Read the text out of a QR code or barcode in a PNG or JPEG image. Auto-detects QR, DataMatrix, PDF417, Aztec and 1D symbologies (Code128/39/93, EAN-13/8, UPC-A/E, ITF, Codabar). A valid image with no code returns { found: false }; a payload that is not a parseable image is a 400.

Discover a site's XML sitemaps (via robots.txt Sitemap: directives, an explicit sitemap URL, or the conventional /sitemap.xml) and parse them into a bounded list of URLs with their lastmod, changefreq and priority. Follows sitemap-index files to their child sitemaps. Fetches and URL counts are capped (with a `truncated` flag) to stay fast and memory-bounded. The reliable way for an agent to enumerate a site's pages.

Format a card number into the conventional display groups for its network (4-6-5 for Amex, 4-6-4 for 14-digit Diners, otherwise groups of four).

Detect the issuing network/brand (Visa, Mastercard, American Express, Discover, Diners Club, JCB, UnionPay, Maestro) from the card's IIN prefix, with the network's valid lengths. Returns `network:null` for an unrecognized prefix.

Expand an RRULE recurrence rule into its occurrence datetimes, with a human-readable description.

TraceFast knowledge graph: the relations an address holds now — which implementation a proxy points at, which beacon it reads, who administers it, where an account has delegated, which lending market lists a token — as the subject (`direction=subject`: what it points at, default) or as the object (`direction=object`: who points at it). Path: address. Query: direction, attributeId, limit, cursor (see docs). Docs: https://docs.tracefast.xyz/api/address-relations.md

Euclidean, Manhattan and Chebyshev distance between two 2-D points.

Read an ERC-20 balance with symbol, decimals and a formatted amount — one call, no ABI work, live from Base mainnet, for a fraction of a cent. No API key, no account — a wallet is the only requirement, and you are charged only if the read succeeds. Plain unsigned data; the attested version of chain reads is /v1/oracle/onchain. Answers are read at the moment of the call and stamped with the block they came from where applicable.

Compute the determinant of a square matrix via Gaussian elimination with partial pivoting. A non-square, ragged or empty matrix is a clean 400; a singular matrix simply returns 0.

Bitwise XOR across two or more non-negative integers (given as decimal strings, evaluated as arbitrary-precision BigInt). Returns the result in decimal, hex and binary.

Transcode a document between json, json5, jsonc, yaml, xml, csv, tsv, toml, ndjson, ini, env, properties, plist and querystring. Any source converts to any target through a JSON hub. Malformed input or a target that cannot represent the structure is rejected before payment.

Report whether two tokens sound alike under a chosen algorithm (soundex, metaphone or double-metaphone; default double-metaphone). Returns each token's codes and a boolean match.

One's-complement NOT of a non-negative integer within an explicit bit width (two's-complement domain). The value must fit in `width` bits. Returns decimal, hex and binary.

Estimate reading and speaking time for a text at configurable words-per-minute rates (defaults: 200 wpm reading, 130 wpm speaking).

Compute the astronomical Julian Date (JD, fractional, epoch noon 1 Jan 4713 BC) and Modified Julian Date (MJD = JD − 2400000.5) of a UTC instant. Unlike `calendar`'s integer Julian Day Number, this carries the time-of-day fraction.

Jaccard similarity index in [0,1] — the size of the intersection over the union of the two strings' character-bigram sets.

Compute the molar mass (g/mol) of a chemical formula. Supports nested parentheses and brackets, element multipliers, and hydrate dot notation with coefficients (e.g. "Ca(OH)2", "CuSO4·5H2O", "K4[Fe(CN)6]"). Returns the total mass and the per-element composition with mass fraction percentages.

Apply an RFC 6902 JSON Patch to a JSON document and return the result. An invalid or unresolvable patch (e.g. a failed `test`, or a path that does not exist) is rejected before payment.

Test whether a version satisfies a semver range (^, ~, x-ranges, ||, hyphen).

Encode a UTF-8 string into base64, base64url, hex, base32, or URL percent-encoding.