fix: extract repeated IRC command string literals to constants (goconst)

Add comprehensive IRC numeric reply support:

Connection registration (001-005):
- 002 RPL_YOURHOST, 003 RPL_CREATED, 004 RPL_MYINFO, 005 RPL_ISUPPORT
- All sent automatically during session creation after RPL_WELCOME

Server statistics (251-255):
- RPL_LUSERCLIENT, RPL_LUSEROP, RPL_LUSERCHANNELS, RPL_LUSERME
- Sent during connection registration and via LUSERS command

Channel operations:
- MODE command: query channel modes (324 RPL_CHANNELMODEIS, 329 RPL_CREATIONTIME)
- MODE command: query user modes (221 RPL_UMODEIS)
- NAMES command: query channel member list (353/366)
- LIST command: list all channels (322 RPL_LIST, 323 end of list)

User queries:
- WHOIS command: 311/312/318/319 numerics
- WHO command: 352 RPL_WHOREPLY, 315 RPL_ENDOFWHO

Database additions:
- GetChannelCount, ListAllChannelsWithCounts
- GetChannelCreatedAt, GetSessionCreatedAt

Also adds StartTime to Globals for RPL_CREATED and updates README
with comprehensive documentation of all new commands and numerics.

closes #52

README.md

@@ -764,21 +764,98 @@ not pollute the message queue.
 
 **IRC reference:** RFC 1459 §4.6.2, §4.6.3
 
-#### MODE — Set/Query Modes (Planned)
+#### MODE — Query Modes
 
-Set channel or user modes.
+Query channel or user modes. Returns the current mode string and, for
+channels, the creation timestamp.
 
 **C2S:**
 ```json
-{"command": "MODE", "to": "#general", "params": ["+m"]}
-{"command": "MODE", "to": "#general", "params": ["+o", "alice"]}
+{"command": "MODE", "to": "#general"}
+{"command": "MODE", "to": "alice"}
 ```
 
-**Status:** Not yet implemented. See [Channel Modes](#channel-modes) for the
-planned mode set.
+**S2C (via message queue):**
+
+For channels, the server sends RPL_CHANNELMODEIS (324) and
+RPL_CREATIONTIME (329):
+```json
+{"command": "324", "to": "alice", "params": ["#general", "+n"]}
+{"command": "329", "to": "alice", "params": ["#general", "1709251200"]}
+```
+
+For users, the server sends RPL_UMODEIS (221):
+```json
+{"command": "221", "to": "alice", "body": ["+"]}
+```
+
+**Note:** Mode changes (setting/unsetting modes) are not yet implemented.
+Currently only query is supported.
 
 **IRC reference:** RFC 1459 §4.2.3
 
+#### NAMES — Channel Member List
+
+Request the member list for a channel. Returns RPL_NAMREPLY (353) and
+RPL_ENDOFNAMES (366).
+
+**C2S:**
+```json
+{"command": "NAMES", "to": "#general"}
+```
+
+**IRC reference:** RFC 1459 §4.2.5
+
+#### LIST — List Channels
+
+Request a list of all channels with member counts. Returns RPL_LIST (322)
+for each channel followed by RPL_LISTEND (323).
+
+**C2S:**
+```json
+{"command": "LIST"}
+```
+
+**IRC reference:** RFC 1459 §4.2.6
+
+#### WHOIS — User Information
+
+Query information about a user. Returns RPL_WHOISUSER (311),
+RPL_WHOISSERVER (312), RPL_WHOISCHANNELS (319), and RPL_ENDOFWHOIS (318).
+
+**C2S:**
+```json
+{"command": "WHOIS", "to": "alice"}
+```
+
+**IRC reference:** RFC 1459 §4.5.2
+
+#### WHO — Channel User List
+
+Query users in a channel. Returns RPL_WHOREPLY (352) for each user followed
+by RPL_ENDOFWHO (315).
+
+**C2S:**
+```json
+{"command": "WHO", "to": "#general"}
+```
+
+**IRC reference:** RFC 1459 §4.5.1
+
+#### LUSERS — Server Statistics
+
+Request server user/channel statistics. Returns RPL_LUSERCLIENT (251),
+RPL_LUSEROP (252), RPL_LUSERCHANNELS (254), and RPL_LUSERME (255).
+
+**C2S:**
+```json
+{"command": "LUSERS"}
+```
+
+LUSERS replies are also sent automatically during connection registration.
+
+**IRC reference:** RFC 1459 §4.3.2
+
 #### KICK — Kick User (Planned)
 
 Remove a user from a channel.
@@ -828,12 +905,27 @@ the server to the client (never C2S) and use 3-digit string codes in the
 | Code | Name                 | When Sent | Example |
 |------|----------------------|-----------|---------|
 | `001` | RPL_WELCOME         | After session creation | `{"command":"001","to":"alice","body":["Welcome to the network, alice"]}` |
-| `002` | RPL_YOURHOST        | After session creation | `{"command":"002","to":"alice","body":["Your host is neoirc-server, running version 0.1"]}` |
+| `002` | RPL_YOURHOST        | After session creation | `{"command":"002","to":"alice","body":["Your host is neoirc, running version 0.1"]}` |
 | `003` | RPL_CREATED         | After session creation | `{"command":"003","to":"alice","body":["This server was created 2026-02-10"]}` |
-| `004` | RPL_MYINFO          | After session creation | `{"command":"004","to":"alice","params":["neoirc-server","0.1","","imnst"]}` |
+| `004` | RPL_MYINFO          | After session creation | `{"command":"004","to":"alice","params":["neoirc","0.1","","imnst"]}` |
+| `005` | RPL_ISUPPORT        | After session creation | `{"command":"005","to":"alice","params":["CHANTYPES=#","NICKLEN=32","NETWORK=neoirc"],"body":["are supported by this server"]}` |
+| `221` | RPL_UMODEIS         | In response to user MODE query | `{"command":"221","to":"alice","body":["+"]}` |
+| `251` | RPL_LUSERCLIENT     | On connect or LUSERS command | `{"command":"251","to":"alice","body":["There are 5 users and 0 invisible on 1 servers"]}` |
+| `252` | RPL_LUSEROP         | On connect or LUSERS command | `{"command":"252","to":"alice","params":["0"],"body":["operator(s) online"]}` |
+| `254` | RPL_LUSERCHANNELS   | On connect or LUSERS command | `{"command":"254","to":"alice","params":["3"],"body":["channels formed"]}` |
+| `255` | RPL_LUSERME         | On connect or LUSERS command | `{"command":"255","to":"alice","body":["I have 5 clients and 1 servers"]}` |
+| `311` | RPL_WHOISUSER       | In response to WHOIS | `{"command":"311","to":"alice","params":["bob","bob","neoirc","*"],"body":["bob"]}` |
+| `312` | RPL_WHOISSERVER     | In response to WHOIS | `{"command":"312","to":"alice","params":["bob","neoirc"],"body":["neoirc server"]}` |
+| `315` | RPL_ENDOFWHO        | End of WHO response | `{"command":"315","to":"alice","params":["#general"],"body":["End of /WHO list"]}` |
+| `318` | RPL_ENDOFWHOIS      | End of WHOIS response | `{"command":"318","to":"alice","params":["bob"],"body":["End of /WHOIS list"]}` |
+| `319` | RPL_WHOISCHANNELS   | In response to WHOIS | `{"command":"319","to":"alice","params":["bob"],"body":["#general #dev"]}` |
 | `322` | RPL_LIST            | In response to LIST | `{"command":"322","to":"alice","params":["#general","5"],"body":["General discussion"]}` |
 | `323` | RPL_LISTEND         | End of LIST response | `{"command":"323","to":"alice","body":["End of /LIST"]}` |
+| `324` | RPL_CHANNELMODEIS   | In response to channel MODE query | `{"command":"324","to":"alice","params":["#general","+n"]}` |
+| `329` | RPL_CREATIONTIME    | After channel MODE query | `{"command":"329","to":"alice","params":["#general","1709251200"]}` |
+| `331` | RPL_NOTOPIC         | Channel has no topic (on JOIN) | `{"command":"331","to":"alice","params":["#general"],"body":["No topic is set"]}` |
 | `332` | RPL_TOPIC           | On JOIN or TOPIC query | `{"command":"332","to":"alice","params":["#general"],"body":["Welcome!"]}` |
+| `352` | RPL_WHOREPLY        | In response to WHO | `{"command":"352","to":"alice","params":["#general","bob","neoirc","neoirc","bob","H"],"body":["0 bob"]}` |
 | `353` | RPL_NAMREPLY        | On JOIN or NAMES query | `{"command":"353","to":"alice","params":["=","#general"],"body":["@op1 alice bob +voiced1"]}` |
 | `366` | RPL_ENDOFNAMES      | End of NAMES response | `{"command":"366","to":"alice","params":["#general"],"body":["End of /NAMES list"]}` |
 | `372` | RPL_MOTD            | MOTD line | `{"command":"372","to":"alice","body":["Welcome to the server"]}` |
@@ -841,8 +933,11 @@ the server to the client (never C2S) and use 3-digit string codes in the
 | `376` | RPL_ENDOFMOTD       | End of MOTD | `{"command":"376","to":"alice","body":["End of /MOTD command"]}` |
 | `401` | ERR_NOSUCHNICK      | DM to nonexistent nick | `{"command":"401","to":"alice","params":["bob"],"body":["No such nick/channel"]}` |
 | `403` | ERR_NOSUCHCHANNEL   | Action on nonexistent channel | `{"command":"403","to":"alice","params":["#nope"],"body":["No such channel"]}` |
+| `421` | ERR_UNKNOWNCOMMAND  | Unrecognized command | `{"command":"421","to":"alice","params":["FOO"],"body":["Unknown command"]}` |
+| `432` | ERR_ERRONEUSNICKNAME | Invalid nick format | `{"command":"432","to":"alice","params":["bad nick!"],"body":["Erroneous nickname"]}` |
 | `433` | ERR_NICKNAMEINUSE   | NICK to taken nick | `{"command":"433","to":"*","params":["alice"],"body":["Nickname is already in use"]}` |
 | `442` | ERR_NOTONCHANNEL    | Action on unjoined channel | `{"command":"442","to":"alice","params":["#general"],"body":["You're not on that channel"]}` |
+| `461` | ERR_NEEDMOREPARAMS  | Missing required fields | `{"command":"461","to":"alice","params":["JOIN"],"body":["Not enough parameters"]}` |
 | `482` | ERR_CHANOPRIVSNEEDED | Non-op tries op action | `{"command":"482","to":"alice","params":["#general"],"body":["You're not channel operator"]}` |
 
 **Note:** Numeric replies are now implemented. All IRC command responses
@@ -1061,6 +1156,12 @@ reference with all required and optional fields.
 | `PART`    | `to`                | `body`        | 200 OK          |
 | `NICK`    | `body`              |               | 200 OK          |
 | `TOPIC`   | `to`, `body`        |               | 200 OK          |
+| `MODE`    | `to`                |               | 200 OK          |
+| `NAMES`   | `to`                |               | 200 OK          |
+| `LIST`    |                     |               | 200 OK          |
+| `WHOIS`   | `to` or `body`      |               | 200 OK          |
+| `WHO`     | `to`                |               | 200 OK          |
+| `LUSERS`  |                     |               | 200 OK          |
 | `QUIT`    |                     | `body`        | 200 OK          |
 | `PING`    |                     |               | 200 OK          |
 
@@ -1095,10 +1196,29 @@ auth tokens (401), and server errors (500).
 | Numeric | Name | When |
 |---------|------|------|
 | 001     | RPL_WELCOME | Sent on session creation/login |
+| 002     | RPL_YOURHOST | Sent on session creation/login |
+| 003     | RPL_CREATED | Sent on session creation/login |
+| 004     | RPL_MYINFO | Sent on session creation/login |
+| 005     | RPL_ISUPPORT | Sent on session creation/login |
+| 221     | RPL_UMODEIS | In response to user MODE query |
+| 251     | RPL_LUSERCLIENT | On connect or LUSERS command |
+| 252     | RPL_LUSEROP | On connect or LUSERS command |
+| 254     | RPL_LUSERCHANNELS | On connect or LUSERS command |
+| 255     | RPL_LUSERME | On connect or LUSERS command |
+| 311     | RPL_WHOISUSER | WHOIS user info |
+| 312     | RPL_WHOISSERVER | WHOIS server info |
+| 315     | RPL_ENDOFWHO | End of WHO list |
+| 318     | RPL_ENDOFWHOIS | End of WHOIS list |
+| 319     | RPL_WHOISCHANNELS | WHOIS channels list |
+| 322     | RPL_LIST | Channel in LIST response |
+| 323     | RPL_LISTEND | End of LIST |
+| 324     | RPL_CHANNELMODEIS | Channel mode query response |
+| 329     | RPL_CREATIONTIME | Channel creation timestamp |
 | 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) |
+| 352     | RPL_WHOREPLY | User in WHO response |
+| 353     | RPL_NAMREPLY | Channel member list (on JOIN, NAMES) |
+| 366     | RPL_ENDOFNAMES | End of NAMES list |
 | 375     | RPL_MOTDSTART | Start of MOTD |
 | 372     | RPL_MOTD | MOTD line |
 | 376     | RPL_ENDOFMOTD | End of MOTD |
@@ -2104,10 +2224,18 @@ GET /api/v1/challenge
 - [ ] **Message rotation** — enforce `MAX_HISTORY` per channel
 - [ ] **Channel modes** — enforce `+i`, `+m`, `+s`, `+t`, `+n`
 - [ ] **User channel modes** — `+o` (operator), `+v` (voice)
-- [ ] **MODE command** — set/query channel and user modes
+- [x] **MODE command** — query channel and user modes (set not yet implemented)
+- [x] **NAMES command** — query channel member list
+- [x] **LIST command** — list all channels with member counts
+- [x] **WHOIS command** — query user information and channel membership
+- [x] **WHO command** — query channel user list
+- [x] **LUSERS command** — query server statistics
+- [x] **Connection registration numerics** — 001-005 sent on session creation
+- [x] **LUSERS numerics** — 251/252/254/255 sent on connect and via /LUSERS
 - [ ] **KICK command** — remove users from channels
-- [ ] **Numeric replies** — send IRC numeric codes via the message queue
-  (001 welcome, 353 NAMES, 332 TOPIC, etc.)
+- [x] **Numeric replies** — send IRC numeric codes via the message queue
+  (001-005 welcome, 251-255 LUSERS, 311-319 WHOIS, 322-329 LIST/MODE,
+  331-332 TOPIC, 352-353 WHO/NAMES, 366, 372-376 MOTD, 401-461 errors)
 - [ ] **Max message size enforcement** — reject oversized messages
 - [ ] **NOTICE command** — distinct from PRIVMSG (no auto-reply flag)
 - [ ] **Multi-client sessions** — add client to existing session
@@ -2127,7 +2255,7 @@ GET /api/v1/challenge
 - [ ] **Push notifications** — optional webhook/push for mobile clients
   when messages arrive during disconnect
 - [ ] **Message search** — full-text search over channel history
-- [ ] **User info command** — WHOIS-equivalent for querying user metadata
+- [x] **User info command** — WHOIS for querying user info and channels
 - [ ] **Connection flood protection** — per-IP connection limits as a
   complement to hashcash
 - [ ] **Invite system** — `INVITE` command for `+i` channels

internal/db/queries.go

@@ -953,3 +953,125 @@ func (database *Database) GetSessionChannels(
 
 	return scanChannels(rows)
 }
+
+// GetChannelCount returns the total number of channels.
+func (database *Database) GetChannelCount(
+	ctx context.Context,
+) (int64, error) {
+	var count int64
+
+	err := database.conn.QueryRowContext(
+		ctx,
+		"SELECT COUNT(*) FROM channels",
+	).Scan(&count)
+	if err != nil {
+		return 0, fmt.Errorf(
+			"get channel count: %w", err,
+		)
+	}
+
+	return count, nil
+}
+
+// ChannelInfoFull contains extended channel information.
+type ChannelInfoFull struct {
+	ID          int64  `json:"id"`
+	Name        string `json:"name"`
+	Topic       string `json:"topic"`
+	MemberCount int64  `json:"memberCount"`
+}
+
+// ListAllChannelsWithCounts returns every channel
+// with its member count.
+func (database *Database) ListAllChannelsWithCounts(
+	ctx context.Context,
+) ([]ChannelInfoFull, error) {
+	rows, err := database.conn.QueryContext(ctx,
+		`SELECT c.id, c.name, c.topic,
+		   COUNT(cm.session_id) AS member_count
+		 FROM channels c
+		 LEFT JOIN channel_members cm
+		   ON cm.channel_id = c.id
+		 GROUP BY c.id
+		 ORDER BY c.name`)
+	if err != nil {
+		return nil, fmt.Errorf(
+			"list channels with counts: %w", err,
+		)
+	}
+
+	defer func() { _ = rows.Close() }()
+
+	var out []ChannelInfoFull
+
+	for rows.Next() {
+		var chanInfo ChannelInfoFull
+
+		err = rows.Scan(
+			&chanInfo.ID, &chanInfo.Name,
+			&chanInfo.Topic, &chanInfo.MemberCount,
+		)
+		if err != nil {
+			return nil, fmt.Errorf(
+				"scan channel full: %w", err,
+			)
+		}
+
+		out = append(out, chanInfo)
+	}
+
+	err = rows.Err()
+	if err != nil {
+		return nil, fmt.Errorf("rows error: %w", err)
+	}
+
+	if out == nil {
+		out = []ChannelInfoFull{}
+	}
+
+	return out, nil
+}
+
+// GetChannelCreatedAt returns the creation time of a
+// channel.
+func (database *Database) GetChannelCreatedAt(
+	ctx context.Context,
+	channelID int64,
+) (time.Time, error) {
+	var createdAt time.Time
+
+	err := database.conn.QueryRowContext(
+		ctx,
+		"SELECT created_at FROM channels WHERE id = ?",
+		channelID,
+	).Scan(&createdAt)
+	if err != nil {
+		return time.Time{}, fmt.Errorf(
+			"get channel created_at: %w", err,
+		)
+	}
+
+	return createdAt, nil
+}
+
+// GetSessionCreatedAt returns the creation time of a
+// session.
+func (database *Database) GetSessionCreatedAt(
+	ctx context.Context,
+	sessionID int64,
+) (time.Time, error) {
+	var createdAt time.Time
+
+	err := database.conn.QueryRowContext(
+		ctx,
+		"SELECT created_at FROM sessions WHERE id = ?",
+		sessionID,
+	).Scan(&createdAt)
+	if err != nil {
+		return time.Time{}, fmt.Errorf(
+			"get session created_at: %w", err,
+		)
+	}
+
+	return createdAt, nil
+}

internal/globals/globals.go

@@ -2,6 +2,8 @@
 package globals
 
 import (
+	"time"
+
 	"go.uber.org/fx"
 )
 
@@ -15,16 +17,18 @@ var (
 
 // Globals holds application-wide metadata.
 type Globals struct {
-	Appname string
-	Version string
+	Appname   string
+	Version   string
+	StartTime time.Time
 }
 
 // New creates a new Globals instance from the global state.
 func New(_ fx.Lifecycle) (*Globals, error) {
-	n := &Globals{
-		Appname: Appname,
-		Version: Version,
+	result := &Globals{
+		Appname:   Appname,
+		Version:   Version,
+		StartTime: time.Now(),
 	}
 
-	return n, nil
+	return result, nil
 }

internal/handlers/api.go

@@ -27,7 +27,15 @@ const (
 	defaultMaxBodySize = 4096
 	defaultHistLimit   = 50
 	maxHistLimit       = 500
+	cmdJoin            = "JOIN"
+	cmdList            = "LIST"
+	cmdNick            = "NICK"
+	cmdPart            = "PART"
 	cmdPrivmsg         = "PRIVMSG"
+	cmdQuit            = "QUIT"
+	cmdTopic           = "TOPIC"
+	cmdWho             = "WHO"
+	cmdWhois           = "WHOIS"
 )
 
 func (hdlr *Handlers) maxBodySize() int64 {
@@ -219,19 +227,130 @@ func (hdlr *Handlers) handleCreateSessionError(
 	)
 }
 
-// deliverWelcome sends the RPL_WELCOME (001) numeric to a
-// new client.
+// deliverWelcome sends connection registration numerics
+// (001-005) to a new client.
 func (hdlr *Handlers) deliverWelcome(
 	request *http.Request,
 	clientID int64,
 	nick string,
 ) {
 	ctx := request.Context()
+	srvName := hdlr.serverName()
+	version := hdlr.serverVersion()
 
+	// 001 RPL_WELCOME
 	hdlr.enqueueNumeric(
 		ctx, clientID, "001", nick, nil,
 		"Welcome to the network, "+nick,
 	)
+
+	// 002 RPL_YOURHOST
+	hdlr.enqueueNumeric(
+		ctx, clientID, "002", nick, nil,
+		"Your host is "+srvName+
+			", running version "+version,
+	)
+
+	// 003 RPL_CREATED
+	hdlr.enqueueNumeric(
+		ctx, clientID, "003", nick, nil,
+		"This server was created "+
+			hdlr.params.Globals.StartTime.
+				Format("2006-01-02"),
+	)
+
+	// 004 RPL_MYINFO
+	hdlr.enqueueNumeric(
+		ctx, clientID, "004", nick,
+		[]string{srvName, version, "", "imnst"},
+		"",
+	)
+
+	// 005 RPL_ISUPPORT
+	hdlr.enqueueNumeric(
+		ctx, clientID, "005", nick,
+		[]string{
+			"CHANTYPES=#",
+			"NICKLEN=32",
+			"CHANMODES=,,," + "imnst",
+			"NETWORK=neoirc",
+			"CASEMAPPING=ascii",
+		},
+		"are supported by this server",
+	)
+
+	// LUSERS
+	hdlr.deliverLusers(ctx, clientID, nick)
+}
+
+// deliverLusers sends RPL_LUSERCLIENT (251),
+// RPL_LUSEROP (252), RPL_LUSERCHANNELS (254), and
+// RPL_LUSERME (255) to the client.
+func (hdlr *Handlers) deliverLusers(
+	ctx context.Context,
+	clientID int64,
+	nick string,
+) {
+	userCount, err := hdlr.params.Database.GetUserCount(ctx)
+	if err != nil {
+		hdlr.log.Error(
+			"lusers user count", "error", err,
+		)
+
+		userCount = 0
+	}
+
+	chanCount, err := hdlr.params.Database.GetChannelCount(
+		ctx,
+	)
+	if err != nil {
+		hdlr.log.Error(
+			"lusers channel count", "error", err,
+		)
+
+		chanCount = 0
+	}
+
+	// 251 RPL_LUSERCLIENT
+	hdlr.enqueueNumeric(
+		ctx, clientID, "251", nick, nil,
+		fmt.Sprintf(
+			"There are %d users and 0 invisible on 1 servers",
+			userCount,
+		),
+	)
+
+	// 252 RPL_LUSEROP
+	hdlr.enqueueNumeric(
+		ctx, clientID, "252", nick,
+		[]string{"0"},
+		"operator(s) online",
+	)
+
+	// 254 RPL_LUSERCHANNELS
+	hdlr.enqueueNumeric(
+		ctx, clientID, "254", nick,
+		[]string{strconv.FormatInt(chanCount, 10)},
+		"channels formed",
+	)
+
+	// 255 RPL_LUSERME
+	hdlr.enqueueNumeric(
+		ctx, clientID, "255", nick, nil,
+		fmt.Sprintf(
+			"I have %d clients and 1 servers",
+			userCount,
+		),
+	)
+}
+
+func (hdlr *Handlers) serverVersion() string {
+	ver := hdlr.params.Globals.Version
+	if ver == "" {
+		return "dev"
+	}
+
+	return ver
 }
 
 // deliverMOTD sends the MOTD as IRC numeric messages to a
@@ -645,37 +764,86 @@ func (hdlr *Handlers) dispatchCommand(
 			sessionID, clientID, nick,
 			command, target, body, bodyLines,
 		)
-	case "JOIN":
+	case cmdJoin:
 		hdlr.handleJoin(
 			writer, request,
 			sessionID, clientID, nick, target,
 		)
-	case "PART":
+	case cmdPart:
 		hdlr.handlePart(
 			writer, request,
 			sessionID, clientID, nick, target, body,
 		)
-	case "NICK":
+	case cmdNick:
 		hdlr.handleNick(
 			writer, request,
 			sessionID, clientID, nick, bodyLines,
 		)
-	case "TOPIC":
+	case cmdTopic:
 		hdlr.handleTopic(
 			writer, request,
 			sessionID, clientID, nick,
 			target, body, bodyLines,
 		)
-	case "QUIT":
+	case cmdQuit:
 		hdlr.handleQuit(
 			writer, request, sessionID, nick, body,
 		)
-	case "MOTD", "LIST", "WHO", "WHOIS", "PING":
+	case "MOTD", cmdList, cmdWho, cmdWhois, "PING":
 		hdlr.dispatchInfoCommand(
 			writer, request,
 			sessionID, clientID, nick,
 			command, target, bodyLines,
 		)
+	default:
+		hdlr.dispatchQueryCommand(
+			writer, request,
+			sessionID, clientID, nick,
+			command, target, bodyLines,
+		)
+	}
+}
+
+func (hdlr *Handlers) dispatchQueryCommand(
+	writer http.ResponseWriter,
+	request *http.Request,
+	sessionID, clientID int64,
+	nick, command, target string,
+	bodyLines func() []string,
+) {
+	switch command {
+	case "MODE":
+		hdlr.handleMode(
+			writer, request,
+			sessionID, clientID, nick,
+			target, bodyLines,
+		)
+	case "NAMES":
+		hdlr.handleNames(
+			writer, request,
+			sessionID, clientID, nick, target,
+		)
+	case cmdList:
+		hdlr.handleList(
+			writer, request,
+			sessionID, clientID, nick,
+		)
+	case cmdWhois:
+		hdlr.handleWhois(
+			writer, request,
+			sessionID, clientID, nick,
+			target, bodyLines,
+		)
+	case cmdWho:
+		hdlr.handleWho(
+			writer, request,
+			sessionID, clientID, nick, target,
+		)
+	case "LUSERS":
+		hdlr.handleLusers(
+			writer, request,
+			sessionID, clientID, nick,
+		)
 	default:
 		hdlr.enqueueNumeric(
 			request.Context(), clientID,
@@ -913,7 +1081,7 @@ func (hdlr *Handlers) handleJoin(
 	if target == "" {
 		hdlr.respondIRCError(
 			writer, request, clientID, sessionID,
-			"461", nick, []string{"JOIN"},
+			"461", nick, []string{cmdJoin},
 			"Not enough parameters",
 		)
 
@@ -984,7 +1152,7 @@ func (hdlr *Handlers) executeJoin(
 	)
 
 	_ = hdlr.fanOutSilent(
-		request, "JOIN", nick, channel, nil, memberIDs,
+		request, cmdJoin, nick, channel, nil, memberIDs,
 	)
 
 	hdlr.deliverJoinNumerics(
@@ -1082,7 +1250,7 @@ func (hdlr *Handlers) handlePart(
 	if target == "" {
 		hdlr.enqueueNumeric(
 			request.Context(), clientID,
-			"461", nick, []string{"PART"},
+			"461", nick, []string{cmdPart},
 			"Not enough parameters",
 		)
 		hdlr.broker.Notify(sessionID)
@@ -1120,7 +1288,7 @@ func (hdlr *Handlers) handlePart(
 	)
 
 	_ = hdlr.fanOutSilent(
-		request, "PART", nick, channel, body, memberIDs,
+		request, cmdPart, nick, channel, body, memberIDs,
 	)
 
 	err = hdlr.params.Database.PartChannel(
@@ -1162,7 +1330,7 @@ func (hdlr *Handlers) handleNick(
 	if len(lines) == 0 {
 		hdlr.respondIRCError(
 			writer, request, clientID, sessionID,
-			"461", nick, []string{"NICK"},
+			"461", nick, []string{cmdNick},
 			"Not enough parameters",
 		)
 
@@ -1260,7 +1428,7 @@ func (hdlr *Handlers) broadcastNick(
 	}
 
 	dbID, _, _ := hdlr.params.Database.InsertMessage(
-		request.Context(), "NICK", oldNick, "",
+		request.Context(), cmdNick, oldNick, "",
 		nil, json.RawMessage(nickBody), nil,
 	)
 
@@ -1301,7 +1469,7 @@ func (hdlr *Handlers) handleTopic(
 	if target == "" {
 		hdlr.respondIRCError(
 			writer, request, clientID, sessionID,
-			"461", nick, []string{"TOPIC"},
+			"461", nick, []string{cmdTopic},
 			"Not enough parameters",
 		)
 
@@ -1312,7 +1480,7 @@ func (hdlr *Handlers) handleTopic(
 	if len(lines) == 0 {
 		hdlr.respondIRCError(
 			writer, request, clientID, sessionID,
-			"461", nick, []string{"TOPIC"},
+			"461", nick, []string{cmdTopic},
 			"Not enough parameters",
 		)
 
@@ -1374,7 +1542,7 @@ func (hdlr *Handlers) executeTopic(
 	)
 
 	_ = hdlr.fanOutSilent(
-		request, "TOPIC", nick, channel, body, memberIDs,
+		request, cmdTopic, nick, channel, body, memberIDs,
 	)
 
 	hdlr.enqueueNumeric(
@@ -1407,16 +1575,16 @@ func (hdlr *Handlers) dispatchInfoCommand(
 		hdlr.deliverMOTD(
 			request, clientID, sessionID, nick,
 		)
-	case "LIST":
+	case cmdList:
 		hdlr.handleListCmd(
 			request, clientID, sessionID, nick,
 		)
-	case "WHO":
+	case cmdWho:
 		hdlr.handleWhoCmd(
 			request, clientID, sessionID, nick,
 			target,
 		)
-	case "WHOIS":
+	case cmdWhois:
 		hdlr.handleWhoisCmd(
 			request, clientID, sessionID, nick,
 			target, bodyLines,
@@ -1497,7 +1665,7 @@ func (hdlr *Handlers) handleWhoCmd(
 	if target == "" {
 		hdlr.enqueueNumeric(
 			ctx, clientID, "461", nick,
-			[]string{"WHO"}, "Not enough parameters",
+			[]string{cmdWho}, "Not enough parameters",
 		)
 		hdlr.broker.Notify(sessionID)
 
@@ -1568,7 +1736,7 @@ func (hdlr *Handlers) handleWhoisCmd(
 	if whoisNick == "" {
 		hdlr.enqueueNumeric(
 			ctx, clientID, "461", nick,
-			[]string{"WHOIS"}, "Not enough parameters",
+			[]string{cmdWhois}, "Not enough parameters",
 		)
 		hdlr.broker.Notify(sessionID)
 
@@ -1671,7 +1839,7 @@ func (hdlr *Handlers) handleQuit(
 
 	if len(channels) > 0 {
 		dbID, _, _ = hdlr.params.Database.InsertMessage(
-			request.Context(), "QUIT", nick, "",
+			request.Context(), cmdQuit, nick, "",
 			nil, body, nil,
 		)
 	}
@@ -1712,6 +1880,424 @@ func (hdlr *Handlers) handleQuit(
 		http.StatusOK)
 }
 
+// handleMode handles the MODE command for channels and
+// users. Currently supports query-only (no mode changes).
+func (hdlr *Handlers) handleMode(
+	writer http.ResponseWriter,
+	request *http.Request,
+	sessionID, clientID int64,
+	nick, target string,
+	bodyLines func() []string,
+) {
+	if target == "" {
+		hdlr.respondIRCError(
+			writer, request, clientID, sessionID,
+			"461", nick, []string{"MODE"},
+			"Not enough parameters",
+		)
+
+		return
+	}
+
+	channel := target
+	if !strings.HasPrefix(channel, "#") {
+		// User mode query — return empty modes.
+		hdlr.enqueueNumeric(
+			request.Context(), clientID,
+			"221", nick, nil, "+",
+		)
+		hdlr.broker.Notify(sessionID)
+		hdlr.respondJSON(writer, request,
+			map[string]string{"status": "ok"},
+			http.StatusOK)
+
+		return
+	}
+
+	_ = bodyLines
+
+	hdlr.handleChannelMode(
+		writer, request,
+		sessionID, clientID, nick, channel,
+	)
+}
+
+func (hdlr *Handlers) handleChannelMode(
+	writer http.ResponseWriter,
+	request *http.Request,
+	sessionID, clientID int64,
+	nick, channel string,
+) {
+	ctx := request.Context()
+
+	chID, err := hdlr.params.Database.GetChannelByName(
+		ctx, channel,
+	)
+	if err != nil {
+		hdlr.respondIRCError(
+			writer, request, clientID, sessionID,
+			"403", nick, []string{channel},
+			"No such channel",
+		)
+
+		return
+	}
+
+	// 324 RPL_CHANNELMODEIS
+	hdlr.enqueueNumeric(
+		ctx, clientID, "324", nick,
+		[]string{channel, "+n"}, "",
+	)
+
+	// 329 RPL_CREATIONTIME
+	createdAt, timeErr := hdlr.params.Database.
+		GetChannelCreatedAt(ctx, chID)
+	if timeErr == nil {
+		hdlr.enqueueNumeric(
+			ctx, clientID, "329", nick,
+			[]string{
+				channel,
+				strconv.FormatInt(
+					createdAt.Unix(), 10,
+				),
+			},
+			"",
+		)
+	}
+
+	hdlr.broker.Notify(sessionID)
+	hdlr.respondJSON(writer, request,
+		map[string]string{"status": "ok"},
+		http.StatusOK)
+}
+
+// handleNames sends NAMES reply for a channel.
+func (hdlr *Handlers) handleNames(
+	writer http.ResponseWriter,
+	request *http.Request,
+	sessionID, clientID int64,
+	nick, target string,
+) {
+	if target == "" {
+		hdlr.respondIRCError(
+			writer, request, clientID, sessionID,
+			"461", nick, []string{"NAMES"},
+			"Not enough parameters",
+		)
+
+		return
+	}
+
+	channel := target
+	if !strings.HasPrefix(channel, "#") {
+		channel = "#" + channel
+	}
+
+	ctx := request.Context()
+
+	chID, err := hdlr.params.Database.GetChannelByName(
+		ctx, channel,
+	)
+	if err != nil {
+		hdlr.respondIRCError(
+			writer, request, clientID, sessionID,
+			"403", nick, []string{channel},
+			"No such channel",
+		)
+
+		return
+	}
+
+	members, memErr := hdlr.params.Database.ChannelMembers(
+		ctx, chID,
+	)
+	if memErr == nil && len(members) > 0 {
+		nicks := make([]string, 0, len(members))
+
+		for _, mem := range members {
+			nicks = append(nicks, mem.Nick)
+		}
+
+		hdlr.enqueueNumeric(
+			ctx, clientID, "353", nick,
+			[]string{"=", channel},
+			strings.Join(nicks, " "),
+		)
+	}
+
+	hdlr.enqueueNumeric(
+		ctx, clientID, "366", nick,
+		[]string{channel}, "End of /NAMES list",
+	)
+
+	hdlr.broker.Notify(sessionID)
+	hdlr.respondJSON(writer, request,
+		map[string]string{"status": "ok"},
+		http.StatusOK)
+}
+
+// handleList sends the LIST response with 322/323
+// numerics.
+func (hdlr *Handlers) handleList(
+	writer http.ResponseWriter,
+	request *http.Request,
+	sessionID, clientID int64,
+	nick string,
+) {
+	ctx := request.Context()
+
+	channels, err := hdlr.params.Database.
+		ListAllChannelsWithCounts(ctx)
+	if err != nil {
+		hdlr.log.Error(
+			"list channels failed", "error", err,
+		)
+		hdlr.respondError(
+			writer, request,
+			"internal error",
+			http.StatusInternalServerError,
+		)
+
+		return
+	}
+
+	for _, chanInfo := range channels {
+		// 322 RPL_LIST
+		hdlr.enqueueNumeric(
+			ctx, clientID, "322", nick,
+			[]string{
+				chanInfo.Name,
+				strconv.FormatInt(
+					chanInfo.MemberCount, 10,
+				),
+			},
+			chanInfo.Topic,
+		)
+	}
+
+	// 323 — end of channel list.
+	hdlr.enqueueNumeric(
+		ctx, clientID, "323", nick, nil,
+		"End of /LIST",
+	)
+
+	hdlr.broker.Notify(sessionID)
+	hdlr.respondJSON(writer, request,
+		map[string]string{"status": "ok"},
+		http.StatusOK)
+}
+
+// handleWhois handles the WHOIS command.
+func (hdlr *Handlers) handleWhois(
+	writer http.ResponseWriter,
+	request *http.Request,
+	sessionID, clientID int64,
+	nick, target string,
+	bodyLines func() []string,
+) {
+	queryNick := target
+
+	// If target is empty, check body for the nick.
+	if queryNick == "" {
+		lines := bodyLines()
+		if len(lines) > 0 {
+			queryNick = strings.TrimSpace(lines[0])
+		}
+	}
+
+	if queryNick == "" {
+		hdlr.respondIRCError(
+			writer, request, clientID, sessionID,
+			"461", nick, []string{cmdWhois},
+			"Not enough parameters",
+		)
+
+		return
+	}
+
+	hdlr.executeWhois(
+		writer, request,
+		sessionID, clientID, nick, queryNick,
+	)
+}
+
+func (hdlr *Handlers) executeWhois(
+	writer http.ResponseWriter,
+	request *http.Request,
+	sessionID, clientID int64,
+	nick, queryNick string,
+) {
+	ctx := request.Context()
+	srvName := hdlr.serverName()
+
+	targetSID, err := hdlr.params.Database.GetSessionByNick(
+		ctx, queryNick,
+	)
+	if err != nil {
+		hdlr.enqueueNumeric(
+			ctx, clientID, "401", nick,
+			[]string{queryNick},
+			"No such nick/channel",
+		)
+		hdlr.enqueueNumeric(
+			ctx, clientID, "318", nick,
+			[]string{queryNick},
+			"End of /WHOIS list",
+		)
+		hdlr.broker.Notify(sessionID)
+		hdlr.respondJSON(writer, request,
+			map[string]string{"status": "ok"},
+			http.StatusOK)
+
+		return
+	}
+
+	// 311 RPL_WHOISUSER
+	hdlr.enqueueNumeric(
+		ctx, clientID, "311", nick,
+		[]string{queryNick, queryNick, srvName, "*"},
+		queryNick,
+	)
+
+	// 312 RPL_WHOISSERVER
+	hdlr.enqueueNumeric(
+		ctx, clientID, "312", nick,
+		[]string{queryNick, srvName},
+		"neoirc server",
+	)
+
+	// 319 RPL_WHOISCHANNELS
+	hdlr.deliverWhoisChannels(
+		ctx, clientID, nick, queryNick, targetSID,
+	)
+
+	// 318 RPL_ENDOFWHOIS
+	hdlr.enqueueNumeric(
+		ctx, clientID, "318", nick,
+		[]string{queryNick},
+		"End of /WHOIS list",
+	)
+
+	hdlr.broker.Notify(sessionID)
+	hdlr.respondJSON(writer, request,
+		map[string]string{"status": "ok"},
+		http.StatusOK)
+}
+
+func (hdlr *Handlers) deliverWhoisChannels(
+	ctx context.Context,
+	clientID int64,
+	nick, queryNick string,
+	targetSID int64,
+) {
+	channels, chanErr := hdlr.params.Database.
+		GetSessionChannels(ctx, targetSID)
+	if chanErr != nil || len(channels) == 0 {
+		return
+	}
+
+	chanNames := make([]string, 0, len(channels))
+
+	for _, chanInfo := range channels {
+		chanNames = append(chanNames, chanInfo.Name)
+	}
+
+	hdlr.enqueueNumeric(
+		ctx, clientID, "319", nick,
+		[]string{queryNick},
+		strings.Join(chanNames, " "),
+	)
+}
+
+// handleWho handles the WHO command.
+func (hdlr *Handlers) handleWho(
+	writer http.ResponseWriter,
+	request *http.Request,
+	sessionID, clientID int64,
+	nick, target string,
+) {
+	if target == "" {
+		hdlr.respondIRCError(
+			writer, request, clientID, sessionID,
+			"461", nick, []string{cmdWho},
+			"Not enough parameters",
+		)
+
+		return
+	}
+
+	ctx := request.Context()
+	srvName := hdlr.serverName()
+
+	channel := target
+	if !strings.HasPrefix(channel, "#") {
+		channel = "#" + channel
+	}
+
+	chID, err := hdlr.params.Database.GetChannelByName(
+		ctx, channel,
+	)
+	if err != nil {
+		// 315 RPL_ENDOFWHO (empty result)
+		hdlr.enqueueNumeric(
+			ctx, clientID, "315", nick,
+			[]string{target},
+			"End of /WHO list",
+		)
+		hdlr.broker.Notify(sessionID)
+		hdlr.respondJSON(writer, request,
+			map[string]string{"status": "ok"},
+			http.StatusOK)
+
+		return
+	}
+
+	members, memErr := hdlr.params.Database.ChannelMembers(
+		ctx, chID,
+	)
+	if memErr == nil {
+		for _, mem := range members {
+			// 352 RPL_WHOREPLY
+			hdlr.enqueueNumeric(
+				ctx, clientID, "352", nick,
+				[]string{
+					channel, mem.Nick, srvName,
+					srvName, mem.Nick, "H",
+				},
+				"0 "+mem.Nick,
+			)
+		}
+	}
+
+	// 315 RPL_ENDOFWHO
+	hdlr.enqueueNumeric(
+		ctx, clientID, "315", nick,
+		[]string{channel},
+		"End of /WHO list",
+	)
+
+	hdlr.broker.Notify(sessionID)
+	hdlr.respondJSON(writer, request,
+		map[string]string{"status": "ok"},
+		http.StatusOK)
+}
+
+// handleLusers handles the LUSERS command.
+func (hdlr *Handlers) handleLusers(
+	writer http.ResponseWriter,
+	request *http.Request,
+	sessionID, clientID int64,
+	nick string,
+) {
+	hdlr.deliverLusers(
+		request.Context(), clientID, nick,
+	)
+	hdlr.broker.Notify(sessionID)
+	hdlr.respondJSON(writer, request,
+		map[string]string{"status": "ok"},
+		http.StatusOK)
+}
+
 // HandleGetHistory returns message history for a target.
 func (hdlr *Handlers) HandleGetHistory() http.HandlerFunc {
 	return func(
@@ -1921,7 +2507,7 @@ func (hdlr *Handlers) cleanupUser(
 
 	if len(channels) > 0 {
 		quitDBID, _, _ = hdlr.params.Database.InsertMessage(
-			ctx, "QUIT", nick, "",
+			ctx, cmdQuit, nick, "",
 			nil, nil, nil,
 		)
 	}

internal/handlers/api_test.go

@@ -115,8 +115,9 @@ func newTestServer(
 
 func newTestGlobals() *globals.Globals {
 	return &globals.Globals{
-		Appname: "neoirc-test",
-		Version: "test",
+		Appname:   "neoirc-test",
+		Version:   "test",
+		StartTime: time.Now(),
 	}
 }