# Urine Anion Gap Calculator (Batlle 1988) > Urine Anion Gap Calculator (Batlle 1988) 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 urine anion gap (Na + K − Cl) from urine electrolytes and returns an interpretive band distinguishing GI bicarbonate loss from renal tubular acidosis (RTA). ## Facts - Endpoint: GET https://api.magentlab.com/api/calc/urine_anion_gap - 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/urine-anion-gap-calculator-batlle-1988-d78ad133 - Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_e4V7ipnGQx2zXKMpUl6Q6 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 urine-anion-gap-calculator-batlle-1988-d78ad133 ``` Example prompt: Calculate the urine anion gap for a patient with urine sodium 40 mmol/L, urine potassium 20 mmol/L, and urine chloride 80 mmol/L, and tell me whether the result suggests GI bicarbonate loss or renal tubular acidosis. ## When to prefer this Choose this endpoint when you need a fast, citable, deterministic urine anion gap calculation with a built-in Batlle 1988 interpretive band for differentiating GI bicarbonate loss from renal tubular acidosis in the workup of non-anion gap metabolic acidosis. Prefer it over manual calculation when you need a machine-readable result with clinical interpretation text, or when logging acid-base assessments in an automated clinical workflow. ## Known failure modes - Missing required query parameter (urine_sodium_mmol_l, urine_potassium_mmol_l, or urine_chloride_mmol_l) returns a validation error - Values outside specified ranges (Na/Cl >300 or K >200 mmol/L) may return a range error or unexpected result - Non-numeric input for electrolyte values returns a parsing error - Payment failure (x402) blocks the request before computation occurs ## How this service works Urine anion gap from urine sodium, potassium, and chloride (Na + K − Cl). Batlle 1988 interpretive band: negative suggests increased NH4+ (GI bicarbonate loss); positive suggests impaired NH4+ (RTA). Deterministic published arithmetic with citation; not a diagnosis. ## Output Returns the numeric urine anion gap value (Na + K − Cl in mmol/L) along with a Batlle 1988 interpretive classification: a negative UAG suggests increased ammonium excretion consistent with GI bicarbonate loss (e.g. diarrhea), while a positive UAG suggests impaired NH4+ excretion consistent with renal tubular acidosis (RTA). Result is a deterministic arithmetic calculation with citation, not a clinical diagnosis. ## 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": [ "urine_sodium_mmol_l", "urine_potassium_mmol_l", "urine_chloride_mmol_l" ], "properties": { "urine_sodium_mmol_l": { "type": "number", "description": "Urine sodium in mmol/L (same as mEq/L). Range 1-300." }, "urine_chloride_mmol_l": { "type": "number", "description": "Urine chloride in mmol/L (same as mEq/L). Range 1-300." }, "urine_potassium_mmol_l": { "type": "number", "description": "Urine potassium in mmol/L (same as mEq/L). Range 1-200." } } } }, "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/urine_anion_gap", "count": 2, "items": [ { "formula": "urine_anion_gap", "citation": { "id": "batlle-1988", "doi": "10.1056/NEJM198803033180902", "title": "The use of the urinary anion gap in the diagnosis of hyperchloremic metabolic acidosis", "source": "N Engl J Med. 1988;318(10):594-599", "authors": "Batlle DC, Hizon M, Cohen E, Gutterman C, Gupta R" }, "uag_band": "negative", "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.", "formula_expression": "urine_anion_gap_mmol_l = urine_sodium_mmol_l + urine_potassium_mmol_l - urine_chloride_mmol_l", "urine_sodium_mmol_l": 20, "urine_chloride_mmol_l": 90, "urine_anion_gap_mmol_l": -40, "urine_potassium_mmol_l": 30 }, { "formula": "urine_anion_gap", "citation": { "id": "batlle-1988", "doi": "10.1056/NEJM198803033180902", "title": "The use of the urinary anion gap in the diagnosis of hyperchloremic metabolic acidosis", "source": "N Engl J Med. 1988;318(10):594-599", "authors": "Batlle DC, Hizon M, Cohen E, Gutterman C, Gupta R" }, "uag_band": "negative", "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.", "formula_expression": "urine_anion_gap_mmol_l = urine_sodium_mmol_l + urine_potassium_mmol_l - urine_chloride_mmol_l", "urine_sodium_mmol_l": 20, "urine_chloride_mmol_l": 90, "urine_anion_gap_mmol_l": -40, "urine_potassium_mmol_l": 30 } ] } } ``` ## More - Live health (JSON, refreshed every minute): https://www.zero.xyz/c/urine-anion-gap-calculator-batlle-1988-d78ad133/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)