All projects on Base matching “topup”

Buy one virtual number for SMS verification. First GET /agent/v1/quote, then POST here with X-Quote-Id and Idempotency-Key (service_id/country_id in the query string). The 402 advertises the locked price. If no number is available the API answers 409 no_numbers and nothing is charged.

Nigerian mobile airtime top-up for MTN, Airtel, Glo and T2mobile. POST {net, msisdn, amount} with amount in Naira; priced in USD at the live NGN rate and paid in USDC or USDT. No API key or signup.