Saylor Innovations Dev Tools
Percentage calculator - percent change between two numbers, percent of a number, what percent one number is of another, and increase or decrease by a percentage
OtherLiveeip155:8453Exactvia facilitator:payAI
CalcPercentCalculator
Calls · 30d
1→ 0%
This endpoint's own trailing-30-day call count, as published by the upstream catalog and snapshotted daily. 30 snapshots so far.
$15.76
Verified settled volume
1,657 settlements proven x402 by their on-chain EIP-3009 marker.
$0.010
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
Never called
—
Upstream on-chain volume
Reported by the source catalog.
Paid to
0xA2A8dF0f7CaaBEa4e120a2568118f141569fc8aaThe 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 required to access this resource.",
"accepts": [
{
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"extra": {
"memo": "saylor:devkit:calc-percent",
"name": "USD Coin",
"note": "Base settles through an x402 facilitator. Send payload.signature and payload.authorization (EIP-3009); there is no self-submitted path on this network.",
"version": "2",
"facilitatorOnly": true,
"assetTransferMethod": "eip3009"
},
"payTo": "0xA2A8dF0f7CaaBEa4e120a2568118f141569fc8aa",
"amount": "10000",
"scheme": "exact",
"network": "eip155:8453",
"maxTimeoutSeconds": 120
},
{
"asset": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",
"extra": {
"memo": "saylor:devkit:calc-percent",
"session": "eyJhcnRpY2xlSWQiOiJkZXZraXQ6Y2FsYy1wZXJjZW50IiwicmVmZXJlbmNlIjoiN1Q1N0o2bWJTbnNDMlBLdVpGc0RZVWVQcXFpUnFpZ0NETHVXaWR0YW9ld28iLCJyZWNpcGllbnQiOiI3TFNqZnJKZjhmTnNCOFZBOXU3TjNXRW4yNXNtUUxwb2IzU3Z5VXZYYWN5NyIsIm1pbnQiOiJFUGpGV2RkNUF1ZnFTU3FlTTJxTjF4enliYXBDOEc0d0VHR2tad3lURHQxdiIsIm1pbkFtb3VudCI6MTAwMDAsImV4cCI6MTc5MjEyMDY1Mzk1Mn0.N2iVnu8j2AVuLbi4aQmv_cPLwRlclZ-u6zpZKK5yRTg",
"feePayer": "GVJJ7rdGiXr5xaYbRwRbjfaJL7fmwRygFi1H6aGqDveb",
"reference": "7T57J6mbSnsC2PKuZFsDYUePqqiRqigCDLuWidtaoewo"
},
"payTo": "7LSjfrJf8fNsB8VA9u7N3WEn25smQLpob3SvyUvXacy7",
"amount": "10000",
"scheme": "exact",
"network": "solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp",
"maxTimeoutSeconds": 120
}
],
"resource": {
"url": "https://saylorinnovations.com/api/calc/percent?op=change&a=80&b=100",
"tags": [
"calc",
"percent",
"calculator"
],
"iconUrl": "https://saylorinnovations.com/og-image.jpg",
"mimeType": "application/json",
"description": "Percentage calculator - percent change between two numbers, percent of a number, what percent one number is of another, and increase or decrease by a percentage",
"serviceName": "Saylor Innovations Dev Tools"
},
"extensions": {
"bazaar": {
"info": {
"input": {
"type": "http",
"method": "GET",
"queryParams": {
"a": "80",
"b": "100",
"op": "change"
}
},
"output": {
"type": "json",
"example": {
"a": 80,
"b": 100,
"op": "change",
"result": 25,
"formula": "(b - a) / |a| * 100",
"description": "percentage change from a to b"
}
}
},
"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",
"POST",
"PUT",
"PATCH",
"DELETE",
"HEAD"
],
"type": "string"
},
"queryParams": {
"type": "object",
"required": [
"op",
"a",
"b"
],
"properties": {
"a": {
"type": "string",
"description": "first number"
},
"b": {
"type": "string",
"description": "second number"
},
"op": {
"type": "string",
"description": "change | of | is | increase | decrease"
}
}
}
},
"additionalProperties": false
},
"output": {
"type": "object",
"required": [
"type"
],
"properties": {
"type": {
"type": "string",
"const": "json"
},
"example": {
"type": "object",
"required": [
"op",
"result",
"formula"
],
"properties": {
"a": {
"type": "number"
},
"b": {
"type": "number"
},
"op": {
"type": "string",
"description": "Operation performed"
},
"result": {
"type": "number",
"description": "Result of the operation"
},
"formula": {
"type": "string",
"description": "Formula used for the calculation"
},
"checked_at": {
"type": [
"string",
"null"
],
"description": "Time the check was run (UTC)"
},
"description": {
"type": "string",
"description": "Short description"
}
}
}
}
}
}
}
},
"method": "GET",
"example": {
"a": 80,
"b": 100,
"op": "change",
"result": 25,
"formula": "(b - a) / |a| * 100",
"description": "percentage change from a to b"
},
"license": "LicenseRef-Saylor-Agent-Use-1.0",
"mimeType": "application/json",
"freshness": "computed on every request; input is not stored",
"freeSample": "https://saylorinnovations.com/api/calc/percent/free",
"tokenCount": null,
"inputSchema": {
"a": "first number",
"b": "second number",
"op": "change | of | is | increase | decrease"
},
"serviceName": "Saylor Innovations Dev Tools",
"instructions": "STANDARD PATH (works with stock x402 clients): send payload.transaction — a base64 partially-signed Solana transaction — and we route verify/settle through an x402 facilitator that sponsors the fee and submits it. Include the chosen accepts entry as \"accepted\" so we can match terms. ALTERNATIVE PATH (no facilitator): Pick ONE entry from accepts and use the reference and session from THAT entry — each asset has its own. USDC or USDT: send an SPL transfer of the exact amount. Native SOL (asset=So11111111111111111111111111111111111111112, extra.native=true): send that many lamports with a system transfer. Either way include extra.reference as a read-only account (Solana Pay style), then retry with PAYMENT-SIGNATURE: base64({x402Version:2, payload:{session, reference}}). If your client cannot attach a reference, send payload.signature instead (USDC only). SOL amounts are quoted live and expire in 120s; stablecoins do not move. The facilitator path verifies and settles in this request. Only the alternative self-submitted Solana path needs retries while the transfer is indexed (typically 3-4 attempts over 10-20s). On that path, a 402 saying \"payment not found on-chain yet\" means keep retrying.",
"outputSchema": {
"type": "object",
"required": [
"op",
"result",
"formula"
],
"properties": {
"a": {
"type": "number"
},
"b": {
"type": "number"
},
"op": {
"type": "string"
},
"result": {
"type": "number"
},
"formula": {
"type": "string"
},
"description": {
"type": "string"
}
}
},
"noPathTemplate": true,
"settlementModes": [
"facilitator-transaction",
"self-submitted-reference"
],
"typicalLatencyMs": 20
},
"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.
0.01USDC≈ $0.01 USD
on Base · exact scheme
Pay 0.01 USDC on Base to 0xA2A8…fc8aa. The signed payment is good for 2 minutes.
- Paid to
- 0xA2A8…fc8aa
- USD Coin contract
- 0x8335…02913
- Payment window
- 2 minutes
- As published
- 10000 smallest units
The catalog’s raw entry
[
{
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"extra": {
"memo": "saylor:devkit:calc-percent",
"name": "USD Coin",
"version": "2",
"facilitatorOnly": true,
"assetTransferMethod": "eip3009"
},
"payTo": "0xA2A8dF0f7CaaBEa4e120a2568118f141569fc8aa",
"amount": "10000",
"scheme": "exact",
"network": "eip155:8453",
"maxTimeoutSeconds": 120
}
]Extensions
{
"bazaar": {
"info": {
"input": {
"type": "http",
"method": "GET",
"queryParams": {
"a": "80",
"b": "100",
"op": "change"
}
},
"output": {
"type": "json",
"example": {
"a": 80,
"b": 100,
"op": "change",
"result": 25,
"formula": "(b - a) / |a| * 100",
"description": "percentage change from a to b"
}
}
},
"schema": {
"type": "object",
"$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",
"POST",
"PUT",
"PATCH",
"DELETE",
"HEAD"
],
"type": "string"
},
"queryParams": {
"type": "object",
"required": [
"op",
"a",
"b"
],
"properties": {
"a": {
"type": "string",
"description": "first number"
},
"b": {
"type": "string",
"description": "second number"
},
"op": {
"type": "string",
"description": "change | of | is | increase | decrease"
}
}
}
},
"additionalProperties": false
},
"output": {
"type": "object",
"required": [
"type"
],
"properties": {
"type": {
"type": "string",
"const": "json"
},
"example": {
"type": "object",
"required": [
"op",
"result",
"formula"
],
"properties": {
"a": {
"type": "number"
},
"b": {
"type": "number"
},
"op": {
"type": "string",
"description": "Operation performed"
},
"result": {
"type": "number",
"description": "Result of the operation"
},
"formula": {
"type": "string",
"description": "Formula used for the calculation"
},
"checked_at": {
"type": [
"string",
"null"
],
"description": "Time the check was run (UTC)"
},
"description": {
"type": "string",
"description": "Short description"
}
}
}
}
}
}
}
}
}Provenance
- Seen in the source catalog
- 2026-10-15 17:49Z
- Last indexed by Roundhouse
- 2026-10-26 21:16Z
- Last enriched (probe, favicon, geo)
- 2026-10-16 03:15Z
- x402 version
- 2
- Max timeout
- 120s
- 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. 30 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 Saylor Innovations Dev Tools 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=Saylor%20Innovations%20Dev%20Tools' 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://saylorinnovations.com/api/calc/percent, 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.