Feature/xpay payment description

.msggen.json

@@ -4073,6 +4073,7 @@
             "Xpay.maxdelay": 7,
             "Xpay.maxfee": 3,
             "Xpay.partial_msat": 6,
+            "Xpay.payer_note": 8,
             "Xpay.retry_for": 5
         },
         "XpayResponse": {
@@ -14044,6 +14045,10 @@
             "added": "v24.11",
             "deprecated": null
         },
+        "Xpay.payer_note": {
+            "added": "v26.04",
+            "deprecated": null
+        },
         "Xpay.payment_preimage": {
             "added": "v24.11",
             "deprecated": null

contrib/msggen/msggen/schema.json

@@ -37474,6 +37474,13 @@
               "A payment may be delayed for up to `maxdelay` blocks by another node; clients should be prepared for this worst case."
             ],
             "default": "2016"
+          },
+          "payer_note": {
+            "type": "string",
+            "added": "v26.04",
+            "description": [
+              "A message that a payer is willing to send to a payee within a payment."
+            ]
           }
         }
       },

contrib/pyln-grpc-proto/pyln/grpc/node_pb2_grpc.py

@@ -5,7 +5,7 @@
 
 from pyln.grpc import node_pb2 as node__pb2
 
-GRPC_GENERATED_VERSION = '1.75.1'
+GRPC_GENERATED_VERSION = '1.76.0'
 GRPC_VERSION = grpc.__version__
 _version_not_supported = False
 
@@ -18,7 +18,7 @@
 if _version_not_supported:
     raise RuntimeError(
         f'The grpc package installed is at version {GRPC_VERSION},'
-        + f' but the generated code in node_pb2_grpc.py depends on'
+        + ' but the generated code in node_pb2_grpc.py depends on'
         + f' grpcio>={GRPC_GENERATED_VERSION}.'
         + f' Please upgrade your grpc module to grpcio>={GRPC_GENERATED_VERSION}'
         + f' or downgrade your generated code using grpcio-tools<={GRPC_VERSION}.'

doc/schemas/xpay.json

@@ -65,6 +65,13 @@
           "A payment may be delayed for up to `maxdelay` blocks by another node; clients should be prepared for this worst case."
         ],
         "default": "2016"
+      },
+      "payer_note": {
+        "type": "string",
+        "added": "v26.04",
+        "description": [
+          "A message that a payer is willing to send to a payee within a payment."
+        ]
       }
     }
   },

plugins/xpay/xpay.c

@@ -181,7 +181,7 @@ static struct command_result *xpay_core(struct command *cmd,
 					u32 retryfor,
 					const struct amount_msat *partial,
 					u32 maxdelay,
-					bool as_pay);
+                                        bool as_pay);
 
 /* Wrapper for pending commands (ignores return) */
 static void was_pending(const struct command_result *res)
@@ -1790,6 +1790,7 @@ struct xpay_params {
 	unsigned int retryfor;
 	u32 maxdelay;
 	const char *bip353;
+	const char *payer_note;
 };
 
 static struct command_result *
@@ -1820,9 +1821,12 @@ do_fetchinvoice(struct command *cmd, const char *offerstr, struct xpay_params *x
 	json_add_string(req->js, "offer", offerstr);
 	if (xparams->msat)
 		json_add_amount_msat(req->js, "amount_msat", *xparams->msat);
-	if (xparams->bip353)
-		json_add_string(req->js, "bip353", xparams->bip353);
-	return send_outreq(req);
+    if (xparams->bip353)
+        json_add_string(req->js, "bip353", xparams->bip353);
+    if (xparams->payer_note)
+        json_add_string(req->js, "payer_note", xparams->payer_note);
+
+    return send_outreq(req);
 }
 
 static struct command_result *
@@ -1867,7 +1871,8 @@ static struct command_result *json_xpay_params(struct command *cmd,
 	const char *invstring;
 	const char **layers;
 	u32 *maxdelay;
-	unsigned int *retryfor;
+    const char *payer_note;
+    unsigned int *retryfor;
 	struct out_req *req;
 	struct xpay_params *xparams;
 
@@ -1879,7 +1884,8 @@ static struct command_result *json_xpay_params(struct command *cmd,
 			 p_opt_def("retry_for", param_number, &retryfor, 60),
 			 p_opt("partial_msat", param_msat, &partial),
 			 p_opt_def("maxdelay", param_u32, &maxdelay, 2016),
-			 NULL))
+                         p_opt("payer_note", param_string, &payer_note),
+                         NULL))
 		return command_param_failed();
 
 	/* Is this a one-shot vibe payment?  Kids these days! */
@@ -1901,6 +1907,7 @@ static struct command_result *json_xpay_params(struct command *cmd,
 		xparams->retryfor = *retryfor;
 		xparams->maxdelay = *maxdelay;
 		xparams->bip353 = NULL;
+                xparams->payer_note = payer_note;
 
 		return do_fetchinvoice(cmd, invstring, xparams);
 	}
@@ -1915,6 +1922,7 @@ static struct command_result *json_xpay_params(struct command *cmd,
 		xparams->retryfor = *retryfor;
 		xparams->maxdelay = *maxdelay;
 		xparams->bip353 = invstring;
+                xparams->payer_note = payer_note;
 
 		req = jsonrpc_request_start(cmd, "fetchbip353",
 					    bip353_fetched,

tests/test_xpay.py

@@ -172,10 +172,10 @@ def test_xpay_simple(node_factory):
     b11 = l4.rpc.invoice('10000msat', 'test_xpay_simple', 'test_xpay_simple bolt11')['bolt11']
     l1.rpc.xpay(b11)
 
-    # BOLT 12.
+    # BOLT 12 (with payer_note specified).
     offer = l3.rpc.offer('any')['bolt12']
     b12 = l1.rpc.fetchinvoice(offer, '100000msat')['invoice']
-    l1.rpc.xpay(b12)
+    l1.rpc.xpay(invstring=b12, payer_note="Payment for a cup of coffee")
 
     # Failure from l4.
     b11 = l4.rpc.invoice('10000msat', 'test_xpay_simple2', 'test_xpay_simple2 bolt11')['bolt11']