Garden Calculators
Carbon-to-nitrogen ratio of a compost mix by the Cornell formula, or the greens-to-browns amounts that reach a target ratio.
The wallet the 402 directs payment to. Its whole payment record — every payer, every chain — is on the merchant page.
Asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913
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 required",
"accepts": [
{
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"extra": {
"name": "USD Coin",
"version": "2"
},
"payTo": "0xb531320805C5BED1D46AEaDcF4F008FDF172DBDa",
"scheme": "exact",
"network": "base",
"mimeType": "application/json",
"resource": "https://garden-calc.x402tookit.com/compost-cn-ratio",
"description": "Carbon-to-nitrogen ratio of a compost mix by the Cornell formula, or the greens-to-browns amounts that reach a target ratio.",
"outputSchema": {
"input": {
"type": "http",
"method": "GET",
"queryParams": {
"ingredients": "grass clippings:10:80; leaves:6:30"
}
},
"output": {
"asOf": "2026-10-11T20:20:02.207Z",
"source": "computed locally",
"cnRatio": 35.375,
"reasons": [
"Cornell formula: R = sum(mass x carbon% x (100 - moisture)/100) / sum(mass x nitrogen% x (100 - moisture)/100).",
"Ingredients with only a C:N ratio use 45% carbon of dry mass."
],
"summary": "The mix has a C:N ratio of 35.4:1 (within common range; about 25 to 30 is the usual start, below about 20 can smell of ammonia, above about 40 composts slowly).",
"verdict": "WITHIN_COMMON_RANGE",
"degraded": false,
"ratioText": "35.4:1",
"disclaimer": "Screening signal computed from the named public source. Not financial, legal or investment advice; provided as is. Verify at the source before acting.",
"notChecked": [
"real ingredient values: C:N and moisture vary a lot between batches; get a lab figure or adjust by smell and temperature (too wet and smelly means more browns, slow and dry means more greens)",
"carbon that is not readily available (woody lignin) breaks down slowly, so effective C:N is higher for chips and sawdust than the table suggests",
"…2 more"
],
"ingredients": [
{
"cn": 19,
"dryMass": 2,
"asIsMass": 10,
"cnSource": "Cornell table (midpoint of range)",
"ingredient": "grass clippings",
"moisturePercent": 80,
"carbonPercentDry": 45,
"nitrogenPercentDry": 2.368
},
{
"cn": 60,
"dryMass": 4.2,
"asIsMass": 6,
"cnSource": "Cornell table (midpoint of range)",
"ingredient": "leaves",
"moisturePercent": 30,
"carbonPercentDry": 45,
"nitrogenPercentDry": 0.75
}
],
"targetRange": "about 25:1 to 30:1 at the start (Cornell: about 30:1)"
}
},
"maxAmountRequired": "20000",
"maxTimeoutSeconds": 300
},
{
"asset": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",
"extra": {
"feePayer": "BFK9TLC3edb13K6v4YyH3DwPb5DSUpkWvb7XnqCL9b4F"
},
"payTo": "DUPiupXtuox38dcGoXUKer5mAydCzmaHjrbQ66qeEm8s",
"scheme": "exact",
"network": "solana",
"mimeType": "application/json",
"resource": "https://garden-calc.x402tookit.com/compost-cn-ratio",
"description": "Carbon-to-nitrogen ratio of a compost mix by the Cornell formula, or the greens-to-browns amounts that reach a target ratio.",
"outputSchema": {
"input": {
"type": "http",
"method": "GET",
"queryParams": {
"ingredients": "grass clippings:10:80; leaves:6:30"
}
},
"output": {
"asOf": "2026-10-11T20:20:02.207Z",
"source": "computed locally",
"cnRatio": 35.375,
"reasons": [
"Cornell formula: R = sum(mass x carbon% x (100 - moisture)/100) / sum(mass x nitrogen% x (100 - moisture)/100).",
"Ingredients with only a C:N ratio use 45% carbon of dry mass."
],
"summary": "The mix has a C:N ratio of 35.4:1 (within common range; about 25 to 30 is the usual start, below about 20 can smell of ammonia, above about 40 composts slowly).",
"verdict": "WITHIN_COMMON_RANGE",
"degraded": false,
"ratioText": "35.4:1",
"disclaimer": "Screening signal computed from the named public source. Not financial, legal or investment advice; provided as is. Verify at the source before acting.",
"notChecked": [
"real ingredient values: C:N and moisture vary a lot between batches; get a lab figure or adjust by smell and temperature (too wet and smelly means more browns, slow and dry means more greens)",
"carbon that is not readily available (woody lignin) breaks down slowly, so effective C:N is higher for chips and sawdust than the table suggests",
"…2 more"
],
"ingredients": [
{
"cn": 19,
"dryMass": 2,
"asIsMass": 10,
"cnSource": "Cornell table (midpoint of range)",
"ingredient": "grass clippings",
"moisturePercent": 80,
"carbonPercentDry": 45,
"nitrogenPercentDry": 2.368
},
{
"cn": 60,
"dryMass": 4.2,
"asIsMass": 6,
"cnSource": "Cornell table (midpoint of range)",
"ingredient": "leaves",
"moisturePercent": 30,
"carbonPercentDry": 45,
"nitrogenPercentDry": 0.75
}
],
"targetRange": "about 25:1 to 30:1 at the start (Cornell: about 30:1)"
}
},
"maxAmountRequired": "20000",
"maxTimeoutSeconds": 300
},
{
"asset": "0x3c499c542cEF5E3811e1192ce70d8cC03d5c3359",
"extra": {
"name": "USD Coin",
"version": "2"
},
"payTo": "0xb531320805C5BED1D46AEaDcF4F008FDF172DBDa",
"scheme": "exact",
"network": "polygon",
"mimeType": "application/json",
"resource": "https://garden-calc.x402tookit.com/compost-cn-ratio",
"description": "Carbon-to-nitrogen ratio of a compost mix by the Cornell formula, or the greens-to-browns amounts that reach a target ratio.",
"outputSchema": {
"input": {
"type": "http",
"method": "GET",
"queryParams": {
"ingredients": "grass clippings:10:80; leaves:6:30"
}
},
"output": {
"asOf": "2026-10-11T20:20:02.207Z",
"source": "computed locally",
"cnRatio": 35.375,
"reasons": [
"Cornell formula: R = sum(mass x carbon% x (100 - moisture)/100) / sum(mass x nitrogen% x (100 - moisture)/100).",
"Ingredients with only a C:N ratio use 45% carbon of dry mass."
],
"summary": "The mix has a C:N ratio of 35.4:1 (within common range; about 25 to 30 is the usual start, below about 20 can smell of ammonia, above about 40 composts slowly).",
"verdict": "WITHIN_COMMON_RANGE",
"degraded": false,
"ratioText": "35.4:1",
"disclaimer": "Screening signal computed from the named public source. Not financial, legal or investment advice; provided as is. Verify at the source before acting.",
"notChecked": [
"real ingredient values: C:N and moisture vary a lot between batches; get a lab figure or adjust by smell and temperature (too wet and smelly means more browns, slow and dry means more greens)",
"carbon that is not readily available (woody lignin) breaks down slowly, so effective C:N is higher for chips and sawdust than the table suggests",
"…2 more"
],
"ingredients": [
{
"cn": 19,
"dryMass": 2,
"asIsMass": 10,
"cnSource": "Cornell table (midpoint of range)",
"ingredient": "grass clippings",
"moisturePercent": 80,
"carbonPercentDry": 45,
"nitrogenPercentDry": 2.368
},
{
"cn": 60,
"dryMass": 4.2,
"asIsMass": 6,
"cnSource": "Cornell table (midpoint of range)",
"ingredient": "leaves",
"moisturePercent": 30,
"carbonPercentDry": 45,
"nitrogenPercentDry": 0.75
}
],
"targetRange": "about 25:1 to 30:1 at the start (Cornell: about 30:1)"
}
},
"maxAmountRequired": "20000",
"maxTimeoutSeconds": 300
}
],
"x402Version": 1,
"alsoAvailable": {
"llms": "https://garden-calc.x402tookit.com/llms.txt",
"catalog": "https://garden-calc.x402tookit.com/catalog",
"message": "Garden Calculators has 8 pay-per-call endpoints (Garden math for agents: growing degree days, plant spacing, bed soil, drip irrigation, fertilizer, compost balance, frost risk and planting dates.), from $0.02 a call. See the full menu and send your agents our way.",
"openapi": "https://garden-calc.x402tookit.com/openapi.json",
"related": [
{
"url": "https://garden-calc.x402tookit.com/soil-volume",
"path": "/soil-volume",
"what": "Soil or mulch for a rectangular or round bed: cubic feet, yards, litres, bags, settling a…",
"price": "$0.02"
},
{
"url": "https://garden-calc.x402tookit.com/drip-irrigation",
"path": "/drip-irrigation",
"what": "Drip irrigation math: gallons for inches of water over an area, emitter flow, supply limi…",
"price": "$0.02"
},
{
"url": "https://garden-calc.x402tookit.com/fertilizer-rate",
"path": "/fertilizer-rate",
"what": "Fertilizer product needed for a nutrient target per 1000 sq ft from its N-P-K analysis, w…",
"price": "$0.02"
}
]
}
}Accepts
The payment requirements as published to the catalog. Read the live 402 before paying — a price here is a claim, not a quote.
Pay 0.02 USDC on Base to 0xb531…2DBDa. The signed payment is good for 5 minutes.
- Paid to
- 0xb531…2DBDa
- USD Coin contract
- 0x8335…02913
- Payment window
- 5 minutes
- As published
- 20000 smallest units
That figure is in the token’s smallest units. Roundhouse does not hold this contract’s decimals, so it is shown as published rather than converted.
- Paid to
- DUPiup…eEm8s
- Token contract
- EPjFWd…TDt1v
- Payment window
- 5 minutes
That figure is in the token’s smallest units. Roundhouse does not hold this contract’s decimals, so it is shown as published rather than converted.
- Paid to
- 0xb531…2DBDa
- Token contract
- 0x3c49…c3359
- Payment window
- 5 minutes
That figure is in the token’s smallest units. Roundhouse does not hold this contract’s decimals, so it is shown as published rather than converted.
- Paid to
- 0xb531…2DBDa
- Token contract
- 0xaf88…e5831
- Payment window
- 5 minutes
The catalog’s raw entry
[
{
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"extra": {
"name": "USD Coin",
"version": "2"
},
"payTo": "0xb531320805C5BED1D46AEaDcF4F008FDF172DBDa",
"amount": "20000",
"scheme": "exact",
"network": "eip155:8453",
"maxTimeoutSeconds": 300
},
{
"asset": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",
"extra": {
"feePayer": "D6ZhtNQ5nT9ZnTHUbqXZsTx5MH2rPFiBBggX4hY1WePM"
},
"payTo": "DUPiupXtuox38dcGoXUKer5mAydCzmaHjrbQ66qeEm8s",
"amount": "20000",
"scheme": "exact",
"network": "solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp",
"maxTimeoutSeconds": 300
},
{
"asset": "0x3c499c542cEF5E3811e1192ce70d8cC03d5c3359",
"extra": {
"name": "USD Coin",
"version": "2"
},
"payTo": "0xb531320805C5BED1D46AEaDcF4F008FDF172DBDa",
"amount": "20000",
"scheme": "exact",
"network": "eip155:137",
"maxTimeoutSeconds": 300
},
{
"asset": "0xaf88d065e77c8cC2239327C5EDb3A432268e5831",
"extra": {
"name": "USD Coin",
"version": "2"
},
"payTo": "0xb531320805C5BED1D46AEaDcF4F008FDF172DBDa",
"amount": "20000",
"scheme": "exact",
"network": "eip155:42161",
"maxTimeoutSeconds": 300
}
]Extensions
{
"bazaar": {
"info": {
"input": {
"type": "http",
"method": "GET",
"queryParams": {
"ingredients": "grass clippings:10:80; leaves:6:30"
}
},
"output": {
"type": "json",
"example": {
"asOf": "2026-10-11T20:20:02.207Z",
"source": "computed locally",
"cnRatio": 35.375,
"reasons": [
"Cornell formula: R = sum(mass x carbon% x (100 - moisture)/100) / sum(mass x nitrogen% x (100 - moisture)/100).",
"Ingredients with only a C:N ratio use 45% carbon of dry mass."
],
"summary": "The mix has a C:N ratio of 35.4:1 (within common range; about 25 to 30 is the usual start, below about 20 can smell of ammonia, above about 40 composts slowly).",
"verdict": "WITHIN_COMMON_RANGE",
"degraded": false,
"ratioText": "35.4:1",
"disclaimer": "Screening signal computed from the named public source. Not financial, legal or investment advice; provided as is. Verify at the source before acting.",
"notChecked": [
"real ingredient values: C:N and moisture vary a lot between batches; get a lab figure or adjust by smell and temperature (too wet and smelly means more browns, slow and dry means more greens)",
"carbon that is not readily available (woody lignin) breaks down slowly, so effective C:N is higher for chips and sawdust than the table suggests",
"…2 more"
],
"ingredients": [
{
"cn": 19,
"dryMass": 2,
"asIsMass": 10,
"cnSource": "Cornell table (midpoint of range)",
"ingredient": "grass clippings",
"moisturePercent": 80,
"carbonPercentDry": 45,
"nitrogenPercentDry": 2.368
},
{
"cn": 60,
"dryMass": 4.2,
"asIsMass": 6,
"cnSource": "Cornell table (midpoint of range)",
"ingredient": "leaves",
"moisturePercent": 30,
"carbonPercentDry": 45,
"nitrogenPercentDry": 0.75
}
],
"targetRange": "about 25:1 to 30:1 at the start (Cornell: about 30:1)"
}
}
},
"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"
],
"type": "string"
},
"queryParams": {
"type": "object",
"required": [],
"properties": {
"brown": {
"type": "string",
"description": "Balance mode: a carbon-rich ingredient (leaves, bark, paper, sawdust) or any name with brownCn"
},
"green": {
"type": "string",
"description": "Balance mode: a nitrogen-rich ingredient (grass clippings, food waste, cow manure, horse manure, digested sewage sludge) or any name with greenCn"
},
"brownCn": {
"type": "number",
"description": "C:N of the brown if not in the table, 30 to 1000"
},
"greenCn": {
"type": "number",
"description": "C:N of the green if not in the table, 5 to 60"
},
"targetCn": {
"type": "number",
"description": "Balance mode target C:N, 15 to 50 (default 30)"
},
"ingredients": {
"type": "string",
"description": "Mix mode: lines name:mass[:moisturePercent[:cn[:nitrogenPercent]]] separated by semicolons, for example 'grass clippings:10:80; leaves:6:30'. Names in the table need no C:N; moisture defaults to 50"
}
}
}
},
"additionalProperties": false
},
"output": {
"type": "object",
"required": [
"type"
],
"properties": {
"type": {
"type": "string"
},
"example": {
"type": "object",
"properties": {
"asOf": {
"type": [
"null",
"string"
]
},
"source": {
"type": [
"null",
"string"
]
},
"cnRatio": {
"type": [
"null",
"number"
]
},
"reasons": {
"type": [
"array",
"null"
],
"items": {
"type": "string"
}
},
"summary": {
"type": [
"null",
"string"
]
},
"verdict": {
"type": [
"null",
"string"
]
},
"degraded": {
"type": [
"boolean",
"null"
]
},
"ratioText": {
"type": [
"null",
"string"
]
},
"disclaimer": {
"type": [
"null",
"string"
]
},
"notChecked": {
"type": [
"array",
"null"
],
"items": {
"type": "string"
}
},
"ingredients": {
"type": [
"array",
"null"
],
"items": {
"type": "object",
"properties": {
"cn": {
"type": [
"null",
"number"
]
},
"dryMass": {
"type": [
"null",
"number"
]
},
"asIsMass": {
"type": [
"null",
"number"
]
},
"cnSource": {
"type": [
"null",
"string"
]
},
"ingredient": {
"type": [
"null",
"string"
]
},
"moisturePercent": {
"type": [
"null",
"number"
]
},
"carbonPercentDry": {
"type": [
"null",
"number"
]
},
"nitrogenPercentDry": {
"type": [
"null",
"number"
]
}
}
}
},
"targetRange": {
"type": [
"null",
"string"
]
}
}
}
}
}
}
}
}
}Provenance
- Seen in the source catalog
- 2026-10-20 20:28Z
- Last indexed by Roundhouse
- 2026-10-22 19:30Z
- Last enriched (probe, favicon, geo)
- 2026-10-20 21:15Z
- x402 version
- 2
- Max timeout
- 300s
- 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. 4 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 Garden Calculators 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=Garden%20Calculators' 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://garden-calc.x402tookit.com/compost-cn-ratio, 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. Either pay over x402 (mint a personal key for $0.01 at GET https://api.roundhouseai.io/v0/test/x402), or ask me for an organization key, which I create at https://roundhouseai.io/dashboard/connections. If you have neither, ask before going further. If you do not have Roundhouse tools or skills installed, read https://roundhouseai.io/skill.md first — it is the whole procedure.