# COVID-GRAM Critical Illness Probability Calculator (Liang 2020) > COVID-GRAM Critical Illness Probability Calculator (Liang 2020) is a paid API for AI agents from api.magentlab.com, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-14). Computes the logistic probability of critical illness (ICU admission, invasive ventilation, or death) in hospitalized COVID-19 patients using the Liang 2020 COVID-GRAM model (Table 3 coefficients). ## Facts - Endpoint: GET https://api.magentlab.com/api/calc/cgram - Price: $0.005/call - Payment: x402 - Status: unknown - Last checked: 2026-09-14 - Activations on Zero: 0 - Tags: x402 - Canonical page: https://www.zero.xyz/c/covid-gram-critical-illness-probability-calculator-liang-2020-13f48497 - Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_qrot8xrS55JF3KxLfLTQn Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently. ## How to call it through Zero Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`): ```sh zero fetch --capability covid-gram-critical-illness-probability-calculator-liang-2020-13f48497 ``` Example prompt: Using the Liang 2020 COVID-GRAM model, estimate the critical illness probability for a 67-year-old COVID-19 inpatient with an abnormal chest X-ray, dyspnea present, no hemoptysis, no unconsciousness, 2 comorbidities, no cancer history, a neutrophil-to-lymphocyte ratio of 8.5, LDH of 420 U/L, and direct bilirubin of 12 umol/L. ## When to prefer this Use this endpoint when you need the validated Liang 2020 COVID-GRAM logistic score specifically, with exact Table 3 coefficients, for hospitalized COVID-19 patients. Prefer it when you already have structured clinical values (NLR, LDH, bilirubin, symptom flags) and want a reproducible, published-model probability rather than a custom heuristic. It is not a replacement for clinical judgment, chest film reading, or comorbidity counting — the caller must supply those assessments. ## Known failure modes - Missing required query parameter (e.g. age, nlr, ldh_u_l) returns a 400 error - Age out of range (< 1 or > 120) or NLR out of range (< 0.01 or > 200) may return a validation error - LDH or bilirubin values in non-supported units (e.g. µkat/L instead of U/L) will produce incorrect scores without warning — caller must convert - Payment not provided or insufficient USDC results in 402 Payment Required - Boolean flags must be true/false; any other value may cause a parse error ## How this service works Liang 2020 COVID-GRAM logistic probability of critical illness (ICU, invasive ventilation, or death) among hospitalized COVID-19 from age, caller-assigned chest radiograph abnormality, hemoptysis, dyspnea, unconsciousness, comorbidity count, cancer history, neutrophil-to-lymphocyte ratio, LDH (U/L), and direct bilirubin (umol/L). Table 3 coefficients. magent does not read the film or count comorbidities. Not a diagnosis or ICU-allocation order. ## Output Returns the COVID-GRAM logistic probability (0–1) of critical illness (ICU admission, invasive mechanical ventilation, or death) for a hospitalized COVID-19 patient, derived from Liang 2020 Table 3 coefficients applied to the supplied clinical inputs. ## Request schema (JSON Schema) ```json { "type": "object", "$schema": "https://json-schema.org/draft/2020-12/schema", "required": [ "input" ], "properties": { "input": { "type": "object", "required": [ "type", "method" ], "properties": { "type": { "type": "string", "const": "http" }, "method": { "enum": [ "GET", "HEAD", "DELETE" ], "type": "string" }, "headers": { "type": "object", "additionalProperties": { "type": "string" } }, "queryParams": { "type": "object", "required": [ "age", "chest_xray_abnormal", "hemoptysis", "dyspnea", "unconsciousness", "number_of_comorbidities", "cancer_history", "nlr", "ldh_u_l", "direct_bilirubin_umol_l" ], "properties": { "age": { "type": "integer", "description": "Age in years (integer 1-120). Liang 2020 Table 3: +0.0276 per year (OR 1.03 per year). Development cohort ages 1-95." }, "nlr": { "type": "number", "description": "Neutrophil-to-lymphocyte ratio (0.01-200). Liang 2020 Table 3: +0.0562 per unit (OR 1.06). Caller assigns the ratio; magent does not compute it from counts." }, "dyspnea": { "type": "boolean", "description": "Dyspnea (shortness of breath) as assigned by the caller (true or false). Liang 2020 Table 3: true adds 0.632 (OR 1.88)." }, "ldh_u_l": { "type": "number", "description": "Lactate dehydrogenase in U/L (1-5000). Liang 2020 Table 3: +0.0024 per U/L (OR 1.002). magent does not convert other LDH units." }, "hemoptysis": { "type": "boolean", "description": "Hemoptysis as assigned by the caller (true or false). Liang 2020 Table 3: true adds 1.5116 (OR 4.53)." }, "cancer_history": { "type": "boolean", "description": "Cancer history as assigned by the caller (true or false). Liang 2020 Table 3: true adds 1.4037 (OR 4.07), separate from the comorbidity count." }, "unconsciousness": { "type": "boolean", "description": "Unconsciousness as assigned by the caller (true or false). Liang 2020 Table 3: true adds 1.5494 (OR 4.71)." }, "chest_xray_abnormal": { "type": "boolean", "description": "Chest radiograph abnormality as assigned by the caller (true or false). Liang 2020 Table 3: true adds 1.2205 (OR 3.39). magent does not read the film." }, … (truncated) ``` ## More - Live health (JSON, refreshed every minute): https://www.zero.xyz/c/covid-gram-critical-illness-probability-calculator-liang-2020-13f48497/health.json - [Zero catalog index](https://www.zero.xyz/llms.txt) - [Other services from api.magentlab.com](https://www.zero.xyz/host/api.magentlab.com/llms.txt)