List the user modes in the 004 reply (closes #220)

Both transports sent an empty string as the user modes in RPL_MYINFO.
On the IRC listener that left an empty parameter in the middle of the
line, so a client that splits on spaces read the channel modes as the
user modes. The reply now lists o and w, the user modes the server
supports. Both transports read them from one constant in
internal/service, next to the code that decides which user modes MODE
accepts. The README and the schema notes now show what the HTTP API
sends.

Model: opus-5-5

README.md

@@ -1236,7 +1236,7 @@ IRC listener sends the usual 3-digit code. Over the HTTP API, 005 arrives named
 | `001` | RPL_WELCOME          | After session creation or login, on MOTD | `{"command":"RPL_WELCOME","code":1,"to":"alice","body":["Welcome to the network, alice"]}`                                                                                                                   |
 | `002` | RPL_YOURHOST         | After session creation or login, on MOTD | `{"command":"RPL_YOURHOST","code":2,"to":"alice","body":["Your host is neoirc, running version 0.1"]}`                                                                                                       |
 | `003` | RPL_CREATED          | After session creation or login, on MOTD | `{"command":"RPL_CREATED","code":3,"to":"alice","body":["This server was created 2026-02-10"]}`                                                                                                              |
-| `004` | RPL_MYINFO           | After session creation or login, on MOTD | `{"command":"RPL_MYINFO","code":4,"to":"alice","params":["neoirc","0.1","","ikmnostl"]}`                                                                                                                     |
+| `004` | RPL_MYINFO           | After session creation or login, on MOTD | `{"command":"RPL_MYINFO","code":4,"to":"alice","params":["neoirc","0.1","ow","ikmnostl"]}`                                                                                                                   |
 | `005` | RPL_ISUPPORT         | After session creation or login, on MOTD | `{"command":"RPL_BOUNCE","code":5,"to":"alice","params":["CHANTYPES=#","NICKLEN=32","PREFIX=(ov)@+","CHANMODES=b,k,Hl,imnst","NETWORK=neoirc","CASEMAPPING=ascii"],"body":["are supported by this server"]}` |
 | `221` | RPL_UMODEIS          | In response to user MODE                 | `{"command":"RPL_UMODEIS","code":221,"to":"alice","body":["+"]}`                                                                                                                                             |
 | `251` | RPL_LUSERCLIENT      | On connect, MOTD or LUSERS               | `{"command":"RPL_LUSERCLIENT","code":251,"to":"alice","body":["There are 5 users and 0 invisible on 1 servers"]}`                                                                                            |

internal/handlers/api.go

@@ -412,7 +412,7 @@ func (hdlr *Handlers) deliverWelcome(
 	// 004 RPL_MYINFO
 	hdlr.enqueueNumeric(
 		ctx, clientID, irc.RplMyInfo, nick,
-		[]string{srvName, version, "", "ikmnostl"},
+		[]string{srvName, version, service.UserModes, "ikmnostl"},
 		"",
 	)
 

internal/handlers/api_test.go

@@ -6797,6 +6797,30 @@ func TestISUPPORT(t *testing.T) {
 	}
 }
 
+// TestMyInfoListsUserModes verifies the 004 numeric lists
+// the user modes o and w as its third parameter.
+func TestMyInfoListsUserModes(t *testing.T) {
+	t.Parallel()
+
+	tserver := newTestServer(t)
+	token := tserver.createSession("myinfo")
+
+	msgs, _ := tserver.pollMessages(token, 0)
+
+	myInfo := findNumericWithParams(msgs, "004")
+	if myInfo == nil {
+		t.Fatal("expected 004 RPL_MYINFO")
+	}
+
+	params := getNumericParams(myInfo)
+	if len(params) != 4 || params[2] != "ow" {
+		t.Fatalf(
+			"004 params %v, want four with user modes ow third",
+			params,
+		)
+	}
+}
+
 // TestNonOpCannotSetModes verifies non-operators
 // cannot set +i, +s, +k, +l, +b.
 func TestNonOpCannotSetModes(t *testing.T) {

internal/ircserver/conn.go

@@ -605,7 +605,7 @@ func (c *Conn) deliverWelcome() {
 	)
 	c.sendNumeric(
 		irc.RplMyInfo,
-		c.serverSfx, "neoirc", "", "mnst",
+		c.serverSfx, "neoirc", service.UserModes, "mnst",
 	)
 	c.sendNumeric(
 		irc.RplIsupport,

internal/ircserver/server_test.go

@@ -486,6 +486,22 @@ func TestWelcomeContainsNick(t *testing.T) {
 	}
 }
 
+// TestMyInfoListsUserModes checks that RPL_MYINFO lists the
+// user modes o and w, with no empty parameter before the
+// channel modes.
+func TestMyInfoListsUserModes(t *testing.T) {
+	t.Parallel()
+
+	env := newTestEnv(t)
+	lines := env.dial(t).register("carol")
+
+	assertContains(
+		t, lines,
+		":test.irc 004 carol test.irc neoirc ow mnst",
+		"RPL_MYINFO with user modes",
+	)
+}
+
 func TestPingPong(t *testing.T) {
 	t.Parallel()
 

internal/service/service.go

@@ -1169,6 +1169,12 @@ func (s *Service) ApplyUserMode(
 	return s.QueryUserMode(ctx, sessionID)
 }
 
+// UserModes lists the user modes the server supports, as
+// RPL_MYINFO sends them: o (server operator) and w
+// (receives WALLOPS). parseUserModeString must accept the
+// same letters.
+const UserModes = "ow"
+
 // parseUserModeString parses a user mode string such as
 // "+w", "-o" or "+w-o" into the new value of each flag it
 // names, or nil for a flag it does not name; a later letter

schema/README.md

@@ -144,8 +144,8 @@ Where a schema file and the HTTP API disagree, the HTTP API is right:
   with `ERR_NEEDMOREPARAMS` (`461`). A `body` of `[""]` clears the topic.
 - `003.json` describes the server's creation date. The HTTP API sends the date
   the server last started.
-- `004.json` has example mode lists. The HTTP API sends an empty string as the
-  user modes and `ikmnostl` as the channel modes.
+- `004.json` has example mode lists. The HTTP API sends `ow` as the user modes
+  and `ikmnostl` as the channel modes.
 - `322.json` says `LIST` gets one reply per channel. The server leaves out a
   secret channel, one with mode `+s`, unless the user is on it.
 - `332.json` says `RPL_TOPIC` answers a `TOPIC` query. The HTTP API has no such