PASAR API

🇻🇳 PayOS ~ VietQR bank-transfer payment gateway by Casso

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Self-serve signup at my.payos.vn; requests use x-client-id + x-api-key headers plus a checksum key for webhook signature verification. SDKs for Node/PHP/Go/Java. Docs Vietnamese-first. VN-first.

View docs ↗ More Payments APIs

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# PayOS ~ VietQR bank-transfer payment gateway by Casso needs an API key ~ get yours at:
# https://payos.vn/docs/
curl 'https://api-merchant.payos.vn' \
  -H 'Authorization: Bearer YOUR_TOKEN'

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I'm integrating a Vietnam API into my app.

API: PayOS ~ VietQR bank-transfer payment gateway by Casso
Provider: Casso (PayOS)
Auth: requires an API key (sign up: https://payos.vn/docs/)
Pricing: freemium
Base URL: https://api-merchant.payos.vn
Important note: Self-serve signup at my.payos.vn; requests use x-client-id + x-api-key headers plus a checksum key for webhook signature verification. SDKs for Node/PHP/Go/Java. Docs Vietnamese-first. VN-first.

Source: Casso (PayOS) (https://payos.vn/docs/)
Source type: Provider API or developer docs
Endpoint type: Provider API base URL
Integration difficulty: Needs API key
Last checked: 2026-07-03
Production caveat: Keep credentials server-side and confirm current limits, pricing, and webhook/error behaviour in the provider docs.

Help me set up the correct onboarding/authentication path and make the first valid request ~ explain exactly where credentials go and what must happen before production.

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