# Glasgow-Blatchford Score (GBS) Calculator > Glasgow-Blatchford Score (GBS) Calculator is a paid API for AI agents from api.magentlab.com, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-15). Computes the Glasgow-Blatchford Score for predicting need for clinical intervention after upper gastrointestinal haemorrhage, using urea, haemoglobin, blood pressure, heart rate, and comorbidities. ## Facts - Endpoint: GET https://api.magentlab.com/api/calc/glasgow_blatchford - Price: $0.005/call - Payment: x402 - Status: unknown - Last checked: 2026-09-15 - Activations on Zero: 0 - Tags: x402 - Canonical page: https://www.zero.xyz/c/glasgow-blatchford-score-gbs-calculator-e752b147 - Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_36gggTuRtuQv6b2pSumtt 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 glasgow-blatchford-score-gbs-calculator-e752b147 ``` Example prompt: Calculate the Glasgow-Blatchford Score for a male patient with a BUN of 22 mg/dL, hemoglobin of 11.5 g/dL, systolic BP of 95 mmHg, heart rate of 102 bpm, melena present, no syncope, no hepatic disease, and no cardiac failure — tell me if he's low risk. ## When to prefer this Use this endpoint when you need a validated, published GBS per Blatchford 2000 specifically — not Rockall score, not AIMS65, and not a proprietary risk model. Ideal for clinical decision support agents triaging upper GI haemorrhage, automated EHR scoring workflows, or audit systems checking whether a patient meets the GBS=0 low-risk threshold for safe outpatient discharge. Supports both mmol/L and mg/dL urea, and both g/L and g/dL haemoglobin, making it flexible for US and international clinical contexts. ## Known failure modes - Missing required parameters (sex, systolic_mm_hg, heart_rate_bpm, melena, syncope, hepatic_disease, cardiac_failure) returns a validation error - Providing both urea_mmol_l and bun_mg_dl simultaneously causes a conflict error - Providing both hemoglobin_g_l and hemoglobin_g_dl simultaneously causes a conflict error - Out-of-range values (e.g. heart rate <30 or >220) are rejected - Invalid sex value (not 'male' or 'female') returns a parameter error - Payment failure (insufficient USDC balance or x402 not configured) blocks the request ## How this service works Glasgow-Blatchford score (Blatchford 2000) for need for treatment after upper-gastrointestinal haemorrhage. Points from urea, haemoglobin (sex-specific), systolic BP, heart rate ≥100, melena, syncope, hepatic disease, and cardiac failure; max 23. Score 0 is the published low-risk screen; magent does not invent other GBS bands. Not a diagnosis, not Rockall, and not AIMS65. Urea may be mmol/L or BUN mg/dL; haemoglobin g/L or g/dL. ## Output Returns the integer Glasgow-Blatchford Score (0–23), with each variable's point contribution mapped according to the Blatchford 2000 published table. A score of 0 corresponds to the validated low-risk threshold (safe for outpatient management); higher scores indicate increasing need for clinical intervention. The endpoint does not output Rockall or AIMS65 scores and does not invent additional GBS risk bands beyond the published criteria. ## 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": [ "sex", "systolic_mm_hg", "heart_rate_bpm", "melena", "syncope", "hepatic_disease", "cardiac_failure" ], "properties": { "sex": { "type": "string", "description": "Sex (female or male). Haemoglobin points use the Blatchford 2000 sex-specific table." }, "melena": { "type": "boolean", "description": "Melena as assigned by the caller. true or false. 1 point if true." }, "syncope": { "type": "boolean", "description": "Syncope as assigned by the caller. true or false. 2 points if true." }, "bun_mg_dl": { "type": "number", "description": "BUN in mg/dL (3-140). Converted as urea_mmol_l = bun_mg_dl / 2.8. Provide this or urea_mmol_l, not both." }, "urea_mmol_l": { "type": "number", "description": "Blood urea in mmol/L (1-50). Provide this or bun_mg_dl, not both. <6.5 scores 0; 6.5–7.9 scores 2; 8.0–9.9 scores 3; 10.0–24.9 scores 4; ≥25.0 scores 6." }, "heart_rate_bpm": { "type": "integer", "description": "Heart rate in beats per minute (integer 30-220). Scores 1 when ≥100; 99 does not score." }, "hemoglobin_g_l": { "type": "number", "description": "Haemoglobin in g/L (30-220). Provide this or hemoglobin_g_dl, not both. Men: <100 → 6; 100–119 → 3; 120–129 → 1; ≥130 → 0. Women: <100 → 6; 100–119 → 1; ≥120 → 0." }, "systolic_mm_hg": { "type": "number", "description": "Systolic blood pressure in mm Hg (50-250). <90 scores 3; 90–99 scores 2; 100–109 scores 1; ≥110 scores 0." }, "cardiac_failure": { "type": "boolean", "description": "Cardiac failure as assigned by the caller. true or false. 2 points if true." }, "hemoglobin_g_dl": { "type": "number", "description": "Haemoglobin in g/dL (3-22). Converted as h … (truncated) ``` ## Response schema (JSON Schema) ```json { "type": "json", "example": { "path": "/api/calc/glasgow_blatchford", "count": 2, "items": [ { "sex": "male", "score": 0, "formula": "glasgow_blatchford", "citation": { "id": "blatchford-2000", "doi": "10.1016/S0140-6736(00)02816-6", "title": "A risk score to predict need for treatment for upper-gastrointestinal haemorrhage", "source": "Lancet. 2000;356(9238):1318-1321", "authors": "Blatchford O, Murray WR, Blatchford M" }, "gbs_risk": "low", "max_score": 23, "components": [ { "value": 5, "factor": "urea", "points": 0, "present": false }, { "value": 140, "factor": "hemoglobin", "points": 0, "present": false }, { "value": 120, "factor": "systolic", "points": 0, "present": false }, { "value": 80, "factor": "heart_rate", "points": 0, "present": false }, { "factor": "melena", "points": 0, "present": false }, { "factor": "syncope", "points": 0, "present": false }, { "factor": "hepatic_disease", "points": 0, "present": false }, { "factor": "cardiac_failure", "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.", "urea_mmol_l": 5, "heart_rate_bpm": 80, "hemoglobin_g_l": 140, "systolic_mm_hg": 120, "formula_expression": "GBS = urea_mmol_l table + haemoglobin_g_l table (sex-specific) + systolic_mm_hg table + (heart_rate_bpm >= 100) + melena + 2*syncope + 2*hepatic_disease + 2*cardiac_failure; max 23; score 0 low, else not_low" }, { "sex": "male", "score": 0, "formula": "glasgow_blatchford", "citation": { "id": "blatchford-2000", "doi": "10.1016/S0140-6736(00)02816-6", "title": "A risk score to predict need for treatment for upper-gastrointestinal haemorrhage", "source": "Lancet. 2000;356(9238):1318-1321", "authors": "Blatchford O, Murray WR, Blatchford M" }, "gbs_risk": "low", "max_score": 23, "components": [ { "value": 5, "factor": "urea", "points": 0, "present": false }, { "value": 140, "factor": "hemoglobin", "points": 0, … (truncated) ``` ## More - Live health (JSON, refreshed every minute): https://www.zero.xyz/c/glasgow-blatchford-score-gbs-calculator-e752b147/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)