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Stellar Testnet Beta

PayGate

Turning ordinary APIs into machine-paid endpoints on Stellar testnet.

Role
Founder · Builder
Year
2026
State
online

PayGate asks what API billing should look like when the customer is software. I designed and built a flow where a machine client receives an HTTP 402 challenge, pays for one request on Stellar testnet, retries with proof, and receives the protected upstream response.

PayGate product cover showing the HTTP 402 pay-per-call flow from an API URL through Stellar payment verification to a paid endpoint.

The problem

Traditional API billing assumes a human account, subscription, and card. Machine clients need a narrower loop for discovering a price, paying for one request, and retrying with payment confirmation.

Built for

Developers monetizing GET and JSON APIs

Backend teams avoiding bespoke payment infrastructure

AI agents and machine clients answering HTTP 402 challenges

How it works

  1. 01

    Register and verify a protected upstream API.

  2. 02

    Return an HTTP 402 challenge for an unpaid call.

  3. 03

    Verify testnet USDC payment identity, amount, recipient, and replay state.

  4. 04

    Record an idempotent Soroban escrow credit before forwarding the request.

  5. 05

    Expose calls, payment evidence, splits, and withdrawal state.

What I built

Founded the product and defined the provider and machine-client experience.

Built the application, API routes, persistence model, proxy, and dashboard flows.

Integrated Stellar MPP verification, Soroban escrow accounting, and Freighter boundaries.

Designed upstream protection, replay controls, evidence packages, deployment, and documentation.

PayGate is founder-led. Wildan owns the product and principal implementation; ArgaAAL contributed focused hardening work for the V1 testnet beta.

Key decisions

Activation must prove upstream protection

A paid proxy is cosmetic if buyers can bypass it.

Tradeoff: Onboarding performs explicit invalid-secret and valid-secret checks before activation.

Bind one payment identity across the system

The challenge, replay store, transaction, and escrow credit need one traceable identity.

Tradeoff: Reconciliation becomes a first-class product and engineering concern.

Results & sources

PROJECT RECORDAS OF 2026-07-15

PayGate is publicly deployed as a Stellar testnet beta.

Live testnet beta
PROJECT RECORDAS OF 2026-07-15

PayGate verifies a testnet payment before forwarding to a protected upstream and recording an escrow credit.

Canonical repository