the402 x402 endpoint directory

RDAP domain lookup — status, registration/expiration dates, registrar, name servers (RDAP is the structured, successor

Foreign exchange / currency conversion reference rates (European Central Bank) for a base currency, source Frankfurter

DNS records lookup for a domain: A, AAAA, MX, TXT, NS. A record type with no entries returns an empty array, not an er

Current TVL (total value locked) of an entire blockchain (all protocols combined) — chain-wide TVL, source DefiLlama.

Circulating market cap of the top stablecoins (USDT, USDC, DAI...), highest first, source DefiLlama. Optional paramete

Top DeFi protocols ranked by TVL (total value locked), highest first, source DefiLlama. Optional parameter: ?limit=<n>

Current gas price on an EVM blockchain, read live via a public RPC endpoint (viem) — no API key, no aggregator. Also a

Latest known block (number, timestamp, hash) of an EVM blockchain, read live via a public RPC endpoint (viem) — no API

Email validation — Syntax check + live MX/deliverability + disposable-domain flag.

DNS lookup — Resolve DNS records via DNS-over-HTTPS.

Stock quote — Delayed quote & key stats for an equity/ETF/index.

Business-day math — Count business days in a range, or add/subtract N business days, skipping weekends & holidays.

Galer 1997 Neuropathic Pain Scale from ten caller-assigned 0-10 items (intensity, sharpness, heat, dullness, cold, sen

Barber 2000 ASPECTS: 10 minus 1 for each caller-assigned MCA region with early ischemic change (C caudate, L lentiform

Sansoni 2008 RUIS: five caller-assigned integers for urgency leakage, activity leakage, and drops leakage (each 0-3),

Scalea 1999 FAST four Ps (pericardial, perihepatic, perisplenic, pelvic). Each window is a caller-assigned boolean for

2023 emergency medical decision making from AMA CPT Table 1 as reprinted by ACEP. Caller assigns problems, data, and r

ACIP 2025 Table 2 catch-up minimum age and previous-dose interval. Eligible if age_months meets the printed minimum an

AABB Standards 28th ed. Standard 5.14 RBC ABO/Rh compatibility from caller-assigned recipient and unit ABO (o, a, b, a

Berend 2014 physiological acid-base assessment. Labels acidemia or alkalemia, primary metabolic vs respiratory process

INS gravity drip rate: gtt/min = (volume_ml × drop_factor_gtt_ml) / time_min, rounded half away from zero to an intege

Net fluid balance in mL: caller-assigned total intake minus total output over the same interval. Optional oral plus IV

AAP 2022 Kemper KAS 10 intensive phototherapy threshold from Supplemental Tables 1 and 2 by completed GA, age in hours

Jacobs 2022 Table 3 Cox linear predictor for overall survival after resected major salivary gland cancer with versus w

McGinnis 2024 VACS-CCI Table 2 Model 7 linear predictor from sex, age, hemoglobin, FIB-4, eGFR, albumin, WBC, BMI, hep

Garibaldi 2020 CIRC day-2/4/7 probability of severe disease or death from admission age, nursing-home residence, calle

AHA/ACC 2018 Table 4 very high-risk ASCVD for known clinical ASCVD. Very high-risk if ≥2 major events (recent ACS, pri

Maurer 2025 FLIPI24: 24-month event probability in newly diagnosed follicular lymphoma from age (nonlinear, inflection

DeCarolis 2007 MINDS (Minnesota Detoxification Scale) 0-46: pulse and diastolic BP lt_90/90_to_110/gt_110 → 0/1/2; tre

Lefere 2025 pFIB-c logistic probability of significant (>=F2) liver fibrosis in pediatric MASLD from sex (boy/girl), h

Fox 2017 GARFIELD-AF 1-year all-cause mortality, ischaemic stroke/systemic embolism, and major bleed from age, sex, we

Armstrong 2018 PREVAIL Cox linear predictor for overall survival in chemotherapy-naïve metastatic castration-resistant

Tate 2019 VACS Index 2.0 (not 1.0): age, CD4, HIV-1 RNA, hemoglobin, caller-assigned FIB-4 and eGFR, hepatitis C, albu

Liang 2020 COVID-GRAM logistic probability of critical illness (ICU, invasive ventilation, or death) among hospitalize

OPTN Policy 9 Table 9-1 PELD-Cr from age, albumin, bilirubin, INR, creatinine or dialysis/CVVHD, and caller-assigned m

Mahmud 2021 VOCAL-Penn 30-day postoperative mortality logistic for cirrhosis. log_odds = -5.472096 + 1.061725*ASA + 0.

Levy 2006 Seattle Heart Failure Model 1-, 2-, and 3-year survival from Table 2 multivariate HRs. Score = sum of ln(HR)

Maupain 2016 CAHP nomogram after OHCA. Integer points from age, home vs public arrest, shockable vs non-shockable rhyt

Webb 2022 Table 6 simplified score for 14-day hospitalization and 28-day mortality. Age decade lookup 0-10=0.5 through

King 2020 VACO Index logistic 30-day all-cause mortality from age, sex, caller-assigned unadjusted Charlson comorbidit

Wang 2024 SEX-SHOCK Supplementary Table S13 sex-specific integer nomogram for in-hospital cardiogenic shock after ACS

Khan 2019 PCP-HF 10-year incident heart-failure percent for age 30-79 from sex, caller-assigned white or black cohort,

Grobman 2007 first prenatal visit logistic probability of vaginal birth after cesarean from maternal age, prepregnancy

Levine 2020 CHOSEN (COVID Home Safely Now): age 18-45 +5, 46-59 +2, 60-73 +1, >73 +0; SpO2 <94 +0, 94-96 +9, 97-98 +14

Granger 2003 in-hospital GRACE 1.0: integer nomogram points from age, heart rate, systolic BP, creatinine (mg/dL or µm

Peterson 2010 GWTG-HF Figure 2 integer points for in-hospital mortality in hospitalized heart failure: age 0-28, systo

Goff 2013 ACC/AHA pooled-cohort 10-year hard ASCVD percent for age 40-79 from sex, caller-assigned white or african_am

Chen 2010 AUSDRISK Box 3 waist model (not BMI). Male 3; age 18-34 0, 35-44 2, 45-54 4, 55-64 6, >=65 8; ancestry atsi_

VanWagner 2017 CAR-OLT integer points (Table 3) for 1-year CVD complication after first orthotopic liver transplant: a

Licurse 2010 AKI hydronephrosis points: history of hydronephrosis +4; nonblack (black=false) +1; recurrent UTI +1; obs