# Caprini VTE score Caprini score Status: LIVE Price: $0.005 USDC `GET /api/calc/caprini` HTML: https://magentlab.com/docs/caprini Markdown: https://magentlab.com/docs/caprini.md Not a medical device. Not a diagnosis, dose, or listing recommendation. ## What it computes Sum Caprini 2005 Table 3 thrombosis risk factors with exclusive age and surgery weights and return the Table 2 band (low / moderate / high / highest). ## When to use When an agent needs the Caprini 2005 point total (not Padua, not Caprini 2009/2013) from caller-assigned Table 3 flags and must not invent a diagnosis or prophylaxis order. ## When not to use - Not a medical device and not a diagnosis of VTE. magent does not examine the patient; every flag is caller-assigned. - Caprini 2005 Table 3 factors and Table 2 bands only. Not Caprini 2009 or 2013 revisions (those use different factors and cutoffs). - Age bands are mutually exclusive (41-60 = 1, 61-74 = 2, >=75 = 3; age 40 or younger scores 0 for age). Surgery categories are mutually exclusive. - Does not return DVT incidence percents or a prophylaxis regimen. - Obesity is a caller-applied BMI >25 flag; magent does not take height or weight. ## Formula ``` Caprini 2005 = exclusive age (<=40: 0, 41-60: 1, 61-74: 2, >=75: 3) + exclusive surgery (none 0, minor 1, arthroscopic 2, major >45 min 2, laparoscopic >45 min 2, elective arthroplasty 5) + Table 3 flags (1, 2, 3, or 5); max 78; 0-1 low, 2 moderate, 3-4 high, >=5 highest ``` ## Citation [Thrombosis risk assessment as a guide to quality patient care](https://doi.org/10.1016/j.disamonth.2005.02.003) Caprini JA Dis Mon. 2005;51(2-3):70-78 DOI: [10.1016/j.disamonth.2005.02.003](https://doi.org/10.1016/j.disamonth.2005.02.003) ## Worked example ### Age 50, no other Table 3 factors Given: `surgery=none, age=50, adverse_pregnancy_history=false, obesity=false, abnormal_pulmonary_function=false, elevated_homocysteine=false, heparin_induced_thrombocytopenia=false, swollen_legs=false, other_risk_factor=false, varicose_veins=false, inflammatory_bowel_disease=false, confined_to_bed_gt_72h=false, malignancy=false, spinal_cord_injury=false, serious_lung_disease=false, pregnancy_or_postpartum=false, congestive_heart_failure=false, oral_contraceptives_or_hrt=false, prior_major_surgery=false, anticardiolipin_antibodies=false, acute_myocardial_infarction=false, medical_bed_rest=false, hip_pelvis_leg_fracture=false, lupus_anticoagulant=false, immobilizing_plaster_cast=false, central_venous_access=false, factor_v_leiden=false, prothrombin_20210a=false, other_thrombophilia=false, sepsis=false, multiple_trauma=false, stroke=false, family_history_thrombosis=false, history_dvt_pe=false` 1. Age 50 is 41-60 → 1; surgery none → 0; all flags false → 0 2. Score = 1 (max 78); risk_band low ## Also searched as - Caprini score - Caprini RAM - Caprini VTE risk - thrombosis risk assessment - Caprini 2005 - venous thromboembolism risk - Caprini risk factor score ## Parameters - `age` (integer, required): Age in years (18-120). Caprini 2005 exclusive bands: 41-60 scores 1; 61-74 scores 2; 75 or older scores 3. Age 40 or younger scores 0 for age. - `surgery` (string, required): Mutually exclusive Caprini 2005 Table 3 surgery category as assigned by the caller. none scores 0. minor (minor surgery planned) scores 1. arthroscopic, major (major surgery >45 minutes), and laparoscopic (laparoscopic surgery >45 minutes) score 2. arthroplasty (elective major lower extremity arthroplasty) scores 5. One category only. History of prior major surgery is a separate 1-point flag. - `prior_major_surgery` (boolean, required): History of prior major surgery (<1 month) as assigned by the caller (Caprini 2005 Table 3). Independent of the exclusive surgery category. true scores 1. - `varicose_veins` (boolean, required): Varicose veins as assigned by the caller (Caprini 2005 Table 3). true scores 1. magent does not examine the patient. - `inflammatory_bowel_disease` (boolean, required): History of inflammatory bowel disease as assigned by the caller (Caprini 2005 Table 3). true scores 1. - `swollen_legs` (boolean, required): Swollen legs (current) as assigned by the caller (Caprini 2005 Table 3). true scores 1. magent does not examine the patient. - `obesity` (boolean, required): Obesity as assigned by the caller (Caprini 2005 BMI >25). true scores 1. magent does not take height or weight. - `acute_myocardial_infarction` (boolean, required): Acute myocardial infarction as assigned by the caller (Caprini 2005 Table 3). true scores 1. - `congestive_heart_failure` (boolean, required): Congestive heart failure (<1 month) as assigned by the caller (Caprini 2005 Table 3). true scores 1. - `sepsis` (boolean, required): Sepsis (<1 month) as assigned by the caller (Caprini 2005 Table 3). true scores 1. - `serious_lung_disease` (boolean, required): Serious lung disease including pneumonia (<1 month) as assigned by the caller (Caprini 2005 Table 3). true scores 1. - `abnormal_pulmonary_function` (boolean, required): Abnormal pulmonary function (COPD) as assigned by the caller (Caprini 2005 Table 3). true scores 1. - `medical_bed_rest` (boolean, required): Medical patient currently at bed rest as assigned by the caller (Caprini 2005 Table 3). true scores 1. Independent of confined_to_bed_gt_72h. - `other_risk_factor` (boolean, required): Other Caprini 2005 Table 3 1-point risk factor as assigned by the caller. true scores 1. magent does not invent a factor from prose. - `oral_contraceptives_or_hrt` (boolean, required): Oral contraceptives or hormone replacement therapy as assigned by the caller (Caprini 2005 Table 3, listed for women). true scores 1. - `pregnancy_or_postpartum` (boolean, required): Pregnancy or postpartum (<1 month) as assigned by the caller (Caprini 2005 Table 3, listed for women). true scores 1. - `adverse_pregnancy_history` (boolean, required): History of unexplained stillborn infant, recurrent spontaneous abortion (>=3), premature birth with toxemia, or growth-restricted infant as assigned by the caller (Caprini 2005 Table 3, listed for women). true scores 1. - `malignancy` (boolean, required): Malignancy (present or previous) as assigned by the caller (Caprini 2005 Table 3). true scores 2. - `confined_to_bed_gt_72h` (boolean, required): Patient confined to bed (>72 hours) as assigned by the caller (Caprini 2005 Table 3). true scores 2. Independent of medical_bed_rest. - `immobilizing_plaster_cast` (boolean, required): Immobilizing plaster cast (<1 month) as assigned by the caller (Caprini 2005 Table 3). true scores 2. - `central_venous_access` (boolean, required): Central venous access as assigned by the caller (Caprini 2005 Table 3). true scores 2. - `history_dvt_pe` (boolean, required): History of DVT or PE as assigned by the caller (Caprini 2005 Table 3). true scores 3. magent does not diagnose VTE. - `family_history_thrombosis` (boolean, required): Family history of thrombosis as assigned by the caller (Caprini 2005 Table 3). true scores 3. - `factor_v_leiden` (boolean, required): Positive Factor V Leiden as assigned by the caller (Caprini 2005 Table 3). true scores 3. - `prothrombin_20210a` (boolean, required): Positive Prothrombin 20210A as assigned by the caller (Caprini 2005 Table 3). true scores 3. - `elevated_homocysteine` (boolean, required): Elevated serum homocysteine as assigned by the caller (Caprini 2005 Table 3). true scores 3. - `lupus_anticoagulant` (boolean, required): Positive lupus anticoagulant as assigned by the caller (Caprini 2005 Table 3). true scores 3. - `anticardiolipin_antibodies` (boolean, required): Elevated anticardiolipin antibodies as assigned by the caller (Caprini 2005 Table 3). true scores 3. - `heparin_induced_thrombocytopenia` (boolean, required): Heparin-induced thrombocytopenia (HIT) as assigned by the caller (Caprini 2005 Table 3). true scores 3. magent does not diagnose HIT. - `other_thrombophilia` (boolean, required): Other congenital or acquired thrombophilia as assigned by the caller (Caprini 2005 Table 3). true scores 3. - `hip_pelvis_leg_fracture` (boolean, required): Hip, pelvis, or leg fracture (<1 month) as assigned by the caller (Caprini 2005 Table 3). true scores 5. Independent of exclusive surgery. - `stroke` (boolean, required): Stroke (<1 month) as assigned by the caller (Caprini 2005 Table 3). true scores 5. - `multiple_trauma` (boolean, required): Multiple trauma (<1 month) as assigned by the caller (Caprini 2005 Table 3). true scores 5. - `spinal_cord_injury` (boolean, required): Acute spinal cord injury (paralysis) (<1 month) as assigned by the caller (Caprini 2005 Table 3). true scores 5. ## 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/caprini` 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": [ { "history_dvt_pe": "false", "family_history_thrombosis": "false", "stroke": "false", "multiple_trauma": "false", "sepsis": "false", "other_thrombophilia": "false", "prothrombin_20210a": "false", "factor_v_leiden": "false", "central_venous_access": "false", "immobilizing_plaster_cast": "false", "lupus_anticoagulant": "false", "hip_pelvis_leg_fracture": "false", "medical_bed_rest": "false", "acute_myocardial_infarction": "false", "anticardiolipin_antibodies": "false", "prior_major_surgery": "false", "oral_contraceptives_or_hrt": "false", "congestive_heart_failure": "false", "pregnancy_or_postpartum": "false", "serious_lung_disease": "false", "spinal_cord_injury": "false", "malignancy": "false", "confined_to_bed_gt_72h": "false", "inflammatory_bowel_disease": "false", "varicose_veins": "false", "other_risk_factor": "false", "swollen_legs": "false", "heparin_induced_thrombocytopenia": "false", "elevated_homocysteine": "false", "abnormal_pulmonary_function": "false", "obesity": "false", "adverse_pregnancy_history": "false", "age": "50", "surgery": "none" }, { "history_dvt_pe": "false", "family_history_thrombosis": "false", "stroke": "false", "multiple_trauma": "false", "sepsis": "false", "other_thrombophilia": "false", "prothrombin_20210a": "false", "factor_v_leiden": "false", "central_venous_access": "false", "immobilizing_plaster_cast": "false", "lupus_anticoagulant": "false", "hip_pelvis_leg_fracture": "false", "medical_bed_rest": "false", "acute_myocardial_infarction": "false", "anticardiolipin_antibodies": "false", "prior_major_surgery": "false", "oral_contraceptives_or_hrt": "false", "congestive_heart_failure": "false", "pregnancy_or_postpartum": "false", "serious_lung_disease": "false", "spinal_cord_injury": "false", "malignancy": "false", "confined_to_bed_gt_72h": "false", "inflammatory_bowel_disease": "false", "varicose_veins": "false", "other_risk_factor": "false", "swollen_legs": "false", "heparin_induced_thrombocytopenia": "false", "elevated_homocysteine": "false", "abnormal_pulmonary_function": "false", "obesity": "false", "adverse_pregnancy_history": "false", "age": "50", "surgery": "none" } ] } ``` Human paywall (two-item fixture): https://api.magentlab.com/paywall/bulk/caprini Example 200: ```json { "count": 2, "path": "/api/calc/caprini", "items": [ { "components": [ { "value": 50, "factor": "age", "points": 1, "present": true }, { "value": "none", "factor": "surgery", "points": 0, "present": false }, { "factor": "prior_major_surgery", "points": 0, "present": false }, { "factor": "varicose_veins", "points": 0, "present": false }, { "factor": "inflammatory_bowel_disease", "points": 0, "present": false }, { "factor": "swollen_legs", "points": 0, "present": false }, { "factor": "obesity", "points": 0, "present": false }, { "factor": "acute_myocardial_infarction", "points": 0, "present": false }, { "factor": "congestive_heart_failure", "points": 0, "present": false }, { "factor": "sepsis", "points": 0, "present": false }, { "factor": "serious_lung_disease", "points": 0, "present": false }, { "factor": "abnormal_pulmonary_function", "points": 0, "present": false }, { "factor": "medical_bed_rest", "points": 0, "present": false }, { "factor": "other_risk_factor", "points": 0, "present": false }, { "factor": "oral_contraceptives_or_hrt", "points": 0, "present": false }, { "factor": "pregnancy_or_postpartum", "points": 0, "present": false }, { "factor": "adverse_pregnancy_history", "points": 0, "present": false }, { "factor": "malignancy", "points": 0, "present": false }, { "factor": "confined_to_bed_gt_72h", "points": 0, "present": false }, { "factor": "immobilizing_plaster_cast", "points": 0, "present": false }, { "factor": "central_venous_access", "points": 0, "present": false }, { "factor": "history_dvt_pe", "points": 0, "present": false }, { "factor": "family_history_thrombosis", "points": 0, "present": false }, { "factor": "factor_v_leiden", "points": 0, "present": false }, { "factor": "prothrombin_20210a", "points": 0, "present": false }, { "factor": "elevated_homocysteine", "points": 0, "present": false }, { "factor": "lupus_anticoagulant", "points": 0, "present": false }, { "factor": "anticardiolipin_antibodies", "points": 0, "present": false }, { "factor": "heparin_induced_thrombocytopenia", "points": 0, "present": false }, { "factor": "other_thrombophilia", "points": 0, "present": false }, { "factor": "hip_pelvis_leg_fracture", "points": 0, "present": false }, { "factor": "stroke", "points": 0, "present": false }, { "factor": "multiple_trauma", "points": 0, "present": false }, { "factor": "spinal_cord_injury", "points": 0, "present": false } ], "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": "Caprini JA", "doi": "10.1016/j.disamonth.2005.02.003", "id": "caprini-2005", "pmid": "15900257", "source": "Dis Mon. 2005;51(2-3):70-78", "title": "Thrombosis risk assessment as a guide to quality patient care" }, "formula": "caprini", "formula_expression": "Caprini 2005 = exclusive age (<=40: 0, 41-60: 1, 61-74: 2, >=75: 3) + exclusive surgery (none 0, minor 1, arthroscopic 2, major >45 min 2, laparoscopic >45 min 2, elective arthroplasty 5) + Table 3 flags (1, 2, 3, or 5); max 78; 0-1 low, 2 moderate, 3-4 high, >=5 highest", "age_years": 50, "max_score": 78, "score": 1, "risk_band": "low", "surgery": "none" }, { "components": [ { "value": 50, "factor": "age", "points": 1, "present": true }, { "value": "none", "factor": "surgery", "points": 0, "present": false }, { "factor": "prior_major_surgery", "points": 0, "present": false }, { "factor": "varicose_veins", "points": 0, "present": false }, { "factor": "inflammatory_bowel_disease", "points": 0, "present": false }, { "factor": "swollen_legs", "points": 0, "present": false }, { "factor": "obesity", "points": 0, "present": false }, { "factor": "acute_myocardial_infarction", "points": 0, "present": false }, { "factor": "congestive_heart_failure", "points": 0, "present": false }, { "factor": "sepsis", "points": 0, "present": false }, { "factor": "serious_lung_disease", "points": 0, "present": false }, { "factor": "abnormal_pulmonary_function", "points": 0, "present": false }, { "factor": "medical_bed_rest", "points": 0, "present": false }, { "factor": "other_risk_factor", "points": 0, "present": false }, { "factor": "oral_contraceptives_or_hrt", "points": 0, "present": false }, { "factor": "pregnancy_or_postpartum", "points": 0, "present": false }, { "factor": "adverse_pregnancy_history", "points": 0, "present": false }, { "factor": "malignancy", "points": 0, "present": false }, { "factor": "confined_to_bed_gt_72h", "points": 0, "present": false }, { "factor": "immobilizing_plaster_cast", "points": 0, "present": false }, { "factor": "central_venous_access", "points": 0, "present": false }, { "factor": "history_dvt_pe", "points": 0, "present": false }, { "factor": "family_history_thrombosis", "points": 0, "present": false }, { "factor": "factor_v_leiden", "points": 0, "present": false }, { "factor": "prothrombin_20210a", "points": 0, "present": false }, { "factor": "elevated_homocysteine", "points": 0, "present": false }, { "factor": "lupus_anticoagulant", "points": 0, "present": false }, { "factor": "anticardiolipin_antibodies", "points": 0, "present": false }, { "factor": "heparin_induced_thrombocytopenia", "points": 0, "present": false }, { "factor": "other_thrombophilia", "points": 0, "present": false }, { "factor": "hip_pelvis_leg_fracture", "points": 0, "present": false }, { "factor": "stroke", "points": 0, "present": false }, { "factor": "multiple_trauma", "points": 0, "present": false }, { "factor": "spinal_cord_injury", "points": 0, "present": false } ], "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": "Caprini JA", "doi": "10.1016/j.disamonth.2005.02.003", "id": "caprini-2005", "pmid": "15900257", "source": "Dis Mon. 2005;51(2-3):70-78", "title": "Thrombosis risk assessment as a guide to quality patient care" }, "formula": "caprini", "formula_expression": "Caprini 2005 = exclusive age (<=40: 0, 41-60: 1, 61-74: 2, >=75: 3) + exclusive surgery (none 0, minor 1, arthroscopic 2, major >45 min 2, laparoscopic >45 min 2, elective arthroplasty 5) + Table 3 flags (1, 2, 3, or 5); max 78; 0-1 low, 2 moderate, 3-4 high, >=5 highest", "age_years": 50, "max_score": 78, "score": 1, "risk_band": "low", "surgery": "none" } ] } ``` ## Response fields - `formula` (string): caprini - `formula_expression` (string): Exact expression used - `score` (integer): Caprini 2005 Table 3 points 0-78 - `max_score` (integer): 78 (exclusive age and surgery) - `risk_band` (string): Caprini 2005 Table 2 band: low (0-1), moderate (2), high (3-4), or highest (>=5). A band, not a diagnosis or prophylaxis order. - `age_years` (integer): Age used for the exclusive age band - `surgery` (string): Exclusive surgery category used (none, minor, arthroscopic, major, laparoscopic, or arthroplasty) - `components` (array): Per-factor points - `citation` (object): Caprini Dis Mon 2005 citation - `disclaimer` (string): Not-a-device notice ## Example JSON Frozen fixture. Not a live lookup. ```json { "components": [ { "value": 50, "factor": "age", "points": 1, "present": true }, { "value": "none", "factor": "surgery", "points": 0, "present": false }, { "factor": "prior_major_surgery", "points": 0, "present": false }, { "factor": "varicose_veins", "points": 0, "present": false }, { "factor": "inflammatory_bowel_disease", "points": 0, "present": false }, { "factor": "swollen_legs", "points": 0, "present": false }, { "factor": "obesity", "points": 0, "present": false }, { "factor": "acute_myocardial_infarction", "points": 0, "present": false }, { "factor": "congestive_heart_failure", "points": 0, "present": false }, { "factor": "sepsis", "points": 0, "present": false }, { "factor": "serious_lung_disease", "points": 0, "present": false }, { "factor": "abnormal_pulmonary_function", "points": 0, "present": false }, { "factor": "medical_bed_rest", "points": 0, "present": false }, { "factor": "other_risk_factor", "points": 0, "present": false }, { "factor": "oral_contraceptives_or_hrt", "points": 0, "present": false }, { "factor": "pregnancy_or_postpartum", "points": 0, "present": false }, { "factor": "adverse_pregnancy_history", "points": 0, "present": false }, { "factor": "malignancy", "points": 0, "present": false }, { "factor": "confined_to_bed_gt_72h", "points": 0, "present": false }, { "factor": "immobilizing_plaster_cast", "points": 0, "present": false }, { "factor": "central_venous_access", "points": 0, "present": false }, { "factor": "history_dvt_pe", "points": 0, "present": false }, { "factor": "family_history_thrombosis", "points": 0, "present": false }, { "factor": "factor_v_leiden", "points": 0, "present": false }, { "factor": "prothrombin_20210a", "points": 0, "present": false }, { "factor": "elevated_homocysteine", "points": 0, "present": false }, { "factor": "lupus_anticoagulant", "points": 0, "present": false }, { "factor": "anticardiolipin_antibodies", "points": 0, "present": false }, { "factor": "heparin_induced_thrombocytopenia", "points": 0, "present": false }, { "factor": "other_thrombophilia", "points": 0, "present": false }, { "factor": "hip_pelvis_leg_fracture", "points": 0, "present": false }, { "factor": "stroke", "points": 0, "present": false }, { "factor": "multiple_trauma", "points": 0, "present": false }, { "factor": "spinal_cord_injury", "points": 0, "present": false } ], "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": "Caprini JA", "doi": "10.1016/j.disamonth.2005.02.003", "id": "caprini-2005", "pmid": "15900257", "source": "Dis Mon. 2005;51(2-3):70-78", "title": "Thrombosis risk assessment as a guide to quality patient care" }, "formula": "caprini", "formula_expression": "Caprini 2005 = exclusive age (<=40: 0, 41-60: 1, 61-74: 2, >=75: 3) + exclusive surgery (none 0, minor 1, arthroscopic 2, major >45 min 2, laparoscopic >45 min 2, elective arthroplasty 5) + Table 3 flags (1, 2, 3, or 5); max 78; 0-1 low, 2 moderate, 3-4 high, >=5 highest", "age_years": 50, "max_score": 78, "score": 1, "risk_band": "low", "surgery": "none" } ``` ## Errors - HTTP 400 `invalid_age`: age must be an integer from 18 to 120 Returned before settlement; you are not charged. - HTTP 400 `invalid_flag`: boolean clinical flags must be true or false Returned before settlement; you are not charged. - HTTP 400 `invalid_caprini`: each Caprini 2005 VTE item must be a published weight for that factor. 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 - [Padua score](https://magentlab.com/docs/padua) — Compute the Barbar 2010 Padua Prediction Score for VTE risk in hospitalized medical patients from age and ten caller-assigned findings. ## 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.