# VACS Index 1.0 Calculator (Tate 2013)

> VACS Index 1.0 Calculator (Tate 2013) 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 Veterans Aging Cohort Study (VACS) Index 1.0 score (0–164) for HIV-positive patients using age, CD4, HIV-1 RNA, hemoglobin, FIB-4, eGFR, and hepatitis C co-infection status.

## Facts

- Endpoint: GET https://api.magentlab.com/api/calc/vacs_1
- 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/vacs-index-1-0-calculator-tate-2013-2f920359
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_lnOp_AW6UQouil5rLCVwN

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 vacs-index-1-0-calculator-tate-2013-2f920359
```

Example prompt: Calculate the VACS Index 1.0 score for a 58-year-old HIV-positive patient with a CD4 count of 320 cells/mm³, HIV-1 RNA of 2500 copies/mL, hemoglobin of 11.5 g/dL, FIB-4 of 1.8, eGFR of 52, and hepatitis C co-infection.

## When to prefer this

Use this endpoint when you need the original Tate 2013 VACS Index 1.0 (not VACS 2.0) for HIV-positive adult patients and already have pre-computed FIB-4 and eGFR values available. Prefer this over manual lookup tables when integrating VACS scoring into automated clinical pipelines or research workflows. Do not use if you need the updated VACS Index 2.0, or if you need the system to compute FIB-4, MDRD, or CKD-EPI from raw labs — those must be supplied by the caller.

## Known failure modes

- Missing required parameters (age, CD4, HIV-1 RNA, hemoglobin, FIB-4, eGFR, or hepatitis_c) returns a validation error
- Out-of-range values (e.g. age <18, CD4 >2000, hemoglobin >22) may be rejected or produce unexpected results
- FIB-4 or eGFR values not pre-computed by caller will produce errors since the endpoint does not derive them
- Payment failure (x402) if USDC balance is insufficient
- Boolean hepatitis_c passed as string instead of true/false may cause a schema error

## How this service works

Tate 2013 VACS Index 1.0 (not VACS 2.0): age, CD4, HIV-1 RNA, hemoglobin g/dL, caller-assigned FIB-4 and eGFR, and hepatitis C. Points 0-164. No published named mortality bands. magent does not compute FIB-4 or MDRD/CKD-EPI and does not order ART.

## Output

Returns an integer VACS Index 1.0 total score between 0 and 164, derived by summing points from each of the seven clinical inputs per the Tate 2013 published scoring bands. Higher scores indicate greater mortality risk. The endpoint does not return named risk bands, percentile ranks, or treatment recommendations.

## 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",
      "cd4_cells_mm3",
      "hiv_rna_copies_ml",
      "hemoglobin_g_dl",
      "fib4",
      "egfr_ml_min_1_73m2",
      "hepatitis_c"
     ],
     "properties": {
      "age": {
       "type": "integer",
       "description": "Age in years (integer 18-120). Tate 2013 VACS Index: <50 scores 0; 50-64 scores 12; ≥65 scores 27."
      },
      "fib4": {
       "type": "number",
       "description": "Caller-assigned FIB-4 (0.1-20). Tate 2013: <1.45 scores 0; 1.45-3.25 scores 6; >3.25 scores 25. magent does not recompute FIB-4."
      },
      "hepatitis_c": {
       "type": "boolean",
       "description": "Caller-assigned hepatitis C co-infection (Tate 2013). true scores 5. magent does not diagnose hepatitis C."
      },
      "cd4_cells_mm3": {
       "type": "integer",
       "description": "CD4 count in cells/mm³ (integer 1-2000). Tate 2013: ≥500 scores 0; 350-499 scores 6; 200-349 scores 6; 100-199 scores 10; 50-99 scores 28; <50 scores 29. magent does not assay CD4."
      },
      "hemoglobin_g_dl": {
       "type": "number",
       "description": "Hemoglobin in g/dL (3-22). Tate 2013: ≥14 scores 0; 12-13.9 scores 10; 10-11.9 scores 22; <10 scores 38. magent does not assay hemoglobin."
      },
      "hiv_rna_copies_ml": {
       "type": "number",
       "description": "HIV-1 RNA in copies/mL (0-10000000). Tate 2013: <500 scores 0; 500-99999 scores 7; ≥100000 scores 14. magent does not assay viral load."
      },
      "egfr_ml_min_1_73m2": {
       "type": "number",
       "description": "Caller-assigned eGFR in mL/min/1.73m² (5-200). Tate 2013: ≥60 scores 0; 45-59.9 scores 6; 30-44.9 scores 8; <30 scores 26. magent does not compute MDRD or CKD-EPI."
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/vacs-index-1-0-calculator-tate-2013-2f920359/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)