Small xpay improvements.

.msggen.json

@@ -3887,6 +3887,7 @@
             "Xpay.maxdelay": 7,
             "Xpay.maxfee": 3,
             "Xpay.partial_msat": 6,
+            "Xpay.payer_note": 8,
             "Xpay.retry_for": 5
         },
         "XpayResponse": {
@@ -13422,6 +13423,10 @@
             "added": "v24.11",
             "deprecated": null
         },
+        "Xpay.payer_note": {
+            "added": "v25.12",
+            "deprecated": null
+        },
         "Xpay.payment_preimage": {
             "added": "v24.11",
             "deprecated": null

contrib/msggen/msggen/schema.json

@@ -36058,6 +36058,13 @@
               "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": "v25.12",
+            "description": [
+              "To ask the issuer to include in the fetched invoice (only if invstring is a BIP353 address or offer)"
+            ]
           }
         }
       },

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": "v25.12",
+        "description": [
+          "To ask the issuer to include in the fetched invoice (only if invstring is a BIP353 address or offer)"
+        ]
       }
     }
   },

plugins/libplugin.c

@@ -392,6 +392,27 @@ static void destroy_out_req(struct out_req *out_req, struct plugin *plugin)
 	strmap_del(&plugin->out_reqs, out_req->id, NULL);
 }
 
+void forward_notified(struct command *cmd,
+		      const char *method,
+		      const char *buf,
+		      const jsmntok_t *params,
+		      void *arg)
+{
+	const jsmntok_t *msgtok;
+	struct json_stream *js;
+
+	/* FIXME: There are also progress indicators, how to forward them? */
+	msgtok = json_get_member(buf, params, "message");
+	if (!msgtok)
+		return;
+
+	js = plugin_notify_start(cmd, "message");
+	json_add_tok(js, "level", json_get_member(buf, params, "level"), buf);
+	json_add_str_fmt(js, "message", "%s: %s",
+			 method, json_strdup(tmpctx, buf, msgtok));
+	plugin_notify_end(cmd, js);
+}
+
 /* FIXME: Move lightningd/jsonrpc to common/ ? */
 
 struct out_req *
@@ -409,6 +430,11 @@ jsonrpc_request_start_(struct command *cmd,
 						       const char *buf,
 						       const jsmntok_t *result,
 						       void *arg),
+		       void (*notified)(struct command *command,
+					const char *method,
+					const char *buf,
+					const jsmntok_t *params,
+					void *arg),
 		       void *arg)
 {
 	struct out_req *out;
@@ -420,6 +446,7 @@ jsonrpc_request_start_(struct command *cmd,
 	out->cmd = cmd;
 	out->cb = cb;
 	out->errcb = errcb;
+	out->notified = notified;
 	out->arg = arg;
 	strmap_add(&cmd->plugin->out_reqs, out->id, out);
 	tal_add_destructor2(out, destroy_out_req, cmd->plugin);
@@ -1085,9 +1112,19 @@ static void handle_rpc_reply(struct plugin *plugin, const char *buf, const jsmnt
 	bool cmd_freed;
 
 	idtok = json_get_member(buf, toks, "id");
-	if (!idtok)
-		/* FIXME: Don't simply ignore notifications! */
+	if (!idtok) {
+		const jsmntok_t *paramstok;
+		/* It's a notification about a command! */
+		paramstok = json_get_member(buf, toks, "params");
+		idtok = json_get_member(buf, paramstok, "id");
+		out = strmap_getn(&plugin->out_reqs,
+				  json_tok_full(buf, idtok),
+				  json_tok_full_len(idtok));
+		if (!out || !out->notified)
+			return;
+		out->notified(out->cmd, out->method, buf, paramstok, out->arg);
 		return;
+	}
 
 	out = strmap_getn(&plugin->out_reqs,
 			  json_tok_full(buf, idtok),
@@ -1654,6 +1691,13 @@ static struct command_result *handle_init(struct command *cmd,
 		struct command *aux_cmd = aux_command(cmd);
 
 		io_new_conn(p, p->rpc_conn->fd, rpc_conn_init, p);
+
+		/* Enable notifications on all commands */
+		req = jsonrpc_request_start(aux_cmd, "notifications",
+					    ignore_and_complete, plugin_broken_cb, NULL);
+		json_add_bool(req->js, "enable", true);
+		send_outreq(req);
+
 		/* In case they intercept rpc_command, we can't do this sync. */
 		req = jsonrpc_request_start(aux_cmd, "listconfigs",
 					    get_beglist, plugin_broken_cb, NULL);

plugins/libplugin.h

@@ -50,6 +50,12 @@ struct out_req {
 					const char *buf,
 					const jsmntok_t *error,
 					void *arg);
+	/* The callback when we a notification about this command. */
+	void (*notified)(struct command *command,
+			 const char *method,
+			 const char *buf,
+			 const jsmntok_t *params,
+			 void *arg);
 	void *arg;
 };
 
@@ -135,6 +141,13 @@ struct command_result *plugin_broken_cb(struct command *cmd,
 					const jsmntok_t *result,
 					void *arg);
 
+/* Helper to forward notifications */
+void forward_notified(struct command *cmd,
+		      const char *method,
+		      const char *buf,
+		      const jsmntok_t *params,
+		      void *arg);
+
 /* Helper to create a JSONRPC2 request stream. Send it with `send_outreq`. */
 struct out_req *jsonrpc_request_start_(struct command *cmd,
 				       const char *method,
@@ -150,6 +163,11 @@ struct out_req *jsonrpc_request_start_(struct command *cmd,
 								       const char *buf,
 								       const jsmntok_t *result,
 								       void *arg),
+				       void (*notified)(struct command *command,
+							const char *method,
+							const char *buf,
+							const jsmntok_t *params,
+							void *arg),
 				       void *arg)
 	NON_NULL_ARGS(1, 2, 5);
 
@@ -167,6 +185,7 @@ struct out_req *jsonrpc_request_start_(struct command *cmd,
 					 const char *mthod,		\
 					 const char *buf,		\
 					 const jsmntok_t *result),	\
+		     NULL,						\
 		     (arg))
 
 #define jsonrpc_request_with_filter_start(cmd, method, filter, cb, errcb, arg) \
@@ -183,6 +202,7 @@ struct out_req *jsonrpc_request_start_(struct command *cmd,
 					 const char *mthod,			\
 					 const char *buf,		\
 					 const jsmntok_t *result),	\
+		     NULL,						\
 		     (arg))
 
 /* This variant has callbacks received whole obj, not "result" or
@@ -196,8 +216,32 @@ struct out_req *jsonrpc_request_start_(struct command *cmd,
 						   const char *buf,	\
 						   const jsmntok_t *result), \
 			       NULL,					\
+			       NULL,						\
 			       (arg))
 
+/* This one handles notifications as well */
+#define jsonrpc_request_notified_start(cmd, method, cb, errcb, notcb, arg) \
+	jsonrpc_request_start_((cmd), (method), NULL, NULL,		\
+		     typesafe_cb_preargs(struct command_result *, void *, \
+					 (cb), (arg),			\
+					 struct command *command,	\
+					 const char *mthod,		\
+					 const char *buf,		\
+					 const jsmntok_t *result),	\
+		     typesafe_cb_preargs(struct command_result *, void *, \
+					 (errcb), (arg),		\
+					 struct command *command,	\
+					 const char *mthod,		\
+					 const char *buf,		\
+					 const jsmntok_t *result),	\
+		     typesafe_cb_preargs(void, void *, \
+					 (notcb), (arg),		\
+					 struct command *command,	\
+					 const char *mthod,		\
+					 const char *buf,		\
+					 const jsmntok_t *parms),	\
+		     (arg))
+
 /* Batch of requests: cb and errcb are optional, finalcb is called when all complete. */
 struct request_batch *request_batch_new_(const tal_t *ctx,
 					 struct command_result *(*cb)(struct command *,

plugins/xpay/xpay.c

@@ -1348,10 +1348,11 @@ static struct command_result *getroutes_for(struct command *aux_cmd,
 		maxfee = AMOUNT_MSAT(0);
 	}
 
-	req = jsonrpc_request_start(aux_cmd, "getroutes",
-				    getroutes_done,
-				    getroutes_done_err,
-				    payment);
+	req = jsonrpc_request_notified_start(aux_cmd, "getroutes",
+					     getroutes_done,
+					     getroutes_done_err,
+					     forward_notified,
+					     payment);
 
 	json_add_pubkey(req->js, "source", &xpay->local_id);
 	json_add_pubkey(req->js, "destination", dst);
@@ -1695,6 +1696,7 @@ struct xpay_params {
 	unsigned int retryfor;
 	u32 maxdelay, dev_maxparts;
 	const char *bip353;
+	const char *payer_note;
 };
 
 static struct command_result *
@@ -1718,6 +1720,8 @@ do_fetchinvoice(struct command *cmd, const char *offerstr, struct xpay_params *x
 {
 	struct out_req *req;
 
+	plugin_notify_message(cmd, LOG_INFORM, "Fetching invoice for offer");
+	plugin_notify_message(cmd, LOG_DBG, "offer is %s", offerstr);
 	req = jsonrpc_request_start(cmd, "fetchinvoice",
 				    invoice_fetched,
 				    forward_error,
@@ -1727,6 +1731,8 @@ do_fetchinvoice(struct command *cmd, const char *offerstr, struct xpay_params *x
 		json_add_amount_msat(req->js, "amount_msat", *xparams->msat);
 	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);
 }
 
@@ -1775,6 +1781,7 @@ static struct command_result *json_xpay_params(struct command *cmd,
 	unsigned int *retryfor;
 	struct out_req *req;
 	struct xpay_params *xparams;
+	const char *payer_note;
 
 	if (!param_check(cmd, buffer, params,
 			 p_req("invstring", param_invstring, &invstring),
@@ -1784,6 +1791,7 @@ 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),
+			 p_opt("payer_note", param_string, &payer_note),
 			 p_opt_dev("dev_maxparts", param_u32, &maxparts, 100),
 			 NULL))
 		return command_param_failed();
@@ -1810,6 +1818,7 @@ static struct command_result *json_xpay_params(struct command *cmd,
 		xparams->layers = layers;
 		xparams->retryfor = *retryfor;
 		xparams->maxdelay = *maxdelay;
+		xparams->payer_note = tal_steal(xparams, payer_note);
 		xparams->dev_maxparts = *maxparts;
 		xparams->bip353 = NULL;
 
@@ -1825,16 +1834,25 @@ static struct command_result *json_xpay_params(struct command *cmd,
 		xparams->layers = layers;
 		xparams->retryfor = *retryfor;
 		xparams->maxdelay = *maxdelay;
+		xparams->payer_note = tal_steal(xparams, payer_note);
 		xparams->dev_maxparts = *maxparts;
 		xparams->bip353 = invstring;
 
+		if (command_check_only(cmd))
+			return command_check_done(cmd);
+
+		plugin_notify_message(cmd, LOG_INFORM, "DNS lookup for %s", invstring);
 		req = jsonrpc_request_start(cmd, "fetchbip353",
 					    bip353_fetched,
 					    forward_error, xparams);
 		json_add_string(req->js, "address", invstring);
 		return send_outreq(req);
 	}
 
+	if (payer_note)
+		return command_fail(cmd, JSONRPC2_INVALID_PARAMS,
+				    "payer_note only valid when paying an offer or BIP353 address");
+
 	return xpay_core(cmd, invstring,
 			 msat, maxfee, layers, *retryfor, partial, *maxdelay, *maxparts,
 			 as_pay);

tests/test_askrene.py

@@ -1536,3 +1536,20 @@ def test_simple_dummy_channel(node_factory):
         final_cltv=5,
         layers=["mylayer"],
     )
+
+
+def test_askrene_notifications(node_factory):
+    l1, l2, l3 = node_factory.line_graph(3, wait_for_announce=True)
+
+    out = subprocess.check_output(['cli/lightning-cli',
+                                   '--network={}'.format(TEST_NETWORK),
+                                   '--lightning-dir={}'
+                                   .format(l1.daemon.lightning_dir),
+                                   'getroutes',
+                                   l1.info['id'],
+                                   l3.info['id'],
+                                   "10000msat",
+                                   "[]",
+                                   "1000msat",
+                                   "11"]).decode('utf-8').splitlines()
+    assert out == []