# Services from fastx402.tools on Zero

> fastx402.tools serves 36 paid API services for AI agents, indexed by Zero. Each is callable per call with payment handled by Zero.

Canonical page: https://www.zero.xyz/host/fastx402.tools
Live health (JSON, refreshed every minute): https://www.zero.xyz/host/fastx402.tools/health.json

## Services

- [FastX402 Lab HMAC Sign & Verify](https://www.zero.xyz/c/fastx402-lab-hmac-sign-verify-9bd8664e/llms.txt): $0.002/call via x402. Computes HMAC-SHA256 or HMAC-SHA512 of a message with a secret key, and optionally verifies it against a provided signature
- [FastX402 Date Arithmetic](https://www.zero.xyz/c/fastx402-date-arithmetic-60d86da7/llms.txt): $0.001/call via x402. Adds or subtracts years, months, weeks, days, hours, minutes, and seconds to a date using calendar-correct rules, returning the ISO result and its weekday.
- [FastX402 Lab – Hash Digest](https://www.zero.xyz/c/fastx402-lab-hash-digest-9b1c37e2/llms.txt): $0.001/call via x402. Computes SHA-1, SHA-256, SHA-384, or SHA-512 cryptographic digest of UTF-8 text, returning the result as hex or Base64
- [FastX402 Lab String Format Validator](https://www.zero.xyz/c/fastx402-lab-string-format-validator-e4cc0b36/llms.txt): $0.001/call via x402. Validates a string against one of 33 named formats (email, URL, UUID, IP addresses, IBAN, JWT, crypto addresses, ISO dates, and more) using validator.js rules
- [FastX402 Lab Email Syntax Checker & Normalizer](https://www.zero.xyz/c/fastx402-lab-email-syntax-checker-normalizer-66b5131f/llms.txt): $0.001/call via x402. Validates email address syntax and returns its normalized form (lowercase, Gmail dots and +tags stripped), local part, and domain — without contacting any mail server.
- [FastX402 Relative Time Formatter](https://www.zero.xyz/c/fastx402-relative-time-formatter-e90ba6df/llms.txt): $0.001/call via x402. Converts two ISO 8601 dates into a human-friendly relative time string (e.g. 'about 3 hours ago') in English, Turkish, German, French, or Spanish, along with the exact difference in seconds.
- [FastX402 Lab URL Inspector](https://www.zero.xyz/c/fastx402-lab-url-inspector-61431096/llms.txt): $0.001/call via x402. Parses an absolute URL using the WHATWG URL standard and returns its normalized form, ASCII and Unicode hostname, port, path, decoded query parameters, and fragment.
- [FastX402 Lab JSON Pointer Extractor](https://www.zero.xyz/c/fastx402-lab-json-pointer-extractor-38fdc28f/llms.txt): $0.001/call via x402. Extracts a single value from a JSON document using an RFC 6901 JSON Pointer path expression.
- [FastX402 Lab Date Period Boundaries](https://www.zero.xyz/c/fastx402-lab-date-period-boundaries-c947579e/llms.txt): $0.001/call via x402. Returns the start and end timestamps of the day, week, month, quarter, or year that contains a given date, with a configurable week start day.
- [FastX402 Lab ERC-20 Calldata Decoder](https://www.zero.xyz/c/fastx402-lab-erc-20-calldata-decoder-85f84b23/llms.txt): $0.002/call via x402. Decodes ERC-20 transfer, approve, and transferFrom calldata hex into human-readable function name, checksummed addresses, and token amounts
- [FastX402 Lab – EIP-55 Ethereum Address Checksum](https://www.zero.xyz/c/fastx402-lab-eip-55-ethereum-address-checksum-3955c975/llms.txt): $0.001/call via x402. Returns the EIP-55 checksummed form of an Ethereum/EVM address and validates whether the given casing is a correct checksum
- [FastX402 Lab – Date Info](https://www.zero.xyz/c/fastx402-lab-date-info-a27eb471/llms.txt): $0.001/call via x402. Returns calendar facts for a given ISO 8601 date: weekday, ISO week number, week-year, day of year, quarter, days in month, leap year flag, weekend flag, and Unix timestamp.
- [FastX402 Lab JWT Decoder](https://www.zero.xyz/c/fastx402-lab-jwt-decoder-a7509926/llms.txt): $0.001/call via x402. Decodes a JWT's header and payload, reporting algorithm, issue/expiry times, expiration status, and seconds until expiry — without verifying the signature.
- [FastX402 Lab – URL Slug Generator](https://www.zero.xyz/c/fastx402-lab-url-slug-generator-646114fc/llms.txt): $0.001/call via x402. Converts any text title or phrase into a clean URL slug, with correct handling of Turkish and other accented/Unicode characters
- [FastX402 Solidity Selector & Event Topic Calculator](https://www.zero.xyz/c/fastx402-solidity-selector-event-topic-calculator-84b478d7/llms.txt): $0.001/call via x402. Computes the 4-byte function selector and 32-byte event topic hash from a Solidity function or event signature string.
- [FastX402 DNS Lookup](https://www.zero.xyz/c/fastx402-dns-lookup-0541cda0/llms.txt): $0.001/call via x402. Performs a DNS lookup for a given domain name and returns structured DNS record data including answers, TTL, and status.
- [FastX402 Domain WHOIS Lookup](https://www.zero.xyz/c/fastx402-domain-whois-lookup-29f58cb4/llms.txt): $0.002/call via x402. Returns WHOIS registration data for a given domain name, including registrar, creation/expiry dates, nameservers, and status flags.
- [FastX402 Lab – Localized Date Formatter](https://www.zero.xyz/c/fastx402-lab-localized-date-formatter-14a70928/llms.txt): $0.001/call via x402. Formats an ISO 8601 date using a date-fns/Unicode pattern in one of five locales (English, Turkish, German, French, Spanish)
- [FastX402 Lab CSV to JSON Converter](https://www.zero.xyz/c/fastx402-lab-csv-to-json-converter-1a724f4e/llms.txt): $0.002/call via x402. Converts RFC 4180-compliant CSV text into structured JSON rows, supporting optional headers and multiple delimiters (comma, semicolon, tab, pipe).
- [FastX402 Bitcoin Fee Rates](https://www.zero.xyz/c/fastx402-bitcoin-fee-rates-8e1bb6e2/llms.txt): $0.003/call via x402. Returns current Bitcoin network fee rates (sat/vbyte) and mempool statistics for main, testnet3, or testnet4
- [FastX402 Semver Match](https://www.zero.xyz/c/fastx402-semver-match-0b993871/llms.txt): $0.002/call via x402. Given a list of semantic versions and a semver range constraint, returns which versions satisfy the constraint along with the highest matching version and match count.
- [FastX402 RFC 3339 Timestamp Normalizer](https://www.zero.xyz/c/fastx402-rfc-3339-timestamp-normalizer-db8ec307/llms.txt): $0.001/call via x402. Normalizes an RFC 3339 / ISO-8601 timestamp into UTC and returns structured date/time components including Unix epoch values and UTC offset
- [FastX402 CIDR Calculator](https://www.zero.xyz/c/fastx402-cidr-calculator-9d4c3bff/llms.txt): $0.002/call via x402. Calculates network details for an IPv4 CIDR block (netmask, broadcast, host range, usable hosts) and optionally tests whether a given IP address falls within that block.
- [FastX402 Lab – Base64 / Base64url Encode & Decode](https://www.zero.xyz/c/fastx402-lab-base64-base64url-encode-decode-dc2fd8d3/llms.txt): $0.001/call via x402. Encodes UTF-8 text to standard Base64 or Base64url, or decodes Base64/Base64url back to UTF-8 text, returning exact results safe for HTTP headers, data URLs, and API payloads.
- [FastX402 Lab – Punycode Domain Converter](https://www.zero.xyz/c/fastx402-lab-punycode-domain-converter-4911d76d/llms.txt): $0.001/call via x402. Converts internationalized domain names between Unicode (münchen.de) and ASCII Punycode (xn--...) forms for use in DNS lookups, certificate checks, and domain comparisons.
- [FastX402 Byte Size Parser](https://www.zero.xyz/c/fastx402-byte-size-parser-3827b00e/llms.txt): $0.001/call via x402. Parses a human-readable byte size string (e.g. '1.5 MiB', '800 KB') and returns its canonical SI and IEC representations along with the exact byte count.
- [FastX402 Web Page to PDF Converter](https://www.zero.xyz/c/fastx402-web-page-to-pdf-converter-0769b412/llms.txt): $0.005/call via x402. Fetches a web page by URL and returns it as a base64-encoded PDF, with optional paper size selection.
- [FastX402 Screenshot – Web Page Screenshot Capture](https://www.zero.xyz/c/fastx402-screenshot-web-page-screenshot-capture-a3acc8fe/llms.txt): $0.005/call via x402. Captures a screenshot of any public web page (by URL) and returns a base64-encoded PNG image, with configurable viewport width and full-page support.
- [Keccak-256 Hash via FastX402](https://www.zero.xyz/c/keccak-256-hash-via-fastx402-abadff99/llms.txt): $0.001/call via x402. Computes the Keccak-256 (Ethereum-native SHA-3) hash of a UTF-8 string or hex-encoded bytes, returning the hex digest and input byte count.
- [FastX402 Audio Transcription](https://www.zero.xyz/c/fastx402-audio-transcription-3cee29fe/llms.txt): $0.01/call via x402. Transcribes an audio file (mp3, m4a, wav, ogg, webm, flac) at a given URL into text with timestamps and language detection, paid per-call in USDC via x402.
- [FastX402 Web Page Extractor](https://www.zero.xyz/c/fastx402-web-page-extractor-ee05ece3/llms.txt): $0.002/call via x402. Fetches and extracts the visible text content, title, and description from any public web page URL via a pay-per-call HTTP GET request
- [FastX402 PDF Text Extractor](https://www.zero.xyz/c/fastx402-pdf-text-extractor-fdf932e4/llms.txt): $0.002/call via x402. Fetches a PDF from a given URL and extracts its full text content along with metadata like page count, title, and author
- [FastX402 x402 Payment Header Decoder](https://www.zero.xyz/c/fastx402-x402-payment-header-decoder-f7370386/llms.txt): $0.001/call via x402. Decodes a base64-encoded x402 PAYMENT-REQUIRED header into human-readable payment details including network, token, amount, recipient address, and timeout.
- [FastX402 Holiday Date Check](https://www.zero.xyz/c/fastx402-holiday-date-check-5b9f9f15/llms.txt): $0.003/call via x402. Checks whether a specific date is a public holiday in a given country, returning holiday name, type, and metadata.
- [FastX402 Token Unit Converter](https://www.zero.xyz/c/fastx402-token-unit-converter-0668a885/llms.txt): $0.001/call via x402. Converts a token amount between its human-readable decimal form and its on-chain atomic (integer) unit representation given a token's decimal precision.
- [FastX402 OCR – Image Text Extraction](https://www.zero.xyz/c/fastx402-ocr-image-text-extraction-9539bf16/llms.txt): $0.003/call via x402. Extracts text from a publicly accessible image URL using OCR, supporting English and Turkish languages

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

- [Zero catalog index](https://www.zero.xyz/llms.txt)