feat(core): add payments post_session_tokens flow (#6202)

Co-authored-by: hyperswitch-bot[bot] <148525504+hyperswitch-bot[bot]@users.noreply.github.com>

crates/openapi/src/openapi.rs

@@ -82,6 +82,7 @@ Never share your secret api keys. Keep them guarded and secure.
         routes::payment_link::payment_link_retrieve,
         routes::payments::payments_external_authentication,
         routes::payments::payments_complete_authorize,
+        routes::payments::payments_post_session_tokens,
 
         // Routes for refunds
         routes::refunds::refunds_create,
@@ -646,6 +647,8 @@ Never share your secret api keys. Keep them guarded and secure.
         api_models::payments::WalletResponseData,
         api_models::payments::PaymentsDynamicTaxCalculationResponse,
         api_models::payments::DisplayAmountOnSdk,
+        api_models::payments::PaymentsPostSessionTokensRequest,
+        api_models::payments::PaymentsPostSessionTokensResponse,
     )),
     modifiers(&SecurityAddon)
 )]

crates/openapi/src/routes/payments.rs

@@ -583,6 +583,24 @@ pub fn payments_complete_authorize() {}
 
 pub fn payments_dynamic_tax_calculation() {}
 
+/// Payments - Post Session Tokens
+///
+///
+#[utoipa::path(
+    post,
+    path = "/payments/{payment_id}/post_session_tokens",
+    request_body=PaymentsPostSessionTokensRequest,
+    responses(
+        (status = 200, description = "Post Session Token is done", body = PaymentsPostSessionTokensResponse),
+        (status = 400, description = "Missing mandatory fields")
+    ),
+    tag = "Payments",
+    operation_id = "Create Post Session Tokens for a Payment",
+    security(("publishable_key" = []))
+)]
+
+pub fn payments_post_session_tokens() {}
+
 /// Payments - Create Intent
 ///
 /// **Creates a payment intent object when amount_details are passed.**