GITBOOK-184: feat: add Fees page to the docs

Author: Aimen Sahnoun

docs/SUMMARY.md

@@ -5,6 +5,7 @@
 ## Request Network API
 
 * [Create and Pay Requests](request-network-api/create-and-pay-requests.md)
+* [Fees](request-network-api/fees.md)
 * [Crosschain Payments](request-network-api/crosschain-payments.md)
 * [Crypto-to-fiat Payments](request-network-api/crypto-to-fiat-payments.md)
 * [Batch Payments](request-network-api/batch-payments.md)

docs/request-network-api/fees.md

@@ -0,0 +1,78 @@
+# Fees
+
+### Protocol Fee
+
+Request Network charges a protocol fee on all payments processed through the API.
+
+### Fee Structure
+
+| Fee Type     | Rate                   | Cap                                               |
+| ------------ | ---------------------- | ------------------------------------------------- |
+| Protocol Fee | 5 basis points (0.05%) | \~$25/€25 for main USD and EUR backed stablecoins |
+
+The protocol fees applies to all the payment types
+
+* ERC20 token payments
+* Native currency payments (ETH, POL, etc.)
+* Conversion payments
+* Batch payments
+* Crosschain payments
+* Subscription (coming soon)
+
+### Who Pays the Fee?
+
+By default, the payer bears the protocol fee. The fee is added on top of the invoice amount.
+
+#### Example
+
+* Invoice amount: 1000 USDC
+* Protocol fee: 1000 x 0.05% = 0.50 USDC
+* Total paid by payer: 1000.50 USDC + gas fee
+* Amount received by payee: 1000 USDC
+
+For larger payments with stablecoins, the fee is capped:
+
+* Payment of 100,000 USDC -> Fee capped at 25 USDC (not 50 USDC)
+
+### Shifting the Fee to the Payee
+
+If you want the payee to bear the protocol fee instead of the payer, simple reduce the invoice amount by 5bps (0.05%) before creating the request.
+
+#### Example:
+
+* Original intended payment: 1000 USDC
+* Reduce by 0.05%: 1000 - (1000 x 0.05%) = 999.50 USDC
+* Total paid by the payer: 1000 USDC + gas fee
+* Amount received by payee: 999.95 USDC
+
+This way, the payer pays approximately the original amount while the payee effectively absorbs the fee.
+
+### Platform Fees
+
+You can add your own platform fee on top of the protocol fee. Both fees are handled automatically when you configure a platform fee in your request.
+
+To set up platform fees, include the following parameters in your payment request:
+
+* `feePercentage` : Your platform fee percentage (e.g., "2.5").
+* `feeAddress` : The wallet address to receive your platform fees.
+
+When both protocol and platform fees are configured, the API automatically batches them into a single transaction for the payer.
+
+#### Fee Information In Responses
+
+Every API response includes the fee details in the metadata:
+
+```json
+  {
+    "metadata": {
+      "protocolFee": {
+        "percentage": "0.05",
+        "address": "0x..."
+      },
+      "platformFee": {
+        "percentage": "2.5",
+        "address": "0x..."
+      }
+    }
+  }
+```