diff --git a/schema/README.md b/schema/README.md
index 25e2b8d..c40c61a 100644
--- a/schema/README.md
+++ b/schema/README.md
@@ -2,7 +2,8 @@
 
 JSON Schema (draft 2020-12) definitions for the IRC-style message protocol.
 
-All messages share a common envelope defined in [`message.schema.json`](message.schema.json).
+All messages share a common envelope defined in
+[`message.schema.json`](message.schema.json).
 
 ## Base Envelope
 
@@ -30,7 +31,7 @@ All messages share a common envelope defined in [`message.schema.json`](message.
 | MODE     | [`c2s/mode.schema.json`](c2s/mode.schema.json) | Set/query modes |
 | TOPIC    | [`c2s/topic.schema.json`](c2s/topic.schema.json) | Set/query topic |
 | KICK     | [`c2s/kick.schema.json`](c2s/kick.schema.json) | Kick user |
-| PING     | [`c2s/ping.schema.json`](c2s/ping.schema.json) | Client ping |
+| PING     | [`c2s/ping.schema.json`](c2s/ping.schema.json) | Client keepalive |
 | PUBKEY   | [`c2s/pubkey.schema.json`](c2s/pubkey.schema.json) | Announce public key |
 
 ## Server-to-Client (S2C)
diff --git a/schema/c2s/join.json b/schema/c2s/join.json
deleted file mode 100644
index a1b569c..0000000
--- a/schema/c2s/join.json
+++ /dev/null
@@ -1,17 +0,0 @@
-{
-  "$schema": "https://json-schema.org/draft/2020-12/schema",
-  "$id": "https://git.eeqj.de/sneak/chat/schema/c2s/join.json",
-  "title": "C2S Join",
-  "description": "Join a channel. Submitted via POST /api/v1/channels/join.",
-  "type": "object",
-  "properties": {
-    "channel": {
-      "type": "string",
-      "description": "Channel name (# prefix optional, server will add it).",
-      "pattern": "^#?[a-zA-Z0-9_-]+$",
-      "examples": ["#general", "dev"]
-    }
-  },
-  "required": ["channel"],
-  "additionalProperties": false
-}
diff --git a/schema/c2s/join.schema.json b/schema/c2s/join.schema.json
new file mode 100644
index 0000000..aab9a7c
--- /dev/null
+++ b/schema/c2s/join.schema.json
@@ -0,0 +1,23 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://git.eeqj.de/sneak/chat/schema/c2s/join.schema.json",
+  "title": "JOIN (C2S)",
+  "description": "Join a channel",
+  "$ref": "../message.schema.json",
+  "properties": {
+    "command": {
+      "const": "JOIN"
+    },
+    "body": {
+      "type": "array",
+      "items": {
+        "type": "string"
+      },
+      "description": "Not used"
+    }
+  },
+  "required": [
+    "command",
+    "to"
+  ]
+}
diff --git a/schema/c2s/kick.schema.json b/schema/c2s/kick.schema.json
new file mode 100644
index 0000000..7042bd6
--- /dev/null
+++ b/schema/c2s/kick.schema.json
@@ -0,0 +1,23 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://git.eeqj.de/sneak/chat/schema/c2s/kick.schema.json",
+  "title": "KICK (C2S)",
+  "description": "Kick user from channel",
+  "$ref": "../message.schema.json",
+  "properties": {
+    "command": {
+      "const": "KICK"
+    },
+    "body": {
+      "type": "array",
+      "items": {
+        "type": "string"
+      },
+      "description": "Kick reason"
+    }
+  },
+  "required": [
+    "command",
+    "to"
+  ]
+}
diff --git a/schema/c2s/mode.json b/schema/c2s/mode.json
deleted file mode 100644
index 402d0a5..0000000
--- a/schema/c2s/mode.json
+++ /dev/null
@@ -1,26 +0,0 @@
-{
-  "$schema": "https://json-schema.org/draft/2020-12/schema",
-  "$id": "https://git.eeqj.de/sneak/chat/schema/c2s/mode.json",
-  "title": "C2S Mode",
-  "description": "Set channel or user mode flags.",
-  "type": "object",
-  "properties": {
-    "channel": {
-      "type": "string",
-      "description": "Target channel.",
-      "pattern": "^#[a-zA-Z0-9_-]+$"
-    },
-    "mode": {
-      "type": "string",
-      "description": "Mode string (e.g. +o, -m, +v).",
-      "pattern": "^[+-][a-zA-Z]+$",
-      "examples": ["+o", "-m", "+v", "+i"]
-    },
-    "target": {
-      "type": "string",
-      "description": "Target nick for user modes (e.g. +o alice). Omit for channel modes."
-    }
-  },
-  "required": ["channel", "mode"],
-  "additionalProperties": false
-}
diff --git a/schema/c2s/mode.schema.json b/schema/c2s/mode.schema.json
new file mode 100644
index 0000000..3f8cc8a
--- /dev/null
+++ b/schema/c2s/mode.schema.json
@@ -0,0 +1,23 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://git.eeqj.de/sneak/chat/schema/c2s/mode.schema.json",
+  "title": "MODE (C2S)",
+  "description": "Set/query modes",
+  "$ref": "../message.schema.json",
+  "properties": {
+    "command": {
+      "const": "MODE"
+    },
+    "body": {
+      "type": "array",
+      "items": {
+        "type": "string"
+      },
+      "description": "Mode params"
+    }
+  },
+  "required": [
+    "command",
+    "to"
+  ]
+}
diff --git a/schema/c2s/nick.json b/schema/c2s/nick.json
deleted file mode 100644
index 7eda376..0000000
--- a/schema/c2s/nick.json
+++ /dev/null
@@ -1,18 +0,0 @@
-{
-  "$schema": "https://json-schema.org/draft/2020-12/schema",
-  "$id": "https://git.eeqj.de/sneak/chat/schema/c2s/nick.json",
-  "title": "C2S Nick",
-  "description": "Change the user's nickname.",
-  "type": "object",
-  "properties": {
-    "nick": {
-      "type": "string",
-      "description": "Desired new nickname.",
-      "minLength": 1,
-      "maxLength": 32,
-      "pattern": "^[a-zA-Z][a-zA-Z0-9_-]*$"
-    }
-  },
-  "required": ["nick"],
-  "additionalProperties": false
-}
diff --git a/schema/c2s/nick.schema.json b/schema/c2s/nick.schema.json
new file mode 100644
index 0000000..0341173
--- /dev/null
+++ b/schema/c2s/nick.schema.json
@@ -0,0 +1,23 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://git.eeqj.de/sneak/chat/schema/c2s/nick.schema.json",
+  "title": "NICK (C2S)",
+  "description": "Request nick change",
+  "$ref": "../message.schema.json",
+  "properties": {
+    "command": {
+      "const": "NICK"
+    },
+    "body": {
+      "type": "array",
+      "items": {
+        "type": "string"
+      },
+      "description": "Not used"
+    }
+  },
+  "required": [
+    "command",
+    "to"
+  ]
+}
diff --git a/schema/c2s/notice.schema.json b/schema/c2s/notice.schema.json
new file mode 100644
index 0000000..89cb838
--- /dev/null
+++ b/schema/c2s/notice.schema.json
@@ -0,0 +1,24 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://git.eeqj.de/sneak/chat/schema/c2s/notice.schema.json",
+  "title": "NOTICE (C2S)",
+  "description": "Send a notice (no auto-reply expected)",
+  "$ref": "../message.schema.json",
+  "properties": {
+    "command": {
+      "const": "NOTICE"
+    },
+    "body": {
+      "type": "array",
+      "items": {
+        "type": "string"
+      },
+      "description": "Text lines"
+    }
+  },
+  "required": [
+    "command",
+    "to",
+    "body"
+  ]
+}
diff --git a/schema/c2s/part.json b/schema/c2s/part.json
deleted file mode 100644
index 20e0a2f..0000000
--- a/schema/c2s/part.json
+++ /dev/null
@@ -1,22 +0,0 @@
-{
-  "$schema": "https://json-schema.org/draft/2020-12/schema",
-  "$id": "https://git.eeqj.de/sneak/chat/schema/c2s/part.json",
-  "title": "C2S Part",
-  "description": "Leave a channel. Submitted via DELETE /api/v1/channels/{name}.",
-  "type": "object",
-  "properties": {
-    "channel": {
-      "type": "string",
-      "description": "Channel name to leave.",
-      "pattern": "^#[a-zA-Z0-9_-]+$",
-      "examples": ["#general"]
-    },
-    "reason": {
-      "type": "string",
-      "description": "Optional part reason message.",
-      "maxLength": 256
-    }
-  },
-  "required": ["channel"],
-  "additionalProperties": false
-}
diff --git a/schema/c2s/part.schema.json b/schema/c2s/part.schema.json
new file mode 100644
index 0000000..c572558
--- /dev/null
+++ b/schema/c2s/part.schema.json
@@ -0,0 +1,23 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://git.eeqj.de/sneak/chat/schema/c2s/part.schema.json",
+  "title": "PART (C2S)",
+  "description": "Leave a channel",
+  "$ref": "../message.schema.json",
+  "properties": {
+    "command": {
+      "const": "PART"
+    },
+    "body": {
+      "type": "array",
+      "items": {
+        "type": "string"
+      },
+      "description": "Part message"
+    }
+  },
+  "required": [
+    "command",
+    "to"
+  ]
+}
diff --git a/schema/c2s/ping.json b/schema/c2s/ping.json
deleted file mode 100644
index e604ad5..0000000
--- a/schema/c2s/ping.json
+++ /dev/null
@@ -1,14 +0,0 @@
-{
-  "$schema": "https://json-schema.org/draft/2020-12/schema",
-  "$id": "https://git.eeqj.de/sneak/chat/schema/c2s/ping.json",
-  "title": "C2S Ping",
-  "description": "Client keepalive. Server responds with a pong.",
-  "type": "object",
-  "properties": {
-    "token": {
-      "type": "string",
-      "description": "Optional opaque token echoed back in the pong response."
-    }
-  },
-  "additionalProperties": false
-}
diff --git a/schema/c2s/ping.schema.json b/schema/c2s/ping.schema.json
new file mode 100644
index 0000000..6f6b5fe
--- /dev/null
+++ b/schema/c2s/ping.schema.json
@@ -0,0 +1,22 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://git.eeqj.de/sneak/chat/schema/c2s/ping.schema.json",
+  "title": "PING (C2S)",
+  "description": "Client keepalive",
+  "$ref": "../message.schema.json",
+  "properties": {
+    "command": {
+      "const": "PING"
+    },
+    "body": {
+      "type": "array",
+      "items": {
+        "type": "string"
+      },
+      "description": "Ping token"
+    }
+  },
+  "required": [
+    "command"
+  ]
+}
diff --git a/schema/c2s/privmsg.schema.json b/schema/c2s/privmsg.schema.json
new file mode 100644
index 0000000..a8032b4
--- /dev/null
+++ b/schema/c2s/privmsg.schema.json
@@ -0,0 +1,24 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://git.eeqj.de/sneak/chat/schema/c2s/privmsg.schema.json",
+  "title": "PRIVMSG (C2S)",
+  "description": "Send message to channel or user",
+  "$ref": "../message.schema.json",
+  "properties": {
+    "command": {
+      "const": "PRIVMSG"
+    },
+    "body": {
+      "type": "array",
+      "items": {
+        "type": "string"
+      },
+      "description": "Text lines"
+    }
+  },
+  "required": [
+    "command",
+    "to",
+    "body"
+  ]
+}
diff --git a/schema/c2s/pubkey.schema.json b/schema/c2s/pubkey.schema.json
new file mode 100644
index 0000000..47093f5
--- /dev/null
+++ b/schema/c2s/pubkey.schema.json
@@ -0,0 +1,33 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://git.eeqj.de/sneak/chat/schema/c2s/pubkey.schema.json",
+  "title": "PUBKEY (C2S)",
+  "description": "Announce public signing key",
+  "$ref": "../message.schema.json",
+  "properties": {
+    "command": {
+      "const": "PUBKEY"
+    },
+    "body": {
+      "type": "object",
+      "required": [
+        "alg",
+        "key"
+      ],
+      "properties": {
+        "alg": {
+          "type": "string",
+          "description": "Key algorithm (e.g. ed25519)"
+        },
+        "key": {
+          "type": "string",
+          "description": "Base64-encoded public key"
+        }
+      }
+    }
+  },
+  "required": [
+    "command",
+    "body"
+  ]
+}
diff --git a/schema/c2s/quit.schema.json b/schema/c2s/quit.schema.json
new file mode 100644
index 0000000..9fd70e4
--- /dev/null
+++ b/schema/c2s/quit.schema.json
@@ -0,0 +1,22 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://git.eeqj.de/sneak/chat/schema/c2s/quit.schema.json",
+  "title": "QUIT (C2S)",
+  "description": "Disconnect from server",
+  "$ref": "../message.schema.json",
+  "properties": {
+    "command": {
+      "const": "QUIT"
+    },
+    "body": {
+      "type": "array",
+      "items": {
+        "type": "string"
+      },
+      "description": "Quit message"
+    }
+  },
+  "required": [
+    "command"
+  ]
+}
diff --git a/schema/c2s/send.json b/schema/c2s/send.json
deleted file mode 100644
index 033717f..0000000
--- a/schema/c2s/send.json
+++ /dev/null
@@ -1,22 +0,0 @@
-{
-  "$schema": "https://json-schema.org/draft/2020-12/schema",
-  "$id": "https://git.eeqj.de/sneak/chat/schema/c2s/send.json",
-  "title": "C2S Send",
-  "description": "Send a message to a channel or user. Submitted via POST /api/v1/messages.",
-  "type": "object",
-  "properties": {
-    "to": {
-      "type": "string",
-      "description": "Target: channel name (prefixed with #) or nick for DM.",
-      "examples": ["#general", "alice"]
-    },
-    "content": {
-      "type": "string",
-      "description": "Message body (UTF-8 text).",
-      "minLength": 1,
-      "maxLength": 4096
-    }
-  },
-  "required": ["to", "content"],
-  "additionalProperties": false
-}
diff --git a/schema/c2s/topic.json b/schema/c2s/topic.json
deleted file mode 100644
index b6c30a0..0000000
--- a/schema/c2s/topic.json
+++ /dev/null
@@ -1,21 +0,0 @@
-{
-  "$schema": "https://json-schema.org/draft/2020-12/schema",
-  "$id": "https://git.eeqj.de/sneak/chat/schema/c2s/topic.json",
-  "title": "C2S Topic",
-  "description": "Set a channel's topic.",
-  "type": "object",
-  "properties": {
-    "channel": {
-      "type": "string",
-      "description": "Target channel.",
-      "pattern": "^#[a-zA-Z0-9_-]+$"
-    },
-    "topic": {
-      "type": "string",
-      "description": "New topic text. Empty string clears the topic.",
-      "maxLength": 512
-    }
-  },
-  "required": ["channel", "topic"],
-  "additionalProperties": false
-}
diff --git a/schema/c2s/topic.schema.json b/schema/c2s/topic.schema.json
new file mode 100644
index 0000000..5df67cd
--- /dev/null
+++ b/schema/c2s/topic.schema.json
@@ -0,0 +1,23 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://git.eeqj.de/sneak/chat/schema/c2s/topic.schema.json",
+  "title": "TOPIC (C2S)",
+  "description": "Set/query topic",
+  "$ref": "../message.schema.json",
+  "properties": {
+    "command": {
+      "const": "TOPIC"
+    },
+    "body": {
+      "type": "array",
+      "items": {
+        "type": "string"
+      },
+      "description": "Topic lines"
+    }
+  },
+  "required": [
+    "command",
+    "to"
+  ]
+}
diff --git a/schema/commands/JOIN.json b/schema/commands/JOIN.json
new file mode 100644
index 0000000..23e9c63
--- /dev/null
+++ b/schema/commands/JOIN.json
@@ -0,0 +1,23 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://git.eeqj.de/sneak/chat/schema/commands/JOIN.json",
+  "title": "JOIN",
+  "description": "Join a channel. C2S: request to join. S2C: notification that a user joined. RFC 1459 §4.2.1.",
+  "$ref": "../message.json",
+  "properties": {
+    "command": { "const": "JOIN" },
+    "from": {
+      "type": "string",
+      "description": "Nick that joined (S2C only)."
+    },
+    "to": {
+      "type": "string",
+      "description": "Channel name.",
+      "pattern": "^#[a-zA-Z0-9_-]+$"
+    }
+  },
+  "required": ["command", "to"],
+  "examples": [
+    { "command": "JOIN", "from": "alice", "to": "#general" }
+  ]
+}
diff --git a/schema/commands/NOTICE.json b/schema/commands/NOTICE.json
new file mode 100644
index 0000000..0f5e873
--- /dev/null
+++ b/schema/commands/NOTICE.json
@@ -0,0 +1,23 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://git.eeqj.de/sneak/chat/schema/commands/NOTICE.json",
+  "title": "NOTICE",
+  "description": "Send a notice. Like PRIVMSG but must not trigger automatic replies. RFC 1459 §4.4.2.",
+  "$ref": "../message.json",
+  "properties": {
+    "command": { "const": "NOTICE" },
+    "from": { "type": "string" },
+    "to": {
+      "type": "string",
+      "description": "Target: #channel, nick, or * (global)."
+    },
+    "body": {
+      "type": "string",
+      "description": "Notice text."
+    }
+  },
+  "required": ["command", "to", "body"],
+  "examples": [
+    { "command": "NOTICE", "from": "server.example.com", "to": "*", "body": "Server restarting in 5 minutes" }
+  ]
+}
diff --git a/schema/commands/PART.json b/schema/commands/PART.json
new file mode 100644
index 0000000..f71a02a
--- /dev/null
+++ b/schema/commands/PART.json
@@ -0,0 +1,27 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://git.eeqj.de/sneak/chat/schema/commands/PART.json",
+  "title": "PART",
+  "description": "Leave a channel. C2S: request to leave. S2C: notification that a user left. RFC 1459 §4.2.2.",
+  "$ref": "../message.json",
+  "properties": {
+    "command": { "const": "PART" },
+    "from": {
+      "type": "string",
+      "description": "Nick that left (S2C only)."
+    },
+    "to": {
+      "type": "string",
+      "description": "Channel name.",
+      "pattern": "^#[a-zA-Z0-9_-]+$"
+    },
+    "body": {
+      "type": "string",
+      "description": "Optional part reason."
+    }
+  },
+  "required": ["command", "to"],
+  "examples": [
+    { "command": "PART", "from": "alice", "to": "#general", "body": "later" }
+  ]
+}
diff --git a/schema/commands/PRIVMSG.json b/schema/commands/PRIVMSG.json
new file mode 100644
index 0000000..ea56928
--- /dev/null
+++ b/schema/commands/PRIVMSG.json
@@ -0,0 +1,29 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://git.eeqj.de/sneak/chat/schema/commands/PRIVMSG.json",
+  "title": "PRIVMSG",
+  "description": "Send a message to a channel or user. C2S: client sends to server. S2C: server relays to recipients. RFC 1459 §4.4.1.",
+  "$ref": "../message.json",
+  "properties": {
+    "command": { "const": "PRIVMSG" },
+    "from": {
+      "type": "string",
+      "description": "Sender nick (set by server on S2C relay)."
+    },
+    "to": {
+      "type": "string",
+      "description": "Target: #channel or nick.",
+      "examples": ["#general", "alice"]
+    },
+    "body": {
+      "type": "string",
+      "description": "Message text.",
+      "minLength": 1
+    }
+  },
+  "required": ["command", "to", "body"],
+  "examples": [
+    { "command": "PRIVMSG", "from": "bob", "to": "#general", "body": "hello world" },
+    { "command": "PRIVMSG", "from": "bob", "to": "alice", "body": "hey" }
+  ]
+}
diff --git a/schema/message.json b/schema/message.json
new file mode 100644
index 0000000..286d0ea
--- /dev/null
+++ b/schema/message.json
@@ -0,0 +1,46 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://git.eeqj.de/sneak/chat/schema/message.json",
+  "title": "IRC Message Envelope",
+  "description": "Base envelope for all messages. Mirrors IRC wire format (RFC 1459/2812) encoded as JSON over HTTP. The 'command' field carries either an IRC command name (PRIVMSG, JOIN, etc.) or a three-digit numeric reply code (001, 353, 433, etc.).",
+  "type": "object",
+  "properties": {
+    "id": {
+      "type": "integer",
+      "description": "Server-assigned message ID, monotonically increasing. Present on all server-originated messages."
+    },
+    "command": {
+      "type": "string",
+      "description": "IRC command name (PRIVMSG, JOIN, NICK, etc.) or three-digit numeric reply code (001, 353, 433, etc.).",
+      "examples": ["PRIVMSG", "JOIN", "001", "353", "433"]
+    },
+    "from": {
+      "type": "string",
+      "description": "Source — nick for user messages, server name for server messages. Equivalent to IRC prefix."
+    },
+    "to": {
+      "type": "string",
+      "description": "Target — channel (#name) or nick. Equivalent to first IRC parameter for most commands."
+    },
+    "params": {
+      "type": "array",
+      "items": { "type": "string" },
+      "description": "Additional parameters (used primarily by numeric replies). Equivalent to IRC middle parameters."
+    },
+    "body": {
+      "type": "string",
+      "description": "Message body / trailing parameter. Equivalent to IRC trailing parameter (after the colon)."
+    },
+    "ts": {
+      "type": "string",
+      "format": "date-time",
+      "description": "Server-assigned timestamp (ISO 8601). Not present in original IRC; added for HTTP transport."
+    },
+    "meta": {
+      "type": "object",
+      "description": "Extensible metadata (signatures, rich content hints, etc.). Not present in original IRC.",
+      "additionalProperties": true
+    }
+  },
+  "required": ["command"]
+}
diff --git a/schema/message.schema.json b/schema/message.schema.json
new file mode 100644
index 0000000..40d2dae
--- /dev/null
+++ b/schema/message.schema.json
@@ -0,0 +1,67 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://git.eeqj.de/sneak/chat/schema/message.schema.json",
+  "title": "Chat Message Envelope",
+  "description": "Base message envelope. Bodies MUST be objects or arrays (never raw strings) for deterministic canonicalization (RFC 8785 JCS) and signing.",
+  "type": "object",
+  "required": [
+    "command"
+  ],
+  "properties": {
+    "id": {
+      "type": "string",
+      "format": "uuid",
+      "description": "Server-assigned UUID"
+    },
+    "ts": {
+      "type": "string",
+      "format": "date-time",
+      "description": "Server-assigned timestamp (ISO 8601)"
+    },
+    "command": {
+      "type": "string",
+      "description": "IRC command name or numeric reply code"
+    },
+    "from": {
+      "type": "string",
+      "description": "Sender nick or server name"
+    },
+    "to": {
+      "type": "string",
+      "description": "Destination: channel (#foo) or nick"
+    },
+    "params": {
+      "type": "array",
+      "items": {
+        "type": "string"
+      },
+      "description": "Additional IRC-style parameters"
+    },
+    "body": {
+      "oneOf": [
+        {
+          "type": "array"
+        },
+        {
+          "type": "object"
+        }
+      ],
+      "description": "Message body (array or object, never raw string)"
+    },
+    "meta": {
+      "type": "object",
+      "description": "Extensible metadata",
+      "properties": {
+        "sig": {
+          "type": "string",
+          "description": "Cryptographic signature (base64)"
+        },
+        "alg": {
+          "type": "string",
+          "description": "Signature algorithm (e.g. ed25519)"
+        }
+      }
+    }
+  },
+  "additionalProperties": false
+}
diff --git a/schema/s2c/001.schema.json b/schema/s2c/001.schema.json
new file mode 100644
index 0000000..5786bdd
--- /dev/null
+++ b/schema/s2c/001.schema.json
@@ -0,0 +1,24 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://git.eeqj.de/sneak/chat/schema/s2c/001.schema.json",
+  "title": "001 RPL_WELCOME (S2C)",
+  "description": "Welcome message after registration",
+  "$ref": "../message.schema.json",
+  "properties": {
+    "command": {
+      "const": "001"
+    },
+    "body": {
+      "type": "array",
+      "items": {
+        "type": "string"
+      },
+      "description": "Response lines"
+    }
+  },
+  "required": [
+    "command",
+    "to",
+    "body"
+  ]
+}
diff --git a/schema/s2c/002.schema.json b/schema/s2c/002.schema.json
new file mode 100644
index 0000000..ef8571f
--- /dev/null
+++ b/schema/s2c/002.schema.json
@@ -0,0 +1,24 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://git.eeqj.de/sneak/chat/schema/s2c/002.schema.json",
+  "title": "002 RPL_YOURHOST (S2C)",
+  "description": "Server host information",
+  "$ref": "../message.schema.json",
+  "properties": {
+    "command": {
+      "const": "002"
+    },
+    "body": {
+      "type": "array",
+      "items": {
+        "type": "string"
+      },
+      "description": "Response lines"
+    }
+  },
+  "required": [
+    "command",
+    "to",
+    "body"
+  ]
+}
diff --git a/schema/s2c/322.schema.json b/schema/s2c/322.schema.json
new file mode 100644
index 0000000..f704405
--- /dev/null
+++ b/schema/s2c/322.schema.json
@@ -0,0 +1,24 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://git.eeqj.de/sneak/chat/schema/s2c/322.schema.json",
+  "title": "322 RPL_LIST (S2C)",
+  "description": "Channel list entry",
+  "$ref": "../message.schema.json",
+  "properties": {
+    "command": {
+      "const": "322"
+    },
+    "body": {
+      "type": "array",
+      "items": {
+        "type": "string"
+      },
+      "description": "Response lines"
+    }
+  },
+  "required": [
+    "command",
+    "to",
+    "body"
+  ]
+}
diff --git a/schema/s2c/353.schema.json b/schema/s2c/353.schema.json
new file mode 100644
index 0000000..d28371f
--- /dev/null
+++ b/schema/s2c/353.schema.json
@@ -0,0 +1,24 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://git.eeqj.de/sneak/chat/schema/s2c/353.schema.json",
+  "title": "353 RPL_NAMREPLY (S2C)",
+  "description": "Names list for a channel",
+  "$ref": "../message.schema.json",
+  "properties": {
+    "command": {
+      "const": "353"
+    },
+    "body": {
+      "type": "array",
+      "items": {
+        "type": "string"
+      },
+      "description": "Response lines"
+    }
+  },
+  "required": [
+    "command",
+    "to",
+    "body"
+  ]
+}
diff --git a/schema/s2c/366.schema.json b/schema/s2c/366.schema.json
new file mode 100644
index 0000000..522a411
--- /dev/null
+++ b/schema/s2c/366.schema.json
@@ -0,0 +1,24 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://git.eeqj.de/sneak/chat/schema/s2c/366.schema.json",
+  "title": "366 RPL_ENDOFNAMES (S2C)",
+  "description": "End of names list",
+  "$ref": "../message.schema.json",
+  "properties": {
+    "command": {
+      "const": "366"
+    },
+    "body": {
+      "type": "array",
+      "items": {
+        "type": "string"
+      },
+      "description": "Response lines"
+    }
+  },
+  "required": [
+    "command",
+    "to",
+    "body"
+  ]
+}
diff --git a/schema/s2c/372.schema.json b/schema/s2c/372.schema.json
new file mode 100644
index 0000000..d4469cd
--- /dev/null
+++ b/schema/s2c/372.schema.json
@@ -0,0 +1,24 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://git.eeqj.de/sneak/chat/schema/s2c/372.schema.json",
+  "title": "372 RPL_MOTD (S2C)",
+  "description": "Message of the day line",
+  "$ref": "../message.schema.json",
+  "properties": {
+    "command": {
+      "const": "372"
+    },
+    "body": {
+      "type": "array",
+      "items": {
+        "type": "string"
+      },
+      "description": "Response lines"
+    }
+  },
+  "required": [
+    "command",
+    "to",
+    "body"
+  ]
+}
diff --git a/schema/s2c/375.schema.json b/schema/s2c/375.schema.json
new file mode 100644
index 0000000..bfa7d88
--- /dev/null
+++ b/schema/s2c/375.schema.json
@@ -0,0 +1,24 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://git.eeqj.de/sneak/chat/schema/s2c/375.schema.json",
+  "title": "375 RPL_MOTDSTART (S2C)",
+  "description": "Start of MOTD",
+  "$ref": "../message.schema.json",
+  "properties": {
+    "command": {
+      "const": "375"
+    },
+    "body": {
+      "type": "array",
+      "items": {
+        "type": "string"
+      },
+      "description": "Response lines"
+    }
+  },
+  "required": [
+    "command",
+    "to",
+    "body"
+  ]
+}
diff --git a/schema/s2c/376.schema.json b/schema/s2c/376.schema.json
new file mode 100644
index 0000000..f5d34bb
--- /dev/null
+++ b/schema/s2c/376.schema.json
@@ -0,0 +1,24 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://git.eeqj.de/sneak/chat/schema/s2c/376.schema.json",
+  "title": "376 RPL_ENDOFMOTD (S2C)",
+  "description": "End of MOTD",
+  "$ref": "../message.schema.json",
+  "properties": {
+    "command": {
+      "const": "376"
+    },
+    "body": {
+      "type": "array",
+      "items": {
+        "type": "string"
+      },
+      "description": "Response lines"
+    }
+  },
+  "required": [
+    "command",
+    "to",
+    "body"
+  ]
+}
diff --git a/schema/s2c/401.schema.json b/schema/s2c/401.schema.json
new file mode 100644
index 0000000..1278cba
--- /dev/null
+++ b/schema/s2c/401.schema.json
@@ -0,0 +1,24 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://git.eeqj.de/sneak/chat/schema/s2c/401.schema.json",
+  "title": "401 ERR_NOSUCHNICK (S2C)",
+  "description": "No such nick or channel",
+  "$ref": "../message.schema.json",
+  "properties": {
+    "command": {
+      "const": "401"
+    },
+    "body": {
+      "type": "array",
+      "items": {
+        "type": "string"
+      },
+      "description": "Response lines"
+    }
+  },
+  "required": [
+    "command",
+    "to",
+    "body"
+  ]
+}
diff --git a/schema/s2c/403.schema.json b/schema/s2c/403.schema.json
new file mode 100644
index 0000000..2e0870d
--- /dev/null
+++ b/schema/s2c/403.schema.json
@@ -0,0 +1,24 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://git.eeqj.de/sneak/chat/schema/s2c/403.schema.json",
+  "title": "403 ERR_NOSUCHCHANNEL (S2C)",
+  "description": "No such channel",
+  "$ref": "../message.schema.json",
+  "properties": {
+    "command": {
+      "const": "403"
+    },
+    "body": {
+      "type": "array",
+      "items": {
+        "type": "string"
+      },
+      "description": "Response lines"
+    }
+  },
+  "required": [
+    "command",
+    "to",
+    "body"
+  ]
+}
diff --git a/schema/s2c/433.schema.json b/schema/s2c/433.schema.json
new file mode 100644
index 0000000..cef8c52
--- /dev/null
+++ b/schema/s2c/433.schema.json
@@ -0,0 +1,24 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://git.eeqj.de/sneak/chat/schema/s2c/433.schema.json",
+  "title": "433 ERR_NICKNAMEINUSE (S2C)",
+  "description": "Nickname already in use",
+  "$ref": "../message.schema.json",
+  "properties": {
+    "command": {
+      "const": "433"
+    },
+    "body": {
+      "type": "array",
+      "items": {
+        "type": "string"
+      },
+      "description": "Response lines"
+    }
+  },
+  "required": [
+    "command",
+    "to",
+    "body"
+  ]
+}
diff --git a/schema/s2c/dm.json b/schema/s2c/dm.json
deleted file mode 100644
index a47db8d..0000000
--- a/schema/s2c/dm.json
+++ /dev/null
@@ -1,37 +0,0 @@
-{
-  "$schema": "https://json-schema.org/draft/2020-12/schema",
-  "$id": "https://git.eeqj.de/sneak/chat/schema/s2c/dm.json",
-  "title": "S2C Direct Message",
-  "description": "A direct message delivered via the unified message stream.",
-  "type": "object",
-  "properties": {
-    "id": {
-      "type": "integer",
-      "description": "Server-assigned message ID."
-    },
-    "type": {
-      "const": "dm"
-    },
-    "ts": {
-      "type": "string",
-      "format": "date-time"
-    },
-    "from": {
-      "type": "string",
-      "description": "Sender nick."
-    },
-    "to": {
-      "type": "string",
-      "description": "Recipient nick."
-    },
-    "content": {
-      "type": "string",
-      "description": "Message body."
-    },
-    "meta": {
-      "type": "object",
-      "additionalProperties": true
-    }
-  },
-  "required": ["id", "type", "ts", "from", "to", "content"]
-}
diff --git a/schema/s2c/error.json b/schema/s2c/error.json
deleted file mode 100644
index 3eda1d4..0000000
--- a/schema/s2c/error.json
+++ /dev/null
@@ -1,33 +0,0 @@
-{
-  "$schema": "https://json-schema.org/draft/2020-12/schema",
-  "$id": "https://git.eeqj.de/sneak/chat/schema/s2c/error.json",
-  "title": "S2C Error",
-  "description": "Error message delivered via the message stream.",
-  "type": "object",
-  "properties": {
-    "id": {
-      "type": "integer"
-    },
-    "type": {
-      "const": "error"
-    },
-    "ts": {
-      "type": "string",
-      "format": "date-time"
-    },
-    "code": {
-      "type": "string",
-      "description": "Machine-readable error code.",
-      "examples": ["nick_in_use", "no_such_channel", "not_on_channel", "permission_denied"]
-    },
-    "content": {
-      "type": "string",
-      "description": "Human-readable error message."
-    },
-    "channel": {
-      "type": "string",
-      "description": "Related channel, if applicable."
-    }
-  },
-  "required": ["id", "type", "ts", "code", "content"]
-}
diff --git a/schema/s2c/error.schema.json b/schema/s2c/error.schema.json
new file mode 100644
index 0000000..fd4a92d
--- /dev/null
+++ b/schema/s2c/error.schema.json
@@ -0,0 +1,23 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://git.eeqj.de/sneak/chat/schema/s2c/error.schema.json",
+  "title": "ERROR (S2C)",
+  "description": "Server error",
+  "$ref": "../message.schema.json",
+  "properties": {
+    "command": {
+      "const": "ERROR"
+    },
+    "body": {
+      "type": "array",
+      "items": {
+        "type": "string"
+      },
+      "description": "Error lines"
+    }
+  },
+  "required": [
+    "command",
+    "body"
+  ]
+}
diff --git a/schema/s2c/join.json b/schema/s2c/join.json
deleted file mode 100644
index aa59bc4..0000000
--- a/schema/s2c/join.json
+++ /dev/null
@@ -1,29 +0,0 @@
-{
-  "$schema": "https://json-schema.org/draft/2020-12/schema",
-  "$id": "https://git.eeqj.de/sneak/chat/schema/s2c/join.json",
-  "title": "S2C Join",
-  "description": "A user joined a channel.",
-  "type": "object",
-  "properties": {
-    "id": {
-      "type": "integer"
-    },
-    "type": {
-      "const": "join"
-    },
-    "ts": {
-      "type": "string",
-      "format": "date-time"
-    },
-    "nick": {
-      "type": "string",
-      "description": "The nick that joined."
-    },
-    "channel": {
-      "type": "string",
-      "description": "The channel joined.",
-      "pattern": "^#[a-zA-Z0-9_-]+$"
-    }
-  },
-  "required": ["id", "type", "ts", "nick", "channel"]
-}
diff --git a/schema/s2c/join.schema.json b/schema/s2c/join.schema.json
new file mode 100644
index 0000000..10a0ff9
--- /dev/null
+++ b/schema/s2c/join.schema.json
@@ -0,0 +1,24 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://git.eeqj.de/sneak/chat/schema/s2c/join.schema.json",
+  "title": "JOIN (S2C)",
+  "description": "User joined a channel",
+  "$ref": "../message.schema.json",
+  "properties": {
+    "command": {
+      "const": "JOIN"
+    },
+    "body": {
+      "type": "array",
+      "items": {
+        "type": "string"
+      },
+      "description": "Not used"
+    }
+  },
+  "required": [
+    "command",
+    "from",
+    "to"
+  ]
+}
diff --git a/schema/s2c/kick.schema.json b/schema/s2c/kick.schema.json
new file mode 100644
index 0000000..b4503a6
--- /dev/null
+++ b/schema/s2c/kick.schema.json
@@ -0,0 +1,24 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://git.eeqj.de/sneak/chat/schema/s2c/kick.schema.json",
+  "title": "KICK (S2C)",
+  "description": "User kicked from channel",
+  "$ref": "../message.schema.json",
+  "properties": {
+    "command": {
+      "const": "KICK"
+    },
+    "body": {
+      "type": "array",
+      "items": {
+        "type": "string"
+      },
+      "description": "Kick reason"
+    }
+  },
+  "required": [
+    "command",
+    "from",
+    "to"
+  ]
+}
diff --git a/schema/s2c/message.json b/schema/s2c/message.json
deleted file mode 100644
index 8cd4d3b..0000000
--- a/schema/s2c/message.json
+++ /dev/null
@@ -1,40 +0,0 @@
-{
-  "$schema": "https://json-schema.org/draft/2020-12/schema",
-  "$id": "https://git.eeqj.de/sneak/chat/schema/s2c/message.json",
-  "title": "S2C Message",
-  "description": "A channel message delivered via the unified message stream.",
-  "type": "object",
-  "properties": {
-    "id": {
-      "type": "integer",
-      "description": "Server-assigned message ID, monotonically increasing."
-    },
-    "type": {
-      "const": "message"
-    },
-    "ts": {
-      "type": "string",
-      "format": "date-time",
-      "description": "Server-assigned timestamp (ISO 8601)."
-    },
-    "from": {
-      "type": "string",
-      "description": "Sender nick."
-    },
-    "channel": {
-      "type": "string",
-      "description": "Channel the message was sent to.",
-      "pattern": "^#[a-zA-Z0-9_-]+$"
-    },
-    "content": {
-      "type": "string",
-      "description": "Message body."
-    },
-    "meta": {
-      "type": "object",
-      "description": "Extensible metadata (signatures, rich content, etc.).",
-      "additionalProperties": true
-    }
-  },
-  "required": ["id", "type", "ts", "from", "channel", "content"]
-}
diff --git a/schema/s2c/mode.json b/schema/s2c/mode.json
deleted file mode 100644
index c2d5043..0000000
--- a/schema/s2c/mode.json
+++ /dev/null
@@ -1,37 +0,0 @@
-{
-  "$schema": "https://json-schema.org/draft/2020-12/schema",
-  "$id": "https://git.eeqj.de/sneak/chat/schema/s2c/mode.json",
-  "title": "S2C Mode",
-  "description": "A channel or user mode was changed.",
-  "type": "object",
-  "properties": {
-    "id": {
-      "type": "integer"
-    },
-    "type": {
-      "const": "mode"
-    },
-    "ts": {
-      "type": "string",
-      "format": "date-time"
-    },
-    "nick": {
-      "type": "string",
-      "description": "The nick that set the mode."
-    },
-    "channel": {
-      "type": "string",
-      "pattern": "^#[a-zA-Z0-9_-]+$"
-    },
-    "mode": {
-      "type": "string",
-      "description": "Mode string applied (e.g. +o, -m).",
-      "pattern": "^[+-][a-zA-Z]+$"
-    },
-    "target": {
-      "type": "string",
-      "description": "Target nick for user modes. Absent for channel modes."
-    }
-  },
-  "required": ["id", "type", "ts", "nick", "channel", "mode"]
-}
diff --git a/schema/s2c/mode.schema.json b/schema/s2c/mode.schema.json
new file mode 100644
index 0000000..be04679
--- /dev/null
+++ b/schema/s2c/mode.schema.json
@@ -0,0 +1,24 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://git.eeqj.de/sneak/chat/schema/s2c/mode.schema.json",
+  "title": "MODE (S2C)",
+  "description": "Mode change notification",
+  "$ref": "../message.schema.json",
+  "properties": {
+    "command": {
+      "const": "MODE"
+    },
+    "body": {
+      "type": "array",
+      "items": {
+        "type": "string"
+      },
+      "description": "Mode params"
+    }
+  },
+  "required": [
+    "command",
+    "from",
+    "to"
+  ]
+}
diff --git a/schema/s2c/nick.json b/schema/s2c/nick.json
deleted file mode 100644
index 32e1940..0000000
--- a/schema/s2c/nick.json
+++ /dev/null
@@ -1,28 +0,0 @@
-{
-  "$schema": "https://json-schema.org/draft/2020-12/schema",
-  "$id": "https://git.eeqj.de/sneak/chat/schema/s2c/nick.json",
-  "title": "S2C Nick",
-  "description": "A user changed their nickname.",
-  "type": "object",
-  "properties": {
-    "id": {
-      "type": "integer"
-    },
-    "type": {
-      "const": "nick"
-    },
-    "ts": {
-      "type": "string",
-      "format": "date-time"
-    },
-    "oldNick": {
-      "type": "string",
-      "description": "Previous nickname."
-    },
-    "newNick": {
-      "type": "string",
-      "description": "New nickname."
-    }
-  },
-  "required": ["id", "type", "ts", "oldNick", "newNick"]
-}
diff --git a/schema/s2c/nick.schema.json b/schema/s2c/nick.schema.json
new file mode 100644
index 0000000..8b0cce0
--- /dev/null
+++ b/schema/s2c/nick.schema.json
@@ -0,0 +1,24 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://git.eeqj.de/sneak/chat/schema/s2c/nick.schema.json",
+  "title": "NICK (S2C)",
+  "description": "User changed nick",
+  "$ref": "../message.schema.json",
+  "properties": {
+    "command": {
+      "const": "NICK"
+    },
+    "body": {
+      "type": "array",
+      "items": {
+        "type": "string"
+      },
+      "description": "Not used"
+    }
+  },
+  "required": [
+    "command",
+    "from",
+    "to"
+  ]
+}
diff --git a/schema/s2c/notice.json b/schema/s2c/notice.json
deleted file mode 100644
index b9bf1e3..0000000
--- a/schema/s2c/notice.json
+++ /dev/null
@@ -1,32 +0,0 @@
-{
-  "$schema": "https://json-schema.org/draft/2020-12/schema",
-  "$id": "https://git.eeqj.de/sneak/chat/schema/s2c/notice.json",
-  "title": "S2C Notice",
-  "description": "A server notice. May be targeted to a channel or user, or global.",
-  "type": "object",
-  "properties": {
-    "id": {
-      "type": "integer"
-    },
-    "type": {
-      "const": "notice"
-    },
-    "ts": {
-      "type": "string",
-      "format": "date-time"
-    },
-    "from": {
-      "type": "string",
-      "description": "Origin (server name or nick)."
-    },
-    "channel": {
-      "type": "string",
-      "description": "Target channel, if channel-scoped."
-    },
-    "content": {
-      "type": "string",
-      "description": "Notice text."
-    }
-  },
-  "required": ["id", "type", "ts", "content"]
-}
diff --git a/schema/s2c/notice.schema.json b/schema/s2c/notice.schema.json
new file mode 100644
index 0000000..738719a
--- /dev/null
+++ b/schema/s2c/notice.schema.json
@@ -0,0 +1,23 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://git.eeqj.de/sneak/chat/schema/s2c/notice.schema.json",
+  "title": "NOTICE (S2C)",
+  "description": "Server or user notice",
+  "$ref": "../message.schema.json",
+  "properties": {
+    "command": {
+      "const": "NOTICE"
+    },
+    "body": {
+      "type": "array",
+      "items": {
+        "type": "string"
+      },
+      "description": "Text lines"
+    }
+  },
+  "required": [
+    "command",
+    "body"
+  ]
+}
diff --git a/schema/s2c/part.json b/schema/s2c/part.json
deleted file mode 100644
index 69930fe..0000000
--- a/schema/s2c/part.json
+++ /dev/null
@@ -1,32 +0,0 @@
-{
-  "$schema": "https://json-schema.org/draft/2020-12/schema",
-  "$id": "https://git.eeqj.de/sneak/chat/schema/s2c/part.json",
-  "title": "S2C Part",
-  "description": "A user left a channel.",
-  "type": "object",
-  "properties": {
-    "id": {
-      "type": "integer"
-    },
-    "type": {
-      "const": "part"
-    },
-    "ts": {
-      "type": "string",
-      "format": "date-time"
-    },
-    "nick": {
-      "type": "string",
-      "description": "The nick that left."
-    },
-    "channel": {
-      "type": "string",
-      "pattern": "^#[a-zA-Z0-9_-]+$"
-    },
-    "reason": {
-      "type": "string",
-      "description": "Optional part reason."
-    }
-  },
-  "required": ["id", "type", "ts", "nick", "channel"]
-}
diff --git a/schema/s2c/part.schema.json b/schema/s2c/part.schema.json
new file mode 100644
index 0000000..9c05a99
--- /dev/null
+++ b/schema/s2c/part.schema.json
@@ -0,0 +1,24 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://git.eeqj.de/sneak/chat/schema/s2c/part.schema.json",
+  "title": "PART (S2C)",
+  "description": "User left a channel",
+  "$ref": "../message.schema.json",
+  "properties": {
+    "command": {
+      "const": "PART"
+    },
+    "body": {
+      "type": "array",
+      "items": {
+        "type": "string"
+      },
+      "description": "Part message"
+    }
+  },
+  "required": [
+    "command",
+    "from",
+    "to"
+  ]
+}
diff --git a/schema/s2c/pong.json b/schema/s2c/pong.json
deleted file mode 100644
index 57ff903..0000000
--- a/schema/s2c/pong.json
+++ /dev/null
@@ -1,24 +0,0 @@
-{
-  "$schema": "https://json-schema.org/draft/2020-12/schema",
-  "$id": "https://git.eeqj.de/sneak/chat/schema/s2c/pong.json",
-  "title": "S2C Pong",
-  "description": "Keepalive response to a client ping.",
-  "type": "object",
-  "properties": {
-    "id": {
-      "type": "integer"
-    },
-    "type": {
-      "const": "pong"
-    },
-    "ts": {
-      "type": "string",
-      "format": "date-time"
-    },
-    "token": {
-      "type": "string",
-      "description": "Echoed token from the client's ping, if provided."
-    }
-  },
-  "required": ["id", "type", "ts"]
-}
diff --git a/schema/s2c/pong.schema.json b/schema/s2c/pong.schema.json
new file mode 100644
index 0000000..a184887
--- /dev/null
+++ b/schema/s2c/pong.schema.json
@@ -0,0 +1,22 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://git.eeqj.de/sneak/chat/schema/s2c/pong.schema.json",
+  "title": "PONG (S2C)",
+  "description": "Server keepalive response",
+  "$ref": "../message.schema.json",
+  "properties": {
+    "command": {
+      "const": "PONG"
+    },
+    "body": {
+      "type": "array",
+      "items": {
+        "type": "string"
+      },
+      "description": "Pong token"
+    }
+  },
+  "required": [
+    "command"
+  ]
+}
diff --git a/schema/s2c/privmsg.schema.json b/schema/s2c/privmsg.schema.json
new file mode 100644
index 0000000..3e397d6
--- /dev/null
+++ b/schema/s2c/privmsg.schema.json
@@ -0,0 +1,25 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://git.eeqj.de/sneak/chat/schema/s2c/privmsg.schema.json",
+  "title": "PRIVMSG (S2C)",
+  "description": "Relayed message from a user",
+  "$ref": "../message.schema.json",
+  "properties": {
+    "command": {
+      "const": "PRIVMSG"
+    },
+    "body": {
+      "type": "array",
+      "items": {
+        "type": "string"
+      },
+      "description": "Text lines"
+    }
+  },
+  "required": [
+    "command",
+    "from",
+    "to",
+    "body"
+  ]
+}
diff --git a/schema/s2c/pubkey.schema.json b/schema/s2c/pubkey.schema.json
new file mode 100644
index 0000000..f720b0c
--- /dev/null
+++ b/schema/s2c/pubkey.schema.json
@@ -0,0 +1,34 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://git.eeqj.de/sneak/chat/schema/s2c/pubkey.schema.json",
+  "title": "PUBKEY (S2C)",
+  "description": "Relayed public key announcement",
+  "$ref": "../message.schema.json",
+  "properties": {
+    "command": {
+      "const": "PUBKEY"
+    },
+    "body": {
+      "type": "object",
+      "required": [
+        "alg",
+        "key"
+      ],
+      "properties": {
+        "alg": {
+          "type": "string",
+          "description": "Key algorithm (e.g. ed25519)"
+        },
+        "key": {
+          "type": "string",
+          "description": "Base64-encoded public key"
+        }
+      }
+    }
+  },
+  "required": [
+    "command",
+    "from",
+    "body"
+  ]
+}
diff --git a/schema/s2c/quit.json b/schema/s2c/quit.json
deleted file mode 100644
index e01d61b..0000000
--- a/schema/s2c/quit.json
+++ /dev/null
@@ -1,28 +0,0 @@
-{
-  "$schema": "https://json-schema.org/draft/2020-12/schema",
-  "$id": "https://git.eeqj.de/sneak/chat/schema/s2c/quit.json",
-  "title": "S2C Quit",
-  "description": "A user disconnected from the server.",
-  "type": "object",
-  "properties": {
-    "id": {
-      "type": "integer"
-    },
-    "type": {
-      "const": "quit"
-    },
-    "ts": {
-      "type": "string",
-      "format": "date-time"
-    },
-    "nick": {
-      "type": "string",
-      "description": "The nick that quit."
-    },
-    "reason": {
-      "type": "string",
-      "description": "Optional quit reason."
-    }
-  },
-  "required": ["id", "type", "ts", "nick"]
-}
diff --git a/schema/s2c/quit.schema.json b/schema/s2c/quit.schema.json
new file mode 100644
index 0000000..edb2395
--- /dev/null
+++ b/schema/s2c/quit.schema.json
@@ -0,0 +1,23 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://git.eeqj.de/sneak/chat/schema/s2c/quit.schema.json",
+  "title": "QUIT (S2C)",
+  "description": "User disconnected",
+  "$ref": "../message.schema.json",
+  "properties": {
+    "command": {
+      "const": "QUIT"
+    },
+    "body": {
+      "type": "array",
+      "items": {
+        "type": "string"
+      },
+      "description": "Quit message"
+    }
+  },
+  "required": [
+    "command",
+    "from"
+  ]
+}
diff --git a/schema/s2c/system.json b/schema/s2c/system.json
deleted file mode 100644
index b841d0a..0000000
--- a/schema/s2c/system.json
+++ /dev/null
@@ -1,29 +0,0 @@
-{
-  "$schema": "https://json-schema.org/draft/2020-12/schema",
-  "$id": "https://git.eeqj.de/sneak/chat/schema/s2c/system.json",
-  "title": "S2C System",
-  "description": "Server system message (MOTD, maintenance notices, etc.).",
-  "type": "object",
-  "properties": {
-    "id": {
-      "type": "integer"
-    },
-    "type": {
-      "const": "system"
-    },
-    "ts": {
-      "type": "string",
-      "format": "date-time"
-    },
-    "content": {
-      "type": "string",
-      "description": "System message text."
-    },
-    "code": {
-      "type": "string",
-      "description": "Optional machine-readable system message code.",
-      "examples": ["motd", "maintenance", "server_restart"]
-    }
-  },
-  "required": ["id", "type", "ts", "content"]
-}
diff --git a/schema/s2c/topic.json b/schema/s2c/topic.json
deleted file mode 100644
index a48d72d..0000000
--- a/schema/s2c/topic.json
+++ /dev/null
@@ -1,32 +0,0 @@
-{
-  "$schema": "https://json-schema.org/draft/2020-12/schema",
-  "$id": "https://git.eeqj.de/sneak/chat/schema/s2c/topic.json",
-  "title": "S2C Topic",
-  "description": "A channel topic was changed.",
-  "type": "object",
-  "properties": {
-    "id": {
-      "type": "integer"
-    },
-    "type": {
-      "const": "topic"
-    },
-    "ts": {
-      "type": "string",
-      "format": "date-time"
-    },
-    "nick": {
-      "type": "string",
-      "description": "The nick that changed the topic."
-    },
-    "channel": {
-      "type": "string",
-      "pattern": "^#[a-zA-Z0-9_-]+$"
-    },
-    "topic": {
-      "type": "string",
-      "description": "New topic text."
-    }
-  },
-  "required": ["id", "type", "ts", "nick", "channel", "topic"]
-}
diff --git a/schema/s2c/topic.schema.json b/schema/s2c/topic.schema.json
new file mode 100644
index 0000000..144b89c
--- /dev/null
+++ b/schema/s2c/topic.schema.json
@@ -0,0 +1,25 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://git.eeqj.de/sneak/chat/schema/s2c/topic.schema.json",
+  "title": "TOPIC (S2C)",
+  "description": "Topic change notification",
+  "$ref": "../message.schema.json",
+  "properties": {
+    "command": {
+      "const": "TOPIC"
+    },
+    "body": {
+      "type": "array",
+      "items": {
+        "type": "string"
+      },
+      "description": "Topic lines"
+    }
+  },
+  "required": [
+    "command",
+    "from",
+    "to",
+    "body"
+  ]
+}
diff --git a/schema/s2s/link.json b/schema/s2s/link.json
deleted file mode 100644
index f588f00..0000000
--- a/schema/s2s/link.json
+++ /dev/null
@@ -1,41 +0,0 @@
-{
-  "$schema": "https://json-schema.org/draft/2020-12/schema",
-  "$id": "https://git.eeqj.de/sneak/chat/schema/s2s/link.json",
-  "title": "S2S Link",
-  "description": "Server link establishment request/response.",
-  "type": "object",
-  "properties": {
-    "id": {
-      "type": "string",
-      "format": "uuid"
-    },
-    "type": {
-      "const": "link"
-    },
-    "ts": {
-      "type": "string",
-      "format": "date-time"
-    },
-    "origin": {
-      "type": "string",
-      "description": "Requesting server name."
-    },
-    "version": {
-      "type": "string",
-      "description": "Protocol version of the requesting server."
-    },
-    "auth": {
-      "type": "string",
-      "description": "HMAC signature over the link request using the shared federation key."
-    },
-    "capabilities": {
-      "type": "array",
-      "items": {
-        "type": "string"
-      },
-      "description": "List of supported protocol capabilities.",
-      "examples": [["relay", "sync", "presence"]]
-    }
-  },
-  "required": ["id", "type", "ts", "origin", "auth"]
-}
diff --git a/schema/s2s/link.schema.json b/schema/s2s/link.schema.json
new file mode 100644
index 0000000..1e07586
--- /dev/null
+++ b/schema/s2s/link.schema.json
@@ -0,0 +1,20 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://git.eeqj.de/sneak/chat/schema/s2s/link.schema.json",
+  "title": "LINK (S2S)",
+  "description": "Establish server link",
+  "$ref": "../message.schema.json",
+  "properties": {
+    "command": {
+      "const": "LINK"
+    },
+    "body": {
+      "type": "object",
+      "description": "Link parameters"
+    }
+  },
+  "required": [
+    "command",
+    "body"
+  ]
+}
diff --git a/schema/s2s/ping.json b/schema/s2s/ping.json
deleted file mode 100644
index 1fb7e10..0000000
--- a/schema/s2s/ping.json
+++ /dev/null
@@ -1,29 +0,0 @@
-{
-  "$schema": "https://json-schema.org/draft/2020-12/schema",
-  "$id": "https://git.eeqj.de/sneak/chat/schema/s2s/ping.json",
-  "title": "S2S Ping",
-  "description": "Inter-server keepalive.",
-  "type": "object",
-  "properties": {
-    "id": {
-      "type": "string",
-      "format": "uuid"
-    },
-    "type": {
-      "const": "ping"
-    },
-    "ts": {
-      "type": "string",
-      "format": "date-time"
-    },
-    "origin": {
-      "type": "string",
-      "description": "Pinging server."
-    },
-    "token": {
-      "type": "string",
-      "description": "Opaque token to be echoed in pong."
-    }
-  },
-  "required": ["id", "type", "ts", "origin"]
-}
diff --git a/schema/s2s/ping.schema.json b/schema/s2s/ping.schema.json
new file mode 100644
index 0000000..14911ed
--- /dev/null
+++ b/schema/s2s/ping.schema.json
@@ -0,0 +1,22 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://git.eeqj.de/sneak/chat/schema/s2s/ping.schema.json",
+  "title": "PING (S2S)",
+  "description": "Server-to-server keepalive",
+  "$ref": "../message.schema.json",
+  "properties": {
+    "command": {
+      "const": "PING"
+    },
+    "body": {
+      "type": "array",
+      "items": {
+        "type": "string"
+      },
+      "description": "Ping token"
+    }
+  },
+  "required": [
+    "command"
+  ]
+}
diff --git a/schema/s2s/pong.json b/schema/s2s/pong.json
deleted file mode 100644
index 7b0d5ac..0000000
--- a/schema/s2s/pong.json
+++ /dev/null
@@ -1,29 +0,0 @@
-{
-  "$schema": "https://json-schema.org/draft/2020-12/schema",
-  "$id": "https://git.eeqj.de/sneak/chat/schema/s2s/pong.json",
-  "title": "S2S Pong",
-  "description": "Inter-server keepalive response.",
-  "type": "object",
-  "properties": {
-    "id": {
-      "type": "string",
-      "format": "uuid"
-    },
-    "type": {
-      "const": "pong"
-    },
-    "ts": {
-      "type": "string",
-      "format": "date-time"
-    },
-    "origin": {
-      "type": "string",
-      "description": "Responding server."
-    },
-    "token": {
-      "type": "string",
-      "description": "Echoed token from the ping."
-    }
-  },
-  "required": ["id", "type", "ts", "origin"]
-}
diff --git a/schema/s2s/pong.schema.json b/schema/s2s/pong.schema.json
new file mode 100644
index 0000000..ae8c628
--- /dev/null
+++ b/schema/s2s/pong.schema.json
@@ -0,0 +1,22 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://git.eeqj.de/sneak/chat/schema/s2s/pong.schema.json",
+  "title": "PONG (S2S)",
+  "description": "Server-to-server keepalive response",
+  "$ref": "../message.schema.json",
+  "properties": {
+    "command": {
+      "const": "PONG"
+    },
+    "body": {
+      "type": "array",
+      "items": {
+        "type": "string"
+      },
+      "description": "Pong token"
+    }
+  },
+  "required": [
+    "command"
+  ]
+}
diff --git a/schema/s2s/relay.json b/schema/s2s/relay.json
deleted file mode 100644
index 4f6cf09..0000000
--- a/schema/s2s/relay.json
+++ /dev/null
@@ -1,49 +0,0 @@
-{
-  "$schema": "https://json-schema.org/draft/2020-12/schema",
-  "$id": "https://git.eeqj.de/sneak/chat/schema/s2s/relay.json",
-  "title": "S2S Relay",
-  "description": "A message relayed from a remote server in the federation.",
-  "type": "object",
-  "properties": {
-    "id": {
-      "type": "string",
-      "format": "uuid",
-      "description": "Message UUID, globally unique across the federation."
-    },
-    "type": {
-      "const": "relay"
-    },
-    "ts": {
-      "type": "string",
-      "format": "date-time"
-    },
-    "origin": {
-      "type": "string",
-      "description": "Originating server name."
-    },
-    "message": {
-      "type": "object",
-      "description": "The original S2C message being relayed. Preserves the original type, from, channel, content, etc.",
-      "properties": {
-        "type": {
-          "type": "string"
-        },
-        "from": {
-          "type": "string"
-        },
-        "channel": {
-          "type": "string"
-        },
-        "content": {
-          "type": "string"
-        },
-        "ts": {
-          "type": "string",
-          "format": "date-time"
-        }
-      },
-      "required": ["type", "from"]
-    }
-  },
-  "required": ["id", "type", "ts", "origin", "message"]
-}
diff --git a/schema/s2s/relay.schema.json b/schema/s2s/relay.schema.json
new file mode 100644
index 0000000..aa6b833
--- /dev/null
+++ b/schema/s2s/relay.schema.json
@@ -0,0 +1,20 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://git.eeqj.de/sneak/chat/schema/s2s/relay.schema.json",
+  "title": "RELAY (S2S)",
+  "description": "Relay message to linked server",
+  "$ref": "../message.schema.json",
+  "properties": {
+    "command": {
+      "const": "RELAY"
+    },
+    "body": {
+      "type": "object",
+      "description": "Wrapped message"
+    }
+  },
+  "required": [
+    "command",
+    "body"
+  ]
+}
diff --git a/schema/s2s/sync.json b/schema/s2s/sync.json
deleted file mode 100644
index 03b9f4d..0000000
--- a/schema/s2s/sync.json
+++ /dev/null
@@ -1,69 +0,0 @@
-{
-  "$schema": "https://json-schema.org/draft/2020-12/schema",
-  "$id": "https://git.eeqj.de/sneak/chat/schema/s2s/sync.json",
-  "title": "S2S Sync",
-  "description": "State synchronization between federated servers. Sent after link establishment to share channel and user state.",
-  "type": "object",
-  "properties": {
-    "id": {
-      "type": "string",
-      "format": "uuid"
-    },
-    "type": {
-      "const": "sync"
-    },
-    "ts": {
-      "type": "string",
-      "format": "date-time"
-    },
-    "origin": {
-      "type": "string",
-      "description": "Server sending the sync."
-    },
-    "channels": {
-      "type": "array",
-      "description": "Channels on the origin server.",
-      "items": {
-        "type": "object",
-        "properties": {
-          "name": {
-            "type": "string",
-            "pattern": "^#[a-zA-Z0-9_-]+$"
-          },
-          "topic": {
-            "type": "string"
-          },
-          "modes": {
-            "type": "string"
-          },
-          "members": {
-            "type": "array",
-            "items": {
-              "type": "string"
-            },
-            "description": "List of nicks in the channel."
-          }
-        },
-        "required": ["name"]
-      }
-    },
-    "users": {
-      "type": "array",
-      "description": "Users on the origin server.",
-      "items": {
-        "type": "object",
-        "properties": {
-          "nick": {
-            "type": "string"
-          },
-          "server": {
-            "type": "string",
-            "description": "Home server for this user."
-          }
-        },
-        "required": ["nick"]
-      }
-    }
-  },
-  "required": ["id", "type", "ts", "origin"]
-}
diff --git a/schema/s2s/sync.schema.json b/schema/s2s/sync.schema.json
new file mode 100644
index 0000000..9218714
--- /dev/null
+++ b/schema/s2s/sync.schema.json
@@ -0,0 +1,20 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://git.eeqj.de/sneak/chat/schema/s2s/sync.schema.json",
+  "title": "SYNC (S2S)",
+  "description": "Synchronize state between servers",
+  "$ref": "../message.schema.json",
+  "properties": {
+    "command": {
+      "const": "SYNC"
+    },
+    "body": {
+      "type": "object",
+      "description": "State data"
+    }
+  },
+  "required": [
+    "command",
+    "body"
+  ]
+}
diff --git a/schema/s2s/unlink.json b/schema/s2s/unlink.json
deleted file mode 100644
index 32d669b..0000000
--- a/schema/s2s/unlink.json
+++ /dev/null
@@ -1,30 +0,0 @@
-{
-  "$schema": "https://json-schema.org/draft/2020-12/schema",
-  "$id": "https://git.eeqj.de/sneak/chat/schema/s2s/unlink.json",
-  "title": "S2S Unlink",
-  "description": "Server link teardown notification.",
-  "type": "object",
-  "properties": {
-    "id": {
-      "type": "string",
-      "format": "uuid"
-    },
-    "type": {
-      "const": "unlink"
-    },
-    "ts": {
-      "type": "string",
-      "format": "date-time"
-    },
-    "origin": {
-      "type": "string",
-      "description": "Server initiating the unlink."
-    },
-    "reason": {
-      "type": "string",
-      "description": "Optional reason for the unlink.",
-      "examples": ["shutdown", "configuration change", "timeout"]
-    }
-  },
-  "required": ["id", "type", "ts", "origin"]
-}
diff --git a/schema/s2s/unlink.schema.json b/schema/s2s/unlink.schema.json
new file mode 100644
index 0000000..dc181d3
--- /dev/null
+++ b/schema/s2s/unlink.schema.json
@@ -0,0 +1,22 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://git.eeqj.de/sneak/chat/schema/s2s/unlink.schema.json",
+  "title": "UNLINK (S2S)",
+  "description": "Tear down server link",
+  "$ref": "../message.schema.json",
+  "properties": {
+    "command": {
+      "const": "UNLINK"
+    },
+    "body": {
+      "type": "array",
+      "items": {
+        "type": "string"
+      },
+      "description": "Unlink reason"
+    }
+  },
+  "required": [
+    "command"
+  ]
+}