W-2 tax calculation API for 2025, pay-per-request via x402 on Base network.
What it does
This endpoint at lowpaymentfee.com provides a W-2 tax calculation service for the 2025 tax year. It is part of a broader platform offering dozens of pay-per-call APIs spanning data analytics, AI/ML, finance, crypto, and utility services — all settled via the x402 protocol on the Base network using USDC.
The specific endpoint `/api/v1/tax/w2/2025` accepts POST requests and costs $0.02 per call (20,000 base units of USDC with 6 decimals). No API keys, rate limits, or upfront commitments are required; callers simply attach an x402 payment header with each request. The endpoint is live and returns a standard 402 challenge when called without payment.
Documentation is extremely sparse. The provider's landing page lists available API categories and uniform pricing, but the docs, API reference, pricing, and README pages all render only a "Connect wallet" prompt with no substantive content. There is no OpenAPI schema, no request/response examples, and no detailed description of what inputs the W-2 tax endpoint expects or what it returns. The endpoint's purpose (W-2 tax computation for 2025) is inferred solely from the URL path and the generic "Premium API Access" label.
Capabilities
Use cases
- —Calculate federal and/or state tax withholdings for W-2 wage earners in 2025
- —Integrate automated tax estimation into payroll or HR software
- —Provide tax projection tools in personal finance applications
Fit
Best for
- —Developers needing on-demand W-2 tax calculations without subscription commitments
- —Agents or bots that can settle micropayments via x402 on Base
- —Prototyping tax-related features with instant API access
Not for
- —Production tax filing or compliance (no evidence of IRS-grade accuracy or certification)
- —Users who need detailed documentation or guaranteed SLAs before integrating
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/tax/w2/2025 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402_payment_header>" \
-d '{"wages": 75000, "filing_status": "single", "state": "CA"}'Example
Request
{
"state": "CA",
"wages": 75000,
"filing_status": "single"
}Endpoint
Quality
The endpoint is live (402 challenge confirmed) and pricing is clear ($0.02/request in USDC on Base). However, there is no documentation, no OpenAPI schema, no request/response examples, and no description of what the endpoint actually computes or returns. The request example above is entirely speculative based on the URL path. This is effectively a stub listing.
Warnings
- —No documentation available — docs, API, pricing, and README pages all render only a wallet-connect prompt with no content.
- —No OpenAPI or input/output schema provided; request format and response structure are unknown.
- —The endpoint's exact functionality (federal tax, state tax, withholding, etc.) is inferred only from the URL path '/api/v1/tax/w2/2025'.
- —Tax calculations may be subject to regulatory requirements; accuracy and compliance status are unknown.
- —Example request JSON is speculative and not sourced from provider documentation.
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/tax/w2/2025
- —Uniform pricing of $0.02 per request across all APIs on the platformhttps://lowpaymentfee.com
- —No API keys, no rate limits, instant access advertisedhttps://lowpaymentfee.com
- —USDC asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base networkhttps://lowpaymentfee.com/api/v1/tax/w2/2025