Guides / Agent payments with x402 on Base

Agent payments with x402 on Base

How an agent pays per call with USDC on Base without a card or a browser checkout.

Problem

What this solves.

An agent can pay per call with USDC on Base through x402, without a card or a browser checkout.

Steps

Do this in order.

  1. The agent requests a quote before spending.
  2. The agent pays the quoted amount in USDC on Base.
  3. Fikra verifies the payment and serves the call.
  4. The agent records the receipt id.
Quickstart

Copy the snippet.

curl https://api.fikraapi.co.ke/v1/chat/completions \
  -H "Authorization: Bearer fk_..." \
  -H "Content-Type: application/json" \
  -d '{"model":"deepseek-v4-1-flash-economy-free","messages":[{"role":"user","content":"Hello"}]}'

Base URL: https://api.fikraapi.co.ke/v1. Default model: deepseek-v4-1-flash-economy-free.

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Troubleshooting

Common errors.

  • Confirm the funding amount and account email with the human before charging anything.
  • Never ask the human for a card. x402 uses USDC on Base.
  • Keep the receipt id for every paid call.

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