the402 x402 endpoint directory

Rotate an image by degrees and/or flip it horizontally or vertically.

Fetch a page, strip boilerplate, and return word count, character count, and reading time.

Get the lead summary, thumbnail, and URL for any Wikipedia article title.

Search Hacker News stories and comments by query, sorted by relevance or date (Algolia HN).

RFC-5322-ish syntax check plus disposable / role-account / free-provider flags.

Test a regex against text; returns matches, capture and named groups, and spans.

Parse CSV/TSV (RFC 4180) into a JSON array of row objects (or arrays).

Flatten a JSON array of objects into CSV with a header row.

Unified diff between two texts, plus added/removed line counts and a similarity ratio.

Parse a phone number to E.164, detect its country calling code and region, and validate length against the E.164 stand

Compute the WCAG 2.1 contrast ratio between a foreground and background color and report AA/AAA pass/fail for normal a

Convert amounts between Ethereum denominations (wei, kwei, mwei, gwei, szabo, finney, ether) with exact integer/decima

ISO 13616 mod-97 IBAN validation with per-country length rules, plus SWIFT/BIC structure validation and country/bank-c

CIDR math for IPv4/IPv6: network, broadcast, netmask, wildcard, prefix, usable host range and count, mask<->prefix, pl

Parse a User-Agent string into browser, version, engine, OS, device class, and bot/AI-crawler flag (GPTBot, ClaudeBot,

Validate and lint JSON, YAML, CSV, or XML. Returns a valid flag, the line/column of the first error when invalid, and

Interconvert tabular data across CSV, TSV, JSON (array of objects), and NDJSON/JSONL. RFC 4180 CSV parsing; great for

Bidirectional JSON/YAML transcode for config files, Helm values, K8s manifests, and CI workflows. Give the source stri

Validate a JSON instance against a JSON Schema (draft 7 / 2020-12 subset); returns a valid flag plus per-field errors

Heuristic token-count estimate for a text (character- and word-based) plus an illustrative per-model input-cost projec

Regex-based entity extraction: pulls emails, URLs, IPv4 addresses, phone numbers, hashtags, mentions, money amounts, a

Regex-based PII redaction: masks emails, phone numbers, SSNs, credit-card numbers, and IP addresses, returning cleaned

Convert a supplied HTML string to clean Markdown: strips scripts/style/nav, preserves headings, bold, italic, links, l

Render common Markdown (headings, bold/italic, links, inline code, fenced code, blockquotes, ordered/unordered lists)

Top-N single tokens and two-word phrases by frequency, with stopword removal and normalized weights.

Word/sentence/syllable counts, reading time, plus Flesch Reading Ease, Flesch-Kincaid, Gunning Fog, SMOG, ARI, and Col

Spell a number in English words: cardinal, ordinal, or currency (dollars and cents) form for checks and invoices.

Deterministically mask emails, phone numbers, credit-card-like numbers, IPv4 addresses, and US SSNs in text. Returns r

One-call date math: diff two datetimes, add/subtract an interval, epoch<->ISO conversion, and reformatting via strftim

Add/subtract business days to a date, or count working days between two dates. Weekend- and custom-holiday-aware (0=Mo

Parse a 5/6-field cron expression or @macro: plain-English summary, per-field breakdown, and the next N run times from

Classify an IPv4/IPv6 address: version, public/private/loopback/link-local flags, integer and hex forms, reverse-DNS p

Compute the keccak256 hash and 4-byte function selector of a signature string, and optionally ABI-decode raw hex calld

Compute a 64-bit SimHash fingerprint for content, or compare two texts and return the Hamming distance and a 0-1 simil

Pull deduped lists of emails, URLs, IPv4 addresses, @mentions and #hashtags out of free text, with counts.

Compute md5, sha1, sha256, sha512, sha3-256 and crc32 digests of text (or hex bytes) in a single call. Returns hex for

Convert a color across hex/rgb/hsl/hsv/cmyk and (optionally) compute the WCAG contrast ratio and AA/AAA pass against a

Generate a solid-color placeholder image with optional centered text (no input image needed).

Report format, dimensions, mode, aspect ratio, transparency, and byte size of an image.

Crop an image to a box (left, top, right, bottom in pixels).

Rotate an image by degrees and/or flip it horizontally or vertically.

Fetch a page, strip boilerplate, and return word count, character count, and reading time.

Search Hacker News stories and comments by query, sorted by relevance or date (Algolia HN).

Get the lead summary, thumbnail, and URL for any Wikipedia article title.

RFC-5322-ish syntax check plus disposable / role-account / free-provider flags.

Test a regex against text; returns matches, capture and named groups, and spans.

Flatten a JSON array of objects into CSV with a header row.

Parse CSV/TSV (RFC 4180) into a JSON array of row objects (or arrays).

Unified diff between two texts, plus added/removed line counts and a similarity ratio.

Decision procedure and verification schema for accepting a cryptographically signed AP2 payment mandate before settlem