← The evidence ledger
Evidence row 2202015
Observed , by sync.x402_bazaar/1.
- Kind
- listing
- About
- source_record x402_bazaar:https://css-design-calc.x402tookit.com/line-length
- Recorded
- Previous row
- None: the first of its kind about this subject
- Body SHA-256
- 608ba53b31ef42a9ff2c886dde99b694e2b070a34ee98cff8cfc92148c62f110
- Leaf
- 0xd66a9be4613aa3dc511bb7b12f313df1dcc3d59f63fe0545574e56ba71e0270f
What was observed
{
"endpoints": [
[
"x402",
"https://css-design-calc.x402tookit.com/line-length"
]
],
"name": "CSS Design Calc",
"owner_address": "0xb531320805c5bed1d46aeadcf4f008fdf172dbda",
"raw": {
"accepts": [
{
"amount": "20000",
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"extra": {
"name": "USD Coin",
"version": "2"
},
"maxTimeoutSeconds": 300,
"network": "eip155:8453",
"payTo": "0xb531320805C5BED1D46AEaDcF4F008FDF172DBDa",
"scheme": "exact"
},
{
"amount": "20000",
"asset": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",
"extra": {
"feePayer": "D6ZhtNQ5nT9ZnTHUbqXZsTx5MH2rPFiBBggX4hY1WePM",
"transactionVersions": [
0
]
},
"maxTimeoutSeconds": 300,
"network": "solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp",
"payTo": "DUPiupXtuox38dcGoXUKer5mAydCzmaHjrbQ66qeEm8s",
"scheme": "exact"
},
{
"amount": "20000",
"asset": "0x3c499c542cEF5E3811e1192ce70d8cC03d5c3359",
"extra": {
"name": "USD Coin",
"version": "2"
},
"maxTimeoutSeconds": 300,
"network": "eip155:137",
"payTo": "0xb531320805C5BED1D46AEaDcF4F008FDF172DBDa",
"scheme": "exact"
},
{
"amount": "20000",
"asset": "0xaf88d065e77c8cC2239327C5EDb3A432268e5831",
"extra": {
"name": "USD Coin",
"version": "2"
},
"maxTimeoutSeconds": 300,
"network": "eip155:42161",
"payTo": "0xb531320805C5BED1D46AEaDcF4F008FDF172DBDa",
"scheme": "exact"
}
],
"description": "Estimate characters per line from column width and font size and rate it for readability (45-75 ideal, WCAG max 80).",
"extensions": {
"bazaar": {
"info": {
"input": {
"method": "GET",
"queryParams": {
"avgCharWidthEm": 0.5,
"fontSizePx": 18,
"widthPx": 720
},
"type": "http"
},
"output": {
"example": {
"asOf": "2026-10-11T14:32:44.449Z",
"avgCharWidthEm": 0.5,
"charactersPerLine": 80,
"degraded": false,
"disclaimer": "Screening signal computed from the named public source. Not financial, legal or investment advice; provided as is. Verify at the source before acting.",
"fontSizePx": 18,
"minimumLineHeight": 1.5,
"minimumParagraphSpacingMultipleOfLineSpacing": 1.5,
"notChecked": [
"the real font: characters per line varies with the typeface, language and text (CJK counts characters, not words)",
"multi-column text, where 40 to 50 characters is acceptable",
"…2 more"
],
"reasons": [
"Within the usual 45 to 75 range (66 is the classic ideal).",
"An estimate: set max-width in ch units so the browser measures the real font."
],
"source": "Bringhurst's 45 to 75 character guideline (66 ideal) and WCAG 2.2 criterion 1.4.8 (80 characters), with the estimate computed locally",
"suggestedCss": "max-width: 66ch;",
"summary": "About 80 characters per line (720px column, 18px type, 0.5em average glyph): long.",
"verdict": "LONG",
"wcagAaaLineLimit": 80,
"wcagTextSpacingOverridePx": {
"letterSpacing": 2.16,
"lineHeight": 27,
"paragraphSpacing": 36,
"wordSpacing": 2.88
},
"widthFor45Px": 405,
"widthFor66Em": 33,
"widthFor66Px": 594,
"widthFor75Px": 675,
"widthFor80Px": 720,
"widthPx": 720,
"withinWcagAaa": true
},
"type": "json"
}
},
"schema": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"method": {
"enum": [
"GET"
],
"type": "string"
},
"queryParams": {
"properties": {
"avgCharWidthEm": {
"description": "Average character width in em; 0.5 is typical for Latin text (default 0.5; 0.45 condensed, 0.55 wide)",
"type": "number"
},
"fontSizePx": {
"description": "Font size in px",
"type": "number"
},
"widthPx": {
"description": "Text column width in px",
"type": "number"
}
},
"required": [
"widthPx",
"fontSizePx"
],
"type": "object"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method"
],
"type": "object"
},
"output": {
"properties": {
"example": {
"properties": {
"asOf": {
"type": [
"null",
"string"
]
},
"avgCharWidthEm": {
"type": [
"null",
"number"
]
},
"charactersPerLine": {
"type": [
"null",
"number"
]
},
"degraded": {
"type": [
"boolean",
"null"
]
},
"disclaimer": {
"type": [
"null",
"string"
]
},
"fontSizePx": {
"type": [
"null",
"number"
]
},
"minimumLineHeight": {
"type": [
"null",
"number"
]
},
"minimumParagraphSpacingMultipleOfLineSpacing": {
"type": [
"null",
"number"
]
},
"notChecked": {
"items": {
"type": "string"
},
"type": [
"array",
"null"
]
},
"reasons": {
"items": {
"type": "string"
},
"type": [
"array",
"null"
]
},
"source": {
"type": [
"null",
"string"
]
},
"suggestedCss": {
"type": [
"null",
"string"
]
},
"summary": {
"type": [
"null",
"string"
]
},
"verdict": {
"type": [
"null",
"string"
]
},
"wcagAaaLineLimit": {
"type": [
"null",
"number"
]
},
"wcagTextSpacingOverridePx": {
"properties": {
"letterSpacing": {
"type": [
"null",
"number"
]
},
"lineHeight": {
"type": [
"null",
"number"
]
},
"paragraphSpacing": {
"type": [
"null",
"number"
]
},
"wordSpacing": {
"type": [
"null",
"number"
]
}
},
"type": [
"null",
"object"
]
},
"widthFor45Px": {
"type": [
"null",
"number"
]
},
"widthFor66Em": {
"type": [
"null",
"number"
]
},
"widthFor66Px": {
"type": [
"null",
"number"
]
},
"widthFor75Px": {
"type": [
"null",
"number"
]
},
"widthFor80Px": {
"type": [
"null",
"number"
]
},
"widthPx": {
"type": [
"null",
"number"
]
},
"withinWcagAaa": {
"type": [
"boolean",
"null"
]
}
},
"type": "object"
},
"type": {
"type": "string"
}
},
"required": [
"type"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}
}
},
"lastUpdated": "2026-11-01T22:46:50.608Z",
"quality": {
"l30DaysTotalCalls": 2,
"l30DaysUniquePayers": 2,
"lastCalledAt": "2026-11-01T22:46:50.433Z"
},
"resource": "https://css-design-calc.x402tookit.com/line-length",
"serviceName": "CSS Design Calc",
"tags": [
"css",
"typography",
"readability",
"accessibility"
],
"type": "http",
"x402Version": 2
},
"source": "x402_bazaar",
"summary": "Estimate characters per line from column width and font size and rate it for readability (45-75 ideal, WCAG max 80)."
}What the leaf hashes
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Fold these into the leaf in order, hashing each sorted pair with keccak256, to reach the root of (444186 rows).
- 0xd66aa88eb7249036cb91115b20fb5a507aa82a226f3bbeab1876b9ed0fdc61cd
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- 0x06c50bcdbf45000166b7ba256668edb9c8e98feeddf7fd50bafb33655b6c397f
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- 0x4ee0fc4c09ec63991c4ad569ad0da9855e65ecd1f4f686535c5a9c89e58ebbad
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- 0x252cce55f1a3d5391c16f82d7f62494429a5f69b03486d4cfcfb7b2c96d6c884
- Day root
- 0x78fecaabbe319e56f5c4b80fc02e2052e198ad24781da8832a475ff65f2002d1
- Chained
- 0xdc35957db5d1371ca382b9152878ffece28ec7c5cb4f98fd71ddb367f8b999b2
- Published
- On Arc Testnet, block 70432815: 0x56b814612eb2e3e544153df3e91e1f7199106d1e430c7d8c6b653feeb9ebe9af