# HFA-ICOS anthracycline baseline CV risk HFA-ICOS anthracycline baseline CV risk Status: LIVE Price: $0.005 USDC `GET /api/calc/hfa_icos_anthracycline` HTML: https://magentlab.com/docs/hfa-icos-anthracycline Markdown: https://magentlab.com/docs/hfa-icos-anthracycline.md Not a medical device. Not a diagnosis, dose, or listing recommendation. ## What it computes Apply the Lyon 2020 HFA-ICOS anthracycline baseline cardiovascular risk proforma from caller-assigned age, LVEF, and published Very high, High, Medium 2, and Medium 1 factors. Returns risk_level, medium_points, and the paper's expert-opinion cardiotoxicity_guide. ## When to use When an agent already has the published anthracycline-table assignments (age, LVEF, and yes/no factors) and needs the HFA-ICOS class. magent does not examine the patient, read imaging, assay labs, or compute BMI. ## When not to use - Not a medical device and not a diagnosis or treatment order. - magent does not examine the patient or read imaging. Age, LVEF, and yes/no factors are caller-assigned. - Classification follows Lyon 2020: very high if any Very high factor; else high if any High factor or medium_points >=5; else medium if medium_points 2-4; else low (no factors or one Medium 1). - medium_points sums only Medium 1 (1) and Medium 2 (2). High and Very high do not add to medium_points. - Age bands are mutually exclusive (highest matching): >=80 High; 65-79 Medium 2; <65 none. LVEF: <50 High; 50-54 Medium 2; >=55 none. - Troponin, BNP or NT-proBNP, hypertension, diabetes, CKD, and obesity are caller-assigned from the published local-ULN, blood-pressure, HbA1c, eGFR, and BMI >30 cutoffs. magent does not assay labs or compute BMI. - cardiotoxicity_guide is the paper's expert-opinion guide (low <2%, medium 2-9%, high 10-19%, very high >=20%), not a validated absolute risk. - Not a chemotherapy, imaging, or cardioprotective-drug order. ## Formula ``` very_high if heart_failure_or_cardiomyopathy; else high if any High factor (severe_valvular_heart_disease, mi_or_coronary_revascularization, stable_angina, lvef_percent<50, age_years>=80, previous_anthracycline, prior_left_chest_or_mediastinal_rt) OR medium_points>=5; else medium if medium_points in 2..4; else low (no factors or one Medium 1). medium_points sums Medium 1 (=1: elevated_troponin, elevated_bnp, hypertension, diabetes, ckd, previous_non_anthracycline_chemo, current_or_significant_smoker, obesity) and Medium 2 (=2: lvef_percent 50-54, age_years 65-79) only. Age and LVEF use the highest matching printed band. Lyon 2020 HFA-ICOS anthracycline table. cardiotoxicity_guide is that paper's expert-opinion guide: low <2%, medium 2-9%, high 10-19%, very high >=20% ``` ## Citation [Baseline cardiovascular risk assessment in cancer patients scheduled to receive cardiotoxic cancer therapies: a position statement and new risk assessment tools from the Cardio-Oncology Study Group of the Heart Failure Association of the European Society of Cardiology in collaboration with the International Cardio-Oncology Society](https://doi.org/10.1002/ejhf.1920) Lyon AR, Dent S, Stanway S, et al. Eur J Heart Fail. 2020;22(11):1945-1960 DOI: [10.1002/ejhf.1920](https://doi.org/10.1002/ejhf.1920) ## Worked example ### No factors, age 50, LVEF 60 Given: `age_years=50, ckd=false, current_or_significant_smoker=false, diabetes=false, elevated_bnp=false, elevated_troponin=false, heart_failure_or_cardiomyopathy=false, hypertension=false, lvef_percent=60, mi_or_coronary_revascularization=false, obesity=false, previous_anthracycline=false, previous_non_anthracycline_chemo=false, prior_left_chest_or_mediastinal_rt=false, severe_valvular_heart_disease=false, stable_angina=false` 1. no Very high or High factor 2. medium_points = 0 3. risk_level is low 4. cardiotoxicity_guide is <2% ### Age 70 only Given: `age_years=70, ckd=false, current_or_significant_smoker=false, diabetes=false, elevated_bnp=false, elevated_troponin=false, heart_failure_or_cardiomyopathy=false, hypertension=false, lvef_percent=60, mi_or_coronary_revascularization=false, obesity=false, previous_anthracycline=false, previous_non_anthracycline_chemo=false, prior_left_chest_or_mediastinal_rt=false, severe_valvular_heart_disease=false, stable_angina=false` 1. age 65-79 is Medium 2 2. medium_points = 2 3. risk_level is medium ### Heart failure or cardiomyopathy Given: `age_years=50, ckd=false, current_or_significant_smoker=false, diabetes=false, elevated_bnp=false, elevated_troponin=false, heart_failure_or_cardiomyopathy=true, hypertension=false, lvef_percent=60, mi_or_coronary_revascularization=false, obesity=false, previous_anthracycline=false, previous_non_anthracycline_chemo=false, prior_left_chest_or_mediastinal_rt=false, severe_valvular_heart_disease=false, stable_angina=false` 1. Very high factor present 2. risk_level is very_high 3. heart failure does not add to medium_points ### LVEF 45 Given: `age_years=50, ckd=false, current_or_significant_smoker=false, diabetes=false, elevated_bnp=false, elevated_troponin=false, heart_failure_or_cardiomyopathy=false, hypertension=false, lvef_percent=45, mi_or_coronary_revascularization=false, obesity=false, previous_anthracycline=false, previous_non_anthracycline_chemo=false, prior_left_chest_or_mediastinal_rt=false, severe_valvular_heart_disease=false, stable_angina=false` 1. LVEF <50 is High 2. medium_points = 0 3. risk_level is high ### Five Medium 1 factors Given: `age_years=50, ckd=true, current_or_significant_smoker=true, diabetes=true, elevated_bnp=false, elevated_troponin=false, heart_failure_or_cardiomyopathy=false, hypertension=true, lvef_percent=60, mi_or_coronary_revascularization=false, obesity=true, previous_anthracycline=false, previous_non_anthracycline_chemo=false, prior_left_chest_or_mediastinal_rt=false, severe_valvular_heart_disease=false, stable_angina=false` 1. five Medium 1 factors 2. medium_points = 5 3. risk_level is high ## Also searched as - HFA-ICOS anthracycline - HFA ICOS baseline CV risk - Lyon 2020 anthracycline risk - cardio-oncology anthracycline - ESC Heart Failure Association ICOS - anthracycline cardiotoxicity risk - HFA-ICOS very high high medium low - baseline cardiovascular risk anthracycline ## Parameters - `age_years` (integer, required): Age in years (18-100, integer). Lyon 2020: >=80 High; 65-79 Medium 2; <65 no age factor. Highest matching band only. - `lvef_percent` (integer, required): LVEF percent (10-80, integer). Lyon 2020: <50 High; 50-54 Medium 2; >=55 no LVEF factor. Highest matching printed band only. magent does not read imaging. - `heart_failure_or_cardiomyopathy` (boolean, required): Heart failure or cardiomyopathy (Lyon 2020 Very high). true or false as assigned by the caller. magent does not examine the patient or read imaging. - `severe_valvular_heart_disease` (boolean, required): Severe valvular heart disease (Lyon 2020 High). true or false as assigned by the caller. magent does not examine the patient or read imaging. - `mi_or_coronary_revascularization` (boolean, required): Myocardial infarction or previous coronary revascularization (PCI or CABG) (Lyon 2020 High). true or false as assigned by the caller. magent does not read imaging. - `stable_angina` (boolean, required): Stable angina (Lyon 2020 High). true or false as assigned by the caller. magent does not examine the patient. - `previous_anthracycline` (boolean, required): Previous anthracycline exposure (Lyon 2020 High). true or false as assigned by the caller. - `prior_left_chest_or_mediastinal_rt` (boolean, required): Prior radiotherapy to the left chest or mediastinum (Lyon 2020 High). true or false as assigned by the caller. - `elevated_troponin` (boolean, required): Baseline troponin above the local laboratory ULN as assigned by the caller (Lyon 2020 Medium 1). true or false. magent does not assay troponin. - `elevated_bnp` (boolean, required): Baseline BNP or NT-proBNP above the local laboratory ULN as assigned by the caller (Lyon 2020 Medium 1). true or false. magent does not assay natriuretic peptides. - `hypertension` (boolean, required): Hypertension (SBP >140 mmHg or DBP >90 mmHg or on treatment) as assigned by the caller (Lyon 2020 Medium 1). true or false. magent does not measure blood pressure. - `diabetes` (boolean, required): Diabetes mellitus (HbA1c >7.0% or >53 mmol/mol or on treatment) as assigned by the caller (Lyon 2020 Medium 1). true or false. magent does not assay HbA1c. - `ckd` (boolean, required): Chronic kidney disease (eGFR <60 mL/min/1.73 m2) as assigned by the caller (Lyon 2020 Medium 1). true or false. magent does not compute eGFR. - `previous_non_anthracycline_chemo` (boolean, required): Previous non-anthracycline-based chemotherapy (Lyon 2020 Medium 1). true or false as assigned by the caller. - `current_or_significant_smoker` (boolean, required): Current smoker or significant smoking history (Lyon 2020 Medium 1). true or false as assigned by the caller. - `obesity` (boolean, required): Obesity (BMI >30 kg/m2) as assigned by the caller (Lyon 2020 Medium 1). true or false. magent does not compute BMI. ## Bulk (POST) POST the same path with a JSON items array. The first item is the GET unit; each additional item is $0.002. Invalid items return HTTP 400 before settlement. Method: `POST /api/calc/hfa_icos_anthracycline` Max items: 25 Price: unit_amount + extra_item_amount * (n - 1) (unit 5000 atomic, extra 2000 atomic) Status: PREVIEW - 1 to 25 items. Each item uses the same keys as the GET query parameters. - POST of 1 item costs the same as GET. Lists longer than 25: chunk into multiple POSTs. Extra items still execute; do not pad dummy rows. - The first invalid item fails the whole request (index in the 400 JSON). You are not charged. - HTTP 200 is {count, path, items}. Each items[i] is the GET 200 body for that row. - Catalog misses (empty matches, found=false) stay paid 200s inside that slot. - x402 resource URL is this path plus n and body_sha256. Browsers that prefer text/html get the same paywall as GET; Pay retries POST with the same items. Example request: ```json { "items": [ { "age_years": "50", "ckd": "false", "current_or_significant_smoker": "false", "diabetes": "false", "elevated_bnp": "false", "elevated_troponin": "false", "heart_failure_or_cardiomyopathy": "false", "hypertension": "false", "lvef_percent": "60", "mi_or_coronary_revascularization": "false", "obesity": "false", "previous_anthracycline": "false", "previous_non_anthracycline_chemo": "false", "prior_left_chest_or_mediastinal_rt": "false", "severe_valvular_heart_disease": "false", "stable_angina": "false" }, { "age_years": "50", "ckd": "false", "current_or_significant_smoker": "false", "diabetes": "false", "elevated_bnp": "false", "elevated_troponin": "false", "heart_failure_or_cardiomyopathy": "false", "hypertension": "false", "lvef_percent": "60", "mi_or_coronary_revascularization": "false", "obesity": "false", "previous_anthracycline": "false", "previous_non_anthracycline_chemo": "false", "prior_left_chest_or_mediastinal_rt": "false", "severe_valvular_heart_disease": "false", "stable_angina": "false" } ] } ``` Human paywall (two-item fixture): https://api.magentlab.com/paywall/bulk/hfa-icos-anthracycline Example 200: ```json { "count": 2, "path": "/api/calc/hfa_icos_anthracycline", "items": [ { "components": [ { "factor": "heart_failure_or_cardiomyopathy", "points": 0, "present": false, "tier": "very_high" }, { "factor": "severe_valvular_heart_disease", "points": 0, "present": false, "tier": "high" }, { "factor": "mi_or_coronary_revascularization", "points": 0, "present": false, "tier": "high" }, { "factor": "stable_angina", "points": 0, "present": false, "tier": "high" }, { "factor": "previous_anthracycline", "points": 0, "present": false, "tier": "high" }, { "factor": "prior_left_chest_or_mediastinal_rt", "points": 0, "present": false, "tier": "high" }, { "factor": "elevated_troponin", "points": 0, "present": false, "tier": "medium_1" }, { "factor": "elevated_bnp", "points": 0, "present": false, "tier": "medium_1" }, { "factor": "hypertension", "points": 0, "present": false, "tier": "medium_1" }, { "factor": "diabetes", "points": 0, "present": false, "tier": "medium_1" }, { "factor": "ckd", "points": 0, "present": false, "tier": "medium_1" }, { "factor": "previous_non_anthracycline_chemo", "points": 0, "present": false, "tier": "medium_1" }, { "factor": "current_or_significant_smoker", "points": 0, "present": false, "tier": "medium_1" }, { "factor": "obesity", "points": 0, "present": false, "tier": "medium_1" }, { "value": 50, "factor": "age_years", "points": 0, "present": false, "tier": "none" }, { "value": 60, "factor": "lvef_percent", "points": 0, "present": false, "tier": "none" } ], "disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.", "citation": { "authors": "Lyon AR, Dent S, Stanway S, et al.", "doi": "10.1002/ejhf.1920", "id": "lyon-2020", "pmid": "32458582", "source": "Eur J Heart Fail. 2020;22(11):1945-1960", "title": "Baseline cardiovascular risk assessment in cancer patients scheduled to receive cardiotoxic cancer therapies: a position statement and new risk assessment tools from the Cardio-Oncology Study Group of the Heart Failure Association of the European Society of Cardiology in collaboration with the International Cardio-Oncology Society" }, "formula": "hfa_icos_anthracycline", "formula_expression": "very_high if heart_failure_or_cardiomyopathy; else high if any High factor (severe_valvular_heart_disease, mi_or_coronary_revascularization, stable_angina, lvef_percent<50, age_years>=80, previous_anthracycline, prior_left_chest_or_mediastinal_rt) OR medium_points>=5; else medium if medium_points in 2..4; else low (no factors or one Medium 1). medium_points sums Medium 1 (=1: elevated_troponin, elevated_bnp, hypertension, diabetes, ckd, previous_non_anthracycline_chemo, current_or_significant_smoker, obesity) and Medium 2 (=2: lvef_percent 50-54, age_years 65-79) only. Age and LVEF use the highest matching printed band. Lyon 2020 HFA-ICOS anthracycline table. cardiotoxicity_guide is that paper's expert-opinion guide: low <2%, medium 2-9%, high 10-19%, very high >=20%", "age_years": 50, "cardiotoxicity_guide": "<2%", "lvef_percent": 60, "medium_points": 0, "risk_level": "low" }, { "components": [ { "factor": "heart_failure_or_cardiomyopathy", "points": 0, "present": false, "tier": "very_high" }, { "factor": "severe_valvular_heart_disease", "points": 0, "present": false, "tier": "high" }, { "factor": "mi_or_coronary_revascularization", "points": 0, "present": false, "tier": "high" }, { "factor": "stable_angina", "points": 0, "present": false, "tier": "high" }, { "factor": "previous_anthracycline", "points": 0, "present": false, "tier": "high" }, { "factor": "prior_left_chest_or_mediastinal_rt", "points": 0, "present": false, "tier": "high" }, { "factor": "elevated_troponin", "points": 0, "present": false, "tier": "medium_1" }, { "factor": "elevated_bnp", "points": 0, "present": false, "tier": "medium_1" }, { "factor": "hypertension", "points": 0, "present": false, "tier": "medium_1" }, { "factor": "diabetes", "points": 0, "present": false, "tier": "medium_1" }, { "factor": "ckd", "points": 0, "present": false, "tier": "medium_1" }, { "factor": "previous_non_anthracycline_chemo", "points": 0, "present": false, "tier": "medium_1" }, { "factor": "current_or_significant_smoker", "points": 0, "present": false, "tier": "medium_1" }, { "factor": "obesity", "points": 0, "present": false, "tier": "medium_1" }, { "value": 50, "factor": "age_years", "points": 0, "present": false, "tier": "none" }, { "value": 60, "factor": "lvef_percent", "points": 0, "present": false, "tier": "none" } ], "disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.", "citation": { "authors": "Lyon AR, Dent S, Stanway S, et al.", "doi": "10.1002/ejhf.1920", "id": "lyon-2020", "pmid": "32458582", "source": "Eur J Heart Fail. 2020;22(11):1945-1960", "title": "Baseline cardiovascular risk assessment in cancer patients scheduled to receive cardiotoxic cancer therapies: a position statement and new risk assessment tools from the Cardio-Oncology Study Group of the Heart Failure Association of the European Society of Cardiology in collaboration with the International Cardio-Oncology Society" }, "formula": "hfa_icos_anthracycline", "formula_expression": "very_high if heart_failure_or_cardiomyopathy; else high if any High factor (severe_valvular_heart_disease, mi_or_coronary_revascularization, stable_angina, lvef_percent<50, age_years>=80, previous_anthracycline, prior_left_chest_or_mediastinal_rt) OR medium_points>=5; else medium if medium_points in 2..4; else low (no factors or one Medium 1). medium_points sums Medium 1 (=1: elevated_troponin, elevated_bnp, hypertension, diabetes, ckd, previous_non_anthracycline_chemo, current_or_significant_smoker, obesity) and Medium 2 (=2: lvef_percent 50-54, age_years 65-79) only. Age and LVEF use the highest matching printed band. Lyon 2020 HFA-ICOS anthracycline table. cardiotoxicity_guide is that paper's expert-opinion guide: low <2%, medium 2-9%, high 10-19%, very high >=20%", "age_years": 50, "cardiotoxicity_guide": "<2%", "lvef_percent": 60, "medium_points": 0, "risk_level": "low" } ] } ``` ## Response fields - `formula` (string): hfa_icos_anthracycline - `formula_expression` (string): Lyon 2020 HFA-ICOS anthracycline classification - `age_years` (integer): Age in years used (18-100) - `lvef_percent` (integer): LVEF percent used (10-80) - `medium_points` (integer): Sum of Medium 1 (1) and Medium 2 (2) only - `risk_level` (string): low, medium, high, or very_high (Lyon 2020). Not a treatment order. - `cardiotoxicity_guide` (string): Expert-opinion guide from Lyon 2020: <2%, 2-9%, 10-19%, or >=20%. Not a validated absolute risk. - `components` (array): Per-factor Points rows; High and Very high have 0 medium_points - `citation` (object): Lyon 2020 Eur J Heart Fail citation - `disclaimer` (string): Not-a-device notice ## Example JSON Frozen fixture. Not a live lookup. ```json { "components": [ { "factor": "heart_failure_or_cardiomyopathy", "points": 0, "present": false, "tier": "very_high" }, { "factor": "severe_valvular_heart_disease", "points": 0, "present": false, "tier": "high" }, { "factor": "mi_or_coronary_revascularization", "points": 0, "present": false, "tier": "high" }, { "factor": "stable_angina", "points": 0, "present": false, "tier": "high" }, { "factor": "previous_anthracycline", "points": 0, "present": false, "tier": "high" }, { "factor": "prior_left_chest_or_mediastinal_rt", "points": 0, "present": false, "tier": "high" }, { "factor": "elevated_troponin", "points": 0, "present": false, "tier": "medium_1" }, { "factor": "elevated_bnp", "points": 0, "present": false, "tier": "medium_1" }, { "factor": "hypertension", "points": 0, "present": false, "tier": "medium_1" }, { "factor": "diabetes", "points": 0, "present": false, "tier": "medium_1" }, { "factor": "ckd", "points": 0, "present": false, "tier": "medium_1" }, { "factor": "previous_non_anthracycline_chemo", "points": 0, "present": false, "tier": "medium_1" }, { "factor": "current_or_significant_smoker", "points": 0, "present": false, "tier": "medium_1" }, { "factor": "obesity", "points": 0, "present": false, "tier": "medium_1" }, { "value": 50, "factor": "age_years", "points": 0, "present": false, "tier": "none" }, { "value": 60, "factor": "lvef_percent", "points": 0, "present": false, "tier": "none" } ], "disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.", "citation": { "authors": "Lyon AR, Dent S, Stanway S, et al.", "doi": "10.1002/ejhf.1920", "id": "lyon-2020", "pmid": "32458582", "source": "Eur J Heart Fail. 2020;22(11):1945-1960", "title": "Baseline cardiovascular risk assessment in cancer patients scheduled to receive cardiotoxic cancer therapies: a position statement and new risk assessment tools from the Cardio-Oncology Study Group of the Heart Failure Association of the European Society of Cardiology in collaboration with the International Cardio-Oncology Society" }, "formula": "hfa_icos_anthracycline", "formula_expression": "very_high if heart_failure_or_cardiomyopathy; else high if any High factor (severe_valvular_heart_disease, mi_or_coronary_revascularization, stable_angina, lvef_percent<50, age_years>=80, previous_anthracycline, prior_left_chest_or_mediastinal_rt) OR medium_points>=5; else medium if medium_points in 2..4; else low (no factors or one Medium 1). medium_points sums Medium 1 (=1: elevated_troponin, elevated_bnp, hypertension, diabetes, ckd, previous_non_anthracycline_chemo, current_or_significant_smoker, obesity) and Medium 2 (=2: lvef_percent 50-54, age_years 65-79) only. Age and LVEF use the highest matching printed band. Lyon 2020 HFA-ICOS anthracycline table. cardiotoxicity_guide is that paper's expert-opinion guide: low <2%, medium 2-9%, high 10-19%, very high >=20%", "age_years": 50, "cardiotoxicity_guide": "<2%", "lvef_percent": 60, "medium_points": 0, "risk_level": "low" } ``` ## Errors - HTTP 400 `invalid_hfa_icos_anthracycline`: Lyon 2020 HFA-ICOS anthracycline inputs must match that table's age, LVEF, and yes/no factors. Returned before settlement; you are not charged. - HTTP 400 `invalid_items`: POST body must be a JSON object with only an items array Returned before settlement; you are not charged. - HTTP 400 `invalid_item_count`: items must be an array of 1 to 25 objects Returned before settlement; you are not charged. - HTTP 400 `invalid_item`: each items entry must be a JSON object Returned before settlement; you are not charged. Shared HTTP 402 and 503: https://magentlab.com/docs/payments ## Related tools - [NYHA](https://magentlab.com/docs/nyha) — Return the 1994 NYHA functional capacity class 1-4 from a caller-assigned integer, with the published class description. - [MAGGIC](https://magentlab.com/docs/maggic) — Sum the Pocock 2013 MAGGIC integer chart from thirteen caller-supplied heart-failure predictors and return the published Table 4 1-year and 3-year death probabilities for scores 0-50. - [HCM Risk-SCD](https://magentlab.com/docs/hcm-risk-scd) — Compute the O'Mahony 2014 HCM Risk-SCD 5-year sudden cardiac death probability from maximal wall thickness, left-atrial diameter, maximal LVOT gradient, family history of SCD, NSVT, unexplained syncope, and age. - [ACCF/AHA HF stages](https://magentlab.com/docs/acc-aha-hf) — Apply the 2013 ACCF/AHA heart-failure stages (Yancy) from caller-assigned high-risk, structural heart disease, prior or current HF symptoms, and refractory specialized-care flags. Returns hf_stage A, B, C, D, or not_staged. - [Framingham HF criteria](https://magentlab.com/docs/framingham-hf) — Apply the McKee 1971 Framingham concurrent major and minor criteria and return definite or not_definite from nine major flags, seven minor flags, and the dual weight-loss flag. ## Payment Unpaid requests return HTTP 402 even if query parameters or POST items are missing or invalid, so CDP and agents can index the path. After a PAYMENT-SIGNATURE, invalid params return HTTP 400 JSON before settlement. magent does not charge. Fix the params, then request a new 402 quote for that complete URL. Catalog misses (empty matches, found=false) are valid paid 200s. - GET the tool with Accept: application/json (do not send Accept: text/html unless you want the human paywall). - HTTP 402 means you have not paid. Decode the base64 PAYMENT-REQUIRED header. HTTP 503 is not a new quote. - Sign accepts[0] (exact, EIP-3009) with validBefore = now + maxTimeoutSeconds (600 seconds), or accepts[1] (batch-settlement deposit/voucher) on product GET. Ping and POST {items} stay exact. Magent retries transient facilitator 429/5xx before answering. - Retry the same URL with PAYMENT-SIGNATURE (base64 JSON of accepted and payload). Magent attaches canonical extensions.bazaar on CDP verify/settle; echoing 402 bazaar is optional. - Success is HTTP 200 JSON plus PAYMENT-RESPONSE. exact settles before the tool. batch-settlement verifies (and deposit-settles) before the tool and commits the charge after HTTP 2xx. HTTP 503: retry the same PAYMENT-SIGNATURE. Mint a new exact nonce only after a new HTTP 402. - offered `exact` on eip155:8453: Fixed-price USDC on Base. The buyer authorizes the advertised amount (EIP-3009). magent settles before the tool runs (paymentFlow upfront). extra.assetTransferMethod=eip3009 extra.paymentFlow=upfront. - offered `batch-settlement` on eip155:8453: Payment-channel vouchers claimed later in batches. Exact stays accepts[0]. Same-path POST {items} is still exact. extra.assetTransferMethod=eip3009 extra.paymentFlow=authorization. - not offered `upto`: Not offered. Usage-based: buyer authorizes a ceiling, seller settles the actual amount after work. Reserved for a future metered tool. Not for current calculators or code search. Same-path POST {items} is still scheme exact: one EIP-3009 authorization for GET unit plus $0.002 per extra item. That is not x402 batch-settlement (payment channels / vouchers). Shared HTTP 402 and 503 table: https://magentlab.com/docs/payments Stdio MCP (one process per host): https://magentlab.com/docs/mcp ## Guarantees - HTTP 402 is unpaid, including a missing query. After PAYMENT-SIGNATURE, invalid parameters return HTTP 400 before settlement. You are not charged. HTTP 402 never includes the tool JSON. - exact: settlement finishes before the tool (paymentFlow upfront). batch-settlement: verify/deposit before the tool; chargedCumulativeAmount commits after HTTP 2xx. Uncertain or failed settlement fails closed (HTTP 503). Retry the same PAYMENT-SIGNATURE. - HTTP 402 is unpaid only. Do not sign a second authorization because of a 503. - Execution is timeout-bounded and concurrency-capped. - Calculator inputs are stored encrypted for allowlisted operators (Magent Console). They are not in public logs, SSH lookups, catalog, or rollups. Request logs store path without query.