the402 x402 endpoint directory

获取任意位置的天气

Individual arena strategy signal

CoinStats latest crypto news feed — articles on Bitcoin, Ethereum, DeFi, NFTs, regulation

Encode or decode Base64 safely for $0.001 USDC; bounded, deterministic, and keyless.

Convert Unix, ISO 8601, and human timestamps for $0.001 USDC with one normalized response.

Estimate GPT- and Claude-style token counts for a text payload for $0.001 USDC; deterministic and keyless.

UUID generator API for agents: generate one to ten UUIDv4 identifiers for $0.001 USDC with no API key or subscription.

JSON validation API for agents: validate, normalize, and pretty-print a bounded JSON payload for $0.001 USDC with stru

Mint a stateless captcha challenge to gate your OWN endpoint: returns a human prompt plus a salted sha256 answer hash

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

Wrap text to a specified column width, breaking at word boundaries. Words longer than the width are forcibly broken. A

Compute the Jaccard similarity coefficient between two strings using character bigrams or word tokens. Returns the rat

Derive a cryptographic key from a password using scrypt (RFC 7914). Memory-hard by design, making it more resistant to

Compute combinations C(n, r) or permutations P(n, r) using BigInt for exact arbitrary-precision results. Returns the r

Convert text to its binary (base-2) representation (8-bit per character, space-separated) or decode binary back to tex

Expand a compressed IPv6 address to full 8-group notation (:: to 0000:...) or compress a full address by collapsing th

Parse and format phone numbers into E.164 and national formats. Supports US (+1), UK (+44), DE (+49), FR (+33), AU (+6

Top N words and bigrams from text. Lowercase, strip punctuation, filter common English stop words. Returns sorted word

Parse a standard 5-field cron expression (minute hour day-of-month month day-of-week) and return a human-readable expl

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

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

Generate a coordinated palette from a base color using a named color-theory scheme: complementary (2 colors), analogou

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

Group an array of objects by one or more keys and aggregate a numeric field — count (default), sum, avg, min, or max.

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.

Parse a duration like "2h30m" / "1d4h" / "90s" to seconds, or humanize a number of seconds.

Run a regular expression against text. Returns up to 100 matches with index and capture groups. Pattern ≤ 200 chars, t

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.

Compute the date of Easter Sunday for a given year using the Anonymous Gregorian algorithm (Meeus/Jones/Butcher). Also

Analyze the character frequency distribution of a string. Returns counts by category (letters, digits, spaces, punctua

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

Derive a cryptographic key from a password using PBKDF2 (RFC 8018). Returns the hex-encoded derived key along with all

Compute the greatest common divisor (Euclidean algorithm) and least common multiple of two positive integers. Also rep

Compute the American Soundex (NARA) phonetic hash code for one or more words. Soundex maps similar-sounding names to t

Auto-detect the encoding format of a string: base64, base32, hex, binary, decimal, or plain text. Returns confidence s

Generate a URL-safe slug from any string. Handles accented characters (normalize NFD), replaces non-alphanumeric with