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doc://integracoes/mercado-pago
Just like with Stripe, you never paste any credentials into MMNWEB. You authorize Fragasoft's application to charge on your account, and Mercado Pago returns a token to our server. But MP has one quirk that has already broken the split for plenty of merchants — and it's at the end of this page.
| Pair | What it's for | Can it be exposed? |
|---|---|---|
| Public Key + Access Token | payment integrations | Public Key yes; Access Token no |
| Client ID + Client Secret | integrations that use OAuth (access to third-party accounts) | No |
Each pair is unique per application (tied to the application you created, not to a generic account). And there are two sets: test and production. Test credentials come active by default; production credentials must be activated by filling in your business details (including your line of business).
Fragasoft maintains the platform application at Mercado Pago and holds the Client ID, Client Secret, and the webhook secret — global credentials, encrypted at rest, that never reach the browser or the repository. You keep your Mercado Pago account and never hand us your Public Key or Access Token manually. When you authorize, MP delivers to our server a set of credentials tied to you: access_token, refresh_token, user_id (your receiver ID), and public_key — stored encrypted (AES-256-GCM) and used only to charge on your behalf.
The access_token MP issues to the seller is valid for 180 days (the expires_in field returns 15,552,000 seconds). It comes with a refresh_token, made precisely to renew access before expiration. If the token expires without renewal, that merchant's split simply stops — it's not a noisy failure; it's a charge that quietly stops being authorized.
MMNWEB renews it automatically before expiration — you don't have to do anything. But you need to know this exists, for two reasons:
The PIX charge happens inside MMNWEB, on your Mercado Pago account. The platform fee is deducted via application_fee — MP's native split mechanism. The money never passes through Fragasoft's account: using the native split is what keeps the operation outside the regulatory requirements that apply to anyone holding third-party funds. The percentage is set by Fragasoft and configured in the system — you don't edit it. As with Stripe, the rule is "no ready provider, no sale": checkout only offers PIX when the authorization is valid and the ability to charge has been genuinely verified.
Do I need to send my Access Token to support? No. The flow is OAuth; the token goes straight to the server. If anyone asks for your Access Token in a message, be suspicious.
PIX stopped out of nowhere. Two likely causes: authorization revoked in the MP panel, or production credentials manually renewed. Open a support ticket before touching anything.
I tested with test credentials and it worked. Test and production are separate sets. Production must be activated in the panel, with your business details filled in.
Can I use Mercado Pago and Stripe at the same time? Yes. Typically: PIX through Mercado Pago, cards through Stripe.
Credentials (types, test × production) · OAuth — Access Token, validity and refresh · OAuth API reference
Related: Integrations overview · Stripe (cards) · Cielo · Engine concepts
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