diff --git a/src/AI/AIClient.lua b/src/AI/AIClient.lua
new file mode 100644
index 0000000000..cd92dcdd6a
--- /dev/null
+++ b/src/AI/AIClient.lua
@@ -0,0 +1,65 @@
+-- Path of Building
+--
+-- Module: AI Client
+-- Minimal non-streaming OpenAI-compatible chat completions client.
+
+local json = require("dkjson")
+
+local client = { }
+
+local function endpointFromBase(apiBase)
+	apiBase = (apiBase or ""):gsub("%s+$", "")
+	if apiBase:match("/chat/completions$") then
+		return apiBase
+	end
+	apiBase = apiBase:gsub("/+$", "")
+	return apiBase .. "/chat/completions"
+end
+
+local function extractContent(responseText)
+	local data, _, err = json.decode(responseText or "")
+	if not data then
+		return nil, err or "Could not parse API response."
+	end
+	if data.error then
+		if type(data.error) == "table" then
+			return nil, data.error.message or data.error.code or "The API returned an error."
+		end
+		return nil, tostring(data.error)
+	end
+	local choice = data.choices and data.choices[1]
+	local message = choice and choice.message
+	if message and message.content then
+		return message.content
+	end
+	if choice and choice.text then
+		return choice.text
+	end
+	return nil, "The API response did not include displayable content."
+end
+
+function client.Send(settings, messages, callback)
+	local body = json.encode({
+		model = settings.model,
+		messages = messages,
+		temperature = tonumber(settings.temperature) or 0.2,
+		stream = false,
+	})
+	local headers = "Content-Type: application/json"
+	if settings.apiKey and settings.apiKey:match("%S") then
+		headers = headers .. "\r\nAuthorization: Bearer " .. settings.apiKey
+	end
+	launch:DownloadPage(endpointFromBase(settings.apiBase), function(response, errMsg)
+		local content, parseErr = extractContent(response and response.body or "")
+		if content then
+			callback(content)
+		else
+			callback(nil, parseErr or errMsg or "Request failed.")
+		end
+	end, {
+		header = headers,
+		body = body,
+	})
+end
+
+return client
diff --git a/src/AI/BuildSnapshot.lua b/src/AI/BuildSnapshot.lua
new file mode 100644
index 0000000000..2acc02beac
--- /dev/null
+++ b/src/AI/BuildSnapshot.lua
@@ -0,0 +1,229 @@
+-- Path of Building
+--
+-- Module: AI Build Snapshot
+-- Creates a compact English text snapshot of the current build for AI analysis.
+
+local t_insert = table.insert
+
+local snapshot = { }
+
+local itemSlots = {
+	"Weapon 1", "Weapon 2", "Weapon 1 Swap", "Weapon 2 Swap",
+	"Helmet", "Body Armour", "Gloves", "Boots", "Amulet",
+	"Ring 1", "Ring 2", "Ring 3", "Belt",
+	"Charm 1", "Charm 2", "Charm 3", "Flask 1", "Flask 2",
+}
+
+local statOrder = {
+	{ key = "FullDPS", label = "Full DPS" },
+	{ key = "CombinedDPS", label = "Combined DPS" },
+	{ key = "TotalDPS", label = "Hit DPS" },
+	{ key = "TotalDot", label = "DoT DPS" },
+	{ key = "AverageHit", label = "Average Hit" },
+	{ key = "AverageDamage", label = "Average Damage" },
+	{ key = "Speed", label = "Attack/Cast Rate" },
+	{ key = "CritChance", label = "Crit Chance" },
+	{ key = "HitChance", label = "Hit Chance" },
+	{ key = "TotalEHP", label = "Effective Hit Pool" },
+	{ key = "Life", label = "Life" },
+	{ key = "EnergyShield", label = "Energy Shield" },
+	{ key = "Mana", label = "Mana" },
+	{ key = "Spirit", label = "Spirit" },
+	{ key = "Armour", label = "Armour" },
+	{ key = "Evasion", label = "Evasion" },
+	{ key = "FireResist", label = "Fire Resistance" },
+	{ key = "ColdResist", label = "Cold Resistance" },
+	{ key = "LightningResist", label = "Lightning Resistance" },
+	{ key = "ChaosResist", label = "Chaos Resistance" },
+	{ key = "EffectiveBlockChance", label = "Block Chance" },
+	{ key = "TotalNetRegen", label = "Total Net Recovery" },
+	{ key = "EffectiveMovementSpeedMod", label = "Movement Speed Modifier" },
+}
+
+local function clean(value)
+	value = tostring(value or "")
+	if StripEscapes then
+		value = StripEscapes(value)
+	end
+	value = value:gsub("%^x%x%x%x%x%x%x", "")
+	value = value:gsub("%^%d", "")
+	value = value:gsub("%^%a", "")
+	return value
+end
+
+local function fmt(value)
+	if type(value) == "number" then
+		if value >= 1000 then
+			return tostring(round(value))
+		elseif value == math.floor(value) then
+			return tostring(value)
+		else
+			return tostring(round(value, 2))
+		end
+	end
+	return clean(value)
+end
+
+local function addHeader(lines, title)
+	t_insert(lines, "")
+	t_insert(lines, "## " .. title)
+end
+
+local function addKeyValue(lines, key, value)
+	if value ~= nil and value ~= "" then
+		t_insert(lines, "- " .. key .. ": " .. clean(value))
+	end
+end
+
+local function gemName(gem)
+	if not gem then
+		return nil
+	end
+	if gem.gemData and gem.gemData.grantedEffect and gem.gemData.grantedEffect.name then
+		return gem.gemData.grantedEffect.name
+	end
+	return gem.nameSpec or gem.name or "Unknown Gem"
+end
+
+local function addSkillGroups(lines, build)
+	local skillsTab = build.skillsTab
+	if not skillsTab or not skillsTab.socketGroupList then
+		return
+	end
+	addHeader(lines, "Skills")
+	for index, group in ipairs(skillsTab.socketGroupList) do
+		if index > 10 then
+			t_insert(lines, "- Remaining skill groups omitted.")
+			break
+		end
+		local groupLabel = clean(group.displayLabel or group.label or ("Skill Group " .. index))
+		local groupInfo = "- " .. index .. ". " .. groupLabel
+		if index == build.mainSocketGroup then
+			groupInfo = groupInfo .. " [main skill group]"
+		end
+		if group.slot then
+			groupInfo = groupInfo .. " / " .. group.slot
+		end
+		if group.enabled == false or group.slotEnabled == false then
+			groupInfo = groupInfo .. " / disabled"
+		end
+		t_insert(lines, groupInfo)
+		local gemParts = { }
+		for gemIndex, gem in ipairs(group.gemList or { }) do
+			if gemIndex > 8 then
+				t_insert(gemParts, "...")
+				break
+			end
+			local label = clean(gemName(gem))
+			if gem.level then
+				label = label .. " Lv" .. tostring(gem.level)
+			end
+			if gem.quality and tonumber(gem.quality) and tonumber(gem.quality) > 0 then
+				label = label .. " Q" .. tostring(gem.quality)
+			end
+			if gem.enabled == false then
+				label = label .. " disabled"
+			end
+			t_insert(gemParts, label)
+		end
+		if #gemParts > 0 then
+			t_insert(lines, "  Gems: " .. table.concat(gemParts, " + "))
+		end
+	end
+end
+
+local function addItems(lines, build)
+	local itemsTab = build.itemsTab
+	local itemSet = itemsTab and itemsTab.activeItemSet
+	if not itemsTab or not itemSet then
+		return
+	end
+	addHeader(lines, "Items")
+	addKeyValue(lines, "Current item set", itemSet.title or "Default")
+	for _, slotName in ipairs(itemSlots) do
+		local slot = itemSet[slotName]
+		local item = slot and itemsTab.items and itemsTab.items[slot.selItemId]
+		if item then
+			local name = clean(item.name or item.title or item.baseName or "Unknown Item")
+			t_insert(lines, "- " .. slotName .. ": " .. name)
+			local rawLines = item.rawLines or { }
+			local added = 0
+			for _, line in ipairs(rawLines) do
+				line = clean(line)
+				if line ~= "" and not line:match("^Rarity:") and not line:match("^Item Class:") and not line:match("^Unique ID:") then
+					t_insert(lines, "  " .. line)
+					added = added + 1
+					if added >= 12 then
+						break
+					end
+				end
+			end
+		end
+	end
+end
+
+local function addStats(lines, build)
+	local output = build.calcsTab and build.calcsTab.mainOutput
+	if not output then
+		return
+	end
+	addHeader(lines, "Key Stats")
+	for _, stat in ipairs(statOrder) do
+		local value = output[stat.key]
+		if value ~= nil then
+			addKeyValue(lines, stat.label, fmt(value))
+		end
+	end
+	if output.SkillDPS and type(output.SkillDPS) == "table" then
+		t_insert(lines, "- Skill DPS:")
+		for index, skill in ipairs(output.SkillDPS) do
+			if index > 8 then
+				t_insert(lines, "  ...")
+				break
+			end
+			local dps = (skill.dps or 0) * (skill.count or 1)
+			t_insert(lines, "  " .. clean(skill.name or ("Skill " .. index)) .. ": " .. fmt(dps))
+		end
+	end
+end
+
+local function addWarnings(lines, build)
+	local warnings = build.controls and build.controls.warnings and build.controls.warnings.lines
+	if not warnings or not next(warnings) then
+		return
+	end
+	addHeader(lines, "Warnings")
+	for _, warning in pairs(warnings) do
+		t_insert(lines, "- " .. clean(warning))
+	end
+end
+
+function snapshot.Create(build)
+	local lines = {
+		"This is a Path of Building for Path of Exile 2 build snapshot. Use it as context for build analysis.",
+	}
+	addHeader(lines, "Character")
+	addKeyValue(lines, "Build name", build.buildName or "Unnamed build")
+	addKeyValue(lines, "Class", build.spec and build.spec.curClassName)
+	addKeyValue(lines, "Ascendancy", build.spec and build.spec.curAscendClassName)
+	addKeyValue(lines, "Level", build.characterLevel)
+	if build.treeTab and build.treeTab.specList and build.treeTab.activeSpec then
+		local spec = build.treeTab.specList[build.treeTab.activeSpec]
+		addKeyValue(lines, "Passive tree", spec and spec.title or "Default")
+	end
+	if build.skillsTab and build.skillsTab.skillSets and build.skillsTab.activeSkillSetId then
+		local set = build.skillsTab.skillSets[build.skillsTab.activeSkillSetId]
+		addKeyValue(lines, "Skill set", set and set.title or "Default")
+	end
+	if build.configTab and build.configTab.configSets and build.configTab.activeConfigSetId then
+		local set = build.configTab.configSets[build.configTab.activeConfigSetId]
+		addKeyValue(lines, "Config set", set and set.title or "Default")
+	end
+	addSkillGroups(lines, build)
+	addStats(lines, build)
+	addItems(lines, build)
+	addWarnings(lines, build)
+	return table.concat(lines, "\n")
+end
+
+return snapshot
diff --git a/src/AI/ProviderPresets.lua b/src/AI/ProviderPresets.lua
new file mode 100644
index 0000000000..a43adc95d7
--- /dev/null
+++ b/src/AI/ProviderPresets.lua
@@ -0,0 +1,29 @@
+-- Path of Building
+--
+-- Module: AI Provider Presets
+-- OpenAI-compatible defaults for the build assistant.
+
+local presets = {
+	{
+		id = "openai",
+		label = "OpenAI-compatible",
+		apiBase = "https://api.openai.com/v1",
+		model = "",
+	},
+	{
+		id = "custom",
+		label = "Custom",
+		apiBase = "",
+		model = "",
+	},
+}
+
+local byId = { }
+for _, preset in ipairs(presets) do
+	byId[preset.id] = preset
+end
+
+return {
+	list = presets,
+	byId = byId,
+}
diff --git a/src/AI/Settings.lua b/src/AI/Settings.lua
new file mode 100644
index 0000000000..750eeec2bd
--- /dev/null
+++ b/src/AI/Settings.lua
@@ -0,0 +1,67 @@
+-- Path of Building
+--
+-- Module: AI Settings
+-- Stores AI assistant API settings in the user's local PoB data folder.
+
+local json = require("dkjson")
+local providers = LoadModule("AI/ProviderPresets")
+
+local settings = { }
+
+local function copyDefaults()
+	local defaultProvider = providers.byId.openai or providers.list[1]
+	return {
+		provider = defaultProvider.id,
+		apiBase = defaultProvider.apiBase,
+		apiKey = "",
+		model = defaultProvider.model,
+		temperature = 0.2,
+	}
+end
+
+local function getPath()
+	local userPath = main and main.userPath or ""
+	return userPath .. "AIAssistantSettings.json"
+end
+
+function settings.Load()
+	local out = copyDefaults()
+	local file = io.open(getPath(), "r")
+	if file then
+		local text = file:read("*a")
+		file:close()
+		local data = json.decode(text)
+		if type(data) == "table" then
+			for key, value in pairs(data) do
+				out[key] = value
+			end
+		end
+	end
+	return out
+end
+
+function settings.Save(data)
+	local file, err = io.open(getPath(), "w+")
+	if not file then
+		return nil, err
+	end
+	file:write(json.encode(data, { indent = true }))
+	file:close()
+	return true
+end
+
+function settings.IsConfigured(data)
+	if not (data and data.apiBase and data.apiBase:match("%S") and data.model and data.model:match("%S")) then
+		return false
+	end
+	if data.apiBase:match("localhost") or data.apiBase:match("127%.0%.0%.1") then
+		return true
+	end
+	return data.apiKey and data.apiKey:match("%S")
+end
+
+function settings.GetPath()
+	return getPath()
+end
+
+return settings
diff --git a/src/Classes/AIChatPanel.lua b/src/Classes/AIChatPanel.lua
new file mode 100644
index 0000000000..368502e0cf
--- /dev/null
+++ b/src/Classes/AIChatPanel.lua
@@ -0,0 +1,570 @@
+-- Path of Building
+--
+-- Class: AI Chat Panel
+-- Right-side AI assistant drawer for the build editor.
+
+local t_insert = table.insert
+local t_remove = table.remove
+local m_min = math.min
+local m_max = math.max
+local m_floor = math.floor
+local utf8 = require("lua-utf8")
+
+local settingsStore = LoadModule("AI/Settings")
+local providers = LoadModule("AI/ProviderPresets")
+local aiClient = LoadModule("AI/AIClient")
+local buildSnapshot = LoadModule("AI/BuildSnapshot")
+
+local AIChatPanelClass = newClass("AIChatPanel", "ControlHost", function(self, build)
+	self.ControlHost()
+	self.build = build
+	self.settings = settingsStore.Load()
+	self.messages = { }
+	self.history = { }
+	self.messageRows = { }
+	self.pending = false
+	self.collapsed = false
+	self.statusText = "Ready"
+	self.currentSnapshot = nil
+
+	self.anchor = new("Control", nil, {
+		function()
+			return main.screenW - self:GetWidth()
+		end,
+		32,
+		0,
+		0,
+	})
+
+	self.controls.toggle = new("ButtonControl", { "TOPLEFT", self.anchor, "TOPLEFT" }, { 6, 6, 28, 22 }, function()
+		return self.collapsed and "AI" or "<"
+	end, function()
+		self.collapsed = not self.collapsed
+	end)
+	self.controls.toggle.tooltipText = "Show or hide the AI assistant"
+
+	self.controls.settings = new("ButtonControl", { "TOPRIGHT", self.anchor, "TOPLEFT" }, {
+		function()
+			return self:GetWidth() - 8
+		end,
+		6,
+		70,
+		22,
+	}, "Settings", function()
+		self:OpenSettingsPopup()
+	end)
+	self.controls.settings.shown = function()
+		return not self.collapsed
+	end
+
+	self.controls.analyze = new("ButtonControl", { "TOPLEFT", self.anchor, "TOPLEFT" }, { 8, 42, 160, 24 }, "Analyze Current Build", function()
+		self:AnalyzeBuild()
+	end)
+	self.controls.analyze.shown = function()
+		return not self.collapsed
+	end
+	self.controls.analyze.enabled = function()
+		return not self.pending
+	end
+
+	self.controls.clear = new("ButtonControl", { "TOPRIGHT", self.anchor, "TOPLEFT" }, {
+		function()
+			return self:GetWidth() - 8
+		end,
+		42,
+		52,
+		24,
+	}, "Clear", function()
+		self.messages = { }
+		self.history = { }
+		self.currentSnapshot = nil
+		self:UpdateMessageRows()
+	end)
+	self.controls.clear.shown = function()
+		return not self.collapsed
+	end
+	self.controls.clear.enabled = function()
+		return not self.pending and #self.messages > 0
+	end
+
+	self.controls.messages = new("TextListControl", { "TOPLEFT", self.anchor, "TOPLEFT" }, { 8, 92, 0, 0 }, { { x = 4, align = "LEFT" } }, self.messageRows)
+	self.controls.messages.width = function()
+		return self:GetWidth() - 16
+	end
+	self.controls.messages.height = function()
+		return m_max(80, main.screenH - 32 - 92 - 40)
+	end
+	self.controls.messages.shown = function()
+		return not self.collapsed
+	end
+
+	self.controls.input = new("EditControl", { "TOPLEFT", self.anchor, "TOPLEFT" }, {
+		8,
+		function()
+			return main.screenH - 32 - 30
+		end,
+		function()
+			return m_max(120, self:GetWidth() - 70)
+		end,
+		24,
+	}, "", "Ask a question...", "%c", 1000, nil, nil, nil, true)
+	self.controls.input.shown = function()
+		return not self.collapsed
+	end
+	self.controls.input.enabled = function()
+		return not self.pending
+	end
+
+	self.controls.send = new("ButtonControl", { "LEFT", self.controls.input, "RIGHT" }, { 6, 0, 50, 24 }, "Send", function()
+		self:SendUserMessage()
+	end)
+	self.controls.send.shown = function()
+		return not self.collapsed
+	end
+	self.controls.send.enabled = function()
+		return not self.pending and self.controls.input.buf and self.controls.input.buf:match("%S") ~= nil
+	end
+
+	self:AddMessage("system", "Configure an OpenAI-compatible API, then click Analyze Current Build. The assistant only gives advice and will not modify your build.")
+end)
+
+function AIChatPanelClass:GetWidth()
+	if self.collapsed then
+		return 40
+	end
+	local desired = m_min(420, m_max(340, m_floor((main.screenW or 1280) * 0.28)))
+	if main and main.screenW then
+		local maxWidth = main.screenW - 312 - 300
+		if maxWidth < 260 then
+			maxWidth = m_max(240, main.screenW - 312 - 220)
+		end
+		desired = m_min(desired, maxWidth)
+	end
+	return m_max(240, desired)
+end
+
+function AIChatPanelClass:GetViewport()
+	local width = self:GetWidth()
+	return {
+		x = main.screenW - width,
+		y = 32,
+		width = width,
+		height = main.screenH - 32,
+	}
+end
+
+local function cleanText(text)
+	text = tostring(text or "")
+	if StripEscapes then
+		text = StripEscapes(text)
+	end
+	text = text:gsub("\r\n", "\n"):gsub("\r", "\n")
+	text = text:gsub("%^x%x%x%x%x%x%x", "")
+	text = text:gsub("%^%d", "")
+	text = text:gsub("%^%a", "")
+	return text
+end
+
+local function utf8Len(text)
+	local ok, len = pcall(utf8.len, text)
+	if ok and len then
+		return len
+	end
+	return #text
+end
+
+local function utf8Sub(text, first, last)
+	local ok, out = pcall(utf8.sub, text, first, last)
+	if ok and out then
+		return out
+	end
+	return text:sub(first, last)
+end
+
+local function stripInlineMarkdown(text)
+	text = tostring(text or "")
+	text = text:gsub("`([^`]*)`", "%1")
+	text = text:gsub("%*%*(.-)%*%*", "%1")
+	text = text:gsub("__(.-)__", "%1")
+	text = text:gsub("%*([^%*]-)%*", "%1")
+	text = text:gsub("_([^_]-)_", "%1")
+	return text
+end
+
+local function trimText(text)
+	return tostring(text or ""):gsub("^%s+", ""):gsub("%s+$", "")
+end
+
+local function normalizeMessageLines(text)
+	local out = { }
+	text = cleanText(text)
+	for rawLine in (text .. "\n"):gmatch("([^\n]*)\n") do
+		local line = trimText(rawLine)
+		if line:match("^```") then
+			-- Drop code fences; keep following lines as plain text.
+		elseif line == "" then
+			t_insert(out, { kind = "blank", text = "" })
+		else
+			local compact = line:gsub("%s+", "")
+			if #compact >= 3 and compact:match("^[-_=%*]+$") then
+				t_insert(out, { kind = "blank", text = "" })
+			else
+				line = line:gsub("^>%s*", "")
+				line = stripInlineMarkdown(line)
+				local heading = line:match("^#+%s*(.+)$")
+				if heading then
+					t_insert(out, { kind = "heading", text = trimText(stripInlineMarkdown(heading)) })
+				else
+					line = line:gsub("^%s*[%-%*%+]%s+", "- ")
+					line = line:gsub("^%s*(%d+)[%.)]%s+", "%1. ")
+					if line:find("|", 1, true) then
+						line = line:gsub("^%s*|", ""):gsub("|%s*$", ""):gsub("%s*|%s*", " / ")
+					end
+					line = line:gsub("```", "")
+					t_insert(out, { kind = "body", text = trimText(line) })
+				end
+			end
+		end
+	end
+	return out
+end
+
+local function wrapLine(text, width, fontSize)
+	local wrapped = { }
+	text = tostring(text or "")
+	if text == "" then
+		t_insert(wrapped, "")
+		return wrapped
+	end
+	local continuationPrefix = ""
+	if text:match("^%- ") then
+		continuationPrefix = "  "
+	elseif text:match("^%d+%. ") then
+		continuationPrefix = "   "
+	end
+	local line = ""
+	local len = utf8Len(text)
+	for index = 1, len do
+		local ch = utf8Sub(text, index, index)
+		local candidate = line .. ch
+		if line ~= "" and DrawStringWidth(fontSize, "VAR", candidate) > width then
+			t_insert(wrapped, line)
+			line = continuationPrefix .. ch
+		else
+			line = candidate
+		end
+	end
+	if line ~= "" then
+		t_insert(wrapped, line)
+	end
+	return wrapped
+end
+
+local function truncateText(text, limit)
+	text = tostring(text or "")
+	if utf8Len(text) <= limit then
+		return text
+	end
+	return utf8Sub(text, 1, limit) .. "\n[Brief mode omitted part of the build snapshot.]"
+end
+
+function AIChatPanelClass:UpdateMessageRows()
+	local rows = self.messageRows
+	wipeTable(rows)
+	local width = m_max(130, self:GetWidth() - 96)
+	for _, message in ipairs(self.messages) do
+		local name
+		local headerColor
+		local bodyColor
+		if message.role == "assistant" then
+			name = "AI Assistant"
+			headerColor = colorCodes.CURRENCY
+			bodyColor = "^7"
+		elseif message.role == "user" then
+			name = "You"
+			headerColor = colorCodes.MAGIC
+			bodyColor = "^7"
+		else
+			name = "System"
+			headerColor = colorCodes.TIP
+			bodyColor = "^8"
+		end
+		t_insert(rows, { height = 18, font = "VAR", headerColor .. name })
+		for _, visualLine in ipairs(normalizeMessageLines(message.content)) do
+			if visualLine.kind == "blank" then
+				t_insert(rows, { height = 6 })
+			elseif visualLine.kind == "heading" then
+				for _, line in ipairs(wrapLine(visualLine.text, width, 15)) do
+					t_insert(rows, { height = 17, font = "VAR", colorCodes.CURRENCY .. line })
+				end
+			else
+				for _, line in ipairs(wrapLine(visualLine.text, width, 14)) do
+					t_insert(rows, { height = 16, font = "VAR", bodyColor .. line })
+				end
+			end
+		end
+		t_insert(rows, { height = 8 })
+	end
+	self.controls.messages.controls.scrollBar.offset = 999999
+end
+
+function AIChatPanelClass:AddMessage(role, content)
+	local message = { role = role, content = content or "" }
+	t_insert(self.messages, message)
+	while #self.messages > 80 do
+		t_remove(self.messages, 1)
+	end
+	self:UpdateMessageRows()
+	return message
+end
+
+function AIChatPanelClass:RefreshBuildOutput()
+	if self.build and self.build.buildFlag then
+		wipeGlobalCache()
+		self.build.outputRevision = (self.build.outputRevision or 0) + 1
+		self.build.buildFlag = false
+		self.build.calcsTab:BuildOutput()
+		self.build:RefreshStatList()
+	end
+end
+
+function AIChatPanelClass:ClassifyReplyMode(userText, forcedMode)
+	if forcedMode then
+		return forcedMode
+	end
+	local text = cleanText(userText):lower()
+	local briefWords = { "brief", "short", "quick", "one sentence", "summarize", "simple", "tl;dr" }
+	for _, word in ipairs(briefWords) do
+		if text:find(word, 1, true) then
+			return "brief"
+		end
+	end
+	local simpleQuestion = text:match("^%s*what is ") or text:match("^%s*what does ") or text:match("^%s*why is ")
+	if simpleQuestion and utf8Len(text) <= 80 then
+		return "brief"
+	end
+	local normalWords = { "detail", "detailed", "analyze", "analysis", "improve", "upgrade", "optimize", "gear", "item", "items", "skill", "skills", "tree", "defense", "defence", "dps", "damage", "resistance", "build", "advice", "check", "why", "how" }
+	for _, word in ipairs(normalWords) do
+		if text:find(word, 1, true) then
+			return "normal"
+		end
+	end
+	return "brief"
+end
+
+function AIChatPanelClass:GetSystemPrompt(replyMode)
+	local modePrompt
+	if replyMode == "analysis" then
+		modePrompt = "This is Analyze Current Build mode. Give 3-6 highest-priority findings first, then concise checks. Keep the total answer under 900 words."
+	elseif replyMode == "normal" then
+		modePrompt = "This is advice mode. Give up to 5 concise suggestions, with the conclusion before the reason. Do not rewrite a full build audit. Keep the total answer under 450 words."
+	else
+		modePrompt = "This is a normal follow-up question. Prefer 1-3 sentences, or at most 3 short bullets. Unless the user asks, do not expand into a full build analysis. Keep the total answer under 180 words."
+	end
+	return [[You are a Path of Building for Path of Exile 2 build-analysis assistant.
+You only provide analysis, advice, and explanations. Do not claim you modified the build, and do not ask the user to apply automatic changes.
+Answer in English. Prioritize main skill links, damage scaling, defensive layers, resistances, accuracy/crit, resource reservation, gear weaknesses, and possibly incorrect configuration settings.
+Do not output markdown tables, code blocks, ### headings, **bold markers**, backticks, or long --- dividers. Use short plain-text paragraphs. Lists may use "- " or "1. ".
+If the build snapshot is insufficient, say exactly which page or value the user should check.
+]] .. modePrompt
+end
+
+function AIChatPanelClass:BuildRequestMessages(userText, replyMode)
+	local snapshot = self.currentSnapshot or ""
+	local contextPrompt = "Current build snapshot:\n"
+	if replyMode == "brief" then
+		snapshot = truncateText(snapshot, 1800)
+		contextPrompt = "Use the current build snapshot only as background. This is a normal follow-up question; unless required, do not re-analyze the whole build.\n"
+	elseif replyMode == "normal" then
+		snapshot = truncateText(snapshot, 3500)
+		contextPrompt = "Current build snapshot. Answer only the user's question with targeted advice; do not output a complete audit report.\n"
+	end
+	local messages = {
+		{ role = "system", content = self:GetSystemPrompt(replyMode) },
+		{ role = "user", content = contextPrompt .. snapshot },
+	}
+	local startIndex = m_max(1, #self.history - 7)
+	for index = startIndex, #self.history do
+		t_insert(messages, self.history[index])
+	end
+	t_insert(messages, { role = "user", content = userText })
+	return messages
+end
+
+function AIChatPanelClass:EnsureConfigured()
+	self.settings = settingsStore.Load()
+	if settingsStore.IsConfigured(self.settings) then
+		return true
+	end
+	self.statusText = "API not configured"
+	self:AddMessage("system", "Open Settings and enter an API base URL, API key, and model name first.")
+	self:OpenSettingsPopup()
+	return false
+end
+
+function AIChatPanelClass:RunAI(userText, displayText, refreshSnapshot, forcedMode)
+	if self.pending then
+		return
+	end
+	if not self:EnsureConfigured() then
+		return
+	end
+	local replyMode = self:ClassifyReplyMode(userText, forcedMode)
+	if refreshSnapshot or not self.currentSnapshot then
+		self:RefreshBuildOutput()
+		self.currentSnapshot = buildSnapshot.Create(self.build)
+	end
+	local requestMessages = self:BuildRequestMessages(userText, replyMode)
+	self.pending = true
+	self.statusText = "Thinking..."
+	self:AddMessage("user", displayText or userText)
+	local pendingMessage = self:AddMessage("assistant", "Thinking...")
+	t_insert(self.history, { role = "user", content = userText })
+	while #self.history > 16 do
+		t_remove(self.history, 1)
+	end
+	aiClient.Send(self.settings, requestMessages, function(content, errMsg)
+		self.pending = false
+		if content then
+			self.statusText = "Done"
+			pendingMessage.role = "assistant"
+			pendingMessage.content = content
+			self:UpdateMessageRows()
+			t_insert(self.history, { role = "assistant", content = content })
+			while #self.history > 16 do
+				t_remove(self.history, 1)
+			end
+		else
+			self.statusText = "Request failed"
+			pendingMessage.role = "system"
+			pendingMessage.content = "Request failed: " .. tostring(errMsg or "unknown error")
+			self:UpdateMessageRows()
+		end
+	end)
+end
+
+function AIChatPanelClass:AnalyzeBuild()
+	self:RunAI("Analyze the current build. Start with 3-6 highest-priority conclusions, then list the damage, defense, gear, skills, and configuration checks that matter most.", "Analyze Current Build", true, "analysis")
+end
+
+function AIChatPanelClass:SendUserMessage()
+	local text = self.controls.input.buf or ""
+	text = text:gsub("^%s+", ""):gsub("%s+$", "")
+	if text == "" then
+		return
+	end
+	self.controls.input:SetText("")
+	self:RunAI(text, text, false)
+end
+
+function AIChatPanelClass:GetProviderIndex(providerId)
+	for index, provider in ipairs(providers.list) do
+		if provider.id == providerId then
+			return index
+		end
+	end
+	return #providers.list
+end
+
+function AIChatPanelClass:OpenSettingsPopup()
+	local data = settingsStore.Load()
+	local controls = { }
+	local inputX = 170
+	local inputW = 500
+	local function formLabel(key, y, text)
+		controls[key] = new("LabelControl", { "TOPRIGHT", nil, "TOPLEFT" }, { inputX - 12, y, 0, 18 }, "^7" .. text)
+	end
+	formLabel("providerLabel", 24, "Provider:")
+	controls.provider = new("DropDownControl", { "TOPLEFT", nil, "TOPLEFT" }, { inputX, 20, inputW, 22 }, providers.list, function(index, value)
+		data.provider = value.id
+		data.apiBase = value.apiBase or ""
+		data.model = value.model or ""
+		controls.apiBase:SetText(data.apiBase)
+		controls.model:SetText(data.model)
+	end)
+	controls.provider.maxDroppedWidth = inputW
+	controls.provider.selIndex = self:GetProviderIndex(data.provider)
+	formLabel("apiBaseLabel", 62, "API Base URL:")
+	controls.apiBase = new("EditControl", { "TOPLEFT", nil, "TOPLEFT" }, { inputX, 58, inputW, 22 }, data.apiBase or "", nil, "%c", 300)
+	formLabel("apiKeyLabel", 100, "API Key:")
+	controls.apiKey = new("EditControl", { "TOPLEFT", nil, "TOPLEFT" }, { inputX, 96, inputW, 22 }, data.apiKey or "", nil, "%c", 500)
+	controls.apiKey:SetProtected(true)
+	formLabel("modelLabel", 138, "Model:")
+	controls.model = new("EditControl", { "TOPLEFT", nil, "TOPLEFT" }, { inputX, 134, inputW, 22 }, data.model or "", nil, "%c", 160)
+	controls.note = new("LabelControl", { "TOPLEFT", nil, "TOPLEFT" }, { inputX, 176, 0, 16 }, "^8Settings are saved locally to AIAssistantSettings.json.")
+	controls.save = new("ButtonControl", { "TOPLEFT", nil, "TOPLEFT" }, { 260, 218, 90, 24 }, "Save", function()
+		local selected = controls.provider.list[controls.provider.selIndex] or providers.list[#providers.list]
+		data.provider = selected.id
+		data.apiBase = controls.apiBase.buf
+		data.apiKey = controls.apiKey.buf
+		data.model = controls.model.buf
+		data.temperature = tonumber(data.temperature) or 0.2
+		local ok, err = settingsStore.Save(data)
+		if ok then
+			self.settings = settingsStore.Load()
+			self.statusText = "Settings saved"
+			main:ClosePopup()
+		else
+			main:OpenMessagePopup("AI Settings Save Failed", tostring(err))
+		end
+	end)
+	controls.cancel = new("ButtonControl", { "TOPLEFT", nil, "TOPLEFT" }, { 370, 218, 90, 24 }, "Cancel", function()
+		main:ClosePopup()
+	end)
+	main:OpenPopup(720, 268, "AI Assistant Settings", controls, "save", "apiKey", "cancel")
+end
+
+function AIChatPanelClass:ProcessInput(inputEvents)
+	local view = self:GetViewport()
+	for id, event in ipairs(inputEvents) do
+		if event.type == "KeyDown" and event.key == "RETURN" and self.selControl == self.controls.input then
+			self:SendUserMessage()
+			inputEvents[id] = nil
+		elseif event.type == "KeyDown" and event.key == "LEFTBUTTON" and self.selControl and not self.selControl:IsMouseOver() then
+			self:SelectControl()
+		end
+	end
+	self:ProcessControlsInput(inputEvents, view)
+	for id, event in ipairs(inputEvents) do
+		if event and event.key and event.key:match("BUTTON") and isMouseInRegion(view) then
+			inputEvents[id] = nil
+		end
+	end
+end
+
+function AIChatPanelClass:Draw()
+	local view = self:GetViewport()
+	SetDrawLayer(6)
+	SetDrawColor(0.85, 0.85, 0.85)
+	DrawImage(nil, view.x, view.y, 4, view.height)
+	DrawImage(nil, view.x, view.y, view.width, 2)
+	SetDrawColor(0.08, 0.09, 0.1)
+	DrawImage(nil, view.x + 4, view.y + 2, view.width - 4, view.height - 2)
+
+	if self.collapsed then
+		SetDrawColor(1, 1, 1)
+		DrawString(view.x + 8, view.y + 42, "LEFT", 18, "VAR", "AI")
+		self:DrawControls(main.viewPort)
+		SetDrawLayer(0)
+		return
+	end
+
+	SetDrawColor(0.16, 0.17, 0.18)
+	DrawImage(nil, view.x + 4, view.y + 2, view.width - 4, 34)
+	SetDrawColor(1, 1, 1)
+	DrawString(view.x + 42, view.y + 9, "LEFT", 18, "VAR", "AI Assistant")
+	local provider = providers.byId[self.settings.provider]
+	local providerLabel = provider and provider.label or "Custom"
+	local status = self.statusText or ""
+	if not settingsStore.IsConfigured(self.settings) then
+		status = "API not configured"
+	end
+	SetDrawColor(1, 1, 1)
+	SetViewport(view.x + 8, view.y + 70, view.width - 16, 18)
+	DrawString(0, 0, "LEFT", 14, "VAR", "^8" .. providerLabel .. " / " .. status)
+	SetViewport()
+	self:DrawControls(main.viewPort)
+	SetDrawLayer(0)
+end
+
+return AIChatPanelClass
diff --git a/src/Modules/Build.lua b/src/Modules/Build.lua
index d7e124cb5c..6203ac55fa 100644
--- a/src/Modules/Build.lua
+++ b/src/Modules/Build.lua
@@ -606,6 +606,7 @@ function buildMode:Init(dbFileName, buildName, buildXML, convertBuild, importLin
 	self.skillsTab = new("SkillsTab", self)
 	self.calcsTab = new("CalcsTab", self)
 	self.compareTab = new("CompareTab", self)
+	self.aiPanel = new("AIChatPanel", self)
 
 	-- Load sections from the build file
 	self.savers = {
@@ -1138,6 +1139,9 @@ function buildMode:OnFrame(inputEvents)
 			self.spec.allocMode = (self.spec.allocMode + 1) % 3
 		end
 	end
+	if self.aiPanel then
+		self.aiPanel:ProcessInput(inputEvents)
+	end
 	self:ProcessControlsInput(inputEvents, main.viewPort)
 
 	self.controls.classDrop:SelByValue(self.spec.curClassId, "classId")
@@ -1176,10 +1180,11 @@ function buildMode:OnFrame(inputEvents)
 
 	-- Draw contents of current tab
 	local sideBarWidth = 312
+	local aiPanelWidth = self.aiPanel and self.aiPanel:GetWidth() or 0
 	local tabViewPort = {
 		x = sideBarWidth,
 		y = 32,
-		width = main.screenW - sideBarWidth,
+		width = m_max(0, main.screenW - sideBarWidth - aiPanelWidth),
 		height = main.screenH - 32
 	}
 	if self.viewMode == "IMPORT" then
@@ -1220,6 +1225,9 @@ function buildMode:OnFrame(inputEvents)
 	DrawImage(nil, sideBarWidth - 4, 32, 4, main.screenH - 32)
 
 
+	if self.aiPanel then
+		self.aiPanel:Draw()
+	end
 	self:DrawControls(main.viewPort)
 end