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Anion gap

Compute the serum anion gap from sodium, chloride, and bicarbonate, with or without potassium, using the Emmett–Narins 1977 formulas. formula is required.

Also searched as

• anion gap
• serum anion gap
• Na Cl HCO3 gap
• anion gap with potassium
• Emmett Narins anion gap
• AG without K
• AG with K

LIVE $0.005 USDC GET /api/calc/anion_gap

Markdown: /docs/anion-gap.md · Canonical: https://magentlab.com/docs/anion-gap

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

What it computes

Compute the serum anion gap from sodium, chloride, and bicarbonate, with or without potassium, using the Emmett–Narins 1977 formulas. formula is required.

When to use

When an agent needs a published anion gap and must not pick with-K vs without-K silently, assign high/low AG, or apply an albumin correction.

When not to use

• Not a diagnosis. magent does not assign a high or low anion gap.
• Does not correct for albumin. Figge/Fencl albumin-corrected anion gap is not this tool.
• Does not compute a delta gap.

Formula

anion_gap_mmol_l = sodium_mmol_l - chloride_mmol_l - bicarbonate_mmol_l

Citation

Title

Clinical use of the anion gap

Authors

Emmett M, Narins RG

Source

Medicine (Baltimore). 1977;56(1):38-54

DOI

10.1097/00005792-197701000-00002

Worked example

Try

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

/api/calc/anion_gap?sodium_mmol_l=140&chloride_mmol_l=104&bicarbonate_mmol_l=24&formula=without_k

Full URL: https://api.magentlab.com/api/calc/anion_gap?sodium_mmol_l=140&chloride_mmol_l=104&bicarbonate_mmol_l=24&formula=without_k

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/anion_gap?sodium_mmol_l=140&chloride_mmol_l=104&bicarbonate_mmol_l=24&formula=without_k"

Parameters

Bulk (POST)

POST the same path with a JSON items array. Price is n times the GET unit. Invalid items return HTTP 400 before settlement.

POST /api/calc/anion_gap Max 25 unit_amount * n PREVIEW

• 1 to 25 items. Each item uses the same keys as the GET query parameters.
• 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": [
    {
      "bicarbonate_mmol_l": "24",
      "chloride_mmol_l": "104",
      "formula": "without_k",
      "sodium_mmol_l": "140"
    },
    {
      "bicarbonate_mmol_l": "24",
      "chloride_mmol_l": "104",
      "formula": "without_k",
      "sodium_mmol_l": "140"
    }
  ]
}

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/anion_gap",
  "items": [
    {
      "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": "Emmett M, Narins RG",
        "doi": "10.1097/00005792-197701000-00002",
        "id": "emmett-narins-1977",
        "source": "Medicine (Baltimore). 1977;56(1):38-54",
        "title": "Clinical use of the anion gap"
      },
      "formula": "without_k",
      "formula_expression": "anion_gap_mmol_l = sodium_mmol_l - chloride_mmol_l - bicarbonate_mmol_l",
      "anion_gap_mmol_l": 12.0,
      "bicarbonate_mmol_l": 24.0,
      "chloride_mmol_l": 104.0,
      "sodium_mmol_l": 140.0
    },
    {
      "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": "Emmett M, Narins RG",
        "doi": "10.1097/00005792-197701000-00002",
        "id": "emmett-narins-1977",
        "source": "Medicine (Baltimore). 1977;56(1):38-54",
        "title": "Clinical use of the anion gap"
      },
      "formula": "without_k",
      "formula_expression": "anion_gap_mmol_l = sodium_mmol_l - chloride_mmol_l - bicarbonate_mmol_l",
      "anion_gap_mmol_l": 12.0,
      "bicarbonate_mmol_l": 24.0,
      "chloride_mmol_l": 104.0,
      "sodium_mmol_l": 140.0
    }
  ]
}

Response

Example JSON

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

{
  "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": "Emmett M, Narins RG",
    "doi": "10.1097/00005792-197701000-00002",
    "id": "emmett-narins-1977",
    "source": "Medicine (Baltimore). 1977;56(1):38-54",
    "title": "Clinical use of the anion gap"
  },
  "formula": "without_k",
  "formula_expression": "anion_gap_mmol_l = sodium_mmol_l - chloride_mmol_l - bicarbonate_mmol_l",
  "anion_gap_mmol_l": 12.0,
  "bicarbonate_mmol_l": 24.0,
  "chloride_mmol_l": 104.0,
  "sodium_mmol_l": 140.0
}

Client errors (HTTP 400)

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

Related tools

• Winters' formula — Compute expected arterial PCO2 in metabolic acidosis from plasma bicarbonate using the Albert–Winters 1967 formula.
• Serum osmolality — Compute Worthley calculated serum osmolality from sodium, glucose, and BUN, plus an optional osmolar gap when a measured osm is supplied.

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.