LIVE

A1C ↔ eAG

Convert A1C percent to estimated average glucose, or the reverse, using Nathan/ADAG.

LIVE $0.005 USDC GET /api/calc/a1c_eag

Markdown: /docs/a1c-eag.md · Canonical: https://magentlab.com/docs/a1c-eag

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

What it computes

Convert A1C percent to estimated average glucose, or the reverse, using Nathan/ADAG.

When to use

When an agent must apply 28.7×A1C−46.7 instead of inventing an eAG from training data.

When not to use

Not a diagnosis. Provide exactly one of a1c_percent or eAG (mg/dL or mmol/L).
Does not interpret a glucose meter log or diagnose diabetes.

Formula

eAG_mg_dl = 28.7 * A1C_percent - 46.7

Citation

Title: Translating the A1C assay into estimated average glucose values
Authors: Nathan DM, Kuenen J, Borg R, Zheng H, Schoenfeld D, Heine RJ
Source: Diabetes Care. 2008;31(8):1473-1478
DOI: 10.2337/dc08-0545

Worked example

A1C 7.0 → eAG

Given: a1c_percent=7.0

eAG = 28.7 * 7.0 - 46.7 = 154.2 mg/dL
mmol/L = 154.2 / 18

Try

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

/api/calc/a1c_eag?a1c_percent=7.0

Full URL: https://api.magentlab.com/api/calc/a1c_eag?a1c_percent=7.0

x402 V2 curl

Expect HTTP 402 and a PAYMENT-REQUIRED header 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/a1c_eag?a1c_percent=7.0"

Cursor mcp.json

Intended config for @magent/mcp. This is not npm @x402/fetch (a payment fetch wrapper).

{
  "mcpServers": {
    "magent": {
      "args": [
        "-y",
        "@magent/mcp"
      ],
      "command": "npx",
      "env": {
        "X402_PRIVATE_KEY": "0xYOUR_SPENDING_KEY"
      }
    }
  }
}

Parameters

Name	Type	Required	Description
`a1c_percent`	number	optional	HbA1c in percent (4-15). Provide this or an eAG, not both.
`eag_mg_dl`	number	optional	Estimated average glucose in mg/dL (50-500).
`eag_mmol_l`	number	optional	Estimated average glucose in mmol/L. Converted as mg/dL = mmol/L * 18.

Response

Field	Type	Description
`formula`	string	nathan_adag
`formula_expression`	string	Exact expression used
`direction`	string	a1c_to_eag or eag_to_a1c
`a1c_percent`	number	A1C %, 1 decimal
`eag_mg_dl`	number	eAG in mg/dL, 1 decimal
`eag_mmol_l`	number	eAG in mmol/L (mg/dL / 18), 1 decimal
`citation`	object	Nathan Diabetes Care 2008
`disclaimer`	string	Not-a-device notice

Example JSON

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

{
  "direction": "a1c_to_eag",
  "disclaimer": "Not a medical device. Deterministic published-formula or coded-ontology output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.",
  "citation": {
    "authors": "Nathan DM, Kuenen J, Borg R, Zheng H, Schoenfeld D, Heine RJ",
    "doi": "10.2337/dc08-0545",
    "id": "nathan-2008",
    "source": "Diabetes Care. 2008;31(8):1473-1478",
    "title": "Translating the A1C assay into estimated average glucose values"
  },
  "formula": "nathan_adag",
  "formula_expression": "eAG_mg_dl = 28.7 * A1C_percent - 46.7",
  "eag_mg_dl": 154.2,
  "a1c_percent": 7.0,
  "eag_mmol_l": 8.6
}

Errors

HTTP	Code	When
400	`invalid_a1c_input`	provide a1c_percent or eag_mg_dl/eag_mmol_l, not both Returned before settlement; you are not charged.
400	`invalid_a1c`	a1c_percent must be a number from 4 to 15 Returned before settlement; you are not charged.
400	`invalid_eag`	eag_mg_dl (50-500) or eag_mmol_l (2.8-27.8) is required Returned before settlement; you are not charged.
402	`payment_required`	Missing or invalid PAYMENT-SIGNATURE; decode the PAYMENT-REQUIRED header
409	`payment_in_progress`	The same authorization nonce is already being settled; retry shortly
429	`rate_limited`	Too many requests from this client
503	`settlement_uncertain`	Settlement is unconfirmed; retry with the same PAYMENT-SIGNATURE
503	`facilitator_unavailable`	Payment facilitator unavailable
503	`facilitator_misconfigured`	Payment facilitator is not configured
503	`facilitator_unauthorized`	Payment facilitator rejected credentials
503	`ledger_unavailable`	Payment ledger unavailable
503	`payment_unavailable`	Payment processing unavailable

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Also searched as

Nathan ADAG
A1C to eAG 28.7
estimated average glucose
HbA1c eAG

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. Retry the same URL with PAYMENT-SIGNATURE. Settlement completes before the tool runs. Full handshake and shared payment errors: Payments.

Guarantees

Invalid query parameters return HTTP 400 before settlement. You are not charged.
Settlement finishes before the tool executes. Uncertain settlement fails closed (HTTP 503).
Execution is timeout-bounded and concurrency-capped.
Calculator inputs are not persisted. Request logs store path without query.