feat: add per-IP rate limiting to login endpoint

Add a token-bucket rate limiter (golang.org/x/time/rate) that limits login attempts per client IP on POST /api/v1/login. Returns 429 Too Many Requests with a Retry-After header when the limit is exceeded. Configurable via LOGIN_RATE_LIMIT (requests/sec, default 1) and LOGIN_RATE_BURST (burst size, default 5). Stale per-IP entries are automatically cleaned up every 10 minutes. Only the login endpoint is rate-limited per sneak's instruction — session creation and registration use hashcash proof-of-work instead.
2026-03-19 23:13:52 -07:00
11 changed files with 935 additions and 663 deletions
--- a/README.md
+++ b/README.md
@@ -115,7 +115,7 @@ Everything else is IRC. `PRIVMSG`, `JOIN`, `PART`, `NICK`, `TOPIC`, `MODE`,
 Joining a nonexistent channel creates it. Channels disappear when empty. Nicks
 are unique per server. Identity starts with a key — a nick is a display name.
 Accounts are optional: you can create an anonymous session instantly, or
-set a password via the PASS command for multi-client access to a single session.
+register with a password for multi-client access to a single session.

 ### On the resemblance to JSON-RPC

@@ -149,62 +149,63 @@ not arbitrary choices — each one follows from the project's core thesis that
 IRC's command model is correct and only the transport and session management
 need to change.

-### Identity & Sessions — Cookie-Based Authentication
+### Identity & Sessions — Dual Authentication Model

-The server uses **HTTP cookies** for all authentication. There is no separate
-registration step — sessions start anonymous and can optionally set a password
-for multi-client access.
+The server supports two authentication paths: **anonymous sessions** for
+instant access, and **optional account registration** for multi-client access.

-#### Session Creation
+#### Anonymous Sessions (No Account Required)
+
+The simplest entry point. No registration, no passwords.

 - **Session creation**: client sends `POST /api/v1/session` with a desired
-  nick → server sets an **HttpOnly auth cookie** (`neoirc_auth`) containing
-  a cryptographically random value (64 hex characters) and returns the user
-  ID and nick in the JSON response body. No auth credential appears in the
-  JSON body.
- The auth cookie is HttpOnly, SameSite=Strict, and Secure when behind TLS.
-  Browsers handle cookies automatically. **CLI clients (curl, custom HTTP
-  clients) must explicitly save and send cookies** — e.g., using curl's
-  `-c`/`-b` flags or an HTTP cookie jar in their language's HTTP library.
- Sessions start anonymous — no password required. When the session expires
-  or the user QUITs, the nick is released.
+  nick → server assigns an **auth token** (64 hex characters of
+  cryptographically random bytes) and returns the user ID, nick, and token.
+- The auth token implicitly identifies the client. Clients present it via
+  `Authorization: Bearer <token>`.
+- Anonymous sessions are ephemeral — when the session expires or the user
+  QUITs, the nick is released and there is no way to reclaim it.

-#### Setting a Password (Optional, for Multi-Client Access)
+#### Registered Accounts (Optional)

-For users who want to access the same session from multiple devices:
+For users who want multi-client access (multiple devices sharing one session):

- **Set password via IRC PASS command**: the authenticated client sends
-  `POST /api/v1/messages` with `{"command":"PASS","body":["mypassword"]}`.
-  The server hashes the password with bcrypt and stores it on the session.
-  Password must be at least 8 characters.
- **Login from another client**: `POST /api/v1/login` with nick and password →
-  server verifies the password, creates a new client for the existing session,
-  and sets an auth cookie. Channel memberships and message queues are shared.
-  Login only works while the session still exists — if all clients have logged
-  out or the user has sent QUIT, the session is deleted and the password is
-  lost.
+- **Registration**: client sends `POST /api/v1/register` with a nick and
+  password (minimum 8 characters) → server creates a session with the
+  password hashed via bcrypt, and returns the user ID, nick, and auth token.
+- **Login**: client sends `POST /api/v1/login` with nick and password →
+  server verifies the password against the stored bcrypt hash and creates a
+  new client token for the existing session. This enables multi-client
+  access: logging in from a new device adds a client to the existing session
+  rather than creating a new one, so channel memberships and message queues
+  are shared. Note: login only works while the session still exists — if all
+  clients have logged out or the user has sent QUIT, the session is deleted
+  and the registration is lost.
+- Registered accounts cannot be logged into via `POST /api/v1/session` —
+  that endpoint is for anonymous sessions only.
+- Anonymous sessions (created via `/session`) cannot be logged into via
+  `/login` because they have no password set.

-#### Common Properties
+#### Common Properties (Both Paths)

 - Nicks are changeable via the `NICK` command; the server-assigned user ID is
  the stable identity.
 - Server-assigned IDs — clients do not choose their own IDs.
- Auth cookies contain opaque random bytes, **not JWTs**. No claims, no expiry
-  encoded in the cookie value, no client-side decode. The server is the sole
-  authority on cookie validity.
+- Tokens are opaque random bytes, **not JWTs**. No claims, no expiry encoded
+  in the token, no client-side decode. The server is the sole authority on
+  token validity.

 **Rationale:** IRC has no accounts. You connect, pick a nick, and talk.
 Anonymous sessions preserve that simplicity — instant access, zero friction.
 But some users want to access the same session from multiple devices without
-a bouncer. The PASS command enables multi-client login without adding friction
-for casual users: if you don't need multi-client, just create a session and
-go. Cookie-based auth simplifies credential management — browsers handle
-cookies automatically, and CLI clients just need a cookie jar (e.g., curl's
-`-c`/`-b` flags). Note: both anonymous
-and password-protected sessions are deleted when the last client disconnects
-(QUIT or logout). Identity verification at the message layer via cryptographic
-signatures (see [Security Model](#security-model)) remains independent of
-password status.
+a bouncer. Optional registration with password enables multi-client login
+without adding friction for casual users: if you don't want an account,
+don't create one. Note: in the current implementation, both anonymous and
+registered sessions are deleted when the last client disconnects (QUIT or
+logout); registration does not make a session survive all-client
+removal. Identity verification at the message layer via cryptographic
+signatures (see [Security Model](#security-model)) remains independent
+of account registration.

 ### Hostmask (nick!user@host)

@@ -212,13 +213,13 @@ Each session has an IRC-style hostmask composed of three parts:

 - **nick** — the user's current nick (changes with `NICK` command)
 - **username** — an ident-like identifier set at session creation (optional
-  `username` field in the session request; defaults to the nick)
+  `username` field in the session/register request; defaults to the nick)
 - **hostname** — automatically resolved via reverse DNS of the connecting
  client's IP address at session creation time
 - **ip** — the real IP address of the session creator, extracted from
  `X-Forwarded-For`, `X-Real-IP`, or `RemoteAddr`

-Each **client connection** (created at session creation or login)
+Each **client connection** (created at session creation, registration, or login)
 also stores its own **ip** and **hostname**, allowing the server to track the
 network origin of each individual client independently from the session.
 Client-level IP and hostname are **not displayed to regular users**. They are
@@ -262,22 +263,23 @@ A single user session can have multiple clients (phone, laptop, terminal).
 - The server fans out all S2C messages to every active client queue for that
  user session.
 - `GET /api/v1/messages` delivers from the calling client's specific queue,
-  identified by the auth cookie.
+  identified by the auth token.
 - Client queues have **independent expiry/pruning** — one client going offline
  doesn't affect others.

 ```
 User Session
-├── Client A (cookie_a, queue_a)
-├── Client B (cookie_b, queue_b)
-└── Client C (cookie_c, queue_c)
+├── Client A (token_a, queue_a)
+├── Client B (token_b, queue_b)
+└── Client C (token_c, queue_c)
 ```

 **Multi-client via login:** The `POST /api/v1/login` endpoint adds a new
-client to an existing session (one that has a password set via PASS command),
-enabling true multi-client support (multiple cookies sharing one nick/session
-with independent message queues). Sessions without a password cannot be
-logged into.
+client to an existing registered session, enabling true multi-client support
+(multiple tokens sharing one nick/session with independent message queues).
+Anonymous sessions created via `POST /api/v1/session` always create a new
+user with a new nick. A future endpoint to "add a client to an existing
+anonymous session" is planned but not yet implemented.

 **Rationale:** The fundamental IRC mobile problem is that you can't have your
 phone and laptop connected simultaneously without a bouncer. Server-side
@@ -384,22 +386,19 @@ over binary is measured in bytes per message, not meaningful bandwidth. The
 canonicalization story (RFC 8785 JCS) is also well-defined for JSON, which
 matters for signing.

-### Why Opaque Cookies Instead of JWTs
+### Why Opaque Tokens Instead of JWTs

 JWTs encode claims that clients can decode and potentially rely on. This
 creates a coupling between token format and client behavior. If the server
 needs to revoke a token, change the expiry model, or add/remove claims, JWT
 clients may break or behave incorrectly.

-Opaque auth cookies are simpler:
- Server generates 32 random bytes → hex-encodes → stores SHA-256 hash →
-  sets raw hex as an HttpOnly cookie
- On each request, server hashes the cookie value and looks it up
- Revocation is a database delete (cookie becomes invalid immediately)
+Opaque tokens are simpler:
+- Server generates 32 random bytes → hex-encodes → stores SHA-256 hash
+- Client presents the raw token; server hashes and looks it up
+- Revocation is a database delete
 - No clock skew issues, no algorithm confusion, no "none" algorithm attacks
- Cookie format can change without breaking clients
- Browsers and HTTP cookie jars manage cookies automatically; CLI clients
-  must explicitly save and resend cookies (e.g., curl `-c`/`-b` flags)
+- Token format can change without breaking clients

 ---

@@ -423,18 +422,17 @@ The entire read/write loop for a client is two endpoints. Everything else

 ### Session Lifecycle

-#### Session Creation
+#### Anonymous Session

 ```
 ┌─ Client ──────────────────────────────────────────────────┐
 │                                                            │
 │  1. POST /api/v1/session {"nick":"alice"}                  │
-│     → Set-Cookie: neoirc_auth=<random_hex>; HttpOnly; ...  │
-│     → {"id":1, "nick":"alice"}                             │
+│     → {"id":1, "nick":"alice", "token":"a1b2c3..."}       │
 │                                                            │
 │  2. POST /api/v1/messages {"command":"JOIN","to":"#gen"}   │
 │     → {"status":"joined","channel":"#general"}             │
-│     (Cookie must be sent on all subsequent requests)       │
+│     (Server fans out JOIN event to all #general members)   │
 │                                                            │
 │  3. POST /api/v1/messages {"command":"PRIVMSG",            │
 │       "to":"#general","body":["hello"]}                    │
@@ -451,37 +449,31 @@ The entire read/write loop for a client is two endpoints. Everything else
 │  6. POST /api/v1/messages {"command":"QUIT"}               │
 │     → {"status":"quit"}                                    │
 │     (Server broadcasts QUIT, removes from channels,        │
-│      deletes session, releases nick, clears cookie)        │
+│      deletes session, releases nick)                       │
 │                                                            │
 └────────────────────────────────────────────────────────────┘
 ```

-#### Multi-Client via Password
+#### Registered Account

 ```
-┌─ Client A ────────────────────────────────────────────────┐
+┌─ Client ──────────────────────────────────────────────────┐
 │                                                            │
-│  1. POST /api/v1/session {"nick":"alice"}                  │
-│     → Set-Cookie: neoirc_auth=<cookie_a>; HttpOnly; ...    │
-│     → {"id":1, "nick":"alice"}                             │
-│                                                            │
-│  2. POST /api/v1/messages                                  │
-│     {"command":"PASS","body":["s3cret!!"]}                 │
-│     → {"status":"ok"}                                      │
-│     (Password set via IRC PASS command)                    │
+│  1. POST /api/v1/register                                  │
+│     {"nick":"alice", "password":"s3cret!!"}                │
+│     → {"id":1, "nick":"alice", "token":"a1b2c3..."}       │
+│     (Session created with bcrypt-hashed password)          │
 │                                                            │
 │  ... use the API normally (JOIN, PRIVMSG, poll, etc.) ...  │
 │                                                            │
-└────────────────────────────────────────────────────────────┘
-
-┌─ Client B (another device, while session is still active) ┐
+│  (From another device, while session is still active)      │
 │                                                            │
-│  3. POST /api/v1/login                                     │
+│  2. POST /api/v1/login                                     │
 │     {"nick":"alice", "password":"s3cret!!"}                │
-│     → Set-Cookie: neoirc_auth=<cookie_b>; HttpOnly; ...    │
-│     → {"id":1, "nick":"alice"}                             │
+│     → {"id":1, "nick":"alice", "token":"d4e5f6..."}       │
 │     (New client added to existing session — channels       │
-│      and message queues are preserved.)                    │
+│      and message queues are preserved. If all clients      │
+│      have logged out, session no longer exists.)           │
 │                                                            │
 └────────────────────────────────────────────────────────────┘
 ```
@@ -768,35 +760,6 @@ Change the user's nickname.

 **IRC reference:** RFC 1459 §4.1.2

-#### PASS — Set Session Password
-
-Set a password on the current session, enabling multi-client login via
-`POST /api/v1/login`. The password is hashed with bcrypt and stored
-server-side.
-
-**C2S:**
-```json
-{"command": "PASS", "body": ["mypassword"]}
-```
-
-**Behavior:**
-
- `body[0]` is the password. Must be at least 8 characters.
- On success, the server responds with `{"status": "ok"}`.
- If the password is too short or missing, the server sends
-  ERR_NEEDMOREPARAMS (461) via the message queue.
- Calling PASS again overwrites the previous password.
- Once a password is set, `POST /api/v1/login` can be used with the nick
-  and password to create additional clients on the same session.
-
-**Response:** `200 OK`
-```json
-{"status": "ok"}
-```
-
-**IRC reference:** Inspired by RFC 1459 §4.1.1 (PASS), repurposed for
-session password management.
-
 #### TOPIC — Set Channel Topic

 Set or change a channel's topic.
@@ -863,9 +826,9 @@ Destroy the session and disconnect from the server.
  quitting user. The quitting user does **not** receive their own QUIT.
 - The user is removed from all channels.
 - Empty channels are deleted (ephemeral).
- The user's session is destroyed — the auth cookie is invalidated, the nick
+- The user's session is destroyed — the auth token is invalidated, the nick
  is released.
- Subsequent requests with the old auth cookie return HTTP 401.
+- Subsequent requests with the old token return HTTP 401.

 **Response:** `200 OK`
 ```json
@@ -1192,8 +1155,8 @@ to compute stamps. Higher bit counts take exponentially longer to compute.
 ## API Reference

 All endpoints accept and return `application/json`. Authenticated endpoints
-require the `neoirc_auth` cookie, which is set automatically by
-`POST /api/v1/session` and `POST /api/v1/login`.
+require `Authorization: Bearer <token>` header. The token is obtained from
+`POST /api/v1/session`.

 All API responses include appropriate HTTP status codes. Error responses have
 the format:
@@ -1228,18 +1191,11 @@ the connecting client's IP address at session creation time. Together these form
 the hostmask used in WHOIS, WHO, and future ban matching (`+b`).

 **Response:** `201 Created`
-
-The response sets an `neoirc_auth` HttpOnly cookie containing an opaque auth
-value. The JSON body does **not** include the auth credential.
-
-```
-Set-Cookie: neoirc_auth=494ba9fc...e3; Path=/; HttpOnly; SameSite=Strict
-```
-
 ```json
 {
  "id": 1,
-  "nick": "alice"
+  "nick": "alice",
+  "token": "494ba9fc0f2242873fc5c285dd4a24fc3844ba5e67789a17e69b6fe5f8c132e3"
 }
 ```

@@ -1247,16 +1203,7 @@ Set-Cookie: neoirc_auth=494ba9fc...e3; Path=/; HttpOnly; SameSite=Strict
 |---------|---------|-------------|
 | `id`    | integer | Server-assigned user ID |
 | `nick`  | string  | Confirmed nick (always matches request on success) |
-
-**Cookie properties:**
-
-| Property   | Value |
-|------------|-------|
-| `Name`     | `neoirc_auth` |
-| `HttpOnly` | `true` (not accessible from JavaScript) |
-| `SameSite` | `Strict` (prevents CSRF) |
-| `Secure`   | `true` when behind TLS |
-| `Path`     | `/` |
+| `token` | string  | 64-character hex auth token. Store this — it's the only credential. |

 **Errors:**

@@ -1270,18 +1217,71 @@ Set-Cookie: neoirc_auth=494ba9fc...e3; Path=/; HttpOnly; SameSite=Strict

 **curl example:**
 ```bash
-# Use -c to save cookies, -b to send them
-curl -s -c cookies.txt -X POST http://localhost:8080/api/v1/session \
+TOKEN=$(curl -s -X POST http://localhost:8080/api/v1/session \
  -H 'Content-Type: application/json' \
-  -d '{"nick":"alice","pow_token":"1:20:260310:neoirc::3a2f1"}'
+  -d '{"nick":"alice","pow_token":"1:20:260310:neoirc::3a2f1"}' | jq -r .token)
+echo $TOKEN
+```
+
+### POST /api/v1/register — Register Account
+
+Create a new user session with a password. The password is hashed
+with bcrypt and stored server-side. The password enables login from
+additional clients via `POST /api/v1/login` while the session
+remains active.
+
+**Request Body:**
+```json
+{"nick": "alice", "username": "alice", "password": "mypassword"}
+```
+
+| Field      | Type   | Required | Constraints |
+|------------|--------|----------|-------------|
+| `nick`     | string | Yes      | 1–32 characters, must be unique on the server |
+| `username` | string | No       | 1–32 characters, IRC ident-style. Defaults to nick if omitted. |
+| `password` | string | Yes      | Minimum 8 characters |
+
+The `username` and hostname (auto-resolved via reverse DNS) form the IRC
+hostmask (`nick!user@host`) shown in WHOIS and WHO responses.
+
+**Response:** `201 Created`
+```json
+{
+  "id": 1,
+  "nick": "alice",
+  "token": "494ba9fc0f2242873fc5c285dd4a24fc3844ba5e67789a17e69b6fe5f8c132e3"
+}
+```
+
+| Field   | Type    | Description |
+|---------|---------|-------------|
+| `id`    | integer | Server-assigned user ID |
+| `nick`  | string  | Confirmed nick |
+| `token` | string  | 64-character hex auth token |
+
+**Errors:**
+
+| Status | Error | When |
+|--------|-------|------|
+| 400    | `invalid nick format` | Nick doesn't match allowed format |
+| 400    | `invalid username format` | Username doesn't match allowed format |
+| 400    | `password must be at least 8 characters` | Password too short |
+| 409    | `nick already taken` | Another active session holds this nick |
+
+**curl example:**
+```bash
+TOKEN=$(curl -s -X POST http://localhost:8080/api/v1/register \
+  -H 'Content-Type: application/json' \
+  -d '{"nick":"alice","password":"mypassword"}' | jq -r .token)
+echo $TOKEN
 ```

 ### POST /api/v1/login — Login to Account

-Authenticate with a nick and password (set via the PASS IRC command). Creates a
-new client for the existing session, preserving channel memberships and message
-queues. This is how multi-client access works: each login adds a new client to
-the session with its own auth cookie and message delivery queue.
+Authenticate with a previously registered nick and password. Creates a new
+client token for the existing session, preserving channel memberships and
+message queues. This is how multi-client access works for registered accounts:
+each login adds a new client to the session.

 On successful login, the server enqueues MOTD messages and synthetic channel
 state (JOIN + TOPIC + NAMES for each channel the session belongs to) into the
@@ -1294,37 +1294,37 @@ new client's queue, so the client can immediately restore its UI state.

 | Field      | Type   | Required | Constraints |
 |------------|--------|----------|-------------|
-| `nick`     | string | Yes      | Must match an active session with a password set |
-| `password` | string | Yes      | Must match the session's password |
+| `nick`     | string | Yes      | Must match a registered account |
+| `password` | string | Yes      | Must match the account's password |

 **Response:** `200 OK`
-
-The response sets an `neoirc_auth` HttpOnly cookie for the new client.
-
 ```json
 {
  "id": 1,
-  "nick": "alice"
+  "nick": "alice",
+  "token": "7e8f9a0b1c2d3e4f5a6b7c8d9e0f1a2b3c4d5e6f7a8b9c0d1e2f3a4b5c6d7e8f"
 }
 ```

 | Field   | Type    | Description |
 |---------|---------|-------------|
-| `id`    | integer | Session ID |
+| `id`    | integer | Session ID (same as when registered) |
 | `nick`  | string  | Current nick |
+| `token` | string  | New 64-character hex auth token for this client |

 **Errors:**

 | Status | Error | When |
 |--------|-------|------|
 | 400    | `nick and password required` | Missing nick or password |
-| 401    | `invalid credentials` | Wrong password, nick not found, or session has no password set |
+| 401    | `invalid credentials` | Wrong password, nick not found, or account has no password |

 **curl example:**
 ```bash
-curl -s -c cookies.txt -X POST http://localhost:8080/api/v1/login \
+TOKEN=$(curl -s -X POST http://localhost:8080/api/v1/login \
  -H 'Content-Type: application/json' \
-  -d '{"nick":"alice","password":"mypassword"}'
+  -d '{"nick":"alice","password":"mypassword"}' | jq -r .token)
+echo $TOKEN
 ```

 ### GET /api/v1/state — Get Session State
@@ -1368,13 +1368,13 @@ Each channel object:
 **curl example:**
 ```bash
 curl -s http://localhost:8080/api/v1/state \
-  -b cookies.txt | jq .
+  -H "Authorization: Bearer $TOKEN" | jq .
 ```

 **Reconnect with channel state initialization:**
 ```bash
 curl -s "http://localhost:8080/api/v1/state?initChannelState=1" \
-  -b cookies.txt | jq .
+  -H "Authorization: Bearer $TOKEN" | jq .
 ```

 ### GET /api/v1/messages — Poll Messages (Long-Poll)
@@ -1434,12 +1434,14 @@ real-time endpoint — clients call it in a loop.

 **curl example (immediate):**
 ```bash
-curl -s -b cookies.txt "http://localhost:8080/api/v1/messages?after=0&timeout=0" | jq .
+curl -s "http://localhost:8080/api/v1/messages?after=0&timeout=0" \
+  -H "Authorization: Bearer $TOKEN" | jq .
 ```

 **curl example (long-poll, 15s):**
 ```bash
-curl -s -b cookies.txt "http://localhost:8080/api/v1/messages?after=42&timeout=15" | jq .
+curl -s "http://localhost:8080/api/v1/messages?after=42&timeout=15" \
+  -H "Authorization: Bearer $TOKEN" | jq .
 ```

 ### POST /api/v1/messages — Send Command
@@ -1466,7 +1468,6 @@ reference with all required and optional fields.
 | `JOIN`    | `to`                |               | 200 OK          |
 | `PART`    | `to`                | `body`        | 200 OK          |
 | `NICK`    | `body`              |               | 200 OK          |
-| `PASS`    | `body`              |               | 200 OK          |
 | `TOPIC`   | `to`, `body`        |               | 200 OK          |
 | `MODE`    | `to`                |               | 200 OK          |
 | `NAMES`   | `to`                |               | 200 OK          |
@@ -1482,14 +1483,14 @@ 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 cookies (401), and server errors (500).
+auth tokens (401), and server errors (500).

 **HTTP errors (transport-level only):**

 | Status | Error | When |
 |--------|-------|------|
 | 400    | `invalid request` | Malformed JSON or empty command |
-| 401    | `unauthorized` | Missing or invalid auth cookie |
+| 401    | `unauthorized` | Missing or invalid auth token |
 | 500    | `internal error` | Server-side failure |

 **IRC numeric error replies (delivered via message queue):**
@@ -1584,11 +1585,11 @@ events). Event messages are delivered via the live queue only.
 ```bash
 # Latest 50 messages in #general
 curl -s "http://localhost:8080/api/v1/history?target=%23general&limit=50" \
-  -b cookies.txt | jq .
+  -H "Authorization: Bearer $TOKEN" | jq .

 # Older messages (pagination)
 curl -s "http://localhost:8080/api/v1/history?target=%23general&before=100&limit=50" \
-  -b cookies.txt | jq .
+  -H "Authorization: Bearer $TOKEN" | jq .
 ```

 ### GET /api/v1/channels — List Channels
@@ -1619,22 +1620,18 @@ List members of a channel. The `{name}` parameter is the channel name
 **curl example:**
 ```bash
 curl -s http://localhost:8080/api/v1/channels/general/members \
-  -b cookies.txt | jq .
+  -H "Authorization: Bearer $TOKEN" | jq .
 ```

 ### POST /api/v1/logout — Logout

-Destroy the current client's session cookie and server-side client record.
-If no other clients remain on the session, the user is fully cleaned up:
-parted from all channels (with QUIT broadcast to members), session deleted,
-nick released. The auth cookie is cleared in the response.
+Destroy the current client's auth token. If no other clients remain on the
+session, the user is fully cleaned up: parted from all channels (with QUIT
+broadcast to members), session deleted, nick released.

-**Request:** No body. Requires auth cookie.
+**Request:** No body. Requires auth.

 **Response:** `200 OK`
-
-The response clears the `neoirc_auth` cookie.
-
 ```json
 {"status": "ok"}
 ```
@@ -1643,11 +1640,12 @@ The response clears the `neoirc_auth` cookie.

 | Status | Error | When |
 |--------|-------|------|
-| 401    | `unauthorized` | Missing or invalid auth cookie |
+| 401    | `unauthorized` | Missing or invalid auth token |

 **curl example:**
 ```bash
-curl -s -b cookies.txt -c cookies.txt -X POST http://localhost:8080/api/v1/logout | jq .
+curl -s -X POST http://localhost:8080/api/v1/logout \
+  -H "Authorization: Bearer $TOKEN" | jq .
 ```

 ### GET /api/v1/users/me — Current User Info
@@ -1671,7 +1669,7 @@ Return the current user's session state. This is an alias for
 **curl example:**
 ```bash
 curl -s http://localhost:8080/api/v1/users/me \
-  -b cookies.txt | jq .
+  -H "Authorization: Bearer $TOKEN" | jq .
 ```

 ### GET /api/v1/server — Server Info
@@ -1916,21 +1914,20 @@ authenticity.

 ### Authentication

- **Cookie-based auth**: Opaque HttpOnly cookies (64 hex chars = 256 bits of
-  entropy). Cookie values are hashed (SHA-256) before storage and validated on
-  every request. Cookies are HttpOnly (no JavaScript access), SameSite=Strict
-  (CSRF protection), and Secure when behind TLS.
+- **Session auth**: Opaque bearer tokens (64 hex chars = 256 bits of entropy).
+  Tokens are hashed (SHA-256) before storage and validated on every request.
 - **Anonymous sessions**: `POST /api/v1/session` requires only a nick. No
-  password, instant access. The auth cookie is the sole credential.
- **Password-protected sessions**: The PASS IRC command sets a bcrypt-hashed
-  password on the session. `POST /api/v1/login` authenticates against the
-  stored hash and issues a new client cookie.
+  password, instant access. The token is the sole credential.
+- **Registered accounts**: `POST /api/v1/register` accepts a nick and password
+  (minimum 8 characters). The password is hashed with bcrypt at the default
+  cost factor and stored alongside the session. `POST /api/v1/login`
+  authenticates against the stored hash and issues a new client token.
 - **Password security**: Passwords are never stored in plain text. bcrypt
-  handles salting and key stretching automatically. Sessions without a
-  password cannot be logged into via `/login`.
- **Cookie security**: Auth cookies should only be transmitted over HTTPS in
-  production. If a cookie is compromised, the attacker has full access to the
-  session until QUIT or expiry.
+  handles salting and key stretching automatically. Anonymous sessions have
+  an empty `password_hash` and cannot be logged into via `/login`.
+- **Token security**: Tokens should be treated like session cookies. Transmit
+  only over HTTPS in production. If a token is compromised, the attacker has
+  full access to the session until QUIT or expiry.

 ### Message Integrity

@@ -1967,10 +1964,8 @@ authenticity.
 - **HTTPS is strongly recommended** for production deployments. The server
  itself serves plain HTTP — use a reverse proxy (nginx, Caddy, etc.) for TLS
  termination.
- **CORS**: The server allows all origins with credentials
-  (`Access-Control-Allow-Credentials: true`), reflecting the request Origin.
-  This enables cookie-based auth from cross-origin clients. Restrict origins
-  in production via reverse proxy configuration if needed.
+- **CORS**: The server allows all origins by default (`Access-Control-Allow-Origin: *`).
+  Restrict this in production via reverse proxy configuration if needed.
 - **Content-Security-Policy**: The server sets a strict CSP header on all
  responses, restricting resource loading to same-origin and disabling
  dangerous features (object embeds, framing, base tag injection). The
@@ -2096,16 +2091,16 @@ The database schema is managed via embedded SQL migration files in
 Index on `(uuid)`.

 #### `clients`
-| Column       | Type     | Description |
-|--------------|----------|-------------|
-| `id`         | INTEGER  | Primary key (auto-increment) |
-| `uuid`       | TEXT     | Unique client UUID |
-| `session_id` | INTEGER  | FK → sessions.id (cascade delete) |
-| `token`      | TEXT     | Auth cookie value (SHA-256 hash of the 64-hex-char cookie) |
-| `ip`         | TEXT     | Real IP address of this client connection |
-| `hostname`   | TEXT     | Reverse DNS hostname of this client connection |
-| `created_at` | DATETIME | Client creation time |
-| `last_seen`  | DATETIME | Last API request time |
+| Column      | Type     | Description |
+|-------------|----------|-------------|
+| `id`        | INTEGER  | Primary key (auto-increment) |
+| `uuid`      | TEXT     | Unique client UUID |
+| `session_id`| INTEGER  | FK → sessions.id (cascade delete) |
+| `token`     | TEXT     | Unique auth token (SHA-256 hash of 64 hex chars) |
+| `ip`        | TEXT     | Real IP address of this client connection |
+| `hostname`  | TEXT     | Reverse DNS hostname of this client connection |
+| `created_at`| DATETIME | Client creation time |
+| `last_seen` | DATETIME | Last API request time |

 Indexes on `(token)` and `(session_id)`.

@@ -2166,7 +2161,7 @@ skew issues) and simpler than UUIDs (integer comparison vs. string comparison).
 - **Client output queue entries**: Pruned automatically when older than
  `QUEUE_MAX_AGE` (default 30 days).
 - **Channels**: Deleted when the last member leaves (ephemeral).
- **Sessions**: Both anonymous and password-protected sessions are deleted on `QUIT`
+- **Sessions**: Both anonymous and registered sessions are deleted on `QUIT`
  or when the last client logs out (`POST /api/v1/logout` with no remaining
  clients triggers session cleanup). There is no distinction between session
  types in the cleanup path — `handleQuit` and `cleanupUser` both call
@@ -2174,7 +2169,7 @@ skew issues) and simpler than UUIDs (integer comparison vs. string comparison).
  after `SESSION_IDLE_TIMEOUT`
  (default 30 days) — the server runs a background cleanup loop that parts
  idle users from all channels, broadcasts QUIT, and releases their nicks.
- **Clients**: Individual client auth cookies are invalidated on `POST /api/v1/logout`.
+- **Clients**: Individual client tokens are deleted on `POST /api/v1/logout`.
  A session can have multiple clients; removing one doesn't affect others.
  However, when the last client is removed (via logout), the entire session
  is deleted — the user is parted from all channels, QUIT is broadcast, and
@@ -2322,7 +2317,7 @@ with an HTTP client library.
 A complete client needs only four HTTP calls:

 ```
-1. POST /api/v1/session          → get auth cookie
+1. POST /api/v1/session          → get token
 2. POST /api/v1/messages (JOIN)  → join channels
 3. GET  /api/v1/messages (loop)  → receive messages
 4. POST /api/v1/messages         → send messages
@@ -2331,59 +2326,68 @@ A complete client needs only four HTTP calls:
 ### Step-by-Step with curl

 ```bash
-# 1a. Create a session (cookie saved automatically with -c)
-curl -s -c cookies.txt -X POST http://localhost:8080/api/v1/session \
+# 1a. Create an anonymous session (no account)
+export TOKEN=$(curl -s -X POST http://localhost:8080/api/v1/session \
  -H 'Content-Type: application/json' \
-  -d '{"nick":"testuser"}'
+  -d '{"nick":"testuser"}' | jq -r .token)

-# 1b. Optionally set a password for multi-client access
-curl -s -b cookies.txt -X POST http://localhost:8080/api/v1/messages \
+# 1b. Or register an account (multi-client support)
+export TOKEN=$(curl -s -X POST http://localhost:8080/api/v1/register \
  -H 'Content-Type: application/json' \
-  -d '{"command":"PASS","body":["mypassword"]}'
+  -d '{"nick":"testuser","password":"mypassword"}' | jq -r .token)

-# 1c. Login from another device (saves new cookie)
-curl -s -c cookies2.txt -X POST http://localhost:8080/api/v1/login \
+# 1c. Or login to an existing account
+export TOKEN=$(curl -s -X POST http://localhost:8080/api/v1/login \
  -H 'Content-Type: application/json' \
-  -d '{"nick":"testuser","password":"mypassword"}'
+  -d '{"nick":"testuser","password":"mypassword"}' | jq -r .token)

 # 2. Join a channel
-curl -s -b cookies.txt -X POST http://localhost:8080/api/v1/messages \
+curl -s -X POST http://localhost:8080/api/v1/messages \
+  -H "Authorization: Bearer $TOKEN" \
  -H 'Content-Type: application/json' \
  -d '{"command":"JOIN","to":"#general"}'

 # 3. Send a message
-curl -s -b cookies.txt -X POST http://localhost:8080/api/v1/messages \
+curl -s -X POST http://localhost:8080/api/v1/messages \
+  -H "Authorization: Bearer $TOKEN" \
  -H 'Content-Type: application/json' \
  -d '{"command":"PRIVMSG","to":"#general","body":["hello from curl!"]}'

 # 4. Poll for messages (one-shot)
-curl -s -b cookies.txt "http://localhost:8080/api/v1/messages?after=0&timeout=0" | jq .
+curl -s "http://localhost:8080/api/v1/messages?after=0&timeout=0" \
+  -H "Authorization: Bearer $TOKEN" | jq .

 # 5. Long-poll (blocks up to 15s waiting for messages)
-curl -s -b cookies.txt "http://localhost:8080/api/v1/messages?after=0&timeout=15" | jq .
+curl -s "http://localhost:8080/api/v1/messages?after=0&timeout=15" \
+  -H "Authorization: Bearer $TOKEN" | jq .

 # 6. Send a DM
-curl -s -b cookies.txt -X POST http://localhost:8080/api/v1/messages \
+curl -s -X POST http://localhost:8080/api/v1/messages \
+  -H "Authorization: Bearer $TOKEN" \
  -H 'Content-Type: application/json' \
  -d '{"command":"PRIVMSG","to":"othernick","body":["hey!"]}'

 # 7. Change nick
-curl -s -b cookies.txt -X POST http://localhost:8080/api/v1/messages \
+curl -s -X POST http://localhost:8080/api/v1/messages \
+  -H "Authorization: Bearer $TOKEN" \
  -H 'Content-Type: application/json' \
  -d '{"command":"NICK","body":["newnick"]}'

 # 8. Set channel topic
-curl -s -b cookies.txt -X POST http://localhost:8080/api/v1/messages \
+curl -s -X POST http://localhost:8080/api/v1/messages \
+  -H "Authorization: Bearer $TOKEN" \
  -H 'Content-Type: application/json' \
  -d '{"command":"TOPIC","to":"#general","body":["New topic!"]}'

 # 9. Leave a channel
-curl -s -b cookies.txt -X POST http://localhost:8080/api/v1/messages \
+curl -s -X POST http://localhost:8080/api/v1/messages \
+  -H "Authorization: Bearer $TOKEN" \
  -H 'Content-Type: application/json' \
  -d '{"command":"PART","to":"#general","body":["goodbye"]}'

 # 10. Disconnect
-curl -s -b cookies.txt -X POST http://localhost:8080/api/v1/messages \
+curl -s -X POST http://localhost:8080/api/v1/messages \
+  -H "Authorization: Bearer $TOKEN" \
  -H 'Content-Type: application/json' \
  -d '{"command":"QUIT","body":["leaving"]}'
 ```
@@ -2393,25 +2397,27 @@ curl -s -b cookies.txt -X POST http://localhost:8080/api/v1/messages \
 The key to real-time messaging is the poll loop. Here's the pattern:

 ```python
-# Python example — using requests.Session for automatic cookie handling
-import requests, json, time
+# Python example
+import requests, json

 BASE = "http://localhost:8080/api/v1"
-session = requests.Session()  # Manages cookies automatically
+token = None
 last_id = 0

-# Create session (cookie set automatically via Set-Cookie header)
-resp = session.post(f"{BASE}/session", json={"nick": "pybot"})
-print(f"Session: {resp.json()}")
+# Create session
+resp = requests.post(f"{BASE}/session", json={"nick": "pybot"})
+token = resp.json()["token"]
+headers = {"Authorization": f"Bearer {token}"}

 # Join channel
-session.post(f"{BASE}/messages",
-             json={"command": "JOIN", "to": "#general"})
+requests.post(f"{BASE}/messages", headers=headers,
+              json={"command": "JOIN", "to": "#general"})

 # Poll loop
 while True:
    try:
-        resp = session.get(f"{BASE}/messages",
+        resp = requests.get(f"{BASE}/messages",
+                          headers=headers,
                          params={"after": last_id, "timeout": 15},
                          timeout=20)  # HTTP timeout > long-poll timeout
        data = resp.json()
@@ -2428,14 +2434,14 @@ while True:
 ```

 ```javascript
-// JavaScript/browser example — cookies sent automatically
-async function pollLoop() {
+// JavaScript/browser example
+async function pollLoop(token) {
  let lastId = 0;
  while (true) {
    try {
      const resp = await fetch(
        `/api/v1/messages?after=${lastId}&timeout=15`,
-        {credentials: 'same-origin'}  // Include cookies
+        {headers: {'Authorization': `Bearer ${token}`}}
      );
      if (resp.status === 401) { /* session expired */ break; }
      const data = await resp.json();
@@ -2467,10 +2473,11 @@ Clients should handle these message commands from the queue:

 ### Error Handling

- **HTTP 401**: Auth cookie expired or invalid. Re-create session or
-  re-login (if a password was set).
+- **HTTP 401**: Token expired or invalid. Re-create session (anonymous) or
+  re-login (registered account).
 - **HTTP 404**: Channel or user not found.
- **HTTP 409**: Nick already taken (on session creation or NICK change).
+- **HTTP 409**: Nick already taken (on session creation, registration, or
+  NICK change).
 - **HTTP 400**: Malformed request. Check the `error` field in the response.
 - **Network errors**: Back off exponentially (1s, 2s, 4s, ..., max 30s).

@@ -2487,11 +2494,10 @@ Clients should handle these message commands from the queue:
 4. **DM tab logic**: When you receive a PRIVMSG where `to` is not a channel
   (no `#` prefix), the DM tab should be keyed by the **other** user's nick:
   if `from` is you, use `to`; if `from` is someone else, use `from`.
-5. **Reconnection**: If the poll loop fails with 401, the auth cookie is
-   invalid. For sessions without a password, create a new session. For
-   sessions with a password set (via PASS command), log in again via
-   `POST /api/v1/login` to get a fresh cookie on the same session. If it
-   fails with a network error, retry with backoff.
+5. **Reconnection**: If the poll loop fails with 401, the token is invalid.
+   For anonymous sessions, create a new session. For registered accounts,
+   log in again via `POST /api/v1/login` to get a fresh token on the same
+   session. If it fails with a network error, retry with backoff.

 ---

@@ -2693,10 +2699,8 @@ guess is borne by the server (bcrypt), not the client.
  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)
- [x] **Multi-client sessions** — set a password via PASS command, then
-  login from additional devices via `POST /api/v1/login`
- [x] **Cookie-based auth** — HttpOnly cookies replace Bearer tokens for
-  all API authentication
+- [ ] **Multi-client sessions** — add client to existing session
+  (share nick across devices)

 ### Future (1.0+)

@@ -2809,12 +2813,13 @@ neoirc/
   build a working IRC-style TUI client against this API in an afternoon, the
   API is too complex.

-2. **Passwords optional** — anonymous sessions are instant: pick a nick and
+2. **Accounts optional** — anonymous sessions are instant: pick a nick and
   talk. No registration, no email verification. The cost of entry is a
   hashcash proof, not bureaucracy. For users who want multi-client access
-   (multiple devices sharing one session), the PASS command sets a password
-   on the session — but it's never required. Identity verification at the
-   message layer uses cryptographic signing, independent of password status.
+   (multiple devices sharing one session), optional account registration
+   with password is available — but never required. Identity
+   verification at the message layer uses cryptographic signing,
+   independent of account status.

 3. **IRC semantics over HTTP** — command names and numeric codes from
   RFC 1459/2812. If you've built an IRC client or bot, you already know the
--- a/internal/cli/api/client.go
+++ b/internal/cli/api/client.go
@@ -9,7 +9,6 @@ import (
 	"fmt"
 	"io"
 	"net/http"
-	"net/http/cookiejar"
 	"net/url"
 	"strconv"
 	"strings"
@@ -29,19 +28,16 @@ var errHTTP = errors.New("HTTP error")
 // Client wraps HTTP calls to the neoirc server API.
 type Client struct {
 	BaseURL    string
+	Token      string
 	HTTPClient *http.Client
 }

-// NewClient creates a new API client with a cookie jar
-// for automatic auth cookie management.
+// NewClient creates a new API client.
 func NewClient(baseURL string) *Client {
-	jar, _ := cookiejar.New(nil)
-
-	return &Client{
+	return &Client{ //nolint:exhaustruct // Token set after CreateSession
 		BaseURL: baseURL,
 		HTTPClient: &http.Client{ //nolint:exhaustruct // defaults fine
 			Timeout: httpTimeout,
-			Jar:     jar,
 		},
 	}
 }
@@ -83,6 +79,8 @@ func (client *Client) CreateSession(
 		return nil, fmt.Errorf("decode session: %w", err)
 	}

+	client.Token = resp.Token
+
 	return &resp, nil
 }

@@ -123,7 +121,6 @@ func (client *Client) PollMessages(
 		Timeout: time.Duration(
 			timeout+pollExtraTime,
 		) * time.Second,
-		Jar: client.HTTPClient.Jar,
 	}

 	params := url.Values{}
@@ -148,6 +145,10 @@ func (client *Client) PollMessages(
 		return nil, fmt.Errorf("new request: %w", err)
 	}

+	request.Header.Set(
+		"Authorization", "Bearer "+client.Token,
+	)
+
 	resp, err := pollClient.Do(request)
 	if err != nil {
 		return nil, fmt.Errorf("poll request: %w", err)
@@ -303,6 +304,12 @@ func (client *Client) do(
 		"Content-Type", "application/json",
 	)

+	if client.Token != "" {
+		request.Header.Set(
+			"Authorization", "Bearer "+client.Token,
+		)
+	}
+
 	resp, err := client.HTTPClient.Do(request)
 	if err != nil {
 		return nil, fmt.Errorf("http: %w", err)
--- a/internal/cli/api/types.go
+++ b/internal/cli/api/types.go
@@ -10,8 +10,9 @@ type SessionRequest struct {

 // SessionResponse is the response from session creation.
 type SessionResponse struct {
-	ID   int64  `json:"id"`
-	Nick string `json:"nick"`
+	ID    int64  `json:"id"`
+	Nick  string `json:"nick"`
+	Token string `json:"token"`
 }

 // StateResponse is the response from GET /api/v1/state.
--- a/internal/db/auth.go
+++ b/internal/db/auth.go
@@ -21,28 +21,86 @@ var errNoPassword = errors.New(
 	"account has no password set",
 )

-// SetPassword sets a bcrypt-hashed password on a session,
-// enabling multi-client login via POST /api/v1/login.
-func (database *Database) SetPassword(
+// RegisterUser creates a session with a hashed password
+// and returns session ID, client ID, and token.
+func (database *Database) RegisterUser(
 	ctx context.Context,
-	sessionID int64,
-	password string,
-) error {
+	nick, password, username, hostname, remoteIP string,
+) (int64, int64, string, error) {
+	if username == "" {
+		username = nick
+	}
+
 	hash, err := bcrypt.GenerateFromPassword(
 		[]byte(password), bcryptCost,
 	)
 	if err != nil {
-		return fmt.Errorf("hash password: %w", err)
+		return 0, 0, "", fmt.Errorf(
+			"hash password: %w", err,
+		)
 	}

-	_, err = database.conn.ExecContext(ctx,
-		"UPDATE sessions SET password_hash = ? WHERE id = ?",
-		string(hash), sessionID)
+	sessionUUID := uuid.New().String()
+	clientUUID := uuid.New().String()
+
+	token, err := generateToken()
 	if err != nil {
-		return fmt.Errorf("set password: %w", err)
+		return 0, 0, "", err
 	}

-	return nil
+	now := time.Now()
+
+	transaction, err := database.conn.BeginTx(ctx, nil)
+	if err != nil {
+		return 0, 0, "", fmt.Errorf(
+			"begin tx: %w", err,
+		)
+	}
+
+	res, err := transaction.ExecContext(ctx,
+		`INSERT INTO sessions
+		 (uuid, nick, username, hostname, ip,
+		  password_hash, created_at, last_seen)
+		 VALUES (?, ?, ?, ?, ?, ?, ?, ?)`,
+		sessionUUID, nick, username, hostname,
+		remoteIP, string(hash), now, now)
+	if err != nil {
+		_ = transaction.Rollback()
+
+		return 0, 0, "", fmt.Errorf(
+			"create session: %w", err,
+		)
+	}
+
+	sessionID, _ := res.LastInsertId()
+
+	tokenHash := hashToken(token)
+
+	clientRes, err := transaction.ExecContext(ctx,
+		`INSERT INTO clients
+		 (uuid, session_id, token, ip, hostname,
+		  created_at, last_seen)
+		 VALUES (?, ?, ?, ?, ?, ?, ?)`,
+		clientUUID, sessionID, tokenHash,
+		remoteIP, hostname, now, now)
+	if err != nil {
+		_ = transaction.Rollback()
+
+		return 0, 0, "", fmt.Errorf(
+			"create client: %w", err,
+		)
+	}
+
+	clientID, _ := clientRes.LastInsertId()
+
+	err = transaction.Commit()
+	if err != nil {
+		return 0, 0, "", fmt.Errorf(
+			"commit registration: %w", err,
+		)
+	}
+
+	return sessionID, clientID, token, nil
 }

 // LoginUser verifies a nick/password and creates a new
--- a/internal/db/auth_test.go
+++ b/internal/db/auth_test.go
@@ -6,65 +6,126 @@ import (
 	_ "modernc.org/sqlite"
 )

-func TestSetPassword(t *testing.T) {
+func TestRegisterUser(t *testing.T) {
 	t.Parallel()

 	database := setupTestDB(t)
 	ctx := t.Context()

-	sessionID, _, _, err :=
-		database.CreateSession(ctx, "passuser", "", "", "")
+	sessionID, clientID, token, err :=
+		database.RegisterUser(ctx, "reguser", "password123", "", "", "")
 	if err != nil {
 		t.Fatal(err)
 	}

-	err = database.SetPassword(
-		ctx, sessionID, "password123",
-	)
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	// Verify we can now log in with the password.
-	loginSID, loginCID, loginToken, err :=
-		database.LoginUser(ctx, "passuser", "password123", "", "")
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	if loginSID == 0 || loginCID == 0 || loginToken == "" {
+	if sessionID == 0 || clientID == 0 || token == "" {
 		t.Fatal("expected valid ids and token")
 	}
+
+	// Verify session works via token lookup.
+	sid, cid, nick, err :=
+		database.GetSessionByToken(ctx, token)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if sid != sessionID || cid != clientID {
+		t.Fatal("session/client id mismatch")
+	}
+
+	if nick != "reguser" {
+		t.Fatalf("expected reguser, got %s", nick)
+	}
 }

-func TestSetPasswordThenWrongLogin(t *testing.T) {
+func TestRegisterUserWithUserHost(t *testing.T) {
 	t.Parallel()

 	database := setupTestDB(t)
 	ctx := t.Context()

-	sessionID, _, _, err :=
-		database.CreateSession(ctx, "wrongpw", "", "", "")
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	err = database.SetPassword(
-		ctx, sessionID, "correctpass",
+	sessionID, _, _, err := database.RegisterUser(
+		ctx, "reguhost", "password123",
+		"myident", "example.org", "",
 	)
 	if err != nil {
 		t.Fatal(err)
 	}

-	loginSID, loginCID, loginToken, loginErr :=
-		database.LoginUser(ctx, "wrongpw", "wrongpass12", "", "")
-	if loginErr == nil {
-		t.Fatal("expected error for wrong password")
+	info, err := database.GetSessionHostInfo(
+		ctx, sessionID,
+	)
+	if err != nil {
+		t.Fatal(err)
 	}

-	_ = loginSID
-	_ = loginCID
-	_ = loginToken
+	if info.Username != "myident" {
+		t.Fatalf(
+			"expected myident, got %s", info.Username,
+		)
+	}
+
+	if info.Hostname != "example.org" {
+		t.Fatalf(
+			"expected example.org, got %s",
+			info.Hostname,
+		)
+	}
+}
+
+func TestRegisterUserDefaultUsername(t *testing.T) {
+	t.Parallel()
+
+	database := setupTestDB(t)
+	ctx := t.Context()
+
+	sessionID, _, _, err := database.RegisterUser(
+		ctx, "regdefault", "password123", "", "", "",
+	)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	info, err := database.GetSessionHostInfo(
+		ctx, sessionID,
+	)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if info.Username != "regdefault" {
+		t.Fatalf(
+			"expected regdefault, got %s",
+			info.Username,
+		)
+	}
+}
+
+func TestRegisterUserDuplicateNick(t *testing.T) {
+	t.Parallel()
+
+	database := setupTestDB(t)
+	ctx := t.Context()
+
+	regSID, regCID, regToken, err :=
+		database.RegisterUser(ctx, "dupnick", "password123", "", "", "")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	_ = regSID
+	_ = regCID
+	_ = regToken
+
+	dupSID, dupCID, dupToken, dupErr :=
+		database.RegisterUser(ctx, "dupnick", "other12345", "", "", "")
+	if dupErr == nil {
+		t.Fatal("expected error for duplicate nick")
+	}
+
+	_ = dupSID
+	_ = dupCID
+	_ = dupToken
 }

 func TestLoginUser(t *testing.T) {
@@ -73,26 +134,23 @@ func TestLoginUser(t *testing.T) {
 	database := setupTestDB(t)
 	ctx := t.Context()

-	sessionID, _, _, err :=
-		database.CreateSession(ctx, "loginuser", "", "", "")
+	regSID, regCID, regToken, err :=
+		database.RegisterUser(ctx, "loginuser", "mypassword", "", "", "")
 	if err != nil {
 		t.Fatal(err)
 	}

-	err = database.SetPassword(
-		ctx, sessionID, "mypassword",
-	)
-	if err != nil {
-		t.Fatal(err)
-	}
+	_ = regSID
+	_ = regCID
+	_ = regToken

-	loginSID, loginCID, token, err :=
+	sessionID, clientID, token, err :=
 		database.LoginUser(ctx, "loginuser", "mypassword", "", "")
 	if err != nil {
 		t.Fatal(err)
 	}

-	if loginSID == 0 || loginCID == 0 || token == "" {
+	if sessionID == 0 || clientID == 0 || token == "" {
 		t.Fatal("expected valid ids and token")
 	}

@@ -108,6 +166,110 @@ func TestLoginUser(t *testing.T) {
 	}
 }

+func TestLoginUserStoresClientIPHostname(t *testing.T) {
+	t.Parallel()
+
+	database := setupTestDB(t)
+	ctx := t.Context()
+
+	regSID, regCID, regToken, err := database.RegisterUser(
+		ctx, "loginipuser", "password123",
+		"", "", "10.0.0.1",
+	)
+
+	_ = regSID
+	_ = regCID
+	_ = regToken
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	_, clientID, _, err := database.LoginUser(
+		ctx, "loginipuser", "password123",
+		"10.0.0.99", "newhost.example.com",
+	)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	clientInfo, err := database.GetClientHostInfo(
+		ctx, clientID,
+	)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if clientInfo.IP != "10.0.0.99" {
+		t.Fatalf(
+			"expected client IP 10.0.0.99, got %s",
+			clientInfo.IP,
+		)
+	}
+
+	if clientInfo.Hostname != "newhost.example.com" {
+		t.Fatalf(
+			"expected hostname newhost.example.com, got %s",
+			clientInfo.Hostname,
+		)
+	}
+}
+
+func TestRegisterUserStoresSessionIP(t *testing.T) {
+	t.Parallel()
+
+	database := setupTestDB(t)
+	ctx := t.Context()
+
+	sessionID, _, _, err := database.RegisterUser(
+		ctx, "regipuser", "password123",
+		"ident", "host.local", "172.16.0.5",
+	)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	info, err := database.GetSessionHostInfo(
+		ctx, sessionID,
+	)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if info.IP != "172.16.0.5" {
+		t.Fatalf(
+			"expected session IP 172.16.0.5, got %s",
+			info.IP,
+		)
+	}
+}
+
+func TestLoginUserWrongPassword(t *testing.T) {
+	t.Parallel()
+
+	database := setupTestDB(t)
+	ctx := t.Context()
+
+	regSID, regCID, regToken, err :=
+		database.RegisterUser(ctx, "wrongpw", "correctpass", "", "", "")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	_ = regSID
+	_ = regCID
+	_ = regToken
+
+	loginSID, loginCID, loginToken, loginErr :=
+		database.LoginUser(ctx, "wrongpw", "wrongpass12", "", "")
+	if loginErr == nil {
+		t.Fatal("expected error for wrong password")
+	}
+
+	_ = loginSID
+	_ = loginCID
+	_ = loginToken
+}
+
 func TestLoginUserNoPassword(t *testing.T) {
 	t.Parallel()

--- a/internal/handlers/api.go
+++ b/internal/handlers/api.go
@@ -44,7 +44,6 @@ const (
 	defaultMaxBodySize = 4096
 	defaultHistLimit   = 50
 	maxHistLimit       = 500
-	authCookieName     = "neoirc_auth"
 )

 func (hdlr *Handlers) maxBodySize() int64 {
@@ -104,18 +103,23 @@ func resolveHostname(
 	return strings.TrimSuffix(names[0], ".")
 }

-// authSession extracts the session from the auth cookie.
+// authSession extracts the session from the client token.
 func (hdlr *Handlers) authSession(
 	request *http.Request,
 ) (int64, int64, string, error) {
-	cookie, err := request.Cookie(authCookieName)
-	if err != nil || cookie.Value == "" {
+	auth := request.Header.Get("Authorization")
+	if !strings.HasPrefix(auth, "Bearer ") {
+		return 0, 0, "", errUnauthorized
+	}
+
+	token := strings.TrimPrefix(auth, "Bearer ")
+	if token == "" {
 		return 0, 0, "", errUnauthorized
 	}

 	sessionID, clientID, nick, err :=
 		hdlr.params.Database.GetSessionByToken(
-			request.Context(), cookie.Value,
+			request.Context(), token,
 		)
 	if err != nil {
 		return 0, 0, "", fmt.Errorf("auth: %w", err)
@@ -124,46 +128,6 @@ func (hdlr *Handlers) authSession(
 	return sessionID, clientID, nick, nil
 }

-// setAuthCookie sets the authentication cookie on the
-// response.
-func (hdlr *Handlers) setAuthCookie(
-	writer http.ResponseWriter,
-	request *http.Request,
-	token string,
-) {
-	secure := request.TLS != nil ||
-		request.Header.Get("X-Forwarded-Proto") == "https"
-
-	http.SetCookie(writer, &http.Cookie{ //nolint:exhaustruct // optional fields
-		Name:     authCookieName,
-		Value:    token,
-		Path:     "/",
-		HttpOnly: true,
-		Secure:   secure,
-		SameSite: http.SameSiteStrictMode,
-	})
-}
-
-// clearAuthCookie removes the authentication cookie from
-// the client.
-func (hdlr *Handlers) clearAuthCookie(
-	writer http.ResponseWriter,
-	request *http.Request,
-) {
-	secure := request.TLS != nil ||
-		request.Header.Get("X-Forwarded-Proto") == "https"
-
-	http.SetCookie(writer, &http.Cookie{ //nolint:exhaustruct // optional fields
-		Name:     authCookieName,
-		Value:    "",
-		Path:     "/",
-		HttpOnly: true,
-		Secure:   secure,
-		SameSite: http.SameSiteStrictMode,
-		MaxAge:   -1,
-	})
-}
-
 func (hdlr *Handlers) requireAuth(
 	writer http.ResponseWriter,
 	request *http.Request,
@@ -331,11 +295,10 @@ func (hdlr *Handlers) executeCreateSession(

 	hdlr.deliverMOTD(request, clientID, sessionID, nick)

-	hdlr.setAuthCookie(writer, request, token)
-
 	hdlr.respondJSON(writer, request, map[string]any{
-		"id":   sessionID,
-		"nick": nick,
+		"id":    sessionID,
+		"nick":  nick,
+		"token": token,
 	}, http.StatusCreated)
 }

@@ -1040,11 +1003,6 @@ func (hdlr *Handlers) dispatchCommand(
 			writer, request,
 			sessionID, clientID, nick, bodyLines,
 		)
-	case irc.CmdPass:
-		hdlr.handlePass(
-			writer, request,
-			sessionID, clientID, nick, bodyLines,
-		)
 	case irc.CmdTopic:
 		hdlr.handleTopic(
 			writer, request,
@@ -2180,8 +2138,6 @@ func (hdlr *Handlers) handleQuit(
 		request.Context(), sessionID,
 	)

-	hdlr.clearAuthCookie(writer, request)
-
 	hdlr.respondJSON(writer, request,
 		map[string]string{"status": "quit"},
 		http.StatusOK)
@@ -3103,8 +3059,6 @@ func (hdlr *Handlers) HandleLogout() http.HandlerFunc {
 			)
 		}

-		hdlr.clearAuthCookie(writer, request)
-
 		hdlr.respondJSON(writer, request,
 			map[string]string{"status": "ok"},
 			http.StatusOK)
--- a/internal/handlers/api_test.go
+++ b/internal/handlers/api_test.go
@@ -40,16 +40,15 @@ func TestMain(m *testing.M) {
 }

 const (
-	commandKey     = "command"
-	bodyKey        = "body"
-	toKey          = "to"
-	statusKey      = "status"
-	privmsgCmd     = "PRIVMSG"
-	joinCmd        = "JOIN"
-	apiMessages    = "/api/v1/messages"
-	apiSession     = "/api/v1/session"
-	apiState       = "/api/v1/state"
-	authCookieName = "neoirc_auth"
+	commandKey  = "command"
+	bodyKey     = "body"
+	toKey       = "to"
+	statusKey   = "status"
+	privmsgCmd  = "PRIVMSG"
+	joinCmd     = "JOIN"
+	apiMessages = "/api/v1/messages"
+	apiSession  = "/api/v1/session"
+	apiState    = "/api/v1/state"
 )

 // testServer wraps a test HTTP server with helpers.
@@ -268,7 +267,7 @@ func doRequest(

 func doRequestAuth(
 	t *testing.T,
-	method, url, cookie string,
+	method, url, token string,
 	body io.Reader,
 ) (*http.Response, error) {
 	t.Helper()
@@ -286,11 +285,10 @@ func doRequestAuth(
 		)
 	}

-	if cookie != "" {
-		request.AddCookie(&http.Cookie{ //nolint:exhaustruct // only name+value needed
-			Name:  authCookieName,
-			Value: cookie,
-		})
+	if token != "" {
+		request.Header.Set(
+			"Authorization", "Bearer "+token,
+		)
 	}

 	resp, err := http.DefaultClient.Do(request)
@@ -333,19 +331,17 @@ func (tserver *testServer) createSession(
 		)
 	}

-	// Drain the body.
-	_, _ = io.ReadAll(resp.Body)
-
-	// Extract auth cookie from response.
-	for _, cookie := range resp.Cookies() {
-		if cookie.Name == authCookieName {
-			return cookie.Value
-		}
+	var result struct {
+		ID    int64  `json:"id"`
+		Token string `json:"token"`
 	}

-	tserver.t.Fatal("no auth cookie in response")
+	decErr := json.NewDecoder(resp.Body).Decode(&result)
+	if decErr != nil {
+		tserver.t.Fatalf("decode session: %v", decErr)
+	}

-	return ""
+	return result.Token
 }

 func (tserver *testServer) sendCommand(
@@ -502,10 +498,10 @@ func findNumeric(

 func TestCreateSessionValid(t *testing.T) {
 	tserver := newTestServer(t)
-	cookie := tserver.createSession("alice")
+	token := tserver.createSession("alice")

-	if cookie == "" {
-		t.Fatal("expected auth cookie")
+	if token == "" {
+		t.Fatal("expected token")
 	}
 }

@@ -627,7 +623,7 @@ func TestCreateSessionMalformed(t *testing.T) {
 	}
 }

-func TestAuthNoCookie(t *testing.T) {
+func TestAuthNoHeader(t *testing.T) {
 	tserver := newTestServer(t)

 	status, _ := tserver.getState("")
@@ -636,11 +632,11 @@ func TestAuthNoCookie(t *testing.T) {
 	}
 }

-func TestAuthBadCookie(t *testing.T) {
+func TestAuthBadToken(t *testing.T) {
 	tserver := newTestServer(t)

 	status, _ := tserver.getState(
-		"invalid-cookie-12345",
+		"invalid-token-12345",
 	)
 	if status != http.StatusUnauthorized {
 		t.Fatalf("expected 401, got %d", status)
@@ -1837,6 +1833,90 @@ func assertFieldGTE(
 	}
 }

+func TestRegisterValid(t *testing.T) {
+	tserver := newTestServer(t)
+
+	body, err := json.Marshal(map[string]string{
+		"nick": "reguser", "password": "password123",
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	resp, err := doRequest(
+		t,
+		http.MethodPost,
+		tserver.url("/api/v1/register"),
+		bytes.NewReader(body),
+	)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	defer func() { _ = resp.Body.Close() }()
+
+	if resp.StatusCode != http.StatusCreated {
+		respBody, _ := io.ReadAll(resp.Body)
+		t.Fatalf(
+			"expected 201, got %d: %s",
+			resp.StatusCode, respBody,
+		)
+	}
+
+	var result map[string]any
+
+	_ = json.NewDecoder(resp.Body).Decode(&result)
+
+	if result["token"] == nil || result["token"] == "" {
+		t.Fatal("expected token in response")
+	}
+
+	if result["nick"] != "reguser" {
+		t.Fatalf(
+			"expected reguser, got %v", result["nick"],
+		)
+	}
+}
+
+func TestRegisterDuplicate(t *testing.T) {
+	tserver := newTestServer(t)
+
+	body, err := json.Marshal(map[string]string{
+		"nick": "dupuser", "password": "password123",
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	resp, err := doRequest(
+		t,
+		http.MethodPost,
+		tserver.url("/api/v1/register"),
+		bytes.NewReader(body),
+	)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	_ = resp.Body.Close()
+
+	resp2, err := doRequest(
+		t,
+		http.MethodPost,
+		tserver.url("/api/v1/register"),
+		bytes.NewReader(body),
+	)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	defer func() { _ = resp2.Body.Close() }()
+
+	if resp2.StatusCode != http.StatusConflict {
+		t.Fatalf("expected 409, got %d", resp2.StatusCode)
+	}
+}
+
 func postJSONExpectStatus(
 	t *testing.T,
 	tserver *testServer,
@@ -1871,102 +1951,36 @@ func postJSONExpectStatus(
 	}
 }

-func TestPassCommand(t *testing.T) {
+func TestRegisterShortPassword(t *testing.T) {
 	tserver := newTestServer(t)
-	token := tserver.createSession("passuser")

-	// Drain initial messages.
-	_, _ = tserver.pollMessages(token, 0)
-
-	// Set password via PASS command.
-	status, result := tserver.sendCommand(
-		token,
-		map[string]any{
-			commandKey: "PASS",
-			bodyKey:    []string{"s3cure_pass"},
+	postJSONExpectStatus(
+		t, tserver, "/api/v1/register",
+		map[string]string{
+			"nick": "shortpw", "password": "short",
 		},
+		http.StatusBadRequest,
 	)
-	if status != http.StatusOK {
-		t.Fatalf(
-			"expected 200, got %d: %v", status, result,
-		)
-	}
-
-	if result[statusKey] != "ok" {
-		t.Fatalf(
-			"expected ok, got %v", result[statusKey],
-		)
-	}
 }

-func TestPassCommandShortPassword(t *testing.T) {
+func TestRegisterInvalidNick(t *testing.T) {
 	tserver := newTestServer(t)
-	token := tserver.createSession("shortpw")

-	// Drain initial messages.
-	_, lastID := tserver.pollMessages(token, 0)
-
-	// Try short password — should fail.
-	status, _ := tserver.sendCommand(
-		token,
-		map[string]any{
-			commandKey: "PASS",
-			bodyKey:    []string{"short"},
+	postJSONExpectStatus(
+		t, tserver, "/api/v1/register",
+		map[string]string{
+			"nick":     "bad nick!",
+			"password": "password123",
 		},
+		http.StatusBadRequest,
 	)
-	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,
-		)
-	}
-}
-
-func TestPassCommandEmpty(t *testing.T) {
-	tserver := newTestServer(t)
-	token := tserver.createSession("emptypw")
-
-	// Drain initial messages.
-	_, lastID := tserver.pollMessages(token, 0)
-
-	// Try empty password — should fail.
-	status, _ := tserver.sendCommand(
-		token,
-		map[string]any{commandKey: "PASS"},
-	)
-	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,
-		)
-	}
 }

 func TestLoginValid(t *testing.T) {
 	tserver := newTestServer(t)

-	// Create session and set password via PASS command.
-	token := tserver.createSession("loginuser")
-
-	tserver.sendCommand(token, map[string]any{
-		commandKey: "PASS",
-		bodyKey:    []string{"password123"},
-	})
-
-	// Login with nick + password.
-	loginBody, err := json.Marshal(map[string]string{
+	// Register first.
+	regBody, err := json.Marshal(map[string]string{
 		"nick": "loginuser", "password": "password123",
 	})
 	if err != nil {
@@ -1974,6 +1988,26 @@ func TestLoginValid(t *testing.T) {
 	}

 	resp, err := doRequest(
+		t,
+		http.MethodPost,
+		tserver.url("/api/v1/register"),
+		bytes.NewReader(regBody),
+	)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	_ = resp.Body.Close()
+
+	// Login.
+	loginBody, err := json.Marshal(map[string]string{
+		"nick": "loginuser", "password": "password123",
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	resp2, err := doRequest(
 		t,
 		http.MethodPost,
 		tserver.url("/api/v1/login"),
@@ -1983,33 +2017,31 @@ func TestLoginValid(t *testing.T) {
 		t.Fatal(err)
 	}

-	defer func() { _ = resp.Body.Close() }()
+	defer func() { _ = resp2.Body.Close() }()

-	if resp.StatusCode != http.StatusOK {
-		respBody, _ := io.ReadAll(resp.Body)
+	if resp2.StatusCode != http.StatusOK {
+		respBody, _ := io.ReadAll(resp2.Body)
 		t.Fatalf(
 			"expected 200, got %d: %s",
-			resp.StatusCode, respBody,
+			resp2.StatusCode, respBody,
 		)
 	}

-	// Extract auth cookie from login response.
-	var loginCookie string
+	var result map[string]any

-	for _, cookie := range resp.Cookies() {
-		if cookie.Name == authCookieName {
-			loginCookie = cookie.Value
+	_ = json.NewDecoder(resp2.Body).Decode(&result)

-			break
-		}
+	if result["token"] == nil || result["token"] == "" {
+		t.Fatal("expected token in response")
 	}

-	if loginCookie == "" {
-		t.Fatal("expected auth cookie from login")
+	// Verify token works.
+	token, ok := result["token"].(string)
+	if !ok {
+		t.Fatal("token not a string")
 	}

-	// Verify login cookie works for auth.
-	status, state := tserver.getState(loginCookie)
+	status, state := tserver.getState(token)
 	if status != http.StatusOK {
 		t.Fatalf("expected 200, got %d", status)
 	}
@@ -2025,22 +2057,49 @@ func TestLoginValid(t *testing.T) {
 func TestLoginWrongPassword(t *testing.T) {
 	tserver := newTestServer(t)

-	// Create session and set password via PASS command.
-	token := tserver.createSession("wrongpwuser")
-
-	tserver.sendCommand(token, map[string]any{
-		commandKey: "PASS",
-		bodyKey:    []string{"correctpass1"},
+	regBody, err := json.Marshal(map[string]string{
+		"nick": "wrongpwuser", "password": "correctpass1",
 	})
+	if err != nil {
+		t.Fatal(err)
+	}

-	postJSONExpectStatus(
-		t, tserver, "/api/v1/login",
-		map[string]string{
-			"nick":     "wrongpwuser",
-			"password": "wrongpass12",
-		},
-		http.StatusUnauthorized,
+	resp, err := doRequest(
+		t,
+		http.MethodPost,
+		tserver.url("/api/v1/register"),
+		bytes.NewReader(regBody),
 	)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	_ = resp.Body.Close()
+
+	loginBody, err := json.Marshal(map[string]string{
+		"nick": "wrongpwuser", "password": "wrongpass12",
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	resp2, err := doRequest(
+		t,
+		http.MethodPost,
+		tserver.url("/api/v1/login"),
+		bytes.NewReader(loginBody),
+	)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	defer func() { _ = resp2.Body.Close() }()
+
+	if resp2.StatusCode != http.StatusUnauthorized {
+		t.Fatalf(
+			"expected 401, got %d", resp2.StatusCode,
+		)
+	}
 }

 func TestLoginNonexistentUser(t *testing.T) {
@@ -2056,74 +2115,13 @@ func TestLoginNonexistentUser(t *testing.T) {
 	)
 }

-func TestSessionCookie(t *testing.T) {
-	tserver := newTestServer(t)
-
-	body, err := json.Marshal(
-		map[string]string{"nick": "cookietest"},
-	)
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	resp, err := doRequest(
-		t,
-		http.MethodPost,
-		tserver.url(apiSession),
-		bytes.NewReader(body),
-	)
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	defer func() { _ = resp.Body.Close() }()
-
-	if resp.StatusCode != http.StatusCreated {
-		t.Fatalf(
-			"expected 201, got %d", resp.StatusCode,
-		)
-	}
-
-	// Verify Set-Cookie header.
-	var authCookie *http.Cookie
-
-	for _, cookie := range resp.Cookies() {
-		if cookie.Name == authCookieName {
-			authCookie = cookie
-
-			break
-		}
-	}
-
-	if authCookie == nil {
-		t.Fatal("expected neoirc_auth cookie")
-	}
-
-	if !authCookie.HttpOnly {
-		t.Fatal("cookie should be HttpOnly")
-	}
-
-	if authCookie.SameSite != http.SameSiteStrictMode {
-		t.Fatal("cookie should be SameSite=Strict")
-	}
-
-	// Verify JSON body does NOT contain token.
-	var result map[string]any
-
-	_ = json.NewDecoder(resp.Body).Decode(&result)
-
-	if _, hasToken := result["token"]; hasToken {
-		t.Fatal("JSON body should not contain token")
-	}
-}
-
 func TestSessionStillWorks(t *testing.T) {
 	tserver := newTestServer(t)

 	// Verify anonymous session creation still works.
 	token := tserver.createSession("anon_user")
 	if token == "" {
-		t.Fatal("expected cookie for anonymous session")
+		t.Fatal("expected token for anonymous session")
 	}

 	status, state := tserver.getState(token)
@@ -2230,7 +2228,7 @@ func TestWhoisShowsHostInfo(t *testing.T) {
 }

 // createSessionWithUsername creates a session with a
-// specific username and returns the auth cookie value.
+// specific username and returns the token.
 func (tserver *testServer) createSessionWithUsername(
 	nick, username string,
 ) string {
@@ -2264,19 +2262,13 @@ func (tserver *testServer) createSessionWithUsername(
 		)
 	}

-	// Drain the body.
-	_, _ = io.ReadAll(resp.Body)
-
-	// Extract auth cookie from response.
-	for _, cookie := range resp.Cookies() {
-		if cookie.Name == authCookieName {
-			return cookie.Value
-		}
+	var result struct {
+		Token string `json:"token"`
 	}

-	tserver.t.Fatal("no auth cookie in response")
+	_ = json.NewDecoder(resp.Body).Decode(&result)

-	return ""
+	return result.Token
 }

 func TestWhoShowsHostInfo(t *testing.T) {
@@ -2454,13 +2446,25 @@ func TestLoginRateLimitExceeded(t *testing.T) {
 func TestLoginRateLimitAllowsNormalUse(t *testing.T) {
 	tserver := newTestServer(t)

-	// Create session and set password via PASS command.
-	token := tserver.createSession("normaluser")
-
-	tserver.sendCommand(token, map[string]any{
-		commandKey: "PASS",
-		bodyKey:    []string{"password123"},
+	// Register a user.
+	regBody, err := json.Marshal(map[string]string{
+		"nick": "normaluser", "password": "password123",
 	})
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	resp, err := doRequest(
+		t,
+		http.MethodPost,
+		tserver.url("/api/v1/register"),
+		bytes.NewReader(regBody),
+	)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	_ = resp.Body.Close()

 	// A single login should succeed without rate limiting.
 	loginBody, err := json.Marshal(map[string]string{
--- a/internal/handlers/auth.go
+++ b/internal/handlers/auth.go
@@ -5,11 +5,151 @@ import (
 	"net/http"
 	"strings"

-	"git.eeqj.de/sneak/neoirc/pkg/irc"
+	"git.eeqj.de/sneak/neoirc/internal/db"
 )

 const minPasswordLength = 8

+// HandleRegister creates a new user with a password.
+func (hdlr *Handlers) HandleRegister() http.HandlerFunc {
+	return func(
+		writer http.ResponseWriter,
+		request *http.Request,
+	) {
+		request.Body = http.MaxBytesReader(
+			writer, request.Body, hdlr.maxBodySize(),
+		)
+
+		hdlr.handleRegister(writer, request)
+	}
+}
+
+func (hdlr *Handlers) handleRegister(
+	writer http.ResponseWriter,
+	request *http.Request,
+) {
+	type registerRequest struct {
+		Nick     string `json:"nick"`
+		Username string `json:"username,omitempty"`
+		Password string `json:"password"`
+	}
+
+	var payload registerRequest
+
+	err := json.NewDecoder(request.Body).Decode(&payload)
+	if err != nil {
+		hdlr.respondError(
+			writer, request,
+			"invalid request body",
+			http.StatusBadRequest,
+		)
+
+		return
+	}
+
+	payload.Nick = strings.TrimSpace(payload.Nick)
+
+	if !validNickRe.MatchString(payload.Nick) {
+		hdlr.respondError(
+			writer, request,
+			"invalid nick format",
+			http.StatusBadRequest,
+		)
+
+		return
+	}
+
+	username := resolveUsername(
+		payload.Username, payload.Nick,
+	)
+
+	if !validUsernameRe.MatchString(username) {
+		hdlr.respondError(
+			writer, request,
+			"invalid username format",
+			http.StatusBadRequest,
+		)
+
+		return
+	}
+
+	if len(payload.Password) < minPasswordLength {
+		hdlr.respondError(
+			writer, request,
+			"password must be at least 8 characters",
+			http.StatusBadRequest,
+		)
+
+		return
+	}
+
+	hdlr.executeRegister(
+		writer, request,
+		payload.Nick, payload.Password, username,
+	)
+}
+
+func (hdlr *Handlers) executeRegister(
+	writer http.ResponseWriter,
+	request *http.Request,
+	nick, password, username string,
+) {
+	remoteIP := clientIP(request)
+
+	hostname := resolveHostname(
+		request.Context(), remoteIP,
+	)
+
+	sessionID, clientID, token, err :=
+		hdlr.params.Database.RegisterUser(
+			request.Context(),
+			nick, password, username, hostname, remoteIP,
+		)
+	if err != nil {
+		hdlr.handleRegisterError(
+			writer, request, err,
+		)
+
+		return
+	}
+
+	hdlr.stats.IncrSessions()
+	hdlr.stats.IncrConnections()
+
+	hdlr.deliverMOTD(request, clientID, sessionID, nick)
+
+	hdlr.respondJSON(writer, request, map[string]any{
+		"id":    sessionID,
+		"nick":  nick,
+		"token": token,
+	}, http.StatusCreated)
+}
+
+func (hdlr *Handlers) handleRegisterError(
+	writer http.ResponseWriter,
+	request *http.Request,
+	err error,
+) {
+	if db.IsUniqueConstraintError(err) {
+		hdlr.respondError(
+			writer, request,
+			"nick already taken",
+			http.StatusConflict,
+		)
+
+		return
+	}
+
+	hdlr.log.Error(
+		"register user failed", "error", err,
+	)
+	hdlr.respondError(
+		writer, request,
+		"internal error",
+		http.StatusInternalServerError,
+	)
+}
+
 // HandleLogin authenticates a user with nick and password.
 func (hdlr *Handlers) HandleLogin() http.HandlerFunc {
 	return func(
@@ -117,66 +257,9 @@ func (hdlr *Handlers) executeLogin(
 		request, clientID, sessionID, nick,
 	)

-	hdlr.setAuthCookie(writer, request, token)
-
 	hdlr.respondJSON(writer, request, map[string]any{
-		"id":   sessionID,
-		"nick": nick,
+		"id":    sessionID,
+		"nick":  nick,
+		"token": token,
 	}, http.StatusOK)
 }
-
-// handlePass handles the IRC PASS command to set a
-// password on the authenticated session, enabling
-// multi-client login via POST /api/v1/login.
-func (hdlr *Handlers) handlePass(
-	writer http.ResponseWriter,
-	request *http.Request,
-	sessionID, clientID int64,
-	nick string,
-	bodyLines func() []string,
-) {
-	lines := bodyLines()
-	if len(lines) == 0 || lines[0] == "" {
-		hdlr.respondIRCError(
-			writer, request, clientID, sessionID,
-			irc.ErrNeedMoreParams, nick,
-			[]string{irc.CmdPass},
-			"Not enough parameters",
-		)
-
-		return
-	}
-
-	password := lines[0]
-
-	if len(password) < minPasswordLength {
-		hdlr.respondIRCError(
-			writer, request, clientID, sessionID,
-			irc.ErrNeedMoreParams, nick,
-			[]string{irc.CmdPass},
-			"Password must be at least 8 characters",
-		)
-
-		return
-	}
-
-	err := hdlr.params.Database.SetPassword(
-		request.Context(), sessionID, password,
-	)
-	if err != nil {
-		hdlr.log.Error(
-			"set password failed", "error", err,
-		)
-		hdlr.respondError(
-			writer, request,
-			"internal error",
-			http.StatusInternalServerError,
-		)
-
-		return
-	}
-
-	hdlr.respondJSON(writer, request,
-		map[string]string{"status": "ok"},
-		http.StatusOK)
-}
--- a/internal/middleware/middleware.go
+++ b/internal/middleware/middleware.go
@@ -126,23 +126,18 @@ func (mware *Middleware) Logging() func(http.Handler) http.Handler {
 }

 // CORS returns middleware that handles Cross-Origin Resource Sharing.
-// AllowCredentials is true so browsers include cookies in
-// cross-origin API requests.
 func (mware *Middleware) CORS() func(http.Handler) http.Handler {
 	return cors.Handler(cors.Options{ //nolint:exhaustruct // optional fields
-		AllowOriginFunc: func(
-			_ *http.Request, _ string,
-		) bool {
-			return true
-		},
+		AllowedOrigins: []string{"*"},
 		AllowedMethods: []string{
 			"GET", "POST", "PUT", "DELETE", "OPTIONS",
 		},
 		AllowedHeaders: []string{
-			"Accept", "Content-Type", "X-CSRF-Token",
+			"Accept", "Authorization",
+			"Content-Type", "X-CSRF-Token",
 		},
 		ExposedHeaders:   []string{"Link"},
-		AllowCredentials: true,
+		AllowCredentials: false,
 		MaxAge:           corsMaxAge,
 	})
 }
--- a/internal/server/routes.go
+++ b/internal/server/routes.go
@@ -75,6 +75,10 @@ func (srv *Server) setupAPIv1(router chi.Router) {
 		"/session",
 		srv.handlers.HandleCreateSession(),
 	)
+	router.Post(
+		"/register",
+		srv.handlers.HandleRegister(),
+	)
 	router.Post(
 		"/login",
 		srv.handlers.HandleLogin(),
--- a/pkg/irc/commands.go
+++ b/pkg/irc/commands.go
@@ -12,7 +12,6 @@ const (
 	CmdNick    = "NICK"
 	CmdNotice  = "NOTICE"
 	CmdOper    = "OPER"
-	CmdPass    = "PASS"
 	CmdPart    = "PART"
 	CmdPing    = "PING"
 	CmdPong    = "PONG"