payment-ready until 2026-08-20
Read-only personal finance reference-data and calculation API for AI agents: tax estimates, disposable-income comparisons, sub-central tax rates, and social-security contribution data.
Pay from $0.01 per request in USDC on Base, settled onchain via the x402 protocol, no signup, no API key needed.
listed 2026-06-12 · no on-chain settlement recorded yet
ASSESSMENT
updated 4h agoEvidence-backed signals, not a single score. Click any chip for the proof. Measured values stay read-only; unknown is honest.
reliability 100%
- uptime 24h
- 100%
- uptime 7d
- 100%
- uptime 30d
- 100%
- uptime 90d
- 100%
- response p95
- 365ms
- avg response
- 197ms
- total checks
- 2,736
Measured on the unpaid 402 handshake, not the paid call. A service can 402 correctly and still fail after payment.
compliance C (13/14): EIP-712 domain parameters present on every EVM entry
13 of 14 x402 conformance checks pass; failing: EIP-712 domain parameters present on every EVM entry. Full checklist below.
signability route not signable
At least one EVM route on this service returns its 402 without the EIP-712 domain parameters (extra.name and extra.version), so a standard x402 client cannot build the signature for that route.
Measured on the last 402 envelope captured from this service. It is a fact about the envelope, not a judgement on the service or its operator.
This is the only conformance check that caps the compliance grade, at C.
price $0.01 (p45 in Finance)
- price (min)
- $0.01
- category percentile (min)
- p45 in Finance
- endpoints / prices
- 4 / 1
- model
- flat
- stability
- 100%
risk clean
No deterministic risk flag. Risk fires only on an exact blocklist match, or a reserved-brand name with a mismatched verified payTo. Never from low uptime, a high price, or a model guess.
- domain age
- -
- registrar
- -
- hosting
- custom
- domain created
- ---
Identity facts, not a risk score.
traction $0.00 30d · 0 buyers
- volume 30d
- $0.00
- buyers 30d
- 0
- settlements 30d
- 0
- first settlement
- ---
- last settlement
- ---
- top buyer share
- -
- trend 7d vs 30d
- -
- networks
- eip155:8453
- volume all-time
- $0
- settlements all-time
- 0
- median settlement 30d
- -
- max settlement 30d
- -
- settled via
- -
Conservative undercount: only USDC settlements via facilitators we measure are counted. A measured floor, not an estimate.
Top buyer share is a concentration signal, not part of the ranking score.
WHAT IT DOES
ai-derivedProvides personal finance reference data and calculation services for tax estimates and disposable income comparisons
- category
- finance-api
- in
- body
AI-generated summary. The measured data is never altered by it.
ENDPOINTS
| METHOD | PATH | DESCRIPTION | PRICE | NETWORK | ASSET | 402 CHANNEL |
|---|---|---|---|---|---|---|
| POST | /api/v1/calculations/disposable_income_compare | $0.01 | Base | USDC | header | |
| POST | /api/v1/calculations/tax_estimate | $0.01 | Base | USDC | header | |
| GET | /api/v1/reference_data/social_security_rates | $0.01 | Base | USDC | header | |
| GET | /api/v1/reference_data/sub_central_tax_rates | $0.01 | Base | USDC | header |
REQUEST / RESPONSE EXAMPLE
An unpaid request to GET /api/v1/reference_data/social_security_rates returns HTTP 402 with the payment terms. Settle onchain via your facilitator, then retry with the X-Payment header.
curl -i 'https://app.popadex.com/api/v1/reference_data/social_security_rates'
// 402 response (captured by monitor) · 4 payloads · click to expand
[
{
"error": "Payment Required",
"accepts": [
{
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"extra": null,
"payTo": "0x6BF7079D05672646fFC88bD87691b6214B7aad02",
"amount": "10000",
"scheme": "exact",
"network": "eip155:8453",
"maxTimeoutSeconds": 60
}
],
"resource": {
"url": "https://app.popadex.com/api/v1/reference_data/sub_central_tax_rates",
"tags": [
"finance",
"tax",
"api"
],
"mimeType": "application/json",
"description": "PopaDex GET /api/v1/reference_data/sub_central_tax_rates",
"serviceName": "PopaDex"
},
"extensions": {
"popadex": {
"code": "payment_required",
"message": "Payment is required for this endpoint"
}
},
"x402Version": 2
},
{
"error": "Payment Required",
"accepts": [
{
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"extra": null,
"payTo": "0x6BF7079D05672646fFC88bD87691b6214B7aad02",
"amount": "10000",
"scheme": "exact",
"network": "eip155:8453",
"maxTimeoutSeconds": 60
}
],
"resource": {
"url": "https://app.popadex.com/api/v1/calculations/disposable_income_compare",
"tags": [
"finance",
"tax",
"api"
],
"mimeType": "application/json",
"description": "PopaDex POST /api/v1/calculations/disposable_income_compare",
"serviceName": "PopaDex"
},
"extensions": {
"popadex": {
"code": "payment_required",
"message": "Payment is required for this endpoint"
}
},
"x402Version": 2
},
{
"error": "Payment Required",
"accepts": [
{
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"extra": null,
"payTo": "0x6BF7079D05672646fFC88bD87691b6214B7aad02",
"amount": "10000",
"scheme": "exact",
"network": "eip155:8453",
"maxTimeoutSeconds": 60
}
],
"resource": {
"url": "https://app.popadex.com/api/v1/reference_data/social_security_rates",
"tags": [
"finance",
"tax",
"api"
],
"mimeType": "application/json",
"description": "PopaDex GET /api/v1/reference_data/social_security_rates",
"serviceName": "PopaDex"
},
"extensions": {
"popadex": {
"code": "payment_required",
"message": "Payment is required for this endpoint"
}
},
"x402Version": 2
},
{
"error": "Payment Required",
"accepts": [
{
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"extra": null,
"payTo": "0x6BF7079D05672646fFC88bD87691b6214B7aad02",
"amount": "10000",
"scheme": "exact",
"network": "eip155:8453",
"maxTimeoutSeconds": 60
}
],
"resource": {
"url": "https://app.popadex.com/api/v1/calculations/tax_estimate",
"tags": [
"finance",
"tax",
"api"
],
"mimeType": "application/json",
"description": "PopaDex POST /api/v1/calculations/tax_estimate",
"serviceName": "PopaDex"
},
"extensions": {
"popadex": {
"code": "payment_required",
"message": "Payment is required for this endpoint"
}
},
"x402Version": 2
}
] OVER TIME
All charts use the 30d selector; each series spans only the dates it has data for. Every series is also served as JSON at /api/v1/services/popadex-personal-finance-reference-api/price, /scores, /volume and /buyers. On-chain volume and distinct buyers are measured over the service's settlement address and are a conservative undercount (only settlements that reach a measured facilitator are counted). The on-chain series roll up hourly, so the latest day can be up to about an hour behind; distinct buyers are counted per payout address, so a service that settles to more than one address is an upper bound.
Median across 4 endpoints. Use the selector to isolate one.
checklist grew 11->14 on 2026-07-28; a step here is a metric change, not a regression
Measured site and economics pillars from the assessment history, so the latest value shown elsewhere on this page reads as a point on a trend rather than a permanent state.
COMPLIANCE
13/14 checks pass · grade C · failing: EIP-712 domain parameters present on every EVM entrylast 402 captured 2026-06-16 · last up 2026-08-13
- 402 payload captured
- accepts[] array present
- payTo address recoverable
- payTo at accepts[0].payTo (conformant shape)
- payTo is a valid on-chain address
- atomic price declared
- atomic price in a sane range
- asset (token) address declared
- network resolves to CAIP-2
- payment scheme declared
- served over HTTPS
- declares the current x402 version (2)
- EIP-712 domain parameters present on every EVM entry
- x402 v2 envelope delivered in the payment-required header
SITE PILLARS
- homepage reachable
- openapi doc
- pricing page
- llms.txt
- robots.txt
- terms page
recent checks (18) live · click to expand
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