Adding a mirror node update section to HIP-869 (#1026)

HIP/hip-869.md

@@ -11,7 +11,7 @@ status: Accepted
 last-call-date-time: 2023-02-14T07:00:00Z
 created: 2024-01-22 
 discussions-to: https://github.com/hashgraph/hedera-improvement-proposal/pull/869
-updated: 2024-07-31
+updated: 2024-08-19
 ---
 
 ## Abstract
@@ -563,6 +563,61 @@ When executing the next `freeze` transaction with `freeze_type` set to `PREPARE_
 
 All HIPs that introduce backward incompatibilities must include a section describing these incompatibilities and their severity. The HIP must explain how the author proposes to deal with these incompatibilities. HIP submissions without a sufficient backward compatibility treatise may be rejected outright.
 
+### Mirror node update
+The mirror node will process the new Node transactions and service_endpoint information, then return that information through its existing APIs.
+
+The following changes will be made to the GRPC API:
+- Update the network service to add `domain_name` and `admin_key`.
+
+The following changes will be made to the REST API:
+- Update the `/api/v1/network/nodes` endpoint to return `domain_name` and `admin_key`
+
+Example response:
+
+```json
+{
+  "nodes": [
+    {
+      "admin_key": {
+        "_type": "ED25519",
+        "key": "308201a2300d06092a864886f70d01010105000382018f003082018a028100e0"
+      },
+      "description": "address book 1",
+      "file_id": "0.0.102",
+      "max_stake": 50000,
+      "memo": "0.0.4",
+      "min_stake": 1000,
+      "node_account_id": "0.0.4",
+      "node_cert_hash": "0x01d173753810c0aae794ba72d5443c292e9ff962b01046220dd99f5816422696e0569c977e2f169e1e5688afc8f4aa16",
+      "node_id": 1,
+      "public_key": "0x4a5ad514f0957fa170a676210c9bdbddf3bc9519702cf915fa6767a40463b96f",
+      "reward_rate_start": 1000000,
+      "service_endpoints": [
+        {
+          "domain_name": "examplenode.com",
+          "ip_address_v4": "128.0.0.6",
+          "port": 50216
+        }
+      ],
+      "stake": 20000,
+      "stake_not_rewarded": 19900,
+      "stake_rewarded": 100,
+      "staking_period": {
+        "from": "1655164800.000000000",
+        "to": "1655251200.000000000"
+      },
+      "timestamp": {
+        "from": "187654.000123457",
+        "to": null
+      }
+    }
+  ],
+  "links": {
+    "next": null
+  }
+}
+```
+
 ## Security Implications
 
 No security issues identified as of yet