USD/MXN forex rate via x402 micropayment on Base for $0.02 per request.
What it does
This endpoint provides the USD/MXN foreign exchange rate through an x402-protocol pay-per-call API hosted at lowpaymentfee.com. Each request costs $0.02 (20,000 base units of USDC on the Base network, where USDC uses 6 decimals). No API keys or rate limits are required — callers simply attach an X-PAYMENT header with a valid x402 payment proof to receive the response.
The endpoint is part of a broader suite of APIs offered by lowpaymentfee.com spanning data analytics, AI/ML inference, finance/crypto market data, and utility services, all priced uniformly at $0.02 per request. This specific endpoint sits in the Finance & Web3 category and returns JSON. The x402 challenge confirms the endpoint is live, accepts POST requests, and settles payments in USDC (contract 0x8335…2913) on the Base L2 network with a maximum timeout of 300 seconds.
Documentation beyond the landing page is extremely sparse — the /docs, /pricing, /api, and /README pages all render only a "Connect wallet" prompt with no additional technical detail. There is no OpenAPI spec, no example request/response payloads, and no description of the response schema. The actual data source for the USD/MXN rate is not disclosed.
Capabilities
Use cases
- —Fetching the current USD/MXN exchange rate for financial applications
- —Programmatic currency conversion in payment or remittance workflows
- —Agent-driven forex lookups without needing API key registration
- —Embedding live FX data into dashboards or trading bots
Fit
Best for
- —Developers needing quick, keyless access to USD/MXN rates
- —AI agents that can pay per call via x402 on Base
- —Low-volume or sporadic forex data needs at $0.02/call
Not for
- —High-frequency trading requiring sub-second latency guarantees (no SLA documented)
- —Users needing historical forex time-series data (only current rate implied)
- —Anyone requiring detailed documentation or guaranteed data-source provenance
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/forex/USDMXN \
-H "X-PAYMENT: <x402_payment_proof>" \
-H "Content-Type: application/json"Endpoint
Quality
The endpoint is live (402 challenge captured) and pricing is clear ($0.02 USDC on Base), but there is no OpenAPI spec, no request/response schema, no documentation beyond a landing page, and no disclosed data source for the forex rate. Effectively a stub listing.
Warnings
- —No OpenAPI or schema documentation available
- —No example request or response payloads documented
- —Data source for USD/MXN rate is undisclosed
- —All documentation pages (/docs, /pricing, /api, /README) render only 'Connect wallet' with no content
- —Response format and fields are unknown — only mimeType application/json is confirmed
Citations
- —Endpoint returns 402 with x402 challenge accepting USDC on Base networkhttps://lowpaymentfee.com/api/v1/forex/USDMXN
- —maxAmountRequired is 20000 base units of USDC (6 decimals) = $0.02https://lowpaymentfee.com/api/v1/forex/USDMXN
- —All APIs on the platform are priced at $0.02 per request with no API keys or rate limitshttps://lowpaymentfee.com
- —USDC asset contract is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/forex/USDMXN