Pay-per-call premium API access via x402 on Base, settling in USDC at $0.02/request.
What it does
This endpoint at lowpaymentfee.com provides "Premium API Access" behind an x402 paywall on the Base network. The site advertises a broad suite of API categories — data & analytics, AI & machine learning, finance & Web3, and infrastructure utilities — all priced at $0.02 per request with no API keys, no rate limits, and instant access.
The specific endpoint probed (`/api/v1/integrations/openai/secret`) returned a valid x402 challenge requesting up to 20,000 base units of USDC (0x8335…2913 on Base, 6 decimals = $0.02) per call. Payment is made via the x402 exact scheme to the specified payTo address. The challenge confirms the endpoint is live and accepting POST requests.
However, the crawled pages beyond the landing page (including /api, /pricing, and /README) returned only a "Connect wallet" prompt with no additional documentation, schemas, or usage examples. The specific behavior of the `/api/v1/integrations/openai/secret` endpoint — what it accepts as input and what it returns — is not documented anywhere in the crawled material. The name suggests it may proxy or wrap an OpenAI API call, but this is speculative. Without request/response schemas or documentation, agents must discover the interface experimentally.
Capabilities
Use cases
- —Accessing an OpenAI-compatible endpoint without managing API keys
- —Making one-off LLM calls paid per-request in USDC on Base
- —Agent-driven API consumption with on-chain micropayments
Fit
Best for
- —Agents that need keyless, pay-per-call access to an OpenAI-style API
- —Developers who want to avoid subscription commitments for sporadic API usage
- —Crypto-native workflows settling on Base L2
Not for
- —High-volume production workloads needing documented SLAs and schemas
- —Users who need detailed API documentation before integrating
- —Anyone without USDC on Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/integrations/openai/secret \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>" \
-d '{"prompt": "Hello, world!"}'Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, but there is zero documentation on what this specific endpoint accepts or returns. No OpenAPI spec, no examples, no request/response schema. The endpoint name hints at OpenAI integration but nothing is confirmed. Pricing is clear ($0.02/request in USDC on Base).
Warnings
- —No documentation exists for the /api/v1/integrations/openai/secret endpoint — input/output schema is completely unknown
- —The endpoint name suggests OpenAI proxy functionality but this is unconfirmed; actual behavior must be discovered experimentally
- —All non-landing crawled pages returned only 'Connect wallet' with no useful content
- —No OpenAPI spec, no README content, no usage examples available
Citations
- —The endpoint returns a valid x402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/integrations/openai/secret
- —USDC asset address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/integrations/openai/secret
- —All APIs priced at $0.02/request with no API keys, no rate limits, instant access on Base networkhttps://lowpaymentfee.com
- —Site advertises categories: Data & Analytics, AI & Machine Learning, Finance & Web3, Infrastructurehttps://lowpaymentfee.com