Bump protocol to v9 and carry talk-circle ids on the presence frame.

Names stay off the wire; a person not in a circle writes an empty member list and topic.

Co-authored-by: Cursor <cursoragent@cursor.com>

docs/protocol.md

@@ -1,4 +1,4 @@
-# Wire protocol v8
+# Wire protocol v9
 
 The client talks to the server two ways:
 
@@ -308,6 +308,9 @@ grid fetches `GET .../timetable?classId=` with it.
 
 `activity` is the ActionDef name currently in progress, or `null` when idle. `activityLabel`
 is that def in the request locale. HTTP JSON is additive — no protocol version bump.
+`talkCircleMemberIds` is the live circle (including self, sorted) or `[]`; `talkTopicId` is the
+topic def id or `null` when not talking. Same ids as the presence frame; names are not repeated
+here either — the Now tab uses the directory and locale, like the location panel.
 
 `skills` lists only keys the person has, not every `SkillDef` in the catalog. A first-year has
 no Chemistry; a related tongue from the name set may sit beside the native at a low value.
@@ -347,6 +350,8 @@ The client does not compute thresholds. There is no school-wide opinions endpoin
   "needs": [{ "id": "Sleep", "label": "Сон", "value": 1 }],
   "activity": null,
   "activityLabel": null,
+  "talkCircleMemberIds": [],
+  "talkTopicId": null,
   "family": {
     "parents": [{ "id": "f0.p1", "fullName": "Иванова Ольга Михайловна", "female": true }],
     "children": [],
@@ -972,6 +977,12 @@ Each person:
 | string | person id |
 | string | node id they occupy |
 | `u8` | `1` here, `2` walking |
+| `u8` | talk-circle member count, then that many person-id strings |
+| string | topic id (empty when not in a circle) |
+
+Member ids are the live circle, including self, sorted by id. Count `0` and an empty topic mean
+the person is not talking — the same id/node/state as before the circle fields. Names are not
+on this frame; the client builds «говорит с Машей о футболе» from the HTTP directory and locale.
 
 ## Guarantees and limits
 
@@ -986,7 +997,7 @@ Each person:
   the oldest, because a stale clock is worthless once a newer one exists.
 - The map snapshot and presence use a separate reliable queue so ticks cannot crowd them out.
 
-## Not in v8 yet
+## Not in v9 yet
 
 Authentication, Sit orders, an event log, walk animation, and `OpenLocation` on the server —
 the tree and the location panel are filtered on the client from the snapshot plus presence.

src/HSchool.Client/src/net/protocol.test.ts

@@ -262,7 +262,9 @@ describe('decodeServerMessage', () => {
         + 2
         + 2 + personId.length
         + 2 + personNode.length
-        + 1,
+        + 1
+        + 1
+        + 2,
     );
     const view = new DataView(buffer);
     view.setUint8(0, MessageType.ServerPresence);
@@ -296,6 +298,10 @@ describe('decodeServerMessage', () => {
     new Uint8Array(buffer).set(personNode, offset);
     offset += personNode.length;
     view.setUint8(offset, PresenceState.Here);
+    offset += 1;
+    view.setUint8(offset, 0);
+    offset += 1;
+    view.setUint16(offset, 0, true);
 
     expect(decodeServerMessage(buffer)).toEqual({
       type: 'presence',
@@ -308,7 +314,123 @@ describe('decodeServerMessage', () => {
           activityClass: '5А',
         },
       ],
-      people: [{ id: 'f0.c0', nodeId: 'classroom-101', state: PresenceState.Here }],
+      people: [
+        {
+          id: 'f0.c0',
+          nodeId: 'classroom-101',
+          state: PresenceState.Here,
+          talkMemberIds: [],
+          talkTopicId: '',
+        },
+      ],
+    });
+  });
+
+  it('reads a presence person with talk-circle member ids and topic id', () => {
+    const encoder = new TextEncoder();
+    const putString = (target: DataView, at: number, text: Uint8Array): number => {
+      target.setUint16(at, text.length, true);
+      new Uint8Array(target.buffer).set(text, at + 2);
+      return at + 2 + text.length;
+    };
+
+    const corridor = encoder.encode('corridor-1');
+    const selfId = encoder.encode('f0.c0');
+    const partnerId = encoder.encode('f0.c1');
+    const topic = encoder.encode('TopicSport');
+    const buffer = new ArrayBuffer(
+      7
+        + 2
+        + 2
+        + 2 + selfId.length
+        + 2 + corridor.length
+        + 1
+        + 1
+        + 2 + selfId.length
+        + 2 + partnerId.length
+        + 2 + topic.length,
+    );
+    const view = new DataView(buffer);
+    view.setUint8(0, MessageType.ServerPresence);
+    view.setInt32(1, 1, true);
+    view.setUint16(5, 0, true);
+    view.setUint16(7, 1, true);
+    let offset = 9;
+    offset = putString(view, offset, selfId);
+    offset = putString(view, offset, corridor);
+    view.setUint8(offset, PresenceState.Here);
+    offset += 1;
+    view.setUint8(offset, 2);
+    offset += 1;
+    offset = putString(view, offset, selfId);
+    offset = putString(view, offset, partnerId);
+    putString(view, offset, topic);
+
+    expect(decodeServerMessage(buffer)).toEqual({
+      type: 'presence',
+      schoolId: 1,
+      nodes: [],
+      people: [
+        {
+          id: 'f0.c0',
+          nodeId: 'corridor-1',
+          state: PresenceState.Here,
+          talkMemberIds: ['f0.c0', 'f0.c1'],
+          talkTopicId: 'TopicSport',
+        },
+      ],
+    });
+  });
+
+  it('does not carry a person display name in a presence frame', () => {
+    const encoder = new TextEncoder();
+    const putString = (target: DataView, at: number, text: Uint8Array): number => {
+      target.setUint16(at, text.length, true);
+      new Uint8Array(target.buffer).set(text, at + 2);
+      return at + 2 + text.length;
+    };
+
+    const corridor = encoder.encode('corridor-1');
+    const selfId = encoder.encode('f0.c0');
+    const topic = encoder.encode('TopicSport');
+    const buffer = new ArrayBuffer(
+      7 + 2 + 2 + selfId.length + 2 + corridor.length + 1 + 1 + 2 + selfId.length + 2 + topic.length,
+    );
+    const view = new DataView(buffer);
+    view.setUint8(0, MessageType.ServerPresence);
+    view.setInt32(1, 1, true);
+    view.setUint16(5, 0, true);
+    view.setUint16(7, 1, true);
+    let offset = 9;
+    offset = putString(view, offset, selfId);
+    offset = putString(view, offset, corridor);
+    view.setUint8(offset, PresenceState.Here);
+    offset += 1;
+    view.setUint8(offset, 1);
+    offset += 1;
+    offset = putString(view, offset, selfId);
+    putString(view, offset, topic);
+
+    const bytes = new Uint8Array(buffer);
+    const text = new TextDecoder().decode(bytes);
+    expect(text).not.toContain('Мария');
+    expect(text).not.toContain('Иванова');
+    expect(text).not.toContain('Маша');
+    expect(text).toContain('f0.c0');
+    expect(text).toContain('TopicSport');
+    expect(decodeServerMessage(buffer)).toEqual({
+      type: 'presence',
+      schoolId: 1,
+      nodes: [],
+      people: [
+        {
+          id: 'f0.c0',
+          nodeId: 'corridor-1',
+          state: PresenceState.Here,
+          talkMemberIds: ['f0.c0'],
+          talkTopicId: 'TopicSport',
+        },
+      ],
     });
   });
 

src/HSchool.Client/src/net/protocol.ts

@@ -5,7 +5,7 @@
  * changed together and documented in `docs/protocol.md`. All numbers are little-endian.
  */
 
-export const PROTOCOL_VERSION = 8;
+export const PROTOCOL_VERSION = 9;
 
 export const MessageType = {
   ClientHello: 0x01,
@@ -122,6 +122,8 @@ export interface PresencePerson {
   readonly id: string;
   readonly nodeId: string;
   readonly state: number;
+  readonly talkMemberIds: readonly string[];
+  readonly talkTopicId: string;
 }
 
 export interface PresenceMessage {
@@ -375,7 +377,24 @@ function decodePresence(view: DataView): PresenceMessage {
     offset = nodeId.next;
     const state = readU8(view, offset);
     offset += 1;
-    people.push({ id: id.text, nodeId: nodeId.text, state });
+    const memberCount = readU8(view, offset);
+    offset += 1;
+    const talkMemberIds: string[] = [];
+    for (let member = 0; member < memberCount; member++) {
+      const memberId = readString(view, offset);
+      offset = memberId.next;
+      talkMemberIds.push(memberId.text);
+    }
+
+    const topic = readString(view, offset);
+    offset = topic.next;
+    people.push({
+      id: id.text,
+      nodeId: nodeId.text,
+      state,
+      talkMemberIds,
+      talkTopicId: topic.text,
+    });
   }
 
   return { type: 'presence', schoolId, nodes, people };

src/HSchool.Protocol/Messages.cs

@@ -98,8 +98,22 @@ public sealed record PresenceNode(
     string ActivitySubject = "",
     string ActivityClass = "");
 
-/// <summary>One on-campus person. Names are resolved over HTTP, not on this frame.</summary>
-public sealed record PresencePerson(string Id, string NodeId, byte State);
+/// <summary>
+/// One on-campus person. Names are resolved over HTTP, not on this frame. Talk members and
+/// topic are ids; an empty list means the person is not in a circle.
+/// </summary>
+public sealed record PresencePerson(
+    string Id,
+    string NodeId,
+    byte State,
+    IReadOnlyList<string> TalkMemberIds,
+    string TalkTopicId)
+{
+    public PresencePerson(string id, string nodeId, byte state)
+        : this(id, nodeId, state, [], "")
+    {
+    }
+}
 
 /// <summary>
 /// Live occupancy of an open school, about twice a second. Counts and people cover the whole

src/HSchool.Protocol/ProtocolCodec.cs

@@ -202,6 +202,14 @@ public static class ProtocolCodec
         foreach (var person in message.People)
         {
             size += StringSize(person.Id) + StringSize(person.NodeId) + sizeof(byte);
+            var members = person.TalkMemberIds ?? [];
+            size += sizeof(byte);
+            foreach (var memberId in members)
+            {
+                size += StringSize(memberId);
+            }
+
+            size += StringSize(person.TalkTopicId ?? "");
         }
 
         return size;
@@ -242,9 +250,22 @@ public static class ProtocolCodec
         writer.WriteUInt16((ushort)message.People.Count);
         foreach (var person in message.People)
         {
+            var members = person.TalkMemberIds ?? [];
+            if (members.Count > byte.MaxValue)
+            {
+                throw new ProtocolException($"Presence person {person.Id} has {members.Count} talk members; u8 count cannot hold it.");
+            }
+
             writer.WriteString(person.Id);
             writer.WriteString(person.NodeId);
             writer.WriteByte(person.State);
+            writer.WriteByte((byte)members.Count);
+            foreach (var memberId in members)
+            {
+                writer.WriteString(memberId);
+            }
+
+            writer.WriteString(person.TalkTopicId ?? "");
         }
 
         return writer.Position;
@@ -403,7 +424,18 @@ public static class ProtocolCodec
         var people = new PresencePerson[personCount];
         for (var i = 0; i < personCount; i++)
         {
-            people[i] = new PresencePerson(reader.ReadString(), reader.ReadString(), reader.ReadByte());
+            var id = reader.ReadString();
+            var nodeId = reader.ReadString();
+            var state = reader.ReadByte();
+            var memberCount = reader.ReadByte();
+            var members = new string[memberCount];
+            for (var member = 0; member < memberCount; member++)
+            {
+                members[member] = reader.ReadString();
+            }
+
+            var topicId = reader.ReadString();
+            people[i] = new PresencePerson(id, nodeId, state, members, topicId);
         }
 
         return new ServerPresenceMessage(schoolId, nodes, people);

src/HSchool.Protocol/ProtocolConstants.cs

@@ -4,7 +4,7 @@ namespace HSchool.Protocol;
 public static class ProtocolConstants
 {
     /// <summary>Bumped on every breaking change to the binary layout.</summary>
-    public const byte Version = 8;
+    public const byte Version = 9;
 
     /// <summary>Upper bound for a single WebSocket frame accepted by the server.</summary>
     public const int MaxMessageSize = 8 * 1024;

tests/HSchool.Protocol.Tests/ProtocolCodecTests.cs

@@ -246,7 +246,120 @@ public class ProtocolCodecTests
         Assert.Equal("f0.c0", read.People[0].Id);
         Assert.Equal("classroom-101", read.People[0].NodeId);
         Assert.Equal(PresenceState.Here, read.People[0].State);
+        Assert.Empty(read.People[0].TalkMemberIds);
+        Assert.Equal("", read.People[0].TalkTopicId);
         Assert.Equal(PresenceState.Walking, read.People[1].State);
+        Assert.Empty(read.People[1].TalkMemberIds);
+    }
+
+    [Fact]
+    public void Presence_PersonWithoutCircle_WritesEmptyMemberListAndEmptyTopic()
+    {
+        var message = new ServerPresenceMessage(
+            1,
+            [],
+            [new PresencePerson("f0.c0", "corridor-1", PresenceState.Here)]);
+        var buffer = new byte[ProtocolCodec.PresenceSize(message)];
+
+        var length = ProtocolCodec.WritePresence(buffer, message);
+
+        Assert.Equal((byte)MessageType.ServerPresence, buffer[0]);
+        Assert.Equal(1, BitConverter.ToInt32(buffer.AsSpan(1, 4)));
+        Assert.Equal((ushort)0, BitConverter.ToUInt16(buffer.AsSpan(5, 2)));
+        Assert.Equal((ushort)1, BitConverter.ToUInt16(buffer.AsSpan(7, 2)));
+
+        var offset = 9;
+        offset = AssertWireString(buffer, offset, "f0.c0");
+        offset = AssertWireString(buffer, offset, "corridor-1");
+        Assert.Equal(PresenceState.Here, buffer[offset]);
+        offset += 1;
+        Assert.Equal(0, buffer[offset]);
+        offset += 1;
+        offset = AssertWireString(buffer, offset, "");
+        Assert.Equal(length, offset);
+        Assert.Equal(length, ProtocolCodec.PresenceSize(message));
+
+        var read = ProtocolCodec.ReadPresence(buffer.AsSpan(0, length));
+        Assert.Empty(read.People[0].TalkMemberIds);
+        Assert.Equal("", read.People[0].TalkTopicId);
+        Assert.Equal(message.People[0].Id, read.People[0].Id);
+        Assert.Equal(message.People[0].NodeId, read.People[0].NodeId);
+        Assert.Equal(message.People[0].State, read.People[0].State);
+    }
+
+    [Fact]
+    public void Presence_PersonWithCircle_RoundTripsMemberIdsAndTopic()
+    {
+        var members = new[] { "f0.c0", "f0.c1" };
+        var message = new ServerPresenceMessage(
+            1,
+            [new PresenceNode("corridor-1", 2)],
+            [new PresencePerson("f0.c0", "corridor-1", PresenceState.Here, members, "TopicSport")]);
+        var buffer = new byte[ProtocolCodec.PresenceSize(message)];
+
+        var length = ProtocolCodec.WritePresence(buffer, message);
+
+        Assert.Equal((byte)MessageType.ServerPresence, buffer[0]);
+        Assert.Equal(1, BitConverter.ToInt32(buffer.AsSpan(1, 4)));
+        Assert.Equal((ushort)1, BitConverter.ToUInt16(buffer.AsSpan(5, 2)));
+
+        var offset = 7;
+        offset = AssertWireString(buffer, offset, "corridor-1");
+        Assert.Equal((ushort)2, BitConverter.ToUInt16(buffer.AsSpan(offset, 2)));
+        offset += 2;
+        Assert.Equal(0, buffer[offset]);
+        offset += 1;
+        Assert.Equal((ushort)1, BitConverter.ToUInt16(buffer.AsSpan(offset, 2)));
+        offset += 2;
+        offset = AssertWireString(buffer, offset, "f0.c0");
+        offset = AssertWireString(buffer, offset, "corridor-1");
+        Assert.Equal(PresenceState.Here, buffer[offset]);
+        offset += 1;
+        Assert.Equal(2, buffer[offset]);
+        offset += 1;
+        offset = AssertWireString(buffer, offset, "f0.c0");
+        offset = AssertWireString(buffer, offset, "f0.c1");
+        offset = AssertWireString(buffer, offset, "TopicSport");
+        Assert.Equal(length, offset);
+        Assert.Equal(length, ProtocolCodec.PresenceSize(message));
+
+        var read = ProtocolCodec.ReadPresence(buffer.AsSpan(0, length));
+        Assert.Equal(["f0.c0", "f0.c1"], read.People[0].TalkMemberIds);
+        Assert.Equal("TopicSport", read.People[0].TalkTopicId);
+        Assert.Equal(message.SchoolId, read.SchoolId);
+        Assert.Equal(message.People[0].Id, read.People[0].Id);
+    }
+
+    [Fact]
+    public void Presence_DoesNotContainPersonDisplayName()
+    {
+        var message = new ServerPresenceMessage(
+            1,
+            [],
+            [new PresencePerson(
+                "f0.c0",
+                "corridor-1",
+                PresenceState.Here,
+                ["f0.c0", "f0.c1"],
+                "TopicSport")]);
+        var buffer = new byte[ProtocolCodec.PresenceSize(message)];
+
+        ProtocolCodec.WritePresence(buffer, message);
+        var text = System.Text.Encoding.UTF8.GetString(buffer);
+
+        Assert.DoesNotContain("Мария", text);
+        Assert.DoesNotContain("Иванова", text);
+        Assert.DoesNotContain("Маша", text);
+        Assert.Contains("f0.c0", text);
+        Assert.Contains("TopicSport", text);
+    }
+
+    private static int AssertWireString(byte[] buffer, int offset, string expected)
+    {
+        var bytes = System.Text.Encoding.UTF8.GetBytes(expected);
+        Assert.Equal((ushort)bytes.Length, BitConverter.ToUInt16(buffer.AsSpan(offset, 2)));
+        Assert.Equal(bytes, buffer.AsSpan(offset + 2, bytes.Length).ToArray());
+        return offset + 2 + bytes.Length;
     }
 
     [Fact]