docs: document ?replay=1 query parameter for GET /state

When a client reconnects to an existing session (e.g. browser tab
closed and reopened), the server now enqueues synthetic JOIN messages
plus TOPIC/NAMES numerics for every channel the session belongs to.
These are delivered only to the reconnecting client, not broadcast
to other users.

Server changes:
- Add replayChannelState() to handlers that enqueues per-channel
  JOIN + join-numerics (332/353/366) to a specific client.
- HandleState accepts ?replay=1 query parameter to trigger replay.
- HandleLogin (password auth) also replays channel state for the
  new client since it creates a fresh client for an existing session.

SPA changes:
- On resume, call /state?replay=1 instead of /state so the server
  enqueues channel state into the message queue.
- processMessage now creates channel tabs when receiving a JOIN
  where msg.from matches the current nick (handles both live joins
  and replayed joins on reconnect).
- onLogin no longer re-sends JOIN commands for saved channels on
  resume — the server handles it via the replay mechanism, avoiding
  spurious JOIN broadcasts to other channel members.

Closes #60

README.md

@@ -845,10 +845,11 @@ the server to the client (never C2S) and use 3-digit string codes in the
 | `442` | ERR_NOTONCHANNEL    | Action on unjoined channel | `{"command":"442","to":"alice","params":["#general"],"body":["You're not on that channel"]}` |
 | `482` | ERR_CHANOPRIVSNEEDED | Non-op tries op action | `{"command":"482","to":"alice","params":["#general"],"body":["You're not channel operator"]}` |
 
-**Note:** Numeric replies are planned for full implementation. The current MVP
-returns standard HTTP error responses (4xx/5xx with JSON error bodies) instead
-of numeric replies for error conditions. Numeric replies in the message queue
-will be added post-MVP.
+**Note:** Numeric replies are now implemented. All IRC command responses
+(success and error) are delivered as numeric replies through the message queue.
+HTTP error codes are reserved for transport-level issues (auth failures,
+malformed requests, server errors). The `params` field in the message envelope
+carries IRC-style parameters (e.g., channel name, target nick).
 
 ### Channel Modes
 
@@ -936,6 +937,12 @@ Return the current user's session state.
 
 **Request:** No body. Requires auth.
 
+**Query Parameters:**
+
+| Parameter | Type   | Default | Description |
+|-----------|--------|---------|-------------|
+| `replay`  | string | (none)  | When set to `1`, enqueues synthetic JOIN + TOPIC + NAMES messages for every channel the session belongs to into the calling client's queue. Used by the SPA on reconnect to restore channel tabs without re-sending JOIN commands. |
+
 **Response:** `200 OK`
 ```json
 {
@@ -968,6 +975,12 @@ curl -s http://localhost:8080/api/v1/state \
   -H "Authorization: Bearer $TOKEN" | jq .
 ```
 
+**Reconnect with channel replay:**
+```bash
+curl -s "http://localhost:8080/api/v1/state?replay=1" \
+  -H "Authorization: Bearer $TOKEN" | jq .
+```
+
 ### GET /api/v1/messages — Poll Messages (Long-Poll)
 
 Retrieve messages from the client's delivery queue. This is the primary
@@ -1054,8 +1067,8 @@ reference with all required and optional fields.
 
 | Command   | Required Fields     | Optional      | Response Status |
 |-----------|---------------------|---------------|-----------------|
-| `PRIVMSG` | `to`, `body`        | `meta`        | 201 Created     |
-| `NOTICE`  | `to`, `body`        | `meta`        | 201 Created     |
+| `PRIVMSG` | `to`, `body`        | `meta`        | 200 OK          |
+| `NOTICE`  | `to`, `body`        | `meta`        | 200 OK          |
 | `JOIN`    | `to`                |               | 200 OK          |
 | `PART`    | `to`                | `body`        | 200 OK          |
 | `NICK`    | `body`              |               | 200 OK          |
@@ -1063,18 +1076,44 @@ reference with all required and optional fields.
 | `QUIT`    |                     | `body`        | 200 OK          |
 | `PING`    |                     |               | 200 OK          |
 
-**Errors (all commands):**
+All IRC commands return HTTP 200 OK. IRC-level success and error responses
+are delivered as **numeric replies** through the message queue (see
+[Numeric Replies](#numeric-replies) below). HTTP error codes (4xx/5xx) are
+reserved for transport-level problems: malformed JSON (400), missing/invalid
+auth tokens (401), and server errors (500).
+
+**HTTP errors (transport-level only):**
 
 | Status | Error | When |
 |--------|-------|------|
-| 400    | `invalid request` | Malformed JSON |
-| 400    | `to field required` | Missing `to` for commands that need it |
-| 400    | `body required` | Missing `body` for commands that need it |
-| 400    | `unknown command: X` | Unrecognized command |
+| 400    | `invalid request` | Malformed JSON or empty command |
 | 401    | `unauthorized` | Missing or invalid auth token |
-| 404    | `channel not found` | Target channel doesn't exist |
-| 404    | `user not found` | DM target nick doesn't exist |
-| 409    | `nick already in use` | NICK target is taken |
+| 500    | `internal error` | Server-side failure |
+
+**IRC numeric error replies (delivered via message queue):**
+
+| Numeric | Name | When |
+|---------|------|------|
+| 401     | ERR_NOSUCHNICK | DM target nick doesn't exist |
+| 403     | ERR_NOSUCHCHANNEL | Target channel doesn't exist or invalid name |
+| 421     | ERR_UNKNOWNCOMMAND | Unrecognized command |
+| 432     | ERR_ERRONEUSNICKNAME | Invalid nickname format |
+| 433     | ERR_NICKNAMEINUSE | NICK target is taken |
+| 442     | ERR_NOTONCHANNEL | Not a member of the target channel |
+| 461     | ERR_NEEDMOREPARAMS | Missing required fields (to, body) |
+
+**IRC numeric success replies (delivered via message queue):**
+
+| Numeric | Name | When |
+|---------|------|------|
+| 001     | RPL_WELCOME | Sent on session creation/login |
+| 331     | RPL_NOTOPIC | Channel has no topic (on JOIN) |
+| 332     | RPL_TOPIC | Channel topic (on JOIN, TOPIC set) |
+| 353     | RPL_NAMREPLY | Channel member list (on JOIN) |
+| 366     | RPL_ENDOFNAMES | End of NAMES list (on JOIN) |
+| 375     | RPL_MOTDSTART | Start of MOTD |
+| 372     | RPL_MOTD | MOTD line |
+| 376     | RPL_ENDOFMOTD | End of MOTD |
 
 ### GET /api/v1/history — Message History
 

cmd/neoirc-cli/main.go

@@ -138,16 +138,29 @@ func (a *App) dispatchCommand(cmd, args string) {
 		a.cmdQuery(args)
 	case "/topic":
 		a.cmdTopic(args)
-	case "/names":
-		a.cmdNames()
-	case "/list":
-		a.cmdList()
 	case "/window", "/w":
 		a.cmdWindow(args)
 	case "/quit":
 		a.cmdQuit()
 	case "/help":
 		a.cmdHelp()
+	default:
+		a.dispatchInfoCommand(cmd, args)
+	}
+}
+
+func (a *App) dispatchInfoCommand(cmd, args string) {
+	switch cmd {
+	case "/names":
+		a.cmdNames()
+	case "/list":
+		a.cmdList()
+	case "/motd":
+		a.cmdMotd()
+	case "/who":
+		a.cmdWho(args)
+	case "/whois":
+		a.cmdWhois(args)
 	default:
 		a.ui.AddStatus(
 			"[red]Unknown command: " + cmd,
@@ -510,6 +523,96 @@ func (a *App) cmdList() {
 	a.ui.AddStatus("[cyan]*** End of channel list")
 }
 
+func (a *App) cmdMotd() {
+	a.mu.Lock()
+	connected := a.connected
+	a.mu.Unlock()
+
+	if !connected {
+		a.ui.AddStatus("[red]Not connected")
+
+		return
+	}
+
+	err := a.client.SendMessage(
+		&api.Message{Command: "MOTD"}, //nolint:exhaustruct
+	)
+	if err != nil {
+		a.ui.AddStatus(fmt.Sprintf(
+			"[red]MOTD failed: %v", err,
+		))
+	}
+}
+
+func (a *App) cmdWho(args string) {
+	a.mu.Lock()
+	connected := a.connected
+	target := a.target
+	a.mu.Unlock()
+
+	if !connected {
+		a.ui.AddStatus("[red]Not connected")
+
+		return
+	}
+
+	channel := args
+	if channel == "" {
+		channel = target
+	}
+
+	if channel == "" ||
+		!strings.HasPrefix(channel, "#") {
+		a.ui.AddStatus(
+			"[red]Usage: /who #channel",
+		)
+
+		return
+	}
+
+	err := a.client.SendMessage(
+		&api.Message{ //nolint:exhaustruct
+			Command: "WHO", To: channel,
+		},
+	)
+	if err != nil {
+		a.ui.AddStatus(fmt.Sprintf(
+			"[red]WHO failed: %v", err,
+		))
+	}
+}
+
+func (a *App) cmdWhois(args string) {
+	a.mu.Lock()
+	connected := a.connected
+	a.mu.Unlock()
+
+	if !connected {
+		a.ui.AddStatus("[red]Not connected")
+
+		return
+	}
+
+	if args == "" {
+		a.ui.AddStatus(
+			"[red]Usage: /whois <nick>",
+		)
+
+		return
+	}
+
+	err := a.client.SendMessage(
+		&api.Message{ //nolint:exhaustruct
+			Command: "WHOIS", To: args,
+		},
+	)
+	if err != nil {
+		a.ui.AddStatus(fmt.Sprintf(
+			"[red]WHOIS failed: %v", err,
+		))
+	}
+}
+
 func (a *App) cmdWindow(args string) {
 	if args == "" {
 		a.ui.AddStatus(
@@ -574,6 +677,9 @@ func (a *App) cmdHelp() {
 		"  /topic [text]   — View/set topic",
 		"  /names          — List channel members",
 		"  /list           — List channels",
+		"  /who [#channel] — List users in channel",
+		"  /whois <nick>   — Show user info",
+		"  /motd           — Show message of the day",
 		"  /window <n>     — Switch buffer",
 		"  /quit           — Disconnect and exit",
 		"  /help           — This help",

internal/config/config.go

@@ -13,6 +13,14 @@ import (
 	_ "github.com/joho/godotenv/autoload" // loads .env file
 )
 
+const defaultMOTD = ` _ __   ___  ___  (_)_ __ ___
+| '_ \ / _ \/ _ \ | | '__/ __|
+| | | |  __/ (_) || | | | (__
+|_| |_|\___|\___/ |_|_|  \___|
+
+Welcome to NeoIRC — IRC semantics over HTTP.
+Type /help for available commands.`
+
 // Params defines the dependencies for creating a Config.
 type Params struct {
 	fx.In
@@ -62,7 +70,7 @@ func New(
 	viper.SetDefault("METRICS_PASSWORD", "")
 	viper.SetDefault("MAX_HISTORY", "10000")
 	viper.SetDefault("MAX_MESSAGE_SIZE", "4096")
-	viper.SetDefault("MOTD", "")
+	viper.SetDefault("MOTD", defaultMOTD)
 	viper.SetDefault("SERVER_NAME", "")
 	viper.SetDefault("FEDERATION_KEY", "")
 	viper.SetDefault("SESSION_IDLE_TIMEOUT", "24h")

internal/db/queries.go

@@ -35,6 +35,7 @@ type IRCMessage struct {
 	Command string          `json:"command"`
 	From    string          `json:"from,omitempty"`
 	To      string          `json:"to,omitempty"`
+	Params  json.RawMessage `json:"params,omitempty"`
 	Body    json.RawMessage `json:"body,omitempty"`
 	TS      string          `json:"ts"`
 	Meta    json.RawMessage `json:"meta,omitempty"`
@@ -491,12 +492,17 @@ func (database *Database) GetSessionChannelIDs(
 func (database *Database) InsertMessage(
 	ctx context.Context,
 	command, from, target string,
+	params json.RawMessage,
 	body json.RawMessage,
 	meta json.RawMessage,
 ) (int64, string, error) {
 	msgUUID := uuid.New().String()
 	now := time.Now().UTC()
 
+	if params == nil {
+		params = json.RawMessage("[]")
+	}
+
 	if body == nil {
 		body = json.RawMessage("[]")
 	}
@@ -508,10 +514,10 @@ func (database *Database) InsertMessage(
 	res, err := database.conn.ExecContext(ctx,
 		`INSERT INTO messages
 		 (uuid, command, msg_from, msg_to,
-		  body, meta, created_at)
-		 VALUES (?, ?, ?, ?, ?, ?, ?)`,
+		  params, body, meta, created_at)
+		 VALUES (?, ?, ?, ?, ?, ?, ?, ?)`,
 		msgUUID, command, from, target,
-		string(body), string(meta), now)
+		string(params), string(body), string(meta), now)
 	if err != nil {
 		return 0, "", fmt.Errorf(
 			"insert message: %w", err,
@@ -578,7 +584,7 @@ func (database *Database) PollMessages(
 	rows, err := database.conn.QueryContext(ctx,
 		`SELECT cq.id, m.uuid, m.command,
 		   m.msg_from, m.msg_to,
-		   m.body, m.meta, m.created_at
+		   m.params, m.body, m.meta, m.created_at
 		 FROM client_queues cq
 		 INNER JOIN messages m
 		   ON m.id = cq.message_id
@@ -642,7 +648,7 @@ func (database *Database) queryHistory(
 	if beforeID > 0 {
 		rows, err := database.conn.QueryContext(ctx,
 			`SELECT id, uuid, command, msg_from,
-			   msg_to, body, meta, created_at
+			   msg_to, params, body, meta, created_at
 			 FROM messages
 			 WHERE msg_to = ? AND id < ?
 			   AND command = 'PRIVMSG'
@@ -659,7 +665,7 @@ func (database *Database) queryHistory(
 
 	rows, err := database.conn.QueryContext(ctx,
 		`SELECT id, uuid, command, msg_from,
-		   msg_to, body, meta, created_at
+		   msg_to, params, body, meta, created_at
 		 FROM messages
 		 WHERE msg_to = ?
 		   AND command = 'PRIVMSG'
@@ -684,16 +690,16 @@ func scanMessages(
 
 	for rows.Next() {
 		var (
-			msg        IRCMessage
-			qID        int64
-			body, meta string
-			createdAt  time.Time
+			msg                IRCMessage
+			qID                int64
+			params, body, meta string
+			createdAt          time.Time
 		)
 
 		err := rows.Scan(
 			&qID, &msg.ID, &msg.Command,
 			&msg.From, &msg.To,
-			&body, &meta, &createdAt,
+			&params, &body, &meta, &createdAt,
 		)
 		if err != nil {
 			return nil, fallbackQID, fmt.Errorf(
@@ -701,6 +707,10 @@ func scanMessages(
 			)
 		}
 
+		if params != "" && params != "[]" {
+			msg.Params = json.RawMessage(params)
+		}
+
 		msg.Body = json.RawMessage(body)
 		msg.Meta = json.RawMessage(meta)
 		msg.TS = createdAt.Format(time.RFC3339Nano)

internal/db/queries_test.go

@@ -383,7 +383,7 @@ func TestInsertMessage(t *testing.T) {
 	body := json.RawMessage(`["hello"]`)
 
 	dbID, msgUUID, err := database.InsertMessage(
-		ctx, "PRIVMSG", "poller", "#test", body, nil,
+		ctx, "PRIVMSG", "poller", "#test", nil, body, nil,
 	)
 	if err != nil {
 		t.Fatal(err)
@@ -417,7 +417,7 @@ func TestPollMessages(t *testing.T) {
 	body := json.RawMessage(`["hello"]`)
 
 	dbID, _, err := database.InsertMessage(
-		ctx, "PRIVMSG", "poller", "#test", body, nil,
+		ctx, "PRIVMSG", "poller", "#test", nil, body, nil,
 	)
 	if err != nil {
 		t.Fatal(err)
@@ -475,7 +475,7 @@ func TestGetHistory(t *testing.T) {
 	for range msgCount {
 		_, _, err := database.InsertMessage(
 			ctx, "PRIVMSG", "user", "#hist",
-			json.RawMessage(`["msg"]`), nil,
+			nil, json.RawMessage(`["msg"]`), nil,
 		)
 		if err != nil {
 			t.Fatal(err)
@@ -627,7 +627,7 @@ func TestEnqueueToClient(t *testing.T) {
 	body := json.RawMessage(`["test"]`)
 
 	dbID, _, err := database.InsertMessage(
-		ctx, "PRIVMSG", "sender", "#ch", body, nil,
+		ctx, "PRIVMSG", "sender", "#ch", nil, body, nil,
 	)
 	if err != nil {
 		t.Fatal(err)

internal/db/schema/001_initial.sql

@@ -50,6 +50,7 @@ CREATE TABLE IF NOT EXISTS messages (
     command TEXT NOT NULL DEFAULT 'PRIVMSG',
     msg_from TEXT NOT NULL DEFAULT '',
     msg_to TEXT NOT NULL DEFAULT '',
+    params TEXT NOT NULL DEFAULT '[]',
     body TEXT NOT NULL DEFAULT '[]',
     meta TEXT NOT NULL DEFAULT '{}',
     created_at DATETIME DEFAULT CURRENT_TIMESTAMP

internal/handlers/api_test.go

@@ -462,6 +462,19 @@ func findMessage(
 	return false
 }
 
+func findNumeric(
+	msgs []map[string]any,
+	numeric string,
+) bool {
+	for _, msg := range msgs {
+		if msg[commandKey] == numeric {
+			return true
+		}
+	}
+
+	return false
+}
+
 // --- Tests ---
 
 func TestCreateSessionValid(t *testing.T) {
@@ -473,6 +486,47 @@ func TestCreateSessionValid(t *testing.T) {
 	}
 }
 
+func TestWelcomeNumeric(t *testing.T) {
+	tserver := newTestServer(t)
+	token := tserver.createSession("welcomer")
+
+	msgs, _ := tserver.pollMessages(token, 0)
+
+	if !findNumeric(msgs, "001") {
+		t.Fatalf(
+			"expected RPL_WELCOME (001), got %v",
+			msgs,
+		)
+	}
+}
+
+func TestJoinNumerics(t *testing.T) {
+	tserver := newTestServer(t)
+	token := tserver.createSession("jnumtest")
+
+	_, lastID := tserver.pollMessages(token, 0)
+
+	tserver.sendCommand(token, map[string]any{
+		commandKey: joinCmd, toKey: "#numtest",
+	})
+
+	msgs, _ := tserver.pollMessages(token, lastID)
+
+	if !findNumeric(msgs, "353") {
+		t.Fatalf(
+			"expected RPL_NAMREPLY (353), got %v",
+			msgs,
+		)
+	}
+
+	if !findNumeric(msgs, "366") {
+		t.Fatalf(
+			"expected RPL_ENDOFNAMES (366), got %v",
+			msgs,
+		)
+	}
+}
+
 func TestCreateSessionDuplicate(t *testing.T) {
 	tserver := newTestServer(t)
 	tserver.createSession("alice")
@@ -668,11 +722,23 @@ func TestJoinMissingTo(t *testing.T) {
 	tserver := newTestServer(t)
 	token := tserver.createSession("joiner3")
 
+	// Drain initial MOTD/welcome numerics.
+	_, lastID := tserver.pollMessages(token, 0)
+
 	status, _ := tserver.sendCommand(
 		token, map[string]any{commandKey: joinCmd},
 	)
-	if status != http.StatusBadRequest {
-		t.Fatalf("expected 400, got %d", status)
+	if status != http.StatusOK {
+		t.Fatalf("expected 200, got %d", status)
+	}
+
+	msgs, _ := tserver.pollMessages(token, lastID)
+
+	if !findNumeric(msgs, "461") {
+		t.Fatalf(
+			"expected ERR_NEEDMOREPARAMS (461), got %v",
+			msgs,
+		)
 	}
 }
 
@@ -699,9 +765,9 @@ func TestChannelMessage(t *testing.T) {
 			bodyKey:    []string{"hello world"},
 		},
 	)
-	if status != http.StatusCreated {
+	if status != http.StatusOK {
 		t.Fatalf(
-			"expected 201, got %d: %v", status, result,
+			"expected 200, got %d: %v", status, result,
 		)
 	}
 
@@ -728,11 +794,22 @@ func TestMessageMissingBody(t *testing.T) {
 		commandKey: joinCmd, toKey: "#test",
 	})
 
+	_, lastID := tserver.pollMessages(token, 0)
+
 	status, _ := tserver.sendCommand(token, map[string]any{
 		commandKey: privmsgCmd, toKey: "#test",
 	})
-	if status != http.StatusBadRequest {
-		t.Fatalf("expected 400, got %d", status)
+	if status != http.StatusOK {
+		t.Fatalf("expected 200, got %d", status)
+	}
+
+	msgs, _ := tserver.pollMessages(token, lastID)
+
+	if !findNumeric(msgs, "461") {
+		t.Fatalf(
+			"expected ERR_NEEDMOREPARAMS (461), got %v",
+			msgs,
+		)
 	}
 }
 
@@ -740,12 +817,23 @@ func TestMessageMissingTo(t *testing.T) {
 	tserver := newTestServer(t)
 	token := tserver.createSession("noto")
 
+	_, lastID := tserver.pollMessages(token, 0)
+
 	status, _ := tserver.sendCommand(token, map[string]any{
 		commandKey: privmsgCmd,
 		bodyKey:    []string{"hello"},
 	})
-	if status != http.StatusBadRequest {
-		t.Fatalf("expected 400, got %d", status)
+	if status != http.StatusOK {
+		t.Fatalf("expected 200, got %d", status)
+	}
+
+	msgs, _ := tserver.pollMessages(token, lastID)
+
+	if !findNumeric(msgs, "461") {
+		t.Fatalf(
+			"expected ERR_NEEDMOREPARAMS (461), got %v",
+			msgs,
+		)
 	}
 }
 
@@ -759,6 +847,8 @@ func TestNonMemberCannotSend(t *testing.T) {
 		commandKey: joinCmd, toKey: "#private",
 	})
 
+	_, lastID := tserver.pollMessages(aliceToken, 0)
+
 	// Alice tries to send without joining.
 	status, _ := tserver.sendCommand(
 		aliceToken,
@@ -768,8 +858,17 @@ func TestNonMemberCannotSend(t *testing.T) {
 			bodyKey:    []string{"sneaky"},
 		},
 	)
-	if status != http.StatusForbidden {
-		t.Fatalf("expected 403, got %d", status)
+	if status != http.StatusOK {
+		t.Fatalf("expected 200, got %d", status)
+	}
+
+	msgs, _ := tserver.pollMessages(aliceToken, lastID)
+
+	if !findNumeric(msgs, "442") {
+		t.Fatalf(
+			"expected ERR_NOTONCHANNEL (442), got %v",
+			msgs,
+		)
 	}
 }
 
@@ -786,9 +885,9 @@ func TestDirectMessage(t *testing.T) {
 			bodyKey:    []string{"hey bob"},
 		},
 	)
-	if status != http.StatusCreated {
+	if status != http.StatusOK {
 		t.Fatalf(
-			"expected 201, got %d: %v", status, result,
+			"expected 200, got %d: %v", status, result,
 		)
 	}
 
@@ -818,13 +917,24 @@ func TestDMToNonexistentUser(t *testing.T) {
 	tserver := newTestServer(t)
 	token := tserver.createSession("dmsender")
 
+	_, lastID := tserver.pollMessages(token, 0)
+
 	status, _ := tserver.sendCommand(token, map[string]any{
 		commandKey: privmsgCmd,
 		toKey:      "nobody",
 		bodyKey:    []string{"hello?"},
 	})
-	if status != http.StatusNotFound {
-		t.Fatalf("expected 404, got %d", status)
+	if status != http.StatusOK {
+		t.Fatalf("expected 200, got %d", status)
+	}
+
+	msgs, _ := tserver.pollMessages(token, lastID)
+
+	if !findNumeric(msgs, "401") {
+		t.Fatalf(
+			"expected ERR_NOSUCHNICK (401), got %v",
+			msgs,
+		)
 	}
 }
 
@@ -871,12 +981,23 @@ func TestNickCollision(t *testing.T) {
 
 	tserver.createSession("taken_nick")
 
+	_, lastID := tserver.pollMessages(token, 0)
+
 	status, _ := tserver.sendCommand(token, map[string]any{
 		commandKey: "NICK",
 		bodyKey:    []string{"taken_nick"},
 	})
-	if status != http.StatusConflict {
-		t.Fatalf("expected 409, got %d", status)
+	if status != http.StatusOK {
+		t.Fatalf("expected 200, got %d", status)
+	}
+
+	msgs, _ := tserver.pollMessages(token, lastID)
+
+	if !findNumeric(msgs, "433") {
+		t.Fatalf(
+			"expected ERR_NICKNAMEINUSE (433), got %v",
+			msgs,
+		)
 	}
 }
 
@@ -884,12 +1005,23 @@ func TestNickInvalid(t *testing.T) {
 	tserver := newTestServer(t)
 	token := tserver.createSession("nickval")
 
+	_, lastID := tserver.pollMessages(token, 0)
+
 	status, _ := tserver.sendCommand(token, map[string]any{
 		commandKey: "NICK",
 		bodyKey:    []string{"bad nick!"},
 	})
-	if status != http.StatusBadRequest {
-		t.Fatalf("expected 400, got %d", status)
+	if status != http.StatusOK {
+		t.Fatalf("expected 200, got %d", status)
+	}
+
+	msgs, _ := tserver.pollMessages(token, lastID)
+
+	if !findNumeric(msgs, "432") {
+		t.Fatalf(
+			"expected ERR_ERRONEUSNICKNAME (432), got %v",
+			msgs,
+		)
 	}
 }
 
@@ -897,11 +1029,22 @@ func TestNickEmptyBody(t *testing.T) {
 	tserver := newTestServer(t)
 	token := tserver.createSession("nicknobody")
 
+	_, lastID := tserver.pollMessages(token, 0)
+
 	status, _ := tserver.sendCommand(
 		token, map[string]any{commandKey: "NICK"},
 	)
-	if status != http.StatusBadRequest {
-		t.Fatalf("expected 400, got %d", status)
+	if status != http.StatusOK {
+		t.Fatalf("expected 200, got %d", status)
+	}
+
+	msgs, _ := tserver.pollMessages(token, lastID)
+
+	if !findNumeric(msgs, "461") {
+		t.Fatalf(
+			"expected ERR_NEEDMOREPARAMS (461), got %v",
+			msgs,
+		)
 	}
 }
 
@@ -938,12 +1081,23 @@ func TestTopicMissingTo(t *testing.T) {
 	tserver := newTestServer(t)
 	token := tserver.createSession("topicnoto")
 
+	_, lastID := tserver.pollMessages(token, 0)
+
 	status, _ := tserver.sendCommand(token, map[string]any{
 		commandKey: "TOPIC",
 		bodyKey:    []string{"topic"},
 	})
-	if status != http.StatusBadRequest {
-		t.Fatalf("expected 400, got %d", status)
+	if status != http.StatusOK {
+		t.Fatalf("expected 200, got %d", status)
+	}
+
+	msgs, _ := tserver.pollMessages(token, lastID)
+
+	if !findNumeric(msgs, "461") {
+		t.Fatalf(
+			"expected ERR_NEEDMOREPARAMS (461), got %v",
+			msgs,
+		)
 	}
 }
 
@@ -955,11 +1109,22 @@ func TestTopicMissingBody(t *testing.T) {
 		commandKey: joinCmd, toKey: "#topictest",
 	})
 
+	_, lastID := tserver.pollMessages(token, 0)
+
 	status, _ := tserver.sendCommand(token, map[string]any{
 		commandKey: "TOPIC", toKey: "#topictest",
 	})
-	if status != http.StatusBadRequest {
-		t.Fatalf("expected 400, got %d", status)
+	if status != http.StatusOK {
+		t.Fatalf("expected 200, got %d", status)
+	}
+
+	msgs, _ := tserver.pollMessages(token, lastID)
+
+	if !findNumeric(msgs, "461") {
+		t.Fatalf(
+			"expected ERR_NEEDMOREPARAMS (461), got %v",
+			msgs,
+		)
 	}
 }
 
@@ -1027,11 +1192,22 @@ func TestUnknownCommand(t *testing.T) {
 	tserver := newTestServer(t)
 	token := tserver.createSession("cmdtest")
 
+	_, lastID := tserver.pollMessages(token, 0)
+
 	status, _ := tserver.sendCommand(
 		token, map[string]any{commandKey: "BOGUS"},
 	)
-	if status != http.StatusBadRequest {
-		t.Fatalf("expected 400, got %d", status)
+	if status != http.StatusOK {
+		t.Fatalf("expected 200, got %d", status)
+	}
+
+	msgs, _ := tserver.pollMessages(token, lastID)
+
+	if !findNumeric(msgs, "421") {
+		t.Fatalf(
+			"expected ERR_UNKNOWNCOMMAND (421), got %v",
+			msgs,
+		)
 	}
 }
 
@@ -1278,12 +1454,18 @@ func TestLongPollTimeout(t *testing.T) {
 	tserver := newTestServer(t)
 	token := tserver.createSession("lp_timeout")
 
+	// Drain initial welcome/MOTD numerics.
+	_, lastID := tserver.pollMessages(token, 0)
+
 	start := time.Now()
 
 	resp, err := doRequestAuth(
 		t,
 		http.MethodGet,
-		tserver.url(apiMessages+"?timeout=1"),
+		tserver.url(fmt.Sprintf(
+			"%s?timeout=1&after=%d",
+			apiMessages, lastID,
+		)),
 		token,
 		nil,
 	)

internal/handlers/auth.go

@@ -80,7 +80,7 @@ func (hdlr *Handlers) handleRegister(
 		return
 	}
 
-	hdlr.deliverMOTD(request, clientID, sessionID)
+	hdlr.deliverMOTD(request, clientID, sessionID, payload.Nick)
 
 	hdlr.respondJSON(writer, request, map[string]any{
 		"id":    sessionID,
@@ -162,7 +162,7 @@ func (hdlr *Handlers) handleLogin(
 		return
 	}
 
-	sessionID, _, token, err :=
+	sessionID, clientID, token, err :=
 		hdlr.params.Database.LoginUser(
 			request.Context(),
 			payload.Nick,
@@ -178,6 +178,16 @@ func (hdlr *Handlers) handleLogin(
 		return
 	}
 
+	hdlr.deliverMOTD(
+		request, clientID, sessionID, payload.Nick,
+	)
+
+	// Replay channel state so the new client knows which
+	// channels the session already belongs to.
+	hdlr.replayChannelState(
+		request, clientID, sessionID, payload.Nick,
+	)
+
 	hdlr.respondJSON(writer, request, map[string]any{
 		"id":    sessionID,
 		"nick":  payload.Nick,

web/dist/style.css

@@ -70,14 +70,14 @@ body,
 }
 
 .login-box .motd {
-  color: var(--text-dim);
-  font-size: 12px;
+  color: var(--accent);
+  font-size: 11px;
   margin-bottom: 20px;
   text-align: left;
-  white-space: pre-wrap;
+  white-space: pre;
   font-family: inherit;
-  border-left: 2px solid var(--border);
-  padding-left: 12px;
+  line-height: 1.2;
+  overflow-x: auto;
 }
 
 .login-box form {

web/src/app.jsx

@@ -70,8 +70,8 @@ function LoginScreen({ onLogin }) {
       .catch(() => {});
     const saved = localStorage.getItem("neoirc_token");
     if (saved) {
-      api("/state")
-        .then((u) => onLogin(u.nick))
+      api("/state?replay=1")
+        .then((u) => onLogin(u.nick, true))
         .catch(() => localStorage.removeItem("neoirc_token"));
     }
     inputRef.current?.focus();
@@ -333,7 +333,24 @@ function App() {
         case "JOIN": {
           const text = `${msg.from} has joined ${msg.to}`;
           if (msg.to) addMessage(msg.to, { ...base, text, system: true });
-          if (msg.to && msg.to.startsWith("#")) refreshMembers(msg.to);
+          if (msg.to && msg.to.startsWith("#")) {
+            // Create a tab when the current user joins a channel
+            // (including replayed JOINs on reconnect).
+            if (msg.from === nickRef.current) {
+              setTabs((prev) => {
+                if (
+                  prev.find(
+                    (t) => t.type === "channel" && t.name === msg.to,
+                  )
+                )
+                  return prev;
+
+                return [...prev, { type: "channel", name: msg.to }];
+              });
+            }
+
+            refreshMembers(msg.to);
+          }
 
           break;
         }
@@ -419,6 +436,100 @@ function App() {
 
           break;
         }
+        case "322": {
+          // RPL_LIST — channel, member count, topic.
+          if (Array.isArray(msg.params) && msg.params.length >= 2) {
+            const chName = msg.params[0];
+            const count = msg.params[1];
+            const chTopic = body || "";
+            addMessage("Server", {
+              ...base,
+              text: `${chName} (${count} users): ${chTopic.trim()}`,
+              system: true,
+            });
+          }
+
+          break;
+        }
+        case "323":
+          addMessage("Server", {
+            ...base,
+            text: body || "End of channel list",
+            system: true,
+          });
+
+          break;
+        case "352": {
+          // RPL_WHOREPLY — channel, user, host, server, nick, flags.
+          if (Array.isArray(msg.params) && msg.params.length >= 5) {
+            const whoCh = msg.params[0];
+            const whoNick = msg.params[4];
+            const whoFlags = msg.params.length > 5 ? msg.params[5] : "";
+            addMessage("Server", {
+              ...base,
+              text: `${whoCh} ${whoNick} ${whoFlags}`,
+              system: true,
+            });
+          }
+
+          break;
+        }
+        case "315":
+          addMessage("Server", {
+            ...base,
+            text: body || "End of /WHO list",
+            system: true,
+          });
+
+          break;
+        case "311": {
+          // RPL_WHOISUSER — nick, user, host, *, realname.
+          if (Array.isArray(msg.params) && msg.params.length >= 1) {
+            const wiNick = msg.params[0];
+            addMessage("Server", {
+              ...base,
+              text: `${wiNick} (${body})`,
+              system: true,
+            });
+          }
+
+          break;
+        }
+        case "312": {
+          // RPL_WHOISSERVER — nick, server, server info.
+          if (Array.isArray(msg.params) && msg.params.length >= 2) {
+            const wiNick = msg.params[0];
+            const wiServer = msg.params[1];
+            addMessage("Server", {
+              ...base,
+              text: `${wiNick} on ${wiServer}`,
+              system: true,
+            });
+          }
+
+          break;
+        }
+        case "319": {
+          // RPL_WHOISCHANNELS — nick, channels.
+          if (Array.isArray(msg.params) && msg.params.length >= 1) {
+            const wiNick = msg.params[0];
+            addMessage("Server", {
+              ...base,
+              text: `${wiNick} is on: ${body}`,
+              system: true,
+            });
+          }
+
+          break;
+        }
+        case "318":
+          addMessage("Server", {
+            ...base,
+            text: body || "End of /WHOIS list",
+            system: true,
+          });
+
+          break;
         case "375":
         case "372":
         case "376":
@@ -497,6 +608,31 @@ function App() {
     inputRef.current?.focus();
   }, [activeTab]);
 
+  // Global keyboard handler — capture '/' to prevent
+  // Firefox quick search and redirect focus to the input.
+  useEffect(() => {
+    const handleGlobalKeyDown = (e) => {
+      if (
+        e.key === "/" &&
+        document.activeElement !== inputRef.current &&
+        !e.ctrlKey &&
+        !e.altKey &&
+        !e.metaKey
+      ) {
+        e.preventDefault();
+        inputRef.current?.focus();
+      }
+    };
+
+    document.addEventListener("keydown", handleGlobalKeyDown);
+
+    // Also focus input on initial mount.
+    inputRef.current?.focus();
+
+    return () =>
+      document.removeEventListener("keydown", handleGlobalKeyDown);
+  }, []);
+
   // Fetch topic for active channel.
   useEffect(() => {
     if (!loggedIn) return;
@@ -512,10 +648,30 @@ function App() {
   }, [loggedIn, activeTab, tabs]);
 
   const onLogin = useCallback(
-    async (userNick) => {
+    async (userNick, isResumed) => {
       setNick(userNick);
       setLoggedIn(true);
       addSystemMessage("Server", `Connected as ${userNick}`);
+
+      if (isResumed) {
+        // Request MOTD on resumed sessions (new sessions
+        // get it automatically from the server during
+        // creation).  Channel state is replayed by the
+        // server via the message queue (?replay=1), so we
+        // do not need to re-JOIN channels here.
+        try {
+          await api("/messages", {
+            method: "POST",
+            body: JSON.stringify({ command: "MOTD" }),
+          });
+        } catch (e) {
+          // MOTD is non-critical.
+        }
+
+        return;
+      }
+
+      // Fresh session — join any previously saved channels.
       const saved = JSON.parse(
         localStorage.getItem("neoirc_channels") || "[]",
       );
@@ -791,18 +947,127 @@ function App() {
 
         break;
       }
+      case "/motd": {
+        try {
+          await api("/messages", {
+            method: "POST",
+            body: JSON.stringify({ command: "MOTD" }),
+          });
+        } catch (err) {
+          addSystemMessage(
+            "Server",
+            `Failed to request MOTD: ${err.data?.error || "error"}`,
+          );
+        }
+
+        break;
+      }
+      case "/query": {
+        if (parts[1]) {
+          const target = parts[1];
+          openDM(target);
+          const msgText = parts.slice(2).join(" ");
+          if (msgText) {
+            try {
+              await api("/messages", {
+                method: "POST",
+                body: JSON.stringify({
+                  command: "PRIVMSG",
+                  to: target,
+                  body: [msgText],
+                }),
+              });
+            } catch (err) {
+              addSystemMessage(
+                "Server",
+                `Message failed: ${err.data?.error || "error"}`,
+              );
+            }
+          }
+        } else {
+          addSystemMessage("Server", "Usage: /query <nick> [message]");
+        }
+
+        break;
+      }
+      case "/list": {
+        try {
+          await api("/messages", {
+            method: "POST",
+            body: JSON.stringify({ command: "LIST" }),
+          });
+        } catch (err) {
+          addSystemMessage(
+            "Server",
+            `Failed to list channels: ${err.data?.error || "error"}`,
+          );
+        }
+
+        break;
+      }
+      case "/who": {
+        const whoTarget = parts[1] || (tab.type === "channel" ? tab.name : "");
+        if (whoTarget) {
+          try {
+            await api("/messages", {
+              method: "POST",
+              body: JSON.stringify({ command: "WHO", to: whoTarget }),
+            });
+          } catch (err) {
+            addSystemMessage(
+              "Server",
+              `WHO failed: ${err.data?.error || "error"}`,
+            );
+          }
+        } else {
+          addSystemMessage("Server", "Usage: /who #channel");
+        }
+
+        break;
+      }
+      case "/whois": {
+        if (parts[1]) {
+          try {
+            await api("/messages", {
+              method: "POST",
+              body: JSON.stringify({ command: "WHOIS", to: parts[1] }),
+            });
+          } catch (err) {
+            addSystemMessage(
+              "Server",
+              `WHOIS failed: ${err.data?.error || "error"}`,
+            );
+          }
+        } else {
+          addSystemMessage("Server", "Usage: /whois <nick>");
+        }
+
+        break;
+      }
+      case "/clear": {
+        const clearTarget = tab.name;
+        setMessages((prev) => ({ ...prev, [clearTarget]: [] }));
+
+        break;
+      }
       case "/help": {
         const helpLines = [
           "Available commands:",
-          "  /join #channel     — Join a channel",
-          "  /part [reason]     — Part the current channel",
-          "  /msg nick message  — Send a private message",
-          "  /me action         — Send an action",
-          "  /nick newnick      — Change your nickname",
-          "  /topic [text]      — View or set channel topic",
-          "  /mode +/-flags     — Set channel modes",
-          "  /quit [reason]     — Disconnect from server",
-          "  /help              — Show this help",
+          "  /join #channel        — Join a channel",
+          "  /part [reason]        — Part the current channel",
+          "  /msg nick message     — Send a private message",
+          "  /query nick [message] — Open a DM tab (optionally send a message)",
+          "  /me action            — Send an action",
+          "  /nick newnick         — Change your nickname",
+          "  /topic [text]         — View or set channel topic",
+          "  /mode +/-flags        — Set channel modes",
+          "  /motd                 — Display the message of the day",
+          "  /list                 — List all channels",
+          "  /who [#channel]       — List users in a channel",
+          "  /whois nick           — Show info about a user",
+          "  /clear                — Clear messages in the current tab",
+          "  /quit [reason]        — Disconnect from server",
+          "  /help                 — Show this help",
         ];
         for (const line of helpLines) {
           addSystemMessage("Server", line);

web/src/style.css

@@ -70,14 +70,14 @@ body,
 }
 
 .login-box .motd {
-  color: var(--text-dim);
-  font-size: 12px;
+  color: var(--accent);
+  font-size: 11px;
   margin-bottom: 20px;
   text-align: left;
-  white-space: pre-wrap;
+  white-space: pre;
   font-family: inherit;
-  border-left: 2px solid var(--border);
-  padding-left: 12px;
+  line-height: 1.2;
+  overflow-x: auto;
 }
 
 .login-box form {