the402 x402 endpoint directory

Get the ISO 8601 week number, ISO day-of-week, quarter, and day-of-year for any date. Useful for fiscal/reporting cale

Parse a datetime from any format (ISO 8601, Unix timestamp in seconds or milliseconds, RFC 2822, or natural date strin

Look up the Uniswap V3 pool address for a token pair + fee tier on Ethereum, Base, Polygon, Arbitrum, or Optimism. Pas

Convert a nominal annual rate (APR) compounded m times per year into the effective annual rate (EAR / APY): (1 + apr/m

Compound annual growth rate between a beginning and ending value over N years: (end/begin)^(1/years) - 1. Also returns

Build the full per-period amortization schedule for a fully-amortizing loan. Each row reports the period number, payme

Holt's linear trend method - level + trend (no seasonality). Two smoothing parameters: alpha (level) and beta (trend).

Compute simple (SMA) and exponential (EMA) moving averages over a numeric series. Returns one value per input position

Run the same input through gzip, brotli, and raw deflate at max settings and report each one's output size and ratio.

Compress a string with gzip (RFC 1952) and return it as base64. Reports input bytes, output bytes, and the compression

Extract a <table> from an HTML string as JSON rows (header-keyed) or CSV. Useful for prices, schedules, sports stats,

L2 order-book snapshot for a spot pair: best bid/ask, mid price, spread (absolute + %), and the top N aggregated price

Great-circle distance between two latitude/longitude points using the haversine formula. Returns kilometers and miles.

Multi-period weather forecast for a US location from api.weather.gov (NWS, public domain). Give latitude and longitude

Search autocomplete: query suggestions for a partial input as a flat JSON array. Useful for query expansion, did-you-m

Validate an ISBN-10 or ISBN-13 checksum (hyphens/spaces ignored) and report which format it is.

Count business days (Mon–Fri) between two dates, inclusive of the start, exclusive of the end. Optional list of holida

Descriptive statistics for an array of numbers: count, sum, mean, median, mode, min, max, range, variance, stddev, and

Deep-merge two JSON objects (b wins on conflicts; arrays are concatenated).

Sort the lines of a text. order: asc (default) | desc | numeric. unique:true removes duplicates; ci:true is case-insen

Validate an IBAN: country code, length, and the ISO 13616 mod-97 checksum.

Heuristic user-agent string parser: browser, version, OS, device class, and bot detection.

Deep-compare two JSON values. Returns a list of changed/added/removed paths (capped at 1000 differences).

Generate ULIDs (sortable, timestamp-prefixed identifiers). ?count=1..100.

Hex encode or decode text. mode: encode (default) or decode.

Delete a remembered document by id from the recall store.

Verify an Ed25519 execution certificate against the exact SQL statement you are about to run - the gate your database

Convert between Unix epoch timestamps and ISO 8601 date strings in both directions. Provide either an epoch (seconds o

Compute MD5, SHA-1, SHA-256, SHA-512, and CRC32 checksums of a string in a single call. Useful for verifying file or p

Convert a datetime from one IANA timezone to another. Accepts ISO 8601, Unix timestamps (seconds or milliseconds), or

Look up the current Total Value Locked (TVL) for a DeFi protocol via DeFiLlama's public API. Identify the protocol by

Resolve the metadata for a single NFT: title, description, image URLs (original + cached CDN), attributes/traits, and

Break-even point for a product: the units and revenue at which total revenue covers fixed plus variable costs. Also re

Price a fixed-coupon bond from its yield to maturity: present-value the coupons plus face. Returns clean price, coupon

Compute the monthly (or per-period) payment on a fully-amortizing loan: mortgage, auto, student loan, business loan. R

Simple exponential smoothing (SES) - level-only forecast for series without trend or seasonality. Higher alpha (closer

Fit a least-squares line y = slope·x + intercept to two equal-length series. Returns slope, intercept, r² (variance ex

Decompress a base64-encoded Brotli payload. Returns the result as utf8 (text) or base64 (binary). Refuses to expand pa

Extract <title>, <meta description>, OpenGraph/Twitter cards, canonical URL, and JSON-LD blocks from an HTML string. D

Run a CSS selector against an HTML string and return the matches (text, attrs, and optionally outerHTML for each). The

Pure-CPU helper: turn a B20 feature string (e.g. base.b20_asset) into its bytes32 feature id and ready-to-send isActiv

Convert between a JSON array and JSONL/NDJSON (one JSON object per line). mode: to-jsonl (array → lines) or from-jsonl

Validate a UUID and report its version (1-8) and variant. Accepts hyphenated or braced forms.

Add (or subtract) a duration to a date. duration like "2d", "-3h", "1w 2d", "90m". Returns the resulting UTC ISO times

Format a number: thousands separators, fixed decimals, optional currency, or compact (1.2K / 3.4M).

Flatten nested JSON to dot-path keys, or unflatten dot-path keys back to nested JSON. mode: flatten (default) | unflat

Truncate text to a maximum length, adding an ellipsis (or custom suffix). Optionally break on word boundaries.

Fetch a site's robots.txt and answer: may this user-agent crawl this path? Returns the matched rule and all declared s

Look up a MIME type by file extension (?ext=png) or extensions by MIME type (?type=image/png). Covers ~50 common types

Parse a URL into components: protocol, host, port, path, query params (decoded), hash, origin, punycode hostname.