# Centor and McIsaac scores Status: LIVE Price: $0.005 USDC `GET /api/calc/centor` HTML: https://magentlab.com/docs/centor Markdown: https://magentlab.com/docs/centor.md Not a medical device. Not a diagnosis, dose, or listing recommendation. ## What it computes Compute the Centor score or the McIsaac age-modified score from four caller-assigned pharyngitis findings. The edition is required. ## When to use When an agent needs a published Centor or McIsaac total and must not silently pick an edition or invent the four clinical findings. ## When not to use - Not a test-or-treat protocol and not a diagnosis of streptococcal pharyngitis. - The caller assigns the four clinical findings. magent does not examine the throat. - McIsaac age bands are 3-14 / 15-44 / >=45 as published. edition is required; magent does not pick Centor or McIsaac. ## Formula ``` McIsaac = Centor criteria + age 3-14 +1, 15-44 0, >=45 -1; max 5 ``` ## Citation Empirical validation of guidelines for the management of pharyngitis in children and adults McIsaac WJ, Kellner JD, Aufricht P, Vanjaka A, Low DE JAMA. 2004;291(13):1587-1595 DOI: [10.1001/jama.291.13.1587](https://doi.org/10.1001/jama.291.13.1587) ## Worked example ### McIsaac adult all-negative Given: `age=30, cough_absent=false, edition=mcisaac, history_of_fever=false, tender_anterior_cervical_nodes=false, tonsillar_exudates=false` 1. Four findings absent; age 30 is 15-44 → 0 2. Score = 0 (max 5) ### Centor all four present Given: `cough_absent=true, edition=centor, history_of_fever=true, tender_anterior_cervical_nodes=true, tonsillar_exudates=true` 1. Four findings present → 1 each 2. Score = 4 (max 4) ### McIsaac child all-negative Given: `age=8, cough_absent=false, edition=mcisaac, history_of_fever=false, tender_anterior_cervical_nodes=false, tonsillar_exudates=false` 1. Four findings absent; age 8 is 3-14 → +1 2. Score = 1 ## Parameters - `edition` (string, required): Published score. Required; magent does not pick Centor (four findings, max 4) or McIsaac (age-modified, max 5). - `age` (integer, optional): Age in years (3-120). Required when edition=mcisaac (3-14 +1, 15-44 0, >=45 -1). Ignored when edition=centor. - `tonsillar_exudates` (boolean, required): Tonsillar exudates. true or false as assigned by the caller. - `tender_anterior_cervical_nodes` (boolean, required): Tender anterior cervical nodes. true or false as assigned by the caller. - `history_of_fever` (boolean, required): History of fever. true or false as assigned by the caller. - `cough_absent` (boolean, required): Absence of cough. true when cough is absent; false when cough is present. ## Bulk (POST) POST the same path with a JSON items array. Price is n times the GET unit. Invalid items return HTTP 400 before settlement. Method: `POST /api/calc/centor` Max items: 25 Price: unit_amount * n (unit 5000 atomic) Status: PREVIEW - 1 to 25 items. Each item uses the same keys as the GET query parameters. - 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": "30", "cough_absent": "false", "edition": "mcisaac", "history_of_fever": "false", "tender_anterior_cervical_nodes": "false", "tonsillar_exudates": "false" }, { "age": "30", "cough_absent": "false", "edition": "mcisaac", "history_of_fever": "false", "tender_anterior_cervical_nodes": "false", "tonsillar_exudates": "false" } ] } ``` Human paywall (two-item fixture): https://api.magentlab.com/paywall/bulk/centor Example 200: ```json { "count": 2, "path": "/api/calc/centor", "items": [ { "components": [ { "factor": "tonsillar_exudates", "points": 0, "present": false }, { "factor": "tender_anterior_cervical_nodes", "points": 0, "present": false }, { "factor": "history_of_fever", "points": 0, "present": false }, { "factor": "cough_absent", "points": 0, "present": false }, { "value": 30, "factor": "age_adjustment", "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": "McIsaac WJ, Kellner JD, Aufricht P, Vanjaka A, Low DE", "doi": "10.1001/jama.291.13.1587", "id": "mcisaac-2004", "source": "JAMA. 2004;291(13):1587-1595", "title": "Empirical validation of guidelines for the management of pharyngitis in children and adults" }, "formula": "mcisaac", "formula_expression": "McIsaac = Centor criteria + age 3-14 +1, 15-44 0, >=45 -1; max 5", "max_score": 5, "score": 0, "edition": "mcisaac", "age_years": 30 }, { "components": [ { "factor": "tonsillar_exudates", "points": 0, "present": false }, { "factor": "tender_anterior_cervical_nodes", "points": 0, "present": false }, { "factor": "history_of_fever", "points": 0, "present": false }, { "factor": "cough_absent", "points": 0, "present": false }, { "value": 30, "factor": "age_adjustment", "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": "McIsaac WJ, Kellner JD, Aufricht P, Vanjaka A, Low DE", "doi": "10.1001/jama.291.13.1587", "id": "mcisaac-2004", "source": "JAMA. 2004;291(13):1587-1595", "title": "Empirical validation of guidelines for the management of pharyngitis in children and adults" }, "formula": "mcisaac", "formula_expression": "McIsaac = Centor criteria + age 3-14 +1, 15-44 0, >=45 -1; max 5", "max_score": 5, "score": 0, "edition": "mcisaac", "age_years": 30 } ] } ``` ## Response fields - `formula` (string): centor or mcisaac - `formula_expression` (string): Exact expression used - `edition` (string): centor or mcisaac - `score` (integer): Total points (0-4 Centor; -1 to 5 McIsaac) - `max_score` (integer): 4 (Centor) or 5 (McIsaac) - `age_years` (integer): Age used for McIsaac bands. Present when edition=mcisaac. - `components` (array): Per-finding points - `citation` (object): Centor 1981 or McIsaac 2004 - `disclaimer` (string): Not-a-device notice ## Example JSON Frozen fixture. Not a live lookup. ```json { "components": [ { "factor": "tonsillar_exudates", "points": 0, "present": false }, { "factor": "tender_anterior_cervical_nodes", "points": 0, "present": false }, { "factor": "history_of_fever", "points": 0, "present": false }, { "factor": "cough_absent", "points": 0, "present": false }, { "value": 30, "factor": "age_adjustment", "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": "McIsaac WJ, Kellner JD, Aufricht P, Vanjaka A, Low DE", "doi": "10.1001/jama.291.13.1587", "id": "mcisaac-2004", "source": "JAMA. 2004;291(13):1587-1595", "title": "Empirical validation of guidelines for the management of pharyngitis in children and adults" }, "formula": "mcisaac", "formula_expression": "McIsaac = Centor criteria + age 3-14 +1, 15-44 0, >=45 -1; max 5", "max_score": 5, "score": 0, "edition": "mcisaac", "age_years": 30 } ``` ## Errors - HTTP 400 `invalid_centor_edition`: edition must be centor or mcisaac. 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_centor_age`: age must be an integer from 3 to 120 (McIsaac). 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. - HTTP 402 `payment_required`: Missing or invalid PAYMENT-SIGNATURE; decode the PAYMENT-REQUIRED header - HTTP 409 `payment_in_progress`: The same authorization nonce is already being settled; retry shortly - HTTP 429 `rate_limited`: Too many requests from this client - HTTP 503 `settlement_uncertain`: Settlement is unconfirmed; retry with the same PAYMENT-SIGNATURE - HTTP 503 `settle_failed`: Settlement failed; retry with the same PAYMENT-SIGNATURE shortly - HTTP 503 `facilitator_unavailable`: Payment facilitator unavailable - HTTP 503 `facilitator_misconfigured`: Payment facilitator is not configured - HTTP 503 `facilitator_unauthorized`: Payment facilitator rejected credentials - HTTP 503 `ledger_unavailable`: Payment ledger unavailable - HTTP 503 `payment_unavailable`: Payment processing unavailable ## Related tools - [CURB-65](https://magentlab.com/docs/curb65) — Compute the CURB-65 community-acquired pneumonia severity score from age and discrete flags. ## Also searched as - Centor score - McIsaac score - modified Centor score - strep pharyngitis score - streptococcal pharyngitis criteria - tonsillar exudates tender nodes ## Payment Required query parameters must be present and valid. 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 EIP-3009 (scheme exact, assetTransferMethod eip3009) with validBefore = now + accepts[0].maxTimeoutSeconds (600 seconds). That window starts when you sign and must cover wallet confirmation plus CDP verify and settle. Magent retries transient facilitator 429/5xx before answering. Do not send upto or batch-settlement payloads; magent does not offer those schemes. - Retry the same URL with PAYMENT-SIGNATURE (base64 JSON echoing accepted, payload, and extensions when present). - Success is HTTP 200 JSON plus PAYMENT-RESPONSE. Settlement happens before the tool runs. HTTP 503 settlement_uncertain or settle_failed: retry the same PAYMENT-SIGNATURE. Mint a new 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. - 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. - not offered `batch-settlement`: Not offered. Payment-channel vouchers claimed later in batches. Not the same as POST {items} bulk (that is still exact). Same-path POST {items} is still scheme exact: one EIP-3009 authorization for n times the GET unit. That is not x402 batch-settlement (payment channels / vouchers). ## Guarantees - Invalid query parameters return HTTP 400 before settlement. You are not charged. - Settlement finishes before the tool executes (paymentFlow upfront). 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.