CSS Design Calc
Modular type scale: sizes in px and rem for steps below and above a base size, by named ratio (major third, golden) or number.
OtherLiveeip155:8453Exactvia cdp
CssTypographyType-scaleDesign
Calls · 30d
1
This endpoint's own trailing-30-day call count, as published by the upstream catalog and snapshotted daily. 4 snapshots so far.
$24.31
Verified settled volume
1,175 settlements proven x402 by their on-chain EIP-3009 marker.
$0.020
Listed price
As published in the catalog. Always read the live 402 before paying.
1
Calls · 30d
Upstream's own call count for this endpoint, not ours.
1
Unique payers · 30d
Last called 2026-10-20 20:59Z
—
Upstream on-chain volume
Reported by the source catalog.
Paid to
0xb531320805C5BED1D46AEaDcF4F008FDF172DBDaThe 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.
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"payTo": "0xb531320805C5BED1D46AEaDcF4F008FDF172DBDa",
"scheme": "exact",
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"base": 16,
"ratio": 1.25,
"steps": [
{
"px": 48.8281,
"css": "3.0518rem",
"rem": 3.05176,
"step": 5
},
{
"px": 39.0625,
"css": "2.4414rem",
"rem": 2.44141,
"step": 4
}
],
"rootPx": 16,
"source": "Modular scale: size(n) = base x ratio^n (Tim Brown); ratios are the musical-interval values used by common scale tools, computed locally",
"reasons": [
"Each step multiplies by 1.25; step 0 is the base 16px.",
"Steps are exact; round for production if needed."
],
"summary": "8 steps from 10.24px to 48.8281px at ratio 1.25 (major-third) from a 16px base.",
"verdict": "COMPUTED",
"degraded": false,
"ratioName": "major-third",
"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": [
"rounding to whole pixels (sizes are exact; browsers may round text rendering)",
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"verdict": "COMPUTED",
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"disclaimer": "Screening signal computed from the named public source. Not financial, legal or investment advice; provided as is. Verify at the source before acting.",
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"Steps are exact; round for production if needed."
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"verdict": "COMPUTED",
"degraded": false,
"ratioName": "major-third",
"disclaimer": "Screening signal computed from the named public source. Not financial, legal or investment advice; provided as is. Verify at the source before acting.",
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"rounding to whole pixels (sizes are exact; browsers may round text rendering)",
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"…1 more"
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"catalog": "https://css-design-calc.x402tookit.com/catalog",
"message": "CSS Design Calc has 12 pay-per-call endpoints (CSS and layout maths for agents: unit conversion, fluid clamp(), type scales, aspect ratios, grids, specificity and readability.), from $0.02 a call. See the full menu and send your agents our way.",
"openapi": "https://css-design-calc.x402tookit.com/openapi.json",
"related": [
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"url": "https://css-design-calc.x402tookit.com/vertical-rhythm",
"path": "/vertical-rhythm",
"what": "Snap line-heights for font sizes to a baseline grid: baseline unit, lines per element, un…",
"price": "$0.02"
},
{
"url": "https://css-design-calc.x402tookit.com/line-length",
"path": "/line-length",
"what": "Estimate characters per line from column width and font size and rate it for readability…",
"price": "$0.02"
},
{
"url": "https://css-design-calc.x402tookit.com/aspect-ratio",
"path": "/aspect-ratio",
"what": "Aspect ratio of a width and height (simplified, nearest common ratio) or the missing side…",
"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.
0.02USDC≈ $0.02 USD
on Base · exact scheme
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
20000units
on solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp · exact scheme
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
20000units
on Polygon · exact scheme
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
20000units
on Arbitrum · exact scheme
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
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{
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"info": {
"input": {
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"method": "GET",
"queryParams": {
"up": 5,
"base": 16,
"down": 2,
"ratio": "major-third"
}
},
"output": {
"type": "json",
"example": {
"asOf": "2026-10-11T14:32:45.228Z",
"base": 16,
"ratio": 1.25,
"steps": [
{
"px": 48.8281,
"css": "3.0518rem",
"rem": 3.05176,
"step": 5
},
{
"px": 39.0625,
"css": "2.4414rem",
"rem": 2.44141,
"step": 4
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"rootPx": 16,
"source": "Modular scale: size(n) = base x ratio^n (Tim Brown); ratios are the musical-interval values used by common scale tools, computed locally",
"reasons": [
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"verdict": "COMPUTED",
"degraded": false,
"ratioName": "major-third",
"disclaimer": "Screening signal computed from the named public source. Not financial, legal or investment advice; provided as is. Verify at the source before acting.",
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"description": "Base font size in px (step 0), for example 16"
},
"down": {
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}Provenance
- Seen in the source catalog
- 2026-10-20 20:59Z
- Last indexed by Roundhouse
- 2026-10-22 12:40Z
- Last enriched (probe, favicon, geo)
- 2026-10-20 22:15Z
- 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 CSS Design Calc 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=CSS%20Design%20Calc' 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://css-design-calc.x402tookit.com/type-scale, 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.