data.spencermcw.com
No description published for this endpoint.
DataLiveeip155:8453Exactvia facilitator:thirdweb
Calls · 30d
3
This endpoint's own trailing-30-day call count, as published by the upstream catalog and snapshotted daily. 8 snapshots so far.
$0.73
Verified settled volume
28 settlements proven x402 by their on-chain EIP-3009 marker.
$0.050
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
0xE6900aE625875b748f56Fb45C3e06a59Be8870DFThe 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",
"accepts": [
{
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"extra": {
"name": "USD Coin",
"version": "2"
},
"payTo": "0xE6900aE625875b748f56Fb45C3e06a59Be8870DF",
"amount": "50000",
"scheme": "exact",
"network": "eip155:8453",
"maxTimeoutSeconds": 300
}
],
"resource": {
"url": "https://data.spencermcw.com/v1/tax/changes",
"mimeType": "application/json",
"description": "Which US sales tax rates or boundaries changed this quarter? Rate, ZIP+4 and boundary change records for the 24 Streamlined Sales Tax states, computed by Distill from each state’s SST files. Updated quarterly. $0.05 per call (x402, USDC on Base); 3 free calls a day."
},
"extensions": {
"bazaar": {
"info": {
"input": {
"type": "http",
"method": "GET",
"queryParams": {
"limit": 1,
"state": "WA",
"entity": "rate"
}
},
"output": {
"type": "json",
"example": {
"data": {
"records": [
{
"id": "61970",
"key": "44165 (type 01)",
"new": "0.018",
"old": "0.019",
"field": "food_drug_interstate",
"state": "WA",
"entity": "rate",
"effective": "2026-10-01",
"detected_at": "2026-10-19T22:23:30.961Z",
"method_version": "tax.sst@1.0.0",
"source_sha256_new": "fb0d4514b4713057bc4d08f79184fb952ea9442b350bc65a2fb3c0214d7f23e1",
"source_sha256_old": "fb0d4514b4713057bc4d08f79184fb952ea9442b350bc65a2fb3c0214d7f23e1"
}
],
"next_cursor": "61970"
}
}
}
},
"schema": {
"type": "object",
"$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",
"properties": {
"limit": {
"type": "integer",
"maximum": 100,
"minimum": 1
},
"since": {
"type": "string",
"format": "date-time",
"pattern": "^(?:(?:\\d\\d[2468][048]|\\d\\d[13579][26]|\\d\\d0[48]|[02468][048]00|[13579][26]00)-02-29|\\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\\d|30)|(?:02)-(?:0[1-9]|1\\d|2[0-8])))T(?:(?:[01]\\d|2[0-3]):[0-5]\\d:[0-5]\\d(?:\\.\\d+)?(?:Z|([+-](?:[01]\\d|2[0-3]):[0-5]\\d)))$"
},
"state": {
"type": "string",
"pattern": "^[A-Za-z]{2}$"
},
"cursor": {
"type": "string",
"pattern": "^\\d{1,12}$"
},
"entity": {
"enum": [
"rate",
"zip4",
"zip5",
"address_records",
"file"
],
"type": "string"
},
"effective_from": {
"type": "string",
"pattern": "^\\d{4}-\\d{2}-\\d{2}$"
}
}
}
},
"additionalProperties": false
},
"output": {
"type": "object",
"required": [
"type"
],
"properties": {
"type": {
"type": "string"
},
"example": {
"type": "object",
"properties": {
"data": {
"type": "object",
"required": [
"records",
"next_cursor"
],
"properties": {
"records": {
"type": "array",
"items": {
"type": "object",
"required": [
"id",
"entity",
"state",
"key",
"field",
"old",
"new",
"effective",
"detected_at",
"source_sha256_old",
"source_sha256_new",
"method_version"
],
"properties": {
"id": {
"type": "string"
},
"key": {
"type": "string"
},
"new": {
"type": [
"string",
"null"
]
},
"old": {
"type": [
"string",
"null"
]
},
"field": {
"type": "string"
},
"state": {
"type": "string"
},
"entity": {
"enum": [
"rate",
"zip4",
"zip5",
"address_records",
"file"
],
"type": "string"
},
"effective": {
"type": "string"
},
"detected_at": {
"type": "string"
},
"method_version": {
"type": "string"
},
"source_sha256_new": {
"type": [
"string",
"null"
]
},
"source_sha256_old": {
"type": [
"string",
"null"
]
}
},
"additionalProperties": false
}
},
"next_cursor": {
"type": [
"string",
"null"
]
}
},
"additionalProperties": false
}
}
}
}
}
}
}
}
},
"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.
0.05USDC≈ $0.05 USD
on Base · exact scheme
Pay 0.05 USDC on Base to 0xE690…870DF. The signed payment is good for 5 minutes.
- Paid to
- 0xE690…870DF
- USD Coin contract
- 0x8335…02913
- Payment window
- 5 minutes
- As published
- 50000 smallest units
- Returns
- application/json
The catalog’s raw entry
[
{
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"extra": {
"name": "USD Coin",
"version": "2"
},
"payTo": "0xE6900aE625875b748f56Fb45C3e06a59Be8870DF",
"scheme": "exact",
"network": "eip155:8453",
"mimeType": "application/json",
"resource": "https://data.spencermcw.com/v1/tax/changes",
"description": "",
"maxAmountRequired": "50000",
"maxTimeoutSeconds": 300
}
]Provenance
- Seen in the source catalog
- 2026-10-21 20:19Z
- Last indexed by Roundhouse
- 2026-10-23 20:46Z
- Last enriched (probe, favicon, geo)
- 2026-10-24 15:46Z
- x402 version
- 1
- 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. 8 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 data.spencermcw.com 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=data.spencermcw.com' 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://data.spencermcw.com/v1/tax/changes, 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.