# Schwartz 2009 Bedside eGFR Calculator (CKiD) for Children > Schwartz 2009 Bedside eGFR Calculator (CKiD) for Children 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). Calculates estimated GFR in children using the 2009 Schwartz bedside CKiD formula (0.413 × height_cm / creatinine_mg_dL), accepting height and creatinine in multiple units ## Facts - Endpoint: GET https://api.magentlab.com/api/calc/schwartz_gfr - 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/schwartz-2009-bedside-egfr-calculator-ckid-for-children-9be699d4 - Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_NhmLGhrjlhhB7RmASglE4 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 schwartz-2009-bedside-egfr-calculator-ckid-for-children-9be699d4 ``` Example prompt: Calculate the bedside Schwartz 2009 eGFR for a pediatric patient who is 130 cm tall and has a serum creatinine of 0.6 mg/dL. ## When to prefer this Use this endpoint when you need the 2009 Schwartz bedside eGFR specifically for pediatric patients (children with CKD), as validated by the CKiD study. Prefer this over adult formulas like CKD-EPI or Cockcroft–Gault, which are inappropriate for children. Also prefer this over the original 1976 Schwartz formula (k=0.55) which overestimates GFR in modern creatinine assays. Use when input may be in mixed units (inches/cm, mg/dL/µmol/L) and automatic conversion is needed. ## Known failure modes - Missing required parameters (no height or no creatinine provided) — returns error - Height or creatinine value out of acceptable range (e.g. height_cm < 50 or > 250, creatinine_mg_dL < 0.1 or > 20) — returns validation error - Both height_cm and height_in provided simultaneously — ambiguous input may cause error - Both creatinine_mg_dl and creatinine_umol_l provided simultaneously — ambiguous input - Payment not included or insufficient — returns 402 Payment Required ## How this service works Schwartz 2009 bedside eGFR for children with CKD (CKiD): 0.413 × height in cm divided by serum creatinine in mg/dL, rounded to one decimal as mL/min/1.73m2. Height may be centimeters or inches; creatinine may be mg/dL or µmol/L. Not a dosing recommendation, not CKD-EPI, not Cockcroft–Gault, and not the 1976 Schwartz k=0.55 formula. Does not assign CKD stages. ## Output Returns the estimated GFR value rounded to one decimal place in mL/min/1.73m², computed via the 2009 Schwartz bedside formula (0.413 × height_cm / creatinine_mg_dL). Does not include CKD staging, dosing recommendations, or adult eGFR formulas. ## 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": [], "properties": { "height_cm": { "type": "number", "description": "Height in centimeters (50-250). Provide height_cm or height_in." }, "height_in": { "type": "number", "description": "Height in inches (20-98). Converted as cm = in * 2.54." }, "creatinine_mg_dl": { "type": "number", "description": "Serum creatinine in mg/dL (0.1-20). Provide this or creatinine_umol_l." }, "creatinine_umol_l": { "type": "number", "description": "Serum creatinine in µmol/L (9-1768). Converted as mg/dL = µmol/L / 88.42." } } } }, "additionalProperties": false }, "output": { "type": "object", "required": [ "type" ], "properties": { "type": { "type": "string" }, "example": { "type": "object" } } } } } ``` ## Response schema (JSON Schema) ```json { "type": "json", "example": { "path": "/api/calc/schwartz_gfr", "count": 2, "items": [ { "units": "mL/min/1.73m2", "formula": "schwartz_2009", "citation": { "id": "schwartz-2009", "doi": "10.1681/ASN.2008030287", "title": "New equations to estimate GFR in children with CKD", "source": "J Am Soc Nephrol. 2009;20(3):629-637", "authors": "Schwartz GJ, Muñoz A, Schneider MF, et al." }, "height_cm": 140, "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.", "creatinine_mg_dl": 1, "egfr_ml_min_1_73m2": 57.8, "formula_expression": "egfr_ml_min_1_73m2 = 0.413 * height_cm / creatinine_mg_dl" }, { "units": "mL/min/1.73m2", "formula": "schwartz_2009", "citation": { "id": "schwartz-2009", "doi": "10.1681/ASN.2008030287", "title": "New equations to estimate GFR in children with CKD", "source": "J Am Soc Nephrol. 2009;20(3):629-637", "authors": "Schwartz GJ, Muñoz A, Schneider MF, et al." }, "height_cm": 140, "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.", "creatinine_mg_dl": 1, "egfr_ml_min_1_73m2": 57.8, "formula_expression": "egfr_ml_min_1_73m2 = 0.413 * height_cm / creatinine_mg_dl" } ] } } ``` ## More - Live health (JSON, refreshed every minute): https://www.zero.xyz/c/schwartz-2009-bedside-egfr-calculator-ckid-for-children-9be699d4/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)