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SAAG

Compute the Runyon 1992 serum-ascites albumin gradient as serum albumin minus ascites albumin in g/dL, and whether that gradient is >= 1.1 g/dL (portal-hypertension physiology).

LIVE $0.005 USDC GET /api/calc/saag

Markdown: /docs/saag.md · Canonical: https://magentlab.com/docs/saag

Not a medical device. Not a diagnosis, dose, or listing recommendation.

What it computes

Compute the Runyon 1992 serum-ascites albumin gradient as serum albumin minus ascites albumin in g/dL, and whether that gradient is >= 1.1 g/dL (portal-hypertension physiology).

When to use

When an agent needs the published SAAG gradient and must not invent Light-style exudate/transudate rules, a diagnosis of portal hypertension, or peritonitis.

When not to use

• Not a diagnosis. magent does not diagnose portal hypertension or peritonitis.
• Gradient only. This is not an exudate/transudate Light-style rule for ascites.
• Portal-hypertension physiology is saag_g_dl >= 1.1 after rounding to one decimal; 1.0 is below the cutoff.

Formula

saag_g_dl = albumin_g_dl - ascites_albumin_g_dl

Citation

Title

The serum-ascites albumin gradient is superior to the exudate-transudate concept in the differential diagnosis of ascites

Authors

Runyon BA, Montano AA, Akriviadis EA, Antillon MR, Irving MA, McHutchison JG

Source

Ann Intern Med. 1992;117(3):215-220

DOI

10.7326/0003-4819-117-3-215

Worked example

Also searched as

• serum-ascites albumin gradient
• SAAG gradient
• ascites albumin gradient
• Runyon SAAG
• serum ascites albumin
• portal hypertension SAAG

Try

Opens the live endpoint. Unpaid browser requests show the paywall; agents should send Accept: application/json.

/api/calc/saag?albumin_g_dl=3.5&ascites_albumin_g_dl=2.0

Full URL: https://api.magentlab.com/api/calc/saag?albumin_g_dl=3.5&ascites_albumin_g_dl=2.0

Call

Expect HTTP 402 until you retry with PAYMENT-SIGNATURE. Incomplete query params return HTTP 400 before any quote or charge.

curl -i -H "Accept: application/json" "https://api.magentlab.com/api/calc/saag?albumin_g_dl=3.5&ascites_albumin_g_dl=2.0"

Parameters

Bulk (POST)

POST the same path with a JSON items array. The first item is the GET unit; each additional item is $0.002. Invalid items return HTTP 400 before settlement.

POST /api/calc/saag Max 25 unit_amount + extra_item_amount * (n - 1) extra $0.002 PREVIEW

• 1 to 25 items. Each item uses the same keys as the GET query parameters.
• POST of 1 item costs the same as GET. Lists longer than 25: chunk into multiple POSTs. Extra items still execute; do not pad dummy rows.
• The first invalid item fails the whole request (index in the 400 JSON). You are not charged.
• HTTP 200 is {count, path, items}. Each items[i] is the GET 200 body for that row.
• Catalog misses (empty matches, found=false) stay paid 200s inside that slot.
• x402 resource URL is this path plus n and body_sha256. Browsers that prefer text/html get the same paywall as GET; Pay retries POST with the same items.

Example request (fixture)

{
  "items": [
    {
      "albumin_g_dl": "3.5",
      "ascites_albumin_g_dl": "2.0"
    },
    {
      "albumin_g_dl": "3.5",
      "ascites_albumin_g_dl": "2.0"
    }
  ]
}

Open bulk paywall →

Opens a two-item fixture on the API host. Unpaid browsers get the same MetaMask paywall as GET; Pay retries POST with those items.

Example 200 (fixture)

{
  "count": 2,
  "path": "/api/calc/saag",
  "items": [
    {
      "albumin_g_dl": 3.5,
      "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.",
      "citation": {
        "authors": "Runyon BA, Montano AA, Akriviadis EA, Antillon MR, Irving MA, McHutchison JG",
        "doi": "10.7326/0003-4819-117-3-215",
        "id": "runyon-1992",
        "source": "Ann Intern Med. 1992;117(3):215-220",
        "title": "The serum-ascites albumin gradient is superior to the exudate-transudate concept in the differential diagnosis of ascites"
      },
      "formula": "saag",
      "formula_expression": "saag_g_dl = albumin_g_dl - ascites_albumin_g_dl",
      "ascites_albumin_g_dl": 2.0,
      "portal_hypertension_physiology": true,
      "saag_g_dl": 1.5
    },
    {
      "albumin_g_dl": 3.5,
      "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.",
      "citation": {
        "authors": "Runyon BA, Montano AA, Akriviadis EA, Antillon MR, Irving MA, McHutchison JG",
        "doi": "10.7326/0003-4819-117-3-215",
        "id": "runyon-1992",
        "source": "Ann Intern Med. 1992;117(3):215-220",
        "title": "The serum-ascites albumin gradient is superior to the exudate-transudate concept in the differential diagnosis of ascites"
      },
      "formula": "saag",
      "formula_expression": "saag_g_dl = albumin_g_dl - ascites_albumin_g_dl",
      "ascites_albumin_g_dl": 2.0,
      "portal_hypertension_physiology": true,
      "saag_g_dl": 1.5
    }
  ]
}

Response

Example JSON

Machine form of the same example. Frozen fixture. Not a live lookup.

{
  "albumin_g_dl": 3.5,
  "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.",
  "citation": {
    "authors": "Runyon BA, Montano AA, Akriviadis EA, Antillon MR, Irving MA, McHutchison JG",
    "doi": "10.7326/0003-4819-117-3-215",
    "id": "runyon-1992",
    "source": "Ann Intern Med. 1992;117(3):215-220",
    "title": "The serum-ascites albumin gradient is superior to the exudate-transudate concept in the differential diagnosis of ascites"
  },
  "formula": "saag",
  "formula_expression": "saag_g_dl = albumin_g_dl - ascites_albumin_g_dl",
  "ascites_albumin_g_dl": 2.0,
  "portal_hypertension_physiology": true,
  "saag_g_dl": 1.5
}

Client errors (HTTP 400)

Invalid params return 400 without charge. Shared HTTP 402 and 503 meanings: Payments.

Related tools

• Child–Pugh — Compute the Child–Turcotte–Pugh cirrhosis severity score from bilirubin, albumin, INR, encephalopathy, and ascites.

Payment

Required query parameters must be present and valid. Invalid params return HTTP 400 JSON before settlement. magent does not charge. Fix the params, then request a new 402 quote for that complete URL. Catalog misses (empty matches, found=false) are valid paid 200s. Unpaid valid requests return HTTP 402 with a base64 PAYMENT-REQUIRED header. HTTP 503 is not a new quote: retry the same PAYMENT-SIGNATURE. Full handshake and shared payment errors: Payments. Stdio MCP: /docs/mcp.

Guarantees

• Invalid query parameters return HTTP 400 before settlement. You are not charged.
• Settlement finishes before the tool executes (paymentFlow upfront). Uncertain or failed settlement fails closed (HTTP 503). Retry the same PAYMENT-SIGNATURE.
• HTTP 402 is unpaid only. Do not sign a second authorization because of a 503.
• Execution is timeout-bounded and concurrency-capped.
• Calculator inputs are stored encrypted for allowlisted operators (Magent Console). They are not in public logs, SSH lookups, catalog, or rollups. Request logs store path without query.