diff --git a/api/character.zig b/api/character.zig
index 6b7ff9b..6bff90d 100644
--- a/api/character.zig
+++ b/api/character.zig
@@ -44,7 +44,7 @@ air: CombatStats,
 
 equipment: Equipment,
 
-inventory_max_items: i64,
+inventory_max_items: u64,
 inventory: Inventory,
 
 pub fn parse(api: *Server, obj: json.ObjectMap, allocator: Allocator) !Character {
@@ -54,7 +54,14 @@ pub fn parse(api: *Server, obj: json.ObjectMap, allocator: Allocator) !Character
     const x = try json_utils.getIntegerRequired(obj, "x");
     const y = try json_utils.getIntegerRequired(obj, "y");
     const name = (try json_utils.dupeString(allocator, obj, "name")) orelse return error.MissingProperty;
-    assert(name.len > 0);
+    if (name.len == 0) {
+        return error.InvalidName;
+    }
+
+    const inventory_max_items = json_utils.getInteger(obj, "inventory_max_items") orelse return error.MissingProperty;
+    if (inventory_max_items < 0) {
+        return error.InvalidInventoryMaxItems;
+    }
 
     return Character{
         .allocator = allocator,
@@ -84,7 +91,7 @@ pub fn parse(api: *Server, obj: json.ObjectMap, allocator: Allocator) !Character
 
         .equipment = try Equipment.parse(api, obj),
 
-        .inventory_max_items = json_utils.getInteger(obj, "inventory_max_items") orelse return error.MissingProperty,
+        .inventory_max_items = @intCast(inventory_max_items),
         .inventory = try Inventory.parse(api, inventory)
     };
 }
diff --git a/cli/main.zig b/cli/main.zig
index 160a077..990193e 100644
--- a/cli/main.zig
+++ b/cli/main.zig
@@ -1,4 +1,5 @@
 const std = @import("std");
+const builtin = @import("builtin");
 const Artificer = @import("artificer");
 const Allocator = std.mem.Allocator;
 
@@ -29,6 +30,11 @@ pub fn main() !void {
     var artificer = try Artificer.init(allocator, token);
     defer artificer.deinit();
 
+    if (builtin.mode != .Debug) {
+        std.log.info("Prefetching server data", .{});
+        try artificer.server.prefetch();
+    }
+
     std.log.info("Starting main loop", .{});
     while (true) {
         const waitUntil = artificer.nextStepAt();
diff --git a/gui/main.zig b/gui/main.zig
index 4ae120f..3db53e5 100644
--- a/gui/main.zig
+++ b/gui/main.zig
@@ -1,18 +1,76 @@
+const std = @import("std");
+const Artificer = @import("artificer");
 const rl = @import("raylib");
+const Allocator = std.mem.Allocator;
+
+const srcery = @import("./srcery.zig");
+
+const UI = @import("./ui.zig");
+const UIStack = @import("./ui_stack.zig");
+const RectUtils = @import("./rect_utils.zig");
+
+fn getAPITokenFromArgs(allocator: Allocator) !?[]u8 {
+    const args = try std.process.argsAlloc(allocator);
+    defer std.process.argsFree(allocator, args);
+
+    if (args.len < 2) {
+        return null;
+    }
+
+    const filename = args[1];
+    const cwd = std.fs.cwd();
+    var token_buffer: [256]u8 = undefined;
+    const token = try cwd.readFile(filename, &token_buffer);
+
+    return try allocator.dupe(u8, std.mem.trim(u8,token,"\n\t "));
+}
+
+fn drawCharacterInfo(ui: *UI, rect: rl.Rectangle, brain: Artificer.Brain) void {
+    const name_height = 20;
+    UI.drawTextCentered(ui.font, brain.name, .{
+        .x = RectUtils.center(rect).x,
+        .y = rect.y + name_height/2
+    }, 20, 2, srcery.bright_white);
+}
 
 pub fn main() anyerror!void {
+    var gpa = std.heap.GeneralPurposeAllocator(.{}){};
+    defer _ = gpa.deinit();
+    const allocator = gpa.allocator();
+
+    const token = (try getAPITokenFromArgs(allocator)) orelse return error.MissingToken;
+    defer allocator.free(token);
+
+    var artificer = try Artificer.init(allocator, token);
+    defer artificer.deinit();
+
     rl.initWindow(800, 450, "Artificer");
     defer rl.closeWindow();
 
     rl.setTargetFPS(60);
 
+    var ui = UI.init();
+    defer ui.deinit();
+
     while (!rl.windowShouldClose()) {
+        if (std.time.timestamp() > artificer.nextStepAt()) {
+            try artificer.step();
+        }
+
+        const screen_size = rl.Vector2.init(
+            @floatFromInt(rl.getScreenWidth()),
+            @floatFromInt(rl.getScreenHeight())
+        );
 
         rl.beginDrawing();
         defer rl.endDrawing();
 
-        rl.clearBackground(rl.Color.white);
+        rl.clearBackground(srcery.black);
 
-        rl.drawText("Congrats! You created your first window!", 190, 200, 20, rl.Color.light_gray);
+        var info_stack = UIStack.init(rl.Rectangle.init(0, 0, screen_size.x, screen_size.y), .left_to_right);
+        for (artificer.characters.items) |brain| {
+            const info_width = screen_size.x / @as(f32, @floatFromInt(artificer.characters.items.len));
+            drawCharacterInfo(&ui, info_stack.next(info_width), brain);
+        }
     }
 }
diff --git a/gui/rect_utils.zig b/gui/rect_utils.zig
new file mode 100644
index 0000000..94cb0b9
--- /dev/null
+++ b/gui/rect_utils.zig
@@ -0,0 +1,142 @@
+const rl = @import("raylib");
+const Rect = rl.Rectangle;
+
+pub const AlignX = enum { left, center, right };
+pub const AlignY = enum { top, center, bottom };
+
+pub fn initCentered(rect: Rect, width: f32, height: f32) Rect {
+    const unused_width = rect.width - width;
+    const unused_height = rect.height - height;
+    return Rect.init(rect.x + unused_width / 2, rect.y + unused_height / 2, width, height);
+}
+
+pub fn center(rect: Rect) rl.Vector2 {
+    return rl.Vector2{
+        .x = rect.x + rect.width / 2,
+        .y = rect.y + rect.height / 2,
+    };
+}
+
+pub fn bottomLeft(rect: Rect) rl.Vector2 {
+    return rl.Vector2{
+        .x = rect.x,
+        .y = rect.y + rect.height,
+    };
+}
+
+pub fn bottomRight(rect: Rect) rl.Vector2 {
+    return rl.Vector2{
+        .x = rect.x + rect.width,
+        .y = rect.y + rect.height,
+    };
+}
+
+pub fn topLeft(rect: Rect) rl.Vector2 {
+    return rl.Vector2{
+        .x = rect.x,
+        .y = rect.y,
+    };
+}
+
+pub fn topRight(rect: Rect) rl.Vector2 {
+    return rl.Vector2{
+        .x = rect.x + rect.width,
+        .y = rect.y,
+    };
+}
+
+pub fn aligned(rect: Rect, align_x: AlignX, align_y: AlignY) rl.Vector2 {
+    const x = switch(align_x) {
+        .left   => rect.x,
+        .center => rect.x + rect.width/2,
+        .right  => rect.x + rect.width,
+    };
+
+    const y = switch(align_y) {
+        .top    => rect.y,
+        .center => rect.y + rect.height/2,
+        .bottom => rect.y + rect.height,
+    };
+
+    return rl.Vector2.init(x, y);
+}
+
+pub fn shrink(rect: Rect, x: f32, y: f32) rl.Rectangle {
+    return Rect.init(rect.x + x, rect.y + y, rect.width - 2 * x, rect.height - 2 * y);
+}
+
+pub fn shrinkX(rect: rl.Rectangle, offset: f32) rl.Rectangle {
+    return shrink(rect, offset, 0);
+}
+
+pub fn shrinkY(rect: rl.Rectangle, offset: f32) rl.Rectangle {
+    return shrink(rect, 0, offset);
+}
+
+pub fn shrinkTop(rect: rl.Rectangle, offset: f32) rl.Rectangle {
+    return Rect.init(rect.x, rect.y + offset, rect.width, rect.height - offset);
+}
+
+pub fn grow(rect: Rect, x: f32, y: f32) rl.Rectangle {
+    return shrink(rect, -x, -y);
+}
+
+pub fn growY(rect: Rect, offset: f32) rl.Rectangle {
+    return grow(rect, 0, offset);
+}
+
+pub fn position(rect: rl.Rectangle) rl.Vector2 {
+    return rl.Vector2.init(rect.x, rect.y);
+}
+
+pub fn isInside(rect: rl.Rectangle, x: f32, y: f32) bool {
+    return (rect.x <= x and x < rect.x + rect.width) and (rect.y < y and y < rect.y + rect.height);
+}
+
+pub fn isInsideVec2(rect: rl.Rectangle, vec2: rl.Vector2) bool {
+    return isInside(rect, vec2.x, vec2.y);
+}
+
+pub fn top(rect: rl.Rectangle) f32 {
+    return rect.y;
+}
+
+pub fn bottom(rect: rl.Rectangle) f32 {
+    return rect.y + rect.height;
+}
+
+pub fn left(rect: rl.Rectangle) f32 {
+    return rect.x;
+}
+
+pub fn right(rect: rl.Rectangle) f32 {
+    return rect.x + rect.width;
+}
+
+pub fn verticalSplit(rect: rl.Rectangle, left_side_width: f32) [2]rl.Rectangle {
+    var left_side = rect;
+    left_side.width = left_side_width;
+
+    var right_side = rect;
+    right_side.x += left_side_width;
+    right_side.width -= left_side_width;
+
+    return .{
+        left_side,
+        right_side
+    };
+}
+
+pub fn horizontalSplit(rect: rl.Rectangle, top_side_height: f32) [2]rl.Rectangle {
+    var top_side = rect;
+    top_side.height = top_side_height;
+
+    var bottom_side = rect;
+    bottom_side.y += top_side_height;
+    bottom_side.height -= top_side_height;
+
+    return .{
+        top_side,
+        bottom_side
+    };
+}
diff --git a/gui/srcery.zig b/gui/srcery.zig
new file mode 100644
index 0000000..2271ee3
--- /dev/null
+++ b/gui/srcery.zig
@@ -0,0 +1,43 @@
+const rl = @import("raylib");
+
+fn rgb(r: u8, g: u8, b: u8) rl.Color {
+    return rl.Color.init(r, g, b, 255);
+}
+
+// Primary
+pub const black          = rgb(28 , 27 , 25 );
+pub const red            = rgb(239, 47 , 39 );
+pub const green          = rgb(81 , 159, 80 );
+pub const yellow         = rgb(251, 184, 41 );
+pub const blue           = rgb(44 , 120, 191);
+pub const magenta        = rgb(224, 44 , 109);
+pub const cyan           = rgb(10 , 174, 179);
+pub const white          = rgb(186, 166, 127);
+pub const bright_black   = rgb(145, 129, 117);
+pub const bright_red     = rgb(247, 83 , 65 );
+pub const bright_green   = rgb(152, 188, 55 );
+pub const bright_yellow  = rgb(254, 208, 110);
+pub const bright_blue    = rgb(104, 168, 228);
+pub const bright_magenta = rgb(255, 92 , 143);
+pub const bright_cyan    = rgb(43 , 228, 208);
+pub const bright_white   = rgb(252, 232, 195);
+
+// Secondary
+pub const orange        = rgb(255, 95, 0);
+pub const bright_orange = rgb(255, 135, 0);
+pub const hard_black    = rgb(18, 18, 18);
+pub const teal          = rgb(0, 128, 128);
+
+// Grays
+pub const xgray1  = rgb(38 , 38 , 38 );
+pub const xgray2  = rgb(48 , 48 , 48 );
+pub const xgray3  = rgb(58 , 58 , 58 );
+pub const xgray4  = rgb(68 , 68 , 68 );
+pub const xgray5  = rgb(78 , 78 , 78 );
+pub const xgray6  = rgb(88 , 88 , 88 );
+pub const xgray7  = rgb(98 , 98 , 98 );
+pub const xgray8  = rgb(108, 108, 108);
+pub const xgray9  = rgb(118, 118, 118);
+pub const xgray10 = rgb(128, 128, 128);
+pub const xgray11 = rgb(138, 138, 138);
+pub const xgray12 = rgb(148, 148, 148);
diff --git a/gui/ui.zig b/gui/ui.zig
new file mode 100644
index 0000000..e05ae08
--- /dev/null
+++ b/gui/ui.zig
@@ -0,0 +1,159 @@
+const rl = @import("raylib");
+const std = @import("std");
+
+const UI = @This();
+
+font: rl.Font,
+
+pub fn init() UI {
+    return UI{
+        .font = rl.getFontDefault()
+    };
+}
+
+pub fn deinit(self: UI) void {
+    rl.unloadFont(self.font);
+}
+
+// Reimplementation of `GetGlyphIndex` from raylib in src/rtext.c
+fn GetGlyphIndex(font: rl.Font, codepoint: i32) usize {
+    var index: usize = 0;
+
+    var fallbackIndex: usize = 0; // Get index of fallback glyph '?'
+
+    for (0..@intCast(font.glyphCount), font.glyphs) |i, glyph| {
+        if (glyph.value == '?') fallbackIndex = i;
+
+        if (glyph.value == codepoint)
+        {
+            index = i;
+            break;
+        }
+    }
+
+    if ((index == 0) and (font.glyphs[0].value != codepoint)) index = fallbackIndex;
+
+    return index;
+}
+
+fn GetCodePointNext(text: []const u8, next: *usize) i32 {
+    var letter: i32 = '?';
+
+    if (std.unicode.utf8ByteSequenceLength(text[0])) |codepointSize| {
+        next.* = codepointSize;
+        if (std.unicode.utf8Decode(text[0..codepointSize])) |codepoint| {
+            letter = @intCast(codepoint);
+        } else |_| {}
+    } else |_| {}
+
+    return letter;
+}
+
+// NOTE: Line spacing is a global variable, use SetTextLineSpacing() to setup
+const textLineSpacing = 2; // TODO: Assume that line spacing is not changed.
+
+// Reimplementation of `rl.drawTextEx`, so a null terminated would not be required
+pub fn drawTextEx(font: rl.Font, text: []const u8, position: rl.Vector2, font_size: f32, spacing: f32, tint: rl.Color) void {
+    var used_font = font;
+    if (font.texture.id == 0) {
+        used_font = rl.getFontDefault();
+    }
+
+    var text_offset_y: f32 = 0;
+    var text_offset_x: f32 = 0;
+
+    const scale_factor = font_size / @as(f32, @floatFromInt(used_font.baseSize));
+
+    var i: usize = 0;
+    while (i < text.len) {
+        var next: usize = 0;
+
+        const letter = GetCodePointNext(text[i..], &next);
+        const index = GetGlyphIndex(font, letter);
+
+        i += next;
+
+        if (letter == '\n') {
+            text_offset_x = 0;
+            text_offset_y += (font_size + textLineSpacing);
+        } else {
+            if (letter != ' ' and letter != '\t') {
+                rl.drawTextCodepoint(font, letter, .{
+                    .x = position.x + text_offset_x,
+                    .y = position.y + text_offset_y,
+                }, font_size, tint);
+            }
+
+            if (font.glyphs[index].advanceX == 0) {
+                text_offset_x += font.recs[index].width*scale_factor + spacing;
+            } else {
+                text_offset_x += @as(f32, @floatFromInt(font.glyphs[index].advanceX))*scale_factor + spacing;
+            }
+        }
+    }
+}
+
+// Reimplementation of `rl.measureTextEx`, so a null terminated would not be required
+pub fn measureTextEx(font: rl.Font, text: []const u8, fontSize: f32, spacing: f32) rl.Vector2 {
+    var textSize = rl.Vector2.init(0, 0);
+
+    if (font.texture.id == 0) return textSize; // Security check
+
+    var tempByteCounter: i32 = 0;        // Used to count longer text line num chars
+    var byteCounter: i32 = 0;
+
+    var textWidth: f32 = 0;
+    var tempTextWidth: f32 = 0;     // Used to count longer text line width
+
+    var textHeight: f32 = fontSize;
+    const scaleFactor: f32 = fontSize/@as(f32, @floatFromInt(font.baseSize));
+
+    var i: usize = 0;
+    while (i < text.len)
+    {
+        byteCounter += 1;
+
+        var next: usize = 0;
+
+        const letter = GetCodePointNext(text[i..], &next);
+        const index = GetGlyphIndex(font, letter);
+
+        i += next;
+
+        if (letter != '\n')
+        {
+            if (font.glyphs[index].advanceX != 0) {
+                textWidth += @floatFromInt(font.glyphs[index].advanceX);
+            } else {
+                textWidth += font.recs[index].width;
+                textWidth += @floatFromInt(font.glyphs[index].offsetX);
+            }
+        }
+        else
+        {
+            if (tempTextWidth < textWidth) tempTextWidth = textWidth;
+            byteCounter = 0;
+            textWidth = 0;
+
+            textHeight += (fontSize + textLineSpacing);
+        }
+
+        if (tempByteCounter < byteCounter) tempByteCounter = byteCounter;
+    }
+
+    if (tempTextWidth < textWidth) tempTextWidth = textWidth;
+
+    textSize.x = tempTextWidth*scaleFactor + @as(f32, @floatFromInt(tempByteCounter - 1)) * spacing;
+    textSize.y = textHeight;
+
+    return textSize;
+}
+
+pub fn drawTextCentered(font: rl.Font, text: []const u8, position: rl.Vector2, font_size: f32, spacing: f32, color: rl.Color) void {
+    const text_size = measureTextEx(font, text, font_size, spacing);
+    const adjusted_position = rl.Vector2{
+        .x = position.x - text_size.x/2,
+        .y = position.y - text_size.y/2,
+    };
+    drawTextEx(font, text, adjusted_position, font_size, spacing, color);
+}
diff --git a/gui/ui_stack.zig b/gui/ui_stack.zig
new file mode 100644
index 0000000..90bec37
--- /dev/null
+++ b/gui/ui_stack.zig
@@ -0,0 +1,42 @@
+const rl = @import("raylib");
+const Stack = @This();
+
+pub const Direction = enum {
+    top_to_bottom,
+    bottom_to_top,
+    left_to_right
+};
+
+unused_box: rl.Rectangle,
+dir: Direction,
+gap: f32 = 0,
+
+pub fn init(box: rl.Rectangle, dir: Direction) Stack {
+    return Stack{
+        .unused_box = box,
+        .dir = dir
+    };
+}
+
+pub fn next(self: *Stack, size: f32) rl.Rectangle {
+    return switch (self.dir) {
+        .top_to_bottom => {
+            const next_box = rl.Rectangle.init(self.unused_box.x, self.unused_box.y, self.unused_box.width, size);
+            self.unused_box.y += size;
+            self.unused_box.y += self.gap;
+            return next_box;
+        },
+        .bottom_to_top => {
+            const next_box = rl.Rectangle.init(self.unused_box.x, self.unused_box.y + self.unused_box.height - size, self.unused_box.width, size);
+            self.unused_box.height -= size;
+            self.unused_box.height -= self.gap;
+            return next_box;
+        },
+        .left_to_right => {
+            const next_box = rl.Rectangle.init(self.unused_box.x, self.unused_box.y, size, self.unused_box.height);
+            self.unused_box.x += size;
+            self.unused_box.x += self.gap;
+            return next_box;
+        },
+    };
+}
diff --git a/lib/brain.zig b/lib/brain.zig
index af75fd2..205b260 100644
--- a/lib/brain.zig
+++ b/lib/brain.zig
@@ -400,7 +400,7 @@ pub fn isTaskFinished(self: *CharacterBrain) bool {
 
 pub fn performTask(self: *CharacterBrain, api: *Server) !void {
     if (self.task == null) {
-        std.log.debug("[{s}] idle", .{self.name});
+        // TODO: std.log.debug("[{s}] idle", .{self.name});
         return;
     }
 
diff --git a/lib/root.zig b/lib/root.zig
index 2500b95..304909d 100644
--- a/lib/root.zig
+++ b/lib/root.zig
@@ -2,7 +2,7 @@ const std = @import("std");
 const Api = @import("artifacts-api");
 const Allocator = std.mem.Allocator;
 
-const CharacterBrain = @import("./brain.zig");
+pub const Brain = @import("./brain.zig");
 
 const Artificer = @This();
 
@@ -10,7 +10,7 @@ const expiration_margin: u64 = 100 * std.time.ns_per_ms; // 100ms
 const server_down_retry_interval = 5; // minutes
 
 server: Api.Server,
-characters: std.ArrayList(CharacterBrain),
+characters: std.ArrayList(Brain),
 
 paused_until: ?i64 = null,
 
@@ -20,16 +20,15 @@ pub fn init(allocator: Allocator, token: []const u8) !Artificer {
 
     try server.setToken(token);
 
-    var characters = std.ArrayList(CharacterBrain).init(allocator);
-    defer characters.deinit();
-    // TODO: Add character deinit
+    var characters = std.ArrayList(Brain).init(allocator);
+    errdefer characters.deinit(); // TODO: Add character deinit
 
-    // const chars = try api.listMyCharacters();
-    // defer chars.deinit();
+    const chars = try server.listMyCharacters();
+    defer chars.deinit();
 
-    // for (chars.items) |char| {
-    //     try scheduler.addCharacter(char.name);
-    // }
+    for (chars.items) |char| {
+        try characters.append(try Brain.init(allocator, char.name));
+    }
 
     return Artificer{
         .server = server,
@@ -37,11 +36,12 @@ pub fn init(allocator: Allocator, token: []const u8) !Artificer {
     };
 }
 
-pub fn deinit(self: Artificer) void {
+pub fn deinit(self: *Artificer) void {
     for (self.characters.items) |brain| {
         brain.deinit();
     }
     self.characters.deinit();
+    self.server.deinit();
 }
 
 pub fn step(self: *Artificer) !void {
@@ -93,7 +93,7 @@ pub fn nextStepAt(self: *Artificer) i64 {
     return earliestCooldown(self.characters.items, &self.server) orelse 0;
 }
 
-fn earliestCooldown(characters: []CharacterBrain, api: *Api.Server) ?i64 {
+fn earliestCooldown(characters: []Brain, api: *Api.Server) ?i64 {
     var earliest_cooldown: ?i64 = null;
     for (characters) |*brain| {
         if (brain.action_queue.items.len == 0) continue;
@@ -109,7 +109,7 @@ fn earliestCooldown(characters: []CharacterBrain, api: *Api.Server) ?i64 {
     return earliest_cooldown;
 }
 
-fn runNextActions(characters: []CharacterBrain, api: *Api.Server) !void {
+fn runNextActions(characters: []Brain, api: *Api.Server) !void {
     const maybe_earliest_cooldown = earliestCooldown(characters, api);
     if (maybe_earliest_cooldown == null) return;