# FAST windows (Scalea) FAST windows (Scalea) Status: LIVE Price: $0.005 USDC `GET /api/calc/fast` HTML: https://magentlab.com/docs/fast Markdown: https://magentlab.com/docs/fast.md Not a medical device. Not a diagnosis, dose, or listing recommendation. ## What it computes Apply Scalea 1999 FAST four Ps and return positive when any caller-assigned perihepatic, perisplenic, pelvic, or pericardial window has free fluid. ## When to use When an agent already has caller-assigned perihepatic (Morison), perisplenic, pelvic, and pericardial window flags and needs the published FAST positive or negative result. magent does not scan. ## When not to use - Not a medical device. magent does not perform or interpret ultrasound. - Not a laparotomy, thoracotomy, or pericardial-window operative order. - Windows are caller-assigned. magent does not decide whether a view shows free fluid or pericardial fluid. - Scalea 1999 four Ps only (pericardial, perihepatic, perisplenic, pelvic). Not eFAST pleural views; the consensus left pleural extension as not well characterized. - Not Huang or McKenney hemoperitoneum scoring. Not organ-specific injury grading. ## Formula ``` positive iff perihepatic or perisplenic or pelvic or pericardial (Scalea 1999 four Ps: pericardial, perihepatic, perisplenic, pelvic). Each flag is caller-assigned free intraperitoneal fluid (perihepatic/Morison, perisplenic, pelvic) or pericardial fluid. Absence of all four is negative. Sequence is not required. Not pleural/eFAST views. Not Huang or McKenney scoring. Not a laparotomy order ``` ## Citation [Focused Assessment with Sonography for Trauma (FAST): results from an international consensus conference](https://doi.org/10.1097/00005373-199903000-00022) Scalea TM, Rodriguez A, Chiu WC, Brenneman FD, Fallon WF Jr, Kato K, McKenney MG, Nerlich ML, Ochsner MG, Yoshii H J Trauma. 1999;46(3):466-472 DOI: [10.1097/00005373-199903000-00022](https://doi.org/10.1097/00005373-199903000-00022) ## Worked example ### All four windows negative Given: `pelvic=false, pericardial=false, perihepatic=false, perisplenic=false` 1. perihepatic, perisplenic, pelvic, and pericardial are false 2. No window has free fluid; positive is false ### Perihepatic (Morison) window alone positive Given: `pelvic=false, pericardial=false, perihepatic=true, perisplenic=false` 1. perihepatic is true (Morison / right-upper-quadrant free fluid as assigned) 2. perisplenic, pelvic, and pericardial are false 3. Any-window rule; positive is true ## Also searched as - FAST - Focused Assessment with Sonography for Trauma - Scalea FAST consensus - FAST four Ps - perihepatic Morison FAST - perisplenic FAST - FAST pericardial window - trauma ultrasound windows ## Parameters - `perihepatic` (boolean, required): Perihepatic (Morison / right-upper-quadrant) window positive for free intraperitoneal fluid as assigned by the caller (Scalea 1999 four Ps). true or false. magent does not interpret ultrasound. - `perisplenic` (boolean, required): Perisplenic (left-upper-quadrant) window positive for free intraperitoneal fluid as assigned by the caller (Scalea 1999 four Ps). true or false. magent does not interpret ultrasound. - `pelvic` (boolean, required): Pelvic window positive for free intraperitoneal fluid as assigned by the caller (Scalea 1999 four Ps). true or false. magent does not interpret ultrasound. - `pericardial` (boolean, required): Pericardial window positive for pericardial fluid as assigned by the caller (Scalea 1999 four Ps). true or false. magent does not interpret ultrasound. ## 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/fast` 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": [ { "pelvic": "false", "pericardial": "false", "perihepatic": "false", "perisplenic": "false" }, { "pelvic": "false", "pericardial": "false", "perihepatic": "false", "perisplenic": "false" } ] } ``` Human paywall (two-item fixture): https://api.magentlab.com/paywall/bulk/fast Example 200: ```json { "count": 2, "path": "/api/calc/fast", "items": [ { "positive": false, "components": [ { "factor": "perihepatic", "met": false }, { "factor": "perisplenic", "met": false }, { "factor": "pelvic", "met": false }, { "factor": "pericardial", "met": false }, { "factor": "positive", "met": 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": "Scalea TM, Rodriguez A, Chiu WC, Brenneman FD, Fallon WF Jr, Kato K, McKenney MG, Nerlich ML, Ochsner MG, Yoshii H", "doi": "10.1097/00005373-199903000-00022", "id": "scalea-1999", "pmid": "10088853", "source": "J Trauma. 1999;46(3):466-472", "title": "Focused Assessment with Sonography for Trauma (FAST): results from an international consensus conference" }, "formula": "fast", "formula_expression": "positive iff perihepatic or perisplenic or pelvic or pericardial (Scalea 1999 four Ps: pericardial, perihepatic, perisplenic, pelvic). Each flag is caller-assigned free intraperitoneal fluid (perihepatic/Morison, perisplenic, pelvic) or pericardial fluid. Absence of all four is negative. Sequence is not required. Not pleural/eFAST views. Not Huang or McKenney scoring. Not a laparotomy order", "pelvic": false, "pericardial": false, "perihepatic": false, "perisplenic": false }, { "positive": false, "components": [ { "factor": "perihepatic", "met": false }, { "factor": "perisplenic", "met": false }, { "factor": "pelvic", "met": false }, { "factor": "pericardial", "met": false }, { "factor": "positive", "met": 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": "Scalea TM, Rodriguez A, Chiu WC, Brenneman FD, Fallon WF Jr, Kato K, McKenney MG, Nerlich ML, Ochsner MG, Yoshii H", "doi": "10.1097/00005373-199903000-00022", "id": "scalea-1999", "pmid": "10088853", "source": "J Trauma. 1999;46(3):466-472", "title": "Focused Assessment with Sonography for Trauma (FAST): results from an international consensus conference" }, "formula": "fast", "formula_expression": "positive iff perihepatic or perisplenic or pelvic or pericardial (Scalea 1999 four Ps: pericardial, perihepatic, perisplenic, pelvic). Each flag is caller-assigned free intraperitoneal fluid (perihepatic/Morison, perisplenic, pelvic) or pericardial fluid. Absence of all four is negative. Sequence is not required. Not pleural/eFAST views. Not Huang or McKenney scoring. Not a laparotomy order", "pelvic": false, "pericardial": false, "perihepatic": false, "perisplenic": false } ] } ``` ## Response fields - `formula` (string): fast - `formula_expression` (string): Published Scalea 1999 FAST four-P any-window rule - `perihepatic` (boolean): Echo of the caller-assigned perihepatic (Morison) window flag - `perisplenic` (boolean): Echo of the caller-assigned perisplenic window flag - `pelvic` (boolean): Echo of the caller-assigned pelvic window flag - `pericardial` (boolean): Echo of the caller-assigned pericardial window flag - `positive` (boolean): true if any of the four Scalea 1999 windows is positive for free fluid. Not a laparotomy order. - `components` (array): Rows for perihepatic, perisplenic, pelvic, pericardial, and overall positive with factor and met - `citation` (object): Scalea 1999 J Trauma citation - `disclaimer` (string): Not-a-device notice ## Example JSON Frozen fixture. Not a live lookup. ```json { "positive": false, "components": [ { "factor": "perihepatic", "met": false }, { "factor": "perisplenic", "met": false }, { "factor": "pelvic", "met": false }, { "factor": "pericardial", "met": false }, { "factor": "positive", "met": 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": "Scalea TM, Rodriguez A, Chiu WC, Brenneman FD, Fallon WF Jr, Kato K, McKenney MG, Nerlich ML, Ochsner MG, Yoshii H", "doi": "10.1097/00005373-199903000-00022", "id": "scalea-1999", "pmid": "10088853", "source": "J Trauma. 1999;46(3):466-472", "title": "Focused Assessment with Sonography for Trauma (FAST): results from an international consensus conference" }, "formula": "fast", "formula_expression": "positive iff perihepatic or perisplenic or pelvic or pericardial (Scalea 1999 four Ps: pericardial, perihepatic, perisplenic, pelvic). Each flag is caller-assigned free intraperitoneal fluid (perihepatic/Morison, perisplenic, pelvic) or pericardial fluid. Absence of all four is negative. Sequence is not required. Not pleural/eFAST views. Not Huang or McKenney scoring. Not a laparotomy order", "pelvic": false, "pericardial": false, "perihepatic": false, "perisplenic": false } ``` ## Errors - HTTP 400 `invalid_fast`: FAST inputs must match caller-assigned positivity of the published ultrasound windows. 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 - [ABC score](https://magentlab.com/docs/abc-score) — Sum the four Nunez 2009 ABC (assessment of blood consumption) arrival factors and return score_ge_2 at the published ≥2 cutoff. ## 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.