# magent C-DIVA Difficult Intravenous Access Score (Bell 2023)

> magent C-DIVA Difficult Intravenous Access Score (Bell 2023) 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 Bell 2023 C-DIVA score from four caller-assigned domain scores and returns a risk band (low, medium, or high) for difficult intravenous access.

## Facts

- Endpoint: GET https://api.magentlab.com/api/calc/c_diva
- 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/magent-c-diva-difficult-intravenous-access-score-bell-2023-9976beb9
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_HmNIqYZN1w2sjHyL4yPDo

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 magent-c-diva-difficult-intravenous-access-score-bell-2023-9976beb9
```

Example prompt: Calculate the C-DIVA score for a patient with few visible veins (visual appearance 1), no palpable veins (palpable sites 2), a history of reported difficulty with missed attempts (history of difficult access 1), and comorbidities requiring urgent care (clinical factors 2) — give me the total score and difficulty band.

## When to prefer this

Use this endpoint when you need a fast, arithmetic Bell 2023 C-DIVA computation from pre-assigned domain scores and want a standardized low/medium/high band output. Prefer this over manual addition when building clinical documentation workflows, decision-support tools, or EHR integrations that require auditable, reproducible C-DIVA scoring. Note: this endpoint does not perform patient examination, vein visualization, or history-taking — all four domain scores must be supplied by the caller.

## Known failure modes

- Missing required query parameters (visual_appearance, palpable_sites, history_of_difficult_access, clinical_factors) returns a validation error
- Values outside the 0–2 integer range for any domain score return a schema validation error
- Payment not provided or insufficient USDC via x402 protocol results in 402 Payment Required
- Non-integer values for domain scores cause rejection

## How this service works

Bell 2023 C-DIVA from four caller-assigned 0-2 domains (visual appearance, palpable sites, history of difficult access, clinical factors) using that paper's Figure 1 0/1/2 descriptors. magent sums only (max 8) and returns Figure 1 bands low (0-3), medium (4-5), or high (6-8). magent does not examine veins or insert a catheter. Not a vascular-access order, not a medical device.

## Output

Returns the summed C-DIVA integer score (0–8) derived from the four input domain scores, along with the corresponding Bell 2023 Figure 1 difficulty band: low (0–3), medium (4–5), or high (6–8).

## 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": [
      "visual_appearance",
      "palpable_sites",
      "history_of_difficult_access",
      "clinical_factors"
     ],
     "properties": {
      "palpable_sites": {
       "type": "integer",
       "description": "Caller-assigned Bell 2023 Figure 1 palpable sites (integer 0-2): 0 many palpable veins; 1 few palpable veins; 2 no palpable veins. magent does not examine the patient."
      },
      "clinical_factors": {
       "type": "integer",
       "description": "Caller-assigned Bell 2023 Figure 1 clinical factors (integer 0-2): 0 not applicable; 1 pediatric patients or urgent conditions (ESI 3-4); 2 comorbidities or emergency conditions (ESI 1-2). magent does not assign ESI or examine the patient."
      },
      "visual_appearance": {
       "type": "integer",
       "description": "Caller-assigned Bell 2023 Figure 1 visual appearance (integer 0-2): 0 many visible veins; 1 few visible veins; 2 no visible veins. magent does not examine the patient."
      },
      "history_of_difficult_access": {
       "type": "integer",
       "description": "Caller-assigned Bell 2023 Figure 1 history of difficult access (integer 0-2): 0 no difficulty; 1 reported difficulty or recent missed attempts; 2 history of major difficulty as evidenced by previous central lines or PICCs. magent does not take a history."
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/magent-c-diva-difficult-intravenous-access-score-bell-2023-9976beb9/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)