magent
Fractional excretion of sodium (FENa) from plasma and urine sodium and creatinine. Espinel 1976 oliguric ARF strata. Deterministic published formula with citation; not a diagnosis.
OtherLiveeip155:8453Exactvia cdp
FenaKidneyAkiCalculator
Calls · 30d
3→ 0%
This endpoint's own trailing-30-day call count, as published by the upstream catalog and snapshotted daily. 15 snapshots so far.
$13.75
Verified settled volume
2,750 settlements proven x402 by their on-chain EIP-3009 marker.
$0.0050
Listed price
As published in the catalog. Always read the live 402 before paying.
—
Calls · 30d
Upstream's own call count for this endpoint, not ours.
—
Unique payers · 30d
Last called 2026-08-21 06:26Z
—
Upstream on-chain volume
Reported by the source catalog.
Paid to
0x836Be278f1739fB4308091cD1852F7971Bc19Ee2The wallet the 402 directs payment to. Its whole payment record — every payer, every chain — is on the merchant page.
Asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913
Provider
The payTo wallet does not resolve to a registered ERC-8004 agent. That is not a verdict on the service — most of the catalog is unregistered.
Live 402 challenge
Captured by the enrichment pass, not read just now. Prices can change — always read the 402 the endpoint answers with.
{
"error": "PAYMENT-SIGNATURE header is required",
"accepts": [
{
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"extra": {
"name": "USD Coin",
"version": "2",
"paymentFlow": "upfront",
"resourceUrl": "https://api.magentlab.com/api/calc/fena",
"assetTransferMethod": "eip3009"
},
"payTo": "0x836Be278f1739fB4308091cD1852F7971Bc19Ee2",
"amount": "5000",
"scheme": "exact",
"network": "eip155:8453",
"maxTimeoutSeconds": 600
},
{
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"extra": {
"name": "USD Coin",
"version": "2",
"withdrawDelay": 86400,
"receiverAuthorizer": "0x3721824a31197dcDD2984cF43b92B6cc8A87c0Fb",
"assetTransferMethod": "eip3009"
},
"payTo": "0x836Be278f1739fB4308091cD1852F7971Bc19Ee2",
"amount": "5000",
"scheme": "batch-settlement",
"network": "eip155:8453",
"maxTimeoutSeconds": 600
}
],
"resource": {
"url": "https://api.magentlab.com/api/calc/fena",
"tags": [
"fena",
"kidney",
"aki",
"calculator"
],
"mimeType": "application/json",
"description": "Fractional excretion of sodium (FENa) from plasma and urine sodium and creatinine. Espinel 1976 oliguric ARF strata. Deterministic published formula with citation; not a diagnosis.",
"serviceName": "magent"
},
"extensions": {
"bazaar": {
"info": {
"input": {
"type": "http",
"method": "GET",
"queryParams": {
"sodium_mmol_l": 140,
"creatinine_mg_dl": 2,
"creatinine_umol_l": 176.84,
"urine_sodium_mmol_l": 20,
"urine_creatinine_mg_dl": 100,
"urine_creatinine_umol_l": 8842
}
},
"output": {
"type": "json",
"example": {
"formula": "fena",
"citation": {
"id": "espinel-1976",
"doi": "10.1001/jama.1976.03270060029022",
"title": "The FENa test. Use in the differential diagnosis of acute renal failure",
"source": "JAMA. 1976;236(6):579-581",
"authors": "Espinel CH"
},
"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.",
"fena_percent": 0.29,
"sodium_mmol_l": 140,
"espinel_stratum": "prerenal",
"creatinine_mg_dl": 2,
"formula_expression": "FENa_percent = 100 * (urine_sodium_mmol_l * plasma_creatinine_mg_dl) / (plasma_sodium_mmol_l * urine_creatinine_mg_dl)",
"urine_sodium_mmol_l": 20,
"urine_creatinine_mg_dl": 100
}
},
"iconUrl": "https://api.magentlab.com/favicon.ico"
},
"schema": {
"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": [
"sodium_mmol_l",
"urine_sodium_mmol_l"
],
"properties": {
"sodium_mmol_l": {
"type": "number",
"description": "Plasma or serum sodium in mmol/L (110-160)."
},
"creatinine_mg_dl": {
"type": "number",
"description": "Plasma creatinine in mg/dL (0.1-20). Provide this or creatinine_umol_l."
},
"creatinine_umol_l": {
"type": "number",
"description": "Plasma creatinine in µmol/L (9-1768). Converted as mg/dL = µmol/L / 88.42."
},
"urine_sodium_mmol_l": {
"type": "number",
"description": "Urine sodium in mmol/L (1-300)."
},
"urine_creatinine_mg_dl": {
"type": "number",
"description": "Urine creatinine in mg/dL (1-500). Provide this or urine_creatinine_umol_l."
},
"urine_creatinine_umol_l": {
"type": "number",
"description": "Urine creatinine in µmol/L (88-44210). Converted as mg/dL = µmol/L / 88.42."
}
}
}
},
"additionalProperties": false
},
"output": {
"type": "object",
"required": [
"type"
],
"properties": {
"type": {
"type": "string"
},
"example": {
"type": "object"
}
}
}
}
}
}
},
"x402Version": 2
}Accepts
The payment requirements as published to the catalog. Read the live 402 before paying — a price here is a claim, not a quote.
0.005USDC≈ $0.005 USD
on Base · exact scheme
Pay 0.005 USDC on Base to 0x836B…19Ee2. The signed payment is good for 10 minutes.
- Paid to
- 0x836B…19Ee2
- USD Coin contract
- 0x8335…02913
- Payment window
- 10 minutes
- As published
- 5000 smallest units
The catalog’s raw entry
[
{
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"extra": {
"name": "USD Coin",
"version": "2",
"paymentFlow": "upfront",
"resourceUrl": "https://api.magentlab.com/api/calc/fena",
"assetTransferMethod": "eip3009"
},
"payTo": "0x836Be278f1739fB4308091cD1852F7971Bc19Ee2",
"amount": "5000",
"scheme": "exact",
"network": "eip155:8453",
"maxTimeoutSeconds": 600
}
]Extensions
{
"bazaar": {
"info": {
"input": {
"body": {
"items": [
{
"sodium_mmol_l": 140,
"creatinine_mg_dl": 2,
"creatinine_umol_l": 176.84,
"urine_sodium_mmol_l": 20,
"urine_creatinine_mg_dl": 100,
"urine_creatinine_umol_l": 8842
},
{
"sodium_mmol_l": 140,
"creatinine_mg_dl": 2,
"creatinine_umol_l": 176.84,
"urine_sodium_mmol_l": 20,
"urine_creatinine_mg_dl": 100,
"urine_creatinine_umol_l": 8842
}
]
},
"type": "http",
"method": "POST"
},
"output": {
"type": "json",
"example": {
"path": "/api/calc/fena",
"count": 2,
"items": [
{
"formula": "fena",
"citation": {
"id": "espinel-1976",
"doi": "10.1001/jama.1976.03270060029022",
"title": "The FENa test. Use in the differential diagnosis of acute renal failure",
"source": "JAMA. 1976;236(6):579-581",
"authors": "Espinel CH"
},
"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.",
"fena_percent": 0.29,
"sodium_mmol_l": 140,
"espinel_stratum": "prerenal",
"creatinine_mg_dl": 2,
"formula_expression": "FENa_percent = 100 * (urine_sodium_mmol_l * plasma_creatinine_mg_dl) / (plasma_sodium_mmol_l * urine_creatinine_mg_dl)",
"urine_sodium_mmol_l": 20,
"urine_creatinine_mg_dl": 100
},
{
"formula": "fena",
"citation": {
"id": "espinel-1976",
"doi": "10.1001/jama.1976.03270060029022",
"title": "The FENa test. Use in the differential diagnosis of acute renal failure",
"source": "JAMA. 1976;236(6):579-581",
"authors": "Espinel CH"
},
"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.",
"fena_percent": 0.29,
"sodium_mmol_l": 140,
"espinel_stratum": "prerenal",
"creatinine_mg_dl": 2,
"formula_expression": "FENa_percent = 100 * (urine_sodium_mmol_l * plasma_creatinine_mg_dl) / (plasma_sodium_mmol_l * urine_creatinine_mg_dl)",
"urine_sodium_mmol_l": 20,
"urine_creatinine_mg_dl": 100
}
]
}
},
"iconUrl": "https://api.magentlab.com/favicon.ico"
},
"schema": {
"type": "object",
"$schema": "https://json-schema.org/draft/2020-12/schema",
"required": [
"input"
],
"properties": {
"input": {
"type": "object",
"required": [
"type",
"method"
],
"properties": {
"body": {
"type": "object",
"required": [
"items"
],
"properties": {
"items": {
"type": "array",
"items": {
"type": "object",
"required": [
"sodium_mmol_l",
"urine_sodium_mmol_l"
],
"properties": {
"sodium_mmol_l": {
"type": "number",
"description": "Plasma or serum sodium in mmol/L (110-160)."
},
"creatinine_mg_dl": {
"type": "number",
"description": "Plasma creatinine in mg/dL (0.1-20). Provide this or creatinine_umol_l."
},
"creatinine_umol_l": {
"type": "number",
"description": "Plasma creatinine in µmol/L (9-1768). Converted as mg/dL = µmol/L / 88.42."
},
"urine_sodium_mmol_l": {
"type": "number",
"description": "Urine sodium in mmol/L (1-300)."
},
"urine_creatinine_mg_dl": {
"type": "number",
"description": "Urine creatinine in mg/dL (1-500). Provide this or urine_creatinine_umol_l."
},
"urine_creatinine_umol_l": {
"type": "number",
"description": "Urine creatinine in µmol/L (88-44210). Converted as mg/dL = µmol/L / 88.42."
}
}
},
"maxItems": 25,
"minItems": 1
}
},
"additionalProperties": false
},
"type": {
"type": "string",
"const": "http"
},
"method": {
"type": "string",
"const": "POST"
},
"headers": {
"type": "object",
"additionalProperties": {
"type": "string"
}
}
},
"additionalProperties": false
},
"output": {
"type": "object",
"required": [
"type"
],
"properties": {
"type": {
"type": "string"
},
"example": {
"type": "object"
}
}
}
}
}
}
}Provenance
- Seen in the source catalog
- 2026-08-31 12:59Z
- Last indexed by Roundhouse
- 2026-09-07 08:00Z
- Last enriched (probe, favicon, geo)
- 2026-09-24 00:15Z
- x402 version
- 2
- Max timeout
- 600s
- Liveness probe
- HTTP 402
Hand this page to an agent
Copy the prompt and paste it into Claude, an MCP client or your own agent — it will vet this service and call it over the free read API. No key, no account.
GET api.roundhouseai.io/v0/endpoints
This endpoint's own trailing-30-day call count, as published by the upstream catalog and snapshotted daily. 15 snapshots so far. Verified volume counts only settlements with an on-chain EIP-3009 marker.
Show the promptHide the prompt
Using Roundhouse, look up the x402 service magent and tell me whether it is worth paying: what a call costs, whether the endpoint answered when last probed, and what its payment record actually shows. curl -s 'https://api.roundhouseai.io/v0/endpoints?q=magent' curl -s 'https://api.roundhouseai.io/v0/merchants/<the payTo wallet returned above>' Then call it: read the price from the live 402 at https://api.magentlab.com/api/calc/fena, never from a cached figure, and pay with an x402 client. The /v0 API needs an API key (`authorization: Bearer rh_live_…`) on everything except /v0/unified* and /v0/endpoints. Mint a personal key for $0.01 at GET https://api.roundhouseai.io/v0/test/x402, or use an organization key from https://roundhouseai.io/dashboard/team. If you do not have Roundhouse tools or skills installed, read https://roundhouseai.io/skill.md first — it is the whole procedure.