Query JST token wallet balances via x402 micropayment on Base for $0.02/request
What it does
This endpoint at lowpaymentfee.com returns wallet balance information for the JST (JUST) token. It is part of a broader suite of pay-per-call APIs offered by the provider, spanning data analytics, AI/ML inference, finance/Web3, and utility services. All endpoints on the platform use the x402 payment protocol, settling in USDC on the Base network.
The specific endpoint `/api/v1/wallet/JST/balance` accepts POST requests and is gated by an x402 challenge requiring up to 20,000 base units of USDC (i.e., $0.02 given USDC's 6 decimals). No API keys or account registration are needed — callers simply attach an X-PAYMENT header with a valid x402 payment proof. The provider advertises no rate limits and instant access.
Documentation on the site is extremely sparse. The docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no further technical detail. There is no OpenAPI spec, no request/response schema documentation, and no usage examples. The endpoint is confirmed live (returns HTTP 402 with a well-formed x402 challenge), but the actual response format for a successful paid call is unknown and must be inferred. Presumably it returns a JSON object containing the JST balance for a given wallet address, but the exact request body schema and response fields are undocumented.
Capabilities
Use cases
- —Checking JST (JUST) token balances for a given wallet address
- —Integrating real-time token balance data into portfolio trackers or dashboards
- —Automated agents querying on-chain balances without needing API keys
Fit
Best for
- —Agents or apps needing quick, keyless JST balance lookups
- —Developers who prefer pay-per-call micropayments over subscription APIs
- —x402-compatible clients on the Base network
Not for
- —Bulk historical balance queries (no documented batch or historical support)
- —Users needing detailed documentation or guaranteed SLAs
- —Querying balances for tokens other than JST on this specific endpoint
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/wallet/JST/balance \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402_payment_proof>" \
-d '{"address": "0xYourWalletAddress"}'Example
Request
{
"address": "0x1234567890abcdef1234567890abcdef12345678"
}Endpoint
Quality
The endpoint is confirmed live via a valid x402 402 challenge, but documentation is essentially nonexistent — no OpenAPI spec, no request/response schema, no examples. The request body format and response structure are entirely inferred. The provider landing page confirms pricing and general platform capabilities but offers no endpoint-specific detail.
Warnings
- —No documentation available — docs, API, pricing, and README pages all show only 'Connect wallet' with no content
- —Request body schema is unknown; the example request is speculative
- —Response schema is completely undocumented; example_response_json is null
- —No OpenAPI or machine-readable spec provided
- —The broader platform lists many endpoints but none have documented schemas
Citations
- —The endpoint returns HTTP 402 with an x402 challenge requiring up to 20,000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/wallet/JST/balance
- —All endpoints on the platform cost $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —USDC asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base networkhttps://lowpaymentfee.com/api/v1/wallet/JST/balance
- —Docs, API, pricing, and README pages render only 'Connect wallet' with no further contenthttps://lowpaymentfee.com/docs