# AgentTools

> Free tools for humans, machine-native APIs for AI agents.

AgentTools hosts utility tools — calculators, converters, reference databases. Every tool is a free web page AND a paid JSON API for AI agents using the x402 protocol (HTTP 402 + USDC on Base). No accounts, no API keys: unpaid requests receive 402 with payment instructions; attach an X-PAYMENT header (via any x402 client library) and the same request returns 200 with JSON.

## Payment (x402)

- Protocol: x402 v2, scheme "exact", asset USDC
- Network: eip155:8453 (Base mainnet)
- Facilitator: https://x402.org/facilitator
- PayTo (receiving address): 0x8a0F2b0a6C82D1c54B16E2e4DEcd18fF0802b0f6
- Prices: $0.001–$0.005 per call (per-endpoint price listed with each tool)
- Tip jar (any amount 0.01–10 USD): GET https://agenttools-hub.vercel.app/api/tip?amount=1.00&note=thanks

## Machine docs

- OpenAPI 3.1 spec: https://agenttools-hub.vercel.app/api/openapi.json
- Full tool reference: https://agenttools-hub.vercel.app/llms-full.txt
- Integration guide: https://agenttools-hub.vercel.app/for-agents
- MCP server (Streamable HTTP): https://agenttools-hub.vercel.app/api/mcp — 35 tools as MCP tools with x402 payment in _meta; use @x402/mcp x402MCPClient for automatic payment

## Calculators

- [Percentage Calculator](https://agenttools-hub.vercel.app/calculators/percentage-calculator): Calculate X% of Y, what percent X is of Y, and the percent change between two values — with step-by-step working shown.
  - API: GET https://agenttools-hub.vercel.app/api/v1/calculators/percentage-calculator?x=15&y=200&op=percent_of — $0.001/call
- [Discount Calculator](https://agenttools-hub.vercel.app/calculators/discount-calculator): Calculate the final sale price and the amount saved for any price and percent-off discount, with the working shown.
  - API: GET https://agenttools-hub.vercel.app/api/v1/calculators/discount-calculator?price=79.99&discount=20 — $0.001/call
- [Tip Calculator](https://agenttools-hub.vercel.app/calculators/tip-calculator): Calculate the tip for any bill, the grand total, and how much each person pays when splitting. Defaults to a 15% tip.
  - API: GET https://agenttools-hub.vercel.app/api/v1/calculators/tip-calculator?bill=64.5&tipPercent=15&people=1 — $0.001/call
- [VAT Calculator](https://agenttools-hub.vercel.app/calculators/vat-calculator): Add VAT to a net amount or remove VAT from a gross amount. Standard VAT rates for 36 countries are built in, or override with any custom rate.
  - API: GET https://agenttools-hub.vercel.app/api/v1/calculators/vat-calculator?amount=100&country=DE&op=add — $0.001/call
- [BMI Calculator](https://agenttools-hub.vercel.app/calculators/bmi-calculator): Calculate Body Mass Index from weight (kg) and height (cm), with the WHO weight category and the healthy BMI weight range for your height.
  - API: GET https://agenttools-hub.vercel.app/api/v1/calculators/bmi-calculator?weight=70&height=175 — $0.001/call
- [Date Difference Calculator](https://agenttools-hub.vercel.app/calculators/date-difference-calculator): Count the total days between two dates, plus the breakdown in weeks and days and in calendar years, months and days.
  - API: GET https://agenttools-hub.vercel.app/api/v1/calculators/date-difference-calculator?start=2024-01-01&end=2024-12-31 — $0.001/call
- [Age Calculator](https://agenttools-hub.vercel.app/calculators/age-calculator): Calculate a person's exact age in calendar years, months and days from their date of birth, plus total days lived. Reference date defaults to today (UTC).
  - API: GET https://agenttools-hub.vercel.app/api/v1/calculators/age-calculator?birth=1990-06-15&on=2026-09-01 — $0.001/call
- [Loan Payment Calculator](https://agenttools-hub.vercel.app/calculators/loan-payment-calculator): Calculate the fixed monthly payment for a loan from its principal, annual interest rate and term in years, plus total repaid and total interest (annuity formula).
  - API: GET https://agenttools-hub.vercel.app/api/v1/calculators/loan-payment-calculator?principal=300000&annualRate=4.5&years=30 — $0.002/call
- [Compound Interest Calculator](https://agenttools-hub.vercel.app/calculators/compound-interest-calculator): Project the future value of a deposit with compound interest: choose annual, semi-annual, quarterly, monthly, weekly or daily compounding and see total interest earned.
  - API: GET https://agenttools-hub.vercel.app/api/v1/calculators/compound-interest-calculator?principal=10000&annualRate=5&years=10&timesPerYear=12 — $0.002/call
- [Fuel Cost Calculator](https://agenttools-hub.vercel.app/calculators/fuel-cost-calculator): Calculate the liters of fuel a trip needs and its total cost from distance, consumption (L/100 km) and price per liter — with optional cost splitting between passengers.
  - API: GET https://agenttools-hub.vercel.app/api/v1/calculators/fuel-cost-calculator?distance=450&consumption=6.5&pricePerLiter=1.75&people=1 — $0.001/call
- [Reading Time Calculator](https://agenttools-hub.vercel.app/calculators/reading-time-calculator): Estimate reading time from a word count at any reading speed. Defaults to 200 words per minute — the typical silent-reading speed for adults.
  - API: GET https://agenttools-hub.vercel.app/api/v1/calculators/reading-time-calculator?words=1500&wpm=200 — $0.001/call
## Converters

- [Length Converter](https://agenttools-hub.vercel.app/converters/length-converter): Convert between metric and imperial length units: kilometers, meters, centimeters, millimeters, micrometers, nanometers, miles, yards, feet, inches and nautical miles.
  - API: GET https://agenttools-hub.vercel.app/api/v1/converters/length-converter?value=1&from=km&to=m — $0.001/call
- [Weight Converter](https://agenttools-hub.vercel.app/converters/weight-converter): Convert between weight and mass units: metric tons, kilograms, grams, milligrams, pounds, ounces and stones with exact international definitions.
  - API: GET https://agenttools-hub.vercel.app/api/v1/converters/weight-converter?value=1&from=t&to=kg — $0.001/call
- [Temperature Converter](https://agenttools-hub.vercel.app/converters/temperature-converter): Convert between Celsius, Fahrenheit and Kelvin with exact formulas, reference points (freezing and boiling water) and step-by-step working.
  - API: GET https://agenttools-hub.vercel.app/api/v1/converters/temperature-converter?value=20&from=c&to=f — $0.001/call
- [Data Size Converter](https://agenttools-hub.vercel.app/converters/data-size-converter): Convert digital storage units: bits, bytes, KB, MB, GB, TB (decimal, ×1000) and KiB, MiB, GiB, TiB (binary, ×1024) — both systems side by side.
  - API: GET https://agenttools-hub.vercel.app/api/v1/converters/data-size-converter?value=1&from=TB&to=GB — $0.001/call
- [Speed Converter](https://agenttools-hub.vercel.app/converters/speed-converter): Convert speed units: kilometers per hour, miles per hour, meters per second, knots and feet per second with exact definitions.
  - API: GET https://agenttools-hub.vercel.app/api/v1/converters/speed-converter?value=1&from=kmh&to=mph — $0.001/call
- [Area Converter](https://agenttools-hub.vercel.app/converters/area-converter): Convert area units: square millimeters, centimeters, meters and kilometers, hectares, acres, square feet and square miles.
  - API: GET https://agenttools-hub.vercel.app/api/v1/converters/area-converter?value=1&from=km2&to=ha — $0.001/call
- [Volume Converter](https://agenttools-hub.vercel.app/converters/volume-converter): Convert cooking and liquid volume units: milliliters, liters, cubic meters, US gallons, quarts, pints, cups, fluid ounces, tablespoons and teaspoons.
  - API: GET https://agenttools-hub.vercel.app/api/v1/converters/volume-converter?value=1&from=m3&to=L — $0.001/call
- [Unix Timestamp Converter](https://agenttools-hub.vercel.app/converters/unix-timestamp-converter): Convert Unix epoch timestamps to ISO/UTC dates and back. Millisecond timestamps are detected automatically; invalid dates are rejected with clear errors.
  - API: GET https://agenttools-hub.vercel.app/api/v1/converters/unix-timestamp-converter?op=to_date&value=1735689600 — $0.001/call
- [Roman Numeral Converter](https://agenttools-hub.vercel.app/converters/roman-numeral-converter): Convert numbers to Roman numerals (1–3999) and Roman numerals back to numbers, with strict validation that rejects non-standard forms like IIIM or VX.
  - API: GET https://agenttools-hub.vercel.app/api/v1/converters/roman-numeral-converter?value=2026&op=to_roman — $0.001/call
## Databases

- [Countries Database](https://agenttools-hub.vercel.app/databases/countries): Reference database of all 250 countries and territories: ISO 3166-1 codes, capitals, regions, population, area, currencies, languages, TLDs and calling codes. Look up a single country or list by region.
  - API: GET https://agenttools-hub.vercel.app/api/v1/databases/countries?country=Germany — $0.002/call
## Live Data

- [Current Time](https://agenttools-hub.vercel.app/live/now): Returns the current date and time in any IANA time zone, plus Unix seconds/milliseconds, ISO 8601, weekday and day-of-year. Use it whenever an agent needs to know 'now'.
  - API: GET https://agenttools-hub.vercel.app/api/v1/live/now?tz=UTC — $0.0005/call
- [Business Days Calculator](https://agenttools-hub.vercel.app/live/business-days): Count business days (Mon–Fri) between two dates, with weekend and holiday breakdown. Provide a country code and real public holidays (via Nager.Date) are excluded too.
  - API: GET https://agenttools-hub.vercel.app/api/v1/live/business-days?start=2026-09-01&end=2026-09-30 — $0.001/call
- [Exchange Rates (Live)](https://agenttools-hub.vercel.app/live/exchange-rates): Live foreign-exchange reference rates from the European Central Bank (via frankfurter.dev): a full rate table against any base currency, or cross-rate conversion of any amount. Refreshed every business day by the ECB, cached one hour.
  - API: GET https://agenttools-hub.vercel.app/api/v1/live/exchange-rates?op=rates&base=USD — $0.002/call
- [Weather (Live)](https://agenttools-hub.vercel.app/live/weather): Live weather from Open-Meteo: current temperature, humidity, wind and conditions plus a 3-day forecast, by city name or coordinates. No API key, cached 30 minutes.
  - API: GET https://agenttools-hub.vercel.app/api/v1/live/weather?city=Berlin — $0.002/call
- [Public Holidays (Live)](https://agenttools-hub.vercel.app/live/holidays): List upcoming or full-year public holidays for any covered country via Nager.Date — names, dates and whether they're nationwide. Essential for scheduling agents.
  - API: GET https://agenttools-hub.vercel.app/api/v1/live/holidays?country=DE&op=next&count=8 — $0.002/call
- [IP Geolocation (Live)](https://agenttools-hub.vercel.app/live/ip-lookup): Geolocate any IPv4/IPv6 address (or the caller's own IP when omitted) via ipwho.is: country, region, city, coordinates, timezone, ASN/network owner and currency. Cached 24 hours per IP.
  - API: GET https://agenttools-hub.vercel.app/api/v1/live/ip-lookup?ip=8.8.8.8 — $0.002/call
- [DNS Lookup (Live)](https://agenttools-hub.vercel.app/live/dns-lookup): Query live DNS records (A, AAAA, MX, TXT, NS, CNAME, SOA) through Cloudflare's DNS-over-HTTPS resolver. Domain validation, email deliverability pre-checks and infrastructure discovery.
  - API: GET https://agenttools-hub.vercel.app/api/v1/live/dns-lookup?domain=example.com&type=A — $0.002/call
- [URL Metadata (Live)](https://agenttools-hub.vercel.app/live/url-metadata): Fetch a URL server-side and extract its title, meta description, Open Graph and Twitter card tags, canonical URL and favicon — the data agents need to preview or classify a link. SSRF-guarded: private networks are blocked, 10s timeout, 1MB cap.
  - API: GET https://agenttools-hub.vercel.app/api/v1/live/url-metadata?url=https%3A%2F%2Fexample.com — $0.003/call
- [QR Code Generator](https://agenttools-hub.vercel.app/live/qr-code): Generate a QR code for any text, URL or crypto address: returns ready-to-embed SVG markup and a data URI, with configurable size and error-correction level.
  - API: GET https://agenttools-hub.vercel.app/api/v1/live/qr-code?text=https%3A%2F%2Fexample.com&size=300&ec=M — $0.002/call
## Dev Tools

- [Base64 Encoder / Decoder](https://agenttools-hub.vercel.app/dev/base64-encode): Encode text to base64 or decode base64 back to text. Full UTF-8 support including emoji and non-Latin scripts.
  - API: GET https://agenttools-hub.vercel.app/api/v1/dev/base64-encode?text=Hello%2C%20world!&direction=encode — $0.001/call
- [Number Base Converter](https://agenttools-hub.vercel.app/dev/number-base-converter): Convert integers between any bases from 2 to 36 — binary, octal, decimal, hexadecimal and beyond — with BigInt precision (no limit on magnitude).
  - API: GET https://agenttools-hub.vercel.app/api/v1/dev/number-base-converter?value=ff&from=16&to=10 — $0.001/call
- [Case Converter](https://agenttools-hub.vercel.app/dev/case-converter): Convert text between nine letter cases: UPPER, lower, Title, Sentence, camelCase, PascalCase, snake_case, kebab-case and CONSTANT_CASE. camelCase boundaries are split automatically.
  - API: GET https://agenttools-hub.vercel.app/api/v1/dev/case-converter?text=hello%20world&style=camel — $0.001/call
- [JWT Decoder](https://agenttools-hub.vercel.app/dev/jwt-decoder): Decode a JSON Web Token's header and payload to readable JSON. Pure decoding: signatures are NOT verified and no secret is needed. Claims like exp and iat are rendered as dates.
  - API: GET https://agenttools-hub.vercel.app/api/v1/dev/jwt-decoder?token=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkphbmUgRG9lIiwiaWF0IjoxNzAwMDAwMDAwfQ.dummy_signature_part — $0.001/call
- [URL Encoder / Decoder](https://agenttools-hub.vercel.app/dev/url-encoder): Percent-encode text for safe inclusion in URLs and query strings, or decode percent-encoded text back. Uses the standard encodeURIComponent rules.
  - API: GET https://agenttools-hub.vercel.app/api/v1/dev/url-encoder?text=hello%20world%20%26%20more&op=encode — $0.001/call
- [JSON Formatter / Validator](https://agenttools-hub.vercel.app/dev/json-formatter): Validate JSON with precise error messages, pretty-print it with any indent, and inspect its top-level type and element counts.
  - API: GET https://agenttools-hub.vercel.app/api/v1/dev/json-formatter?json=%7B%22name%22%3A%22Ada%22%2C%22langs%22%3A%5B%22ts%22%2C%22py%22%5D%2C%22active%22%3Atrue%7D&indent=2 — $0.001/call
- [HTTP Status Codes Database](https://agenttools-hub.vercel.app/dev/http-status-codes): Reference database of HTTP response status codes with phrase, category and explanation. Look up a specific code or list a whole category (1xx–5xx).
  - API: GET https://agenttools-hub.vercel.app/api/v1/dev/http-status-codes?code=402 — $0.001/call
- [MIME Types Database](https://agenttools-hub.vercel.app/dev/mime-types): Look up MIME content types by type substring or file extension, or list a category — covering text, application, image, audio, video, font and multipart types used in web APIs.
  - API: GET https://agenttools-hub.vercel.app/api/v1/dev/mime-types?query=.png — $0.001/call
- [Token Estimator](https://agenttools-hub.vercel.app/dev/token-estimator): Estimate how many tokens a text consumes for each major model family (GPT, Claude, Gemini, Llama, DeepSeek) using a character/word heuristic that is within ~10% of real BPE tokenizers — enough for context budgeting and cost math, with zero dependencies.
  - API: GET https://agenttools-hub.vercel.app/api/v1/dev/token-estimator?text=The%20quick%20brown%20fox%20jumps%20over%20the%20lazy%20dog.%20Pack%20my%20box%20with%20five%20dozen%20liquor%20jugs. — $0.001/call
- [LLM API Cost Calculator](https://agenttools-hub.vercel.app/dev/llm-cost-calculator): Calculate the API cost of an LLM call: input and output tokens × published per-million prices for 15 current models (OpenAI, Anthropic, Google, DeepSeek, xAI, Meta). Batch multiplier included for monthly estimates.
  - API: GET https://agenttools-hub.vercel.app/api/v1/dev/llm-cost-calculator?inputTokens=12000&outputTokens=1500&model=gpt-4o&calls=1 — $0.001/call
- [Text Chunker](https://agenttools-hub.vercel.app/dev/text-chunker): Split text into retrieval-friendly chunks with a token budget and sentence-aware boundaries. Overlap between consecutive chunks preserves context across splits — the standard preparation step before embedding.
  - API: GET https://agenttools-hub.vercel.app/api/v1/dev/text-chunker?text=Retrieval-augmented%20generation%20improves%20factuality.%20First%2C%20documents%20are%20split%20into%20chunks.%20Second%2C%20chunks%20are%20embedded%20into%20vectors.%20Third%2C%20the%20agent%20retrieves%20the%20top%20matches%20for%20a%20query.%20Overlap%20keeps%20ideas%20that%20straddle%20boundaries%20intact.%20Finally%2C%20the%20model%20answers%20with%20citations.&targetTokens=60&overlapTokens=15 — $0.002/call
- [Hash Calculator](https://agenttools-hub.vercel.app/dev/hash): Compute exact hash digests of UTF-8 text using Web Crypto (SHA family) and a verified pure-JS MD5 for legacy checksums. Deterministic — identical input always yields the identical digest.
  - API: GET https://agenttools-hub.vercel.app/api/v1/dev/hash?text=hello&algo=sha256 — $0.001/call
- [UUID Generator / Validator](https://agenttools-hub.vercel.app/dev/uuid): Generate cryptographically random UUIDv4s or time-sortable UUIDv7s from a real CSPRNG, and validate any UUID's format, version and variant bits.
  - API: GET https://agenttools-hub.vercel.app/api/v1/dev/uuid?op=generate&version=v4 — $0.001/call
- [Text Extractor](https://agenttools-hub.vercel.app/dev/text-extract): Scan unstructured text and extract structured entities: email addresses, URLs, IPv4 addresses, phone numbers and domains. Deduplicated, categorized, machine-ready.
  - API: GET https://agenttools-hub.vercel.app/api/v1/dev/text-extract?text=Reach%20Jane%20at%20jane.doe%40acme-corp.io%2C%20sales%40acme-corp.io%20or%20%2B49%2030%201234567.%20Site%3A%20https%3A%2F%2Facme-corp.io%2Fpricing%20and%20CDN%20151.101.1.140.%20Backup%20mail%20host%3A%20mail.acme-corp.io — $0.002/call
- [Text Diff](https://agenttools-hub.vercel.app/dev/diff): Compare two texts line by line using an LCS diff: exact additions, removals and context — in unified-diff style. Deterministic, unlike asking a model to 'find the differences'.
  - API: GET https://agenttools-hub.vercel.app/api/v1/dev/diff?a=price%3A%20100%0Aquantity%3A%202%0Atotal%3A%20200&b=price%3A%20100%0Aquantity%3A%203%0Atotal%3A%20300&context=1 — $0.002/call
- [URL Parser](https://agenttools-hub.vercel.app/dev/url-parser): Parse a URL into all its components: protocol, hostname, port, path segments, query parameters (as a clean object), hash and credentials. Exact — no guessing by eye.
  - API: GET https://agenttools-hub.vercel.app/api/v1/dev/url-parser?url=https%3A%2F%2Fuser%3Apw%40api.example.com%3A8443%2Fv1%2Fusers%3Fpage%3D2%26sort%3Dname%26tag%3Da%26tag%3Db%23results — $0.001/call
## Crypto & Web3

- [Wei / Gwei / ETH Converter](https://agenttools-hub.vercel.app/crypto/wei-eth-converter): Convert between wei, kwei, mwei, gwei, microether, milliether and ether with exact BigInt arithmetic. Decimal strings of any magnitude convert without floating-point error.
  - API: GET https://agenttools-hub.vercel.app/api/v1/crypto/wei-eth-converter?value=21000&from=gwei&to=eth — $0.001/call
- [Gas Fee Calculator](https://agenttools-hub.vercel.app/crypto/gas-fee-calculator): Calculate a transaction's gas fee: gas units × gas price (gwei) gives the ETH cost, multiplied by the ETH price for USD. Exact BigInt math for the wei amounts.
  - API: GET https://agenttools-hub.vercel.app/api/v1/crypto/gas-fee-calculator?gasUnits=21000&gweiPrice=10&ethPriceUsd=3000 — $0.001/call
- [Crypto Price (Live)](https://agenttools-hub.vercel.app/crypto/price): Live cryptocurrency prices from CoinGecko's public API: current price in USD/EUR/GBP/JPY plus 24-hour change for any coin by id or common ticker (btc, eth, sol…). Cached 60 seconds.
  - API: GET https://agenttools-hub.vercel.app/api/v1/crypto/price?ids=bitcoin%2Cethereum&vs=usd — $0.002/call
- [Secure Random Generator](https://agenttools-hub.vercel.app/crypto/random-generator): Generate cryptographically secure randomness: passwords with charset rules, hex keys of any byte length, and uniform random integers (rejection sampling, no modulo bias). Never use Math.random for secrets.
  - API: GET https://agenttools-hub.vercel.app/api/v1/crypto/random-generator?mode=password&length=24 — $0.001/call
## Finance & Business

- [ROI Calculator](https://agenttools-hub.vercel.app/finance/roi-calculator): Calculate return on investment: profit (or loss) and the percentage return relative to the initial amount invested.
  - API: GET https://agenttools-hub.vercel.app/api/v1/finance/roi-calculator?initial=10000&final=12500 — $0.001/call
- [CAGR Calculator](https://agenttools-hub.vercel.app/finance/cagr-calculator): Calculate the compound annual growth rate that takes an initial value to a final value over a given number of years — the standard way to annualize returns.
  - API: GET https://agenttools-hub.vercel.app/api/v1/finance/cagr-calculator?initial=10000&final=16000&years=3 — $0.001/call
- [Margin & Markup Calculator](https://agenttools-hub.vercel.app/finance/margin-calculator): Calculate gross profit, profit margin (profit as % of price) and markup (profit as % of cost) from a unit cost and selling price — the two numbers people constantly mix up.
  - API: GET https://agenttools-hub.vercel.app/api/v1/finance/margin-calculator?cost=60&price=100 — $0.001/call
- [IBAN Validator](https://agenttools-hub.vercel.app/finance/iban-validator): Validate an International Bank Account Number: country code, country-specific length and the ISO 7064 MOD 97-10 check digits — with the pretty-printed grouping returned when valid.
  - API: GET https://agenttools-hub.vercel.app/api/v1/finance/iban-validator?iban=DE89%203704%200044%200532%200130%2000 — $0.001/call