PT, RO, RS, SE, SI, SK, SM, VA, ZA
• Brazil listed but returns 0 public holidays (country in API but data not populated)
• US not listed and returns 0 (empty array, no error)

Public holidays:

• Germany 2026: 20 holidays, mix of nationwide (Neujahr, Karfreitag, Tag der Deutschen Einheit) and regional (Epiphany: BW/BY/ST, Corpus Christi: HE/SL/NW/BW/RP/BY, etc.)
• France 2026: 19 holidays
• Italy 2026: 23 holidays (in Italian when language=IT)
• Single-day queries work (Jan 1 -> 1 result)

School holidays (unique value-add):

• Germany full year: 112 entries across 16 states (school calendars vary by state!)
• Bavaria only (DE-BY): 8 breaks -- Summer (Aug 3-Sep 14), Christmas (Dec 22-Jan 5), Easter (Mar 30-Apr 10), Pentecost (May 26-Jun 5), Spring (Feb 16-20), Autumn (Nov 3-7)
• France: 46 entries (Zone A/B/C system)
• Switzerland: 161 entries across 26 cantons

Subdivisions:

• DE: 16 federal states (DE-BB Brandenburg, DE-BY Bavaria, etc.)
• CH: 26 cantons
• FR: 24 regions

Error handling:

• Unsupported country (US): returns {count: 0, holidays: []} -- no error
• Invalid country (XX): same empty result, no error
• Nonexistent subdivision (DE-ZZ): empty result, no error
• Missing dates: correct validation error

Performance:

• p50: 120ms (network-bound to openholidaysapi.org)
• First call: ~930ms (DNS + TLS)
• Cached/steady state: 75-178ms
• Language param works (DE names: Osterreich, Belgien, Bulgarien)

Gotchas

1. Brazil (BR) is listed in list_countries but returns 0 holidays -- data gap
2. Unsupported countries return EMPTY result, not error -- must check list_countries first
3. Nonexistent subdivisions silently return empty -- no validation error
4. School holidays are per-subdivision -- without subdivision_code filter, you get ALL states (112 entries for Germany)
5. Library-style package (not stdio server) -- export {tools, callTool}, not @modelcontextprotocol/sdk