Add mainnet x402 facilitator (#2291)

* Add mainnet x402 facilitator

* Update docs/build/apps/x402.mdx

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

* Update docs/build/apps/x402.mdx

Co-authored-by: Marcelo Salloum dos Santos <marcelosalloum@gmail.com>

* Update docs/build/apps/x402.mdx

Co-authored-by: Marcelo Salloum dos Santos <marcelosalloum@gmail.com>

* Add updates

---------

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
Co-authored-by: Marcelo Salloum dos Santos <marcelosalloum@gmail.com>

Author: 3 people

docs/build/apps/x402.mdx

@@ -30,22 +30,25 @@ Freighter Mobile does not currently support x402; use the Freighter browser exte
 
 ## x402 Facilitator
 
-The [OpenZeppelin Relayer x402 Plugin for x402](https://github.com/OpenZeppelin/relayer-plugin-x402-facilitator) implements the x402 facilitator API so you can serve x402 payments directly from a Relayer instance. It works with the Coinbase x402 ecosystem (e.g., @x402/express) and exposes the expected `/verify`, `/settle`, and `/supported` endpoints under the Relayer plugin router.
+The [OpenZeppelin Relayer x402 Plugin for x402](https://github.com/OpenZeppelin/relayer-plugin-x402-facilitator) implements the x402 Facilitator API so you can serve x402 payments directly from a Relayer instance. The x402 Facilitator leverages the OpenZeppelin Relayer Framework. It works with the [Coinbase x402](https://github.com/coinbase/x402) ecosystem and exposes the expected `/verify`, `/settle`, and `/supported` endpoints under the Relayer plugin router.
 
-### Facilitator Service
+### How to Use
 
-The x402 Facilitator Service is now live. Under the hood, the plugin leverages OpenZeppelin Channels to submit transactions onchain via a managed Relayer and Facilitator setup.
+The x402 facilitator Service is now live on Testnet and Mainnet. Under the hood, the plugin leverages OpenZeppelin Channels to submit transactions onchain via a managed Relayer and Facilitator setup.
 
-#### Testnet Facilitator
+#### Testnet
 
-To use the deployed x402 plugin on testnet, you will need:
+To use the facilitator on testnet, you will need:
 
 - An API Key (Relayer Service). Generate your testnet API key here: https://channels.openzeppelin.com/testnet/gen
 - Facilitator URL. Use the following facilitator endpoint in your configuration: `https://channels.openzeppelin.com/x402/testnet`
 
-#### Mainnet Facilitator
+#### Mainnet
 
-Coming soon.
+To use the Facilitator on mainnet, you will need:
+
+- An API Key (Relayer Service). Generate your mainnet API key here: https://channels.openzeppelin.com/gen
+- Facilitator URL. Use the following facilitator endpoint in your configuration: `https://channels.openzeppelin.com/x402`
 
 :::note
 
@@ -68,6 +71,7 @@ This version supports x402 v2 specification. For x402 v1 support, please use a p
 
 ## Learn more
 
+- [x402 Demo](https://x402-stellar-491bf9f7e30b.herokuapp.com/) - A demo site to a x402 transaction on Testnet
 - [x402 protocol (Coinbase Developer Platform)](https://docs.cdp.coinbase.com/x402) — Official x402 protocol overview and spec
 - [x402 protocol specification](https://www.x402.org/) — x402 Specification and Whitepaper
 - [Coinbase x402 GitHub](https://github.com/coinbase/x402) — Official x402 Protocol GitHub Repo