US tax return data for 2020, paid per-request via x402 on Base with USDC.
What it does
This endpoint at lowpaymentfee.com provides access to US tax return data for the year 2020. It is part of a broader suite of pay-per-call APIs offered by the same provider, spanning data analytics, AI/ML inference, finance, crypto, and utility services. All endpoints use the x402 payment protocol, settling in USDC on the Base network.
The specific endpoint `/api/v1/tax/returns/2020` costs $0.02 per request (20,000 base units of USDC with 6 decimals). Payment is handled via the x402 `X-PAYMENT` header — no API keys, accounts, or rate limits are required. The provider advertises a flat $0.02/request pricing model across all its APIs with no minimums or commitments.
Documentation is extremely sparse. The crawled docs, pricing, and API pages all returned only a "Connect wallet" prompt with no further content. There is no OpenAPI schema, no request/response examples, and no description of what fields the tax returns endpoint actually returns or what input parameters it expects beyond being a POST endpoint. The endpoint is confirmed live (returns a proper 402 x402 challenge), but the lack of documentation makes it difficult to assess the actual data quality or coverage.
Capabilities
Use cases
- —Retrieving US tax return information for the 2020 tax year
- —Programmatic access to tax filing data without API key management
- —Agent-driven financial research requiring tax return records
Fit
Best for
- —Developers needing on-demand tax return data without subscription commitments
- —AI agents that can pay per-call via x402 on Base
- —Quick lookups of 2020 US tax return information
Not for
- —Bulk historical tax data retrieval across many years (only 2020 is indicated)
- —Users who need detailed API documentation before integrating
- —Non-crypto users who cannot settle payments in USDC on Base
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/tax/returns/2020 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, but there is no documentation, no OpenAPI schema, no request/response examples, and no description of what data is actually returned. The listing is essentially a stub with only pricing and protocol details confirmed.
Warnings
- —No API documentation available — docs, pricing, and API pages all render only a wallet connect prompt
- —No OpenAPI or input/output schema provided; request parameters and response format are unknown
- —The nature of the tax return data (source, coverage, accuracy) is completely undocumented
- —Cannot verify whether this endpoint returns real IRS data, synthetic data, or something else
Citations
- —The endpoint returns a 402 x402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/tax/returns/2020
- —The provider advertises $0.02/request flat pricing with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 is USDC on Base with 6 decimalshttps://lowpaymentfee.com/api/v1/tax/returns/2020