offers: print out more details, fix up schema for decode of blinded paths.

We need to print out first_node_id, and "node_id" is now called
"blinded_node_id" in the spec.

And the schema didn't include the payment fields in the blinded path
for invoices (which broke as soon as we actually tested one!).

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

doc/lightning-decode.7.md

@@ -45,9 +45,10 @@ If **type** is "bolt12 offer", and **valid** is *true*:
   - **features** (hex, optional): the array of feature bits for this offer
   - **absolute\_expiry** (u64, optional): UNIX timestamp of when this offer expires
   - **paths** (array of objects, optional): Paths to the destination:
+    - **first\_node\_id** (pubkey): the (presumably well-known) public key of the start of the path
     - **blinding** (pubkey): blinding factor for this path
     - **path** (array of objects): an individual path:
-      - **node\_id** (pubkey): node_id of the hop
+      - **blinded\_node\_id** (pubkey): node_id of the hop
       - **encrypted\_recipient\_data** (hex): encrypted TLV entry for this hop
   - **quantity\_min** (u64, optional): the minimum quantity
   - **quantity\_max** (u64, optional): the maximum quantity
@@ -73,7 +74,7 @@ If **type** is "bolt12 offer", and **valid** is *false*:
 If **type** is "bolt12 invoice", and **valid** is *true*:
 
   - **node\_id** (pubkey): public key of the offering node
-  - **signature** (bip340sig): BIP-340 signature of the *node_id* on this offer
+  - **signature** (bip340sig): BIP-340 signature of the *node_id* on this invoice
   - **amount\_msat** (msat): the amount in bitcoin
   - **description** (string): the description of the purpose of the offer
   - **created\_at** (u64): the UNIX timestamp of invoice creation
@@ -87,10 +88,15 @@ If **type** is "bolt12 invoice", and **valid** is *true*:
   - **vendor** (string, optional): the name of the vendor for this offer
   - **features** (hex, optional): the array of feature bits for this offer
   - **paths** (array of objects, optional): Paths to the destination:
+    - **first\_node\_id** (pubkey): the (presumably well-known) public key of the start of the path
     - **blinding** (pubkey): blinding factor for this path
     - **path** (array of objects): an individual path:
-      - **node\_id** (pubkey): node_id of the hop
+      - **blinded\_node\_id** (pubkey): node_id of the hop
       - **encrypted\_recipient\_data** (hex): encrypted TLV entry for this hop
+      - **fee\_base\_msat** (msat, optional): base fee for the entire path
+      - **fee\_proportional\_millionths** (u32, optional): proportional fee for the entire path
+      - **cltv\_expiry\_delta** (u32, optional): total CLTV delta across path
+      - **features** (hex, optional): Features allowed/required for this path
   - **quantity** (u64, optional): the quantity ordered
   - **recurrence\_counter** (u32, optional): the 0-based counter for a recurring payment
   - **recurrence\_start** (u32, optional): the optional start period for a recurring payment
@@ -211,4 +217,4 @@ RESOURCES
 
 Main web site: <https://github.com/ElementsProject/lightning>
 
-[comment]: # ( SHA256STAMP:3348f74162c4a2737f1bc50f1903e7e25484747a1bc9ba7d3cd3f30b57589fdf)
+[comment]: # ( SHA256STAMP:bbe57fd87e729e1203055d983a72757b9647ea67dca23c254a05b38b7b7020d9)

doc/schemas/decode.schema.json

@@ -131,11 +131,16 @@
             "items": {
               "type": "object",
               "required": [
+                "first_node_id",
                 "blinding",
                 "path"
               ],
               "additionalProperties": false,
               "properties": {
+                "first_node_id": {
+                  "type": "pubkey",
+                  "description": "the (presumably well-known) public key of the start of the path"
+                },
                 "blinding": {
                   "type": "pubkey",
                   "description": "blinding factor for this path"
@@ -146,12 +151,12 @@
                   "items": {
                     "type": "object",
                     "required": [
-                      "node_id",
+                      "blinded_node_id",
                       "encrypted_recipient_data"
                     ],
                     "additionalProperties": false,
                     "properties": {
-                      "node_id": {
+                      "blinded_node_id": {
                         "type": "pubkey",
                         "description": "node_id of the hop"
                       },
@@ -330,7 +335,7 @@
           },
           "signature": {
             "type": "bip340sig",
-            "description": "BIP-340 signature of the *node_id* on this offer"
+            "description": "BIP-340 signature of the *node_id* on this invoice"
           },
           "chain": {
             "type": "hex",
@@ -373,11 +378,16 @@
             "items": {
               "type": "object",
               "required": [
+                "first_node_id",
                 "blinding",
                 "path"
               ],
               "additionalProperties": false,
               "properties": {
+                "first_node_id": {
+                  "type": "pubkey",
+                  "description": "the (presumably well-known) public key of the start of the path"
+                },
                 "blinding": {
                   "type": "pubkey",
                   "description": "blinding factor for this path"
@@ -388,18 +398,34 @@
                   "items": {
                     "type": "object",
                     "required": [
-                      "node_id",
+                      "blinded_node_id",
                       "encrypted_recipient_data"
                     ],
                     "additionalProperties": false,
                     "properties": {
-                      "node_id": {
+                      "blinded_node_id": {
                         "type": "pubkey",
                         "description": "node_id of the hop"
                       },
                       "encrypted_recipient_data": {
                         "type": "hex",
                         "description": "encrypted TLV entry for this hop"
+                      },
+                      "fee_base_msat": {
+                        "type": "msat",
+                        "description": "base fee for the entire path"
+                      },
+                      "fee_proportional_millionths": {
+                        "type": "u32",
+                        "description": "proportional fee for the entire path"
+                      },
+                      "cltv_expiry_delta": {
+                        "type": "u32",
+                        "description": "total CLTV delta across path"
+                      },
+                      "features": {
+                        "type": "hex",
+                        "description": "Features allowed/required for this path"
                       }
                     }
                   }

plugins/offers.c

@@ -254,6 +254,7 @@ static bool json_add_blinded_paths(struct json_stream *js,
 	json_array_start(js, "paths");
 	for (size_t i = 0; i < tal_count(paths); i++) {
 		json_object_start(js, NULL);
+		json_add_pubkey(js, "first_node_id", &paths[i]->first_node_id);
 		json_add_pubkey(js, "blinding", &paths[i]->blinding);
 		json_array_start(js, "path");
 		for (size_t j = 0; j < tal_count(paths[i]->path); j++) {