# Tausendwerk > Small, exact software tools for AI agents and people. 24 tools over MCP (https://api.tausendwerk.xyz/mcp) and REST (POST https://api.tausendwerk.xyz/v1/{tool}): business days and public holidays, exact decimal arithmetic, unit and currency conversion, loan maths, JSON repair and validation, file conversion to Markdown, test data, IBAN, VAT and Swiss QR-bill checks, time zones, cron schedules, ISO weeks, CEFR text levels, Sudoku and word search. Each tool has one price per successful call in CHF, from CHF 0.001. 100 calls per day are free without a key. Key facts: - Operator: Tausendwerk, Maxime Perriard, Fribourg, Switzerland. Contact: agentic@tausendwerk.xyz. - Connect: `claude mcp add --transport http tausendwerk https://api.tausendwerk.xyz/mcp`, or add the remote MCP server URL https://api.tausendwerk.xyz/mcp in any MCP client. - Results are computed by plain code, not generated: the same input gives the same output. Only the two language-level tools use a language model. - Invalid input returns HTTP 400 with the schema errors and costs nothing. Over the free allowance the API answers HTTP 402 with the price and a top-up link. - Prepaid credit: CHF 5, 20, 50, 200 through Stripe (card, TWINT). Credit does not expire. No subscription. - Privacy: the content of a call is processed in memory and not stored. The website sets no cookies and has no trackers. ## Agent tools ### Dates and deadlines - [Business days between two dates](https://tausendwerk.xyz/tools/business-days/): Count the business days between two dates for a country or subdivision, and list the public holidays skipped. CHF 0.002 per call. MCP name: business_days. - [Deadline in business days](https://tausendwerk.xyz/tools/add-business-days/): Return the date that is N business days after (or before, with a negative N) a start date, for a country or subdivision. CHF 0.002 per call. MCP name: add_business_days. - [Is this a business day?](https://tausendwerk.xyz/tools/is-business-day/): Say whether a date is a business day in a country or subdivision, and why not if it is not. CHF 0.001 per call. MCP name: is_business_day. - [Public holidays for a year](https://tausendwerk.xyz/tools/holidays/): List the public holidays of one year for a country or subdivision. With region "list", return every supported region code. CHF 0.002 per call. MCP name: holidays. ### Exact maths and money - [Exact calculator](https://tausendwerk.xyz/tools/calculate/): Evaluate an arithmetic expression exactly, with no floating-point error, and return the result as a decimal string. CHF 0.001 per call. MCP name: calculate. - [Unit conversion](https://tausendwerk.xyz/tools/convert-units/): Convert a value between units of length, mass, volume, area, speed, time, data, energy, power, pressure or temperature, using exact definitions. CHF 0.001 per call. MCP name: convert_units. - [Currency conversion at ECB reference rates](https://tausendwerk.xyz/tools/convert-currency/): Convert an amount between currencies at the euro reference rates of the European Central Bank, for today or a date in the last 90 days. CHF 0.002 per call. MCP name: convert_currency. - [Loan, savings and investment maths](https://tausendwerk.xyz/tools/finance/): Compute loan payments, amortisation schedules, future and present values, NPV and IRR with exact arithmetic. CHF 0.003 per call. MCP name: finance. ### JSON - [Repair JSON and match it to a schema](https://tausendwerk.xyz/tools/repair-json/): Turn broken or wrapped JSON (typical language-model output) into valid JSON, list every repair, and optionally coerce and validate it against a JSON Schema. CHF 0.002 per call. MCP name: repair_json. - [Validate JSON against a schema](https://tausendwerk.xyz/tools/validate-json/): Check a JSON value against a JSON Schema and return every error with its path. Does not change the data (use repair-json for that). CHF 0.001 per call. MCP name: validate_json. ### Files - [Convert documents to Markdown or JSON](https://tausendwerk.xyz/tools/convert-file/): Convert a PDF, Word (.docx), Excel (.xlsx), PowerPoint (.pptx), CSV, HTML or text file into clean Markdown, plain text, CSV or structured JSON that a language model can read. CHF 0.01 per call. MCP name: convert_file. ### Test data - [Synthetic test records](https://tausendwerk.xyz/tools/test-data/): Generate realistic fake records for software tests and demos: people, companies, addresses, invoices, bank transactions, products or orders, for one country. CHF 0.005 per call. MCP name: test_data. - [Test records for your JSON Schema](https://tausendwerk.xyz/tools/test-data-from-schema/): Generate fake records that match your JSON Schema, with realistic values chosen from field names (name, email, iban, city, price, created_at …) and formats. CHF 0.005 per call. MCP name: test_data_from_schema. ### Identifiers and Swiss QR-bills - [Validate business identifiers](https://tausendwerk.xyz/tools/validate-identifier/): Check the format and check digits of a business identifier, and return it normalised: IBAN (with QR-IBAN detection), Swiss company number UID (CHE-…), EU VAT number, LEI, ISIN, GTIN/EAN, Swiss QR reference, RF creditor reference. CHF 0.001 per call. MCP name: validate_identifier. - [Swiss QR-bill code](https://tausendwerk.xyz/tools/qr-bill/): Build the Swiss QR-bill code for a payment: validates every field against the Swiss Payment Standards (version 2.3), returns the QR payload text and the QR code as SVG (46 × 46 mm, with the Swiss cross), ready to place on an invoice. CHF 0.01 per call. MCP name: qr_bill. - [Check a Swiss QR-bill payload](https://tausendwerk.xyz/tools/qr-bill-check/): Read the text of a Swiss QR-bill code (as decoded from the QR image) and list every problem against the Swiss Payment Standards, with the parsed fields. CHF 0.002 per call. MCP name: qr_bill_check. ### Time - [Explain a cron schedule and list its next runs](https://tausendwerk.xyz/tools/cron/): Validate a cron expression, describe it in plain English, and list its next run times in a time zone, with daylight-saving changes handled. CHF 0.001 per call. MCP name: cron. - [Convert a time between time zones](https://tausendwerk.xyz/tools/convert-time/): Convert a date and time from one time zone to one or more others, with UTC offsets and daylight-saving status. Detects local times that do not exist (spring forward) or happen twice (fall back). CHF 0.001 per call. MCP name: convert_time. - [ISO week numbers](https://tausendwerk.xyz/tools/iso-week/): Convert a date to its ISO 8601 week (year, week, weekday) with the Monday and Sunday of that week, or a week to its dates. CHF 0.001 per call. MCP name: iso_week. ### Language level - [CEFR level of a text](https://tausendwerk.xyz/tools/text-level/): Estimate the CEFR reading level (A1–C2) of a text, with separate levels for vocabulary, grammar and sentence structure, the reasons, and the words above the overall level. CHF 0.04 per call. MCP name: text_level. - [Rewrite a text for a CEFR level](https://tausendwerk.xyz/tools/rewrite-to-level/): Rewrite a text so a learner at a given CEFR level (A1–C2) can read it, in the same language, keeping the facts and the order of ideas. Lists the main changes. CHF 0.15 per call. MCP name: rewrite_to_level. ### Puzzles and everyday - [Sudoku: generate, solve, grade](https://tausendwerk.xyz/tools/sudoku/): Generate a Sudoku with exactly one solution, or solve and grade a given grid. CHF 0.002 per call. MCP name: sudoku. - [Word search generator](https://tausendwerk.xyz/tools/word-search/): Make a word-search grid from your words, with the answer key. Every word appears exactly once, also after the random fill. CHF 0.002 per call. MCP name: word_search. - [Everyday calculators (30)](https://tausendwerk.xyz/tools/calculator/): Run one of 30 exact everyday calculators: home and DIY, garden, kitchen, car, energy, everyday numbers. CHF 0.001 per call. MCP name: calculator. ## Docs - [Connect an agent](https://tausendwerk.xyz/agents/): MCP setup for Claude, Cursor and other clients; REST; keys and payment. - [Pricing](https://tausendwerk.xyz/pricing/): price per call of every tool, free allowance, prepaid credit. - [All tools](https://tausendwerk.xyz/tools/): every tool with its price, grouped. - [Full text for language models](https://tausendwerk.xyz/llms-full.txt): every tool with its description, input schema and a real example. - [OpenAPI](https://api.tausendwerk.xyz/openapi.json) ## Calculators (free, for people) ### Home and DIY - [Paint calculator](https://tausendwerk.xyz/calculators/home/paint/): How many litres of wall paint a room needs, after doors and windows, for any number of coats. - [Tile calculator](https://tausendwerk.xyz/calculators/home/tiles/): Number of tiles and boxes for a floor or wall, with a waste allowance for cuts. - [Wallpaper calculator](https://tausendwerk.xyz/calculators/home/wallpaper/): Rolls of wallpaper for a room, from the wall length, height, roll size and pattern repeat. - [Concrete slab calculator](https://tausendwerk.xyz/calculators/home/concrete-slab/): Volume, weight and number of ready-mix bags for a concrete slab. - [Laminate and parquet calculator](https://tausendwerk.xyz/calculators/home/flooring/): Packs of laminate or parquet for a room, with a cutting allowance. - [Stair calculator](https://tausendwerk.xyz/calculators/home/stairs/): Number of steps, riser height and tread depth for a comfortable staircase, using the step rule 2 risers + 1 tread = 63 cm. - [Roof pitch calculator](https://tausendwerk.xyz/calculators/home/roof-pitch/): Roof pitch in degrees, percent and the x:12 ratio, from rise and run. - [Fence calculator](https://tausendwerk.xyz/calculators/home/fence/): Fence panels and posts for a straight run of fence. ### Garden and water - [Soil and mulch calculator](https://tausendwerk.xyz/calculators/garden/mulch-soil/): Volume and number of bags of soil, compost or mulch for a bed. - [Gravel calculator](https://tausendwerk.xyz/calculators/garden/gravel/): Volume and weight of gravel for a path or driveway. - [Plant spacing calculator](https://tausendwerk.xyz/calculators/garden/plant-spacing/): How many plants fit in a bed at a given spacing, in a square grid or a triangular (offset) pattern. - [Pool volume calculator](https://tausendwerk.xyz/calculators/garden/pool-volume/): Water volume of a rectangular or round pool in cubic metres and litres. - [Aquarium volume calculator](https://tausendwerk.xyz/calculators/garden/aquarium/): Volume of a rectangular aquarium in litres, the water it actually holds, and its weight. - [Rainwater harvest calculator](https://tausendwerk.xyz/calculators/garden/rainwater/): How much rainwater a roof collects per year and per month. ### Kitchen - [Recipe scaler](https://tausendwerk.xyz/calculators/kitchen/recipe-scaler/): Scale any ingredient amount from one number of servings to another. - [Oven temperature converter](https://tausendwerk.xyz/calculators/kitchen/oven-temperature/): Convert oven temperature from Celsius to Fahrenheit, gas mark and fan-oven setting. - [Cups to grams converter](https://tausendwerk.xyz/calculators/kitchen/cups-to-grams/): Convert US cups to grams for flour, sugar, butter and other common ingredients. - [Cake tin size converter](https://tausendwerk.xyz/calculators/kitchen/cake-tin/): Square tin with the same area as a round tin, and how much to scale a recipe for a different round tin. - [Yeast converter](https://tausendwerk.xyz/calculators/kitchen/yeast/): Convert fresh yeast to active dry and instant yeast. - [Brine and fermentation salt calculator](https://tausendwerk.xyz/calculators/kitchen/brine/): Grams of salt for a brine of a given strength, for fermenting vegetables or brining meat. - [Coffee ratio calculator](https://tausendwerk.xyz/calculators/kitchen/coffee-ratio/): Grams of coffee for a given amount of water and brew ratio. ### Car and travel - [Trip fuel cost calculator](https://tausendwerk.xyz/calculators/travel/trip-fuel-cost/): Fuel and cost of a car trip from distance, consumption and fuel price. - [L/100 km to mpg converter](https://tausendwerk.xyz/calculators/travel/fuel-economy/): Convert fuel consumption from litres per 100 km to miles per gallon (US and UK), and back. ### Energy at home - [Appliance electricity cost calculator](https://tausendwerk.xyz/calculators/energy/appliance-cost/): Yearly electricity use and cost of an appliance from its power and daily use. - [LED savings calculator](https://tausendwerk.xyz/calculators/energy/led-savings/): Energy and money saved by replacing old lamps with LEDs. ### Everyday numbers - [Unit price comparison](https://tausendwerk.xyz/calculators/everyday/unit-price/): Compare two pack sizes and see which is cheaper per unit, and by how much. - [Percentage change calculator](https://tausendwerk.xyz/calculators/everyday/percentage-change/): Percentage increase or decrease from an old value to a new value. - [Tip and bill splitter](https://tausendwerk.xyz/calculators/everyday/tip-split/): Add a tip to a bill and split it between people, rounded to 5 centimes. - [Hours worked calculator](https://tausendwerk.xyz/calculators/everyday/hours-worked/): Working hours between a start and end time, minus breaks, in hours and minutes and as a decimal. - [Days between dates](https://tausendwerk.xyz/calculators/everyday/days-between/): Calendar days and weeks between two dates. ## Other products - [Books](https://tausendwerk.xyz/books/): Sudoku books (English and German) with exactly one solution per puzzle, German word searches, and "Neu in Bern", a graded German reader for level A2. - [Notion templates](https://tausendwerk.xyz/templates/): Swiss Freelancer OS (CHF 19), Language Learning Tracker (CHF 12), Home Renovation Planner (CHF 15). - [Brand kit](https://tausendwerk.xyz/brand/) ## Optional - [About](https://tausendwerk.xyz/about/) - [Image credits](https://tausendwerk.xyz/credits/): Smithsonian Open Access (CC0) and Unsplash. - [Terms](https://tausendwerk.xyz/legal/terms/), [Privacy](https://tausendwerk.xyz/legal/privacy/), [Imprint](https://tausendwerk.xyz/legal/imprint/)