Oh man that's a lot of changes.

API.md

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+# Overview
+
+COMS uses a WebSocket API to communicate with its clients in JSON. In general,
+packets sent to all clients end in `_evt` and packets sent in reply to a client
+action end in `_ack`. Beyond that there isn't really a system.
+
+A packet takes this general form:
+
+```json
+{
+  "type": "<PacketType>",
+  "data": {...}
+}
+```
+
+# Data types
+
+## Packet
+
+**Type:**
+```C
+struct {
+    PacketType type;
+    Any data;
+}
+```
+
+A packet.
+
+## PacketType
+
+**Type:**
+```C
+enum {
+    join,
+    welcome,
+    join_evt,
+    msg,
+    msg_evt,
+    name,
+    name_evt,
+    ping,
+    pong,
+    msg_ack,
+    name_ack,
+    leave_evt,
+    bad,
+}
+```
+
+The type a Packet may assume.
+
+## UserID
+
+**Type:** `uint64_t`
+
+Uniquely identifies a user.
+
+## Name
+
+**Type:** `char[16]`
+
+A name of a user.
+
+## UserData
+
+**Type:**
+```C
+struct {
+  UserID id;
+  Name name;
+}
+```
+
+A user.
+
+## MsgID
+
+**Type:** `uint64_t`
+
+Uniquely identifies a message.
+
+## MsgContent
+
+**Type:** `char[1024]`
+
+The content of a message.
+
+## MsgData
+
+**Type:**
+```C
+struct {
+    MsgID id;
+    UserData author;
+    MsgID parent;
+    MsgContent content;
+    time_t timestamp;
+}
+```
+
+A message.