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API recommendation and x402 discovery for your task. Required query: need. Which API should I call? Recommends which x402 API to use for any task, with evidence. Describe a task in plain words. Compare up to five paid APIs, URLs, prices, payment networks and invocation details. Includes paid delivery evidence and risk flags. Provider calls are paid separately. No picks / non-2xx is never charged.

Real-time Bitcoin price in USD, a median across 10 exchanges including Binance, Coinbase, Kraken and Bullish — Ed25519 signed attestation

Get Arkham intelligence for an address. $0.20 per call.

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Validate IBAN structure and MOD-97 checksum. Does not establish account ownership, beneficiary identity or absence of fraud.

x402 debugging/troubleshooting Q&A: Ask any question, get a cited answer. Whether you need HTTP 402 Payment Required help, facilitator verify & settle (CDP @coinbase/cdp-sdk), Bazaar discovery metadata & listing, protocol documentation, Next.js paid routes, or planning, building, and integrating x402 servers: @x402/core @x402/next @x402/express @x402/hono @x402/fastify @x402/fetch @x402/axios @x40

Spot Check. REQUIRES ?host= on the paid request — a signed request without it is refused before the gate and no money moves. Name a host and get what this observatory already holds on it, signed: corpus rounds and verdicts as recorded, when we last actually knocked, our coverage of the window since we met it, and the gaps with their reasons. Read from the books at the counter — no request is made

TCGPlayer current prices for every card in a set — useful for set value tracking and sealed Pokemon / Magic / Yu-Gi-Oh product pricing.

Japanese business-day calculator: check if a date is a business day, add N business days to a date, or count business days in a range. Accounts for weekends and Japanese national holidays; optional Saturday and year-end/new-year rules.

VAT calculator for EU-27 + UK: net→gross or gross→net at standard or reduced rate. Includes rates table snapshot date.

safe arithmetic eval (+ - * / % ^ parens)

MIDAX402: Evidence+ x402 intelligence with expanded corpus retrieval, local risk brief, contradiction scan and concrete action plan. We do not grade our own answer: the verdict is answered or needs_more_data (grounded in the corpus or not); evidence_grade (thin/moderate/broad) grades that evidence, auditable via retrieved_corpus_ids. confidence_score is DEPRECATED, still served as a band projectio

Live feed of every active rail disruption across the Japanese (JP) network in one call — delays and suspensions with bilingual summaries, refreshed continuously from ODPT. Built for MONITORING agents: poll on an interval (e.g. every 5 minutes) to maintain a nationwide incident watchlist without querying stations one by one.

Translation tuned for skilled-trade work: HVAC, refrigeration, electrical and construction terms stay correct instead of collapsing into a generic word. Handles text typed fast without accent marks.

npm breaking changes between two versions of a package, before a package upgrade: the documented breaking changes per version, read from the real CHANGELOG, GitHub release notes and alpha/beta/rc notes, plus major version bumps, Node.js engine, ESM/CJS, exports and peer dependency changes, migration guide links and a verdict. Exact versions or a major ('4'); a source URL for every item. One call p

Official public holidays by country and year, with regional subdivisions, localized names and normalized dates.

Beer, wine and cider alcohol by volume from original and final gravity, with both standard formulas and attenuation.

Age in years, months, days and days lived, Korean and East Asian ages, next birthday with leap-day rules, and zodiac.

Find US court cases, opinions and dockets naming a business, with case name, court, date, citation, docket number and nature of suit.

Complex number arithmetic, modulus and argument, integer powers, square root and n-th roots, in rectangular and polar form.

BitBooth echo endpoint — pays a tiny USDC fee, returns a JSON echo. Reference implementation of the x402 + CDP Facilitator + Bazaar discovery loop.

Asteroids and comets passing Earth within a lunar-distance limit in the next or last N days: distance, speed, size range.

Determinant of a square matrix (up to 10x10) by LU with partial pivoting, flagging a numerically singular matrix.

Board feet for lumber from thickness, width, length and quantity (nominal sizes), with total cost at a price per board foot.

Estimate quarter-mile time and trap speed from weight and horsepower (Hale), plus a power-limited lower bound for 0-60 mph.

Great-circle distance (miles, km, feet, nautical miles) and initial compass bearing between two latitude/longitude points.

Score needed on a final exam (or any remaining work) to reach a target class grade, from current grade and its weight.

Tip and even bill split in exact cents: tip on subtotal or total, shares that add up, optional round up to whole dollars.

Density altitude from field elevation, altimeter setting and temperature, exact and by rule of thumb, with a performance flag.

How many identical boxes fit inside a larger box or crate: best of six orientations in a simple grid, with utilization.