From 62687fd57de40b78f46f05d8432ea5c8c7659ad4 Mon Sep 17 00:00:00 2001
From: joaopluigi <joao.luigi@nubank.com.br>
Date: Thu, 25 Sep 2025 11:45:44 -0300
Subject: [PATCH 01/10] get config from server, store in state and display in
 sidebar

---
 lua/eca/init.lua     |   3 +-
 lua/eca/mediator.lua |  45 +++++++-
 lua/eca/observer.lua |   4 +-
 lua/eca/sidebar.lua  | 248 ++++++++++++++++++++++++-------------------
 lua/eca/state.lua    | 201 +++++++++++++++++++++++++++++++++++
 5 files changed, 388 insertions(+), 113 deletions(-)
 create mode 100644 lua/eca/state.lua

diff --git a/lua/eca/init.lua b/lua/eca/init.lua
index 3772395..5baed4e 100644
--- a/lua/eca/init.lua
+++ b/lua/eca/init.lua
@@ -242,8 +242,9 @@ function M.setup(opts)
   H.signs()
 
   -- Initialize the ECA server with callbacks
+  M.state = require("eca.state").new()
   M.server = Server.new()
-  M.mediator = require("eca.mediator").new(M.server)
+  M.mediator = require("eca.mediator").new(M.server, M.state)
   -- Start server automatically in background
   vim.defer_fn(function()
     M.server:start()
diff --git a/lua/eca/mediator.lua b/lua/eca/mediator.lua
index a99ec96..499267a 100644
--- a/lua/eca/mediator.lua
+++ b/lua/eca/mediator.lua
@@ -1,12 +1,15 @@
 ---@class eca.Mediator
 ---@field server eca.Server
+---@field state eca.State
 local mediator = {}
 
 ---@param server eca.Server
+---@param state eca.State
 ---@return eca.Mediator
-function mediator.new(server)
+function mediator.new(server, state)
   return setmetatable({
     server = server,
+    state = state,
   }, { __index = mediator })
 end
 
@@ -23,4 +26,44 @@ function mediator:send(method, params, callback)
   self.server:send_request(method, params, callback)
 end
 
+function mediator:selected_behavior()
+  return self.state.config.behaviors.selected
+end
+
+function mediator:selected_model()
+  return self.state.config.models.selected
+end
+
+function mediator:tokens_session()
+  return self.state.usage.tokens.session
+end
+
+function mediator:tokens_limit()
+  return self.state.usage.tokens.limit
+end
+
+function mediator:costs_session()
+  return self.state.usage.costs.session
+end
+
+function mediator:status_state()
+  return self.state.status.state
+end
+
+function mediator:status_text()
+  return self.state.status.text
+end
+
+function mediator:mcps()
+  local mcps = {}
+
+  for _, tool in pairs(self.state.tools) do
+    if tool.type == "mcp" then
+      table.insert(mcps, tool)
+    end
+  end
+
+  return mcps
+end
+
 return mediator
diff --git a/lua/eca/observer.lua b/lua/eca/observer.lua
index 7a8e2ac..e6a4c30 100644
--- a/lua/eca/observer.lua
+++ b/lua/eca/observer.lua
@@ -1,9 +1,9 @@
 local observer = {}
 
----@type { [integer]: fun(message: table) }
+---@type { [string]: fun(message: table) }
 local subscriptions = {}
 
----@param id integer
+---@param id string
 ---@param on_update fun(message: table)
 function observer.subscribe(id, on_update)
   subscriptions[id] = on_update
diff --git a/lua/eca/sidebar.lua b/lua/eca/sidebar.lua
index d302425..09e2fbc 100644
--- a/lua/eca/sidebar.lua
+++ b/lua/eca/sidebar.lua
@@ -31,10 +31,7 @@ local M = {}
 M.__index = M
 
 -- Height calculation constants
-local MIN_CHAT_HEIGHT = 10 -- Minimum lines for chat container to remain usable
-local WINDOW_MARGIN = 3 -- Additional margin for window borders and spacing
 local UI_ELEMENTS_HEIGHT = 2 -- Reserve space for statusline and tabline
-local SAFETY_MARGIN = 2 -- Extra margin to prevent "Not enough room" errors
 
 ---@param id integer Tab ID
 ---@param mediator eca.Mediator
@@ -44,6 +41,7 @@ function M.new(id, mediator)
   instance.id = id
   instance.mediator = mediator
   instance.containers = {}
+  instance.extmarks = {}
   instance._initialized = false
   instance._current_response_buffer = ""
   instance._is_streaming = false
@@ -65,7 +63,7 @@ function M.new(id, mediator)
     assistant = (Config.chat and Config.chat.headers and Config.chat.headers.assistant) or "## 🤖 ECA\n\n",
   }
 
-  require("eca.observer").subscribe(id, function(message)
+  require("eca.observer").subscribe("sidebar-" .. id, function(message)
     instance:handle_chat_content(message)
   end)
   return instance
@@ -228,15 +226,11 @@ function M:_create_containers()
   local todos_height = self:get_todos_height()
   local original_chat_height = self:get_chat_height()
   local chat_height = original_chat_height
+  local config_height = 1
 
   -- Validate total height to prevent "Not enough room" error
   local total_height = chat_height
-    + selected_code_height
-    + todos_height
-    + status_height
-    + contexts_height
-    + input_height
-    + usage_height
+    + config_height
 
   -- Always calculate from total screen minus UI elements (more accurate than current window)
   local available_height = vim.o.lines - UI_ELEMENTS_HEIGHT
@@ -293,7 +287,26 @@ function M:_create_containers()
   local current_winid = self.containers.chat.winid
   Logger.debug("Mounted container: chat (winid: " .. current_winid .. ")")
 
-  -- 2. Create selected_code container (conditional)
+  --2. Create config container in top of chat
+  self.containers.config = Split({
+    relative = {
+      type = "win",
+      winid = current_winid,
+    },
+    position = "top",
+    size = { height = config_height },
+    buf_options = vim.tbl_deep_extend("force", base_buf_options, {
+      modifiable = false,
+    }),
+    win_options = vim.tbl_deep_extend("force", base_win_options, {
+      winhighlight = "Normal:Normal",
+    }),
+  })
+  self.containers.config:mount()
+  self:_setup_container_events(self.containers.config, "config")
+  Logger.debug("Mounted container: config (winid: " .. self.containers.config.winid .. ")")
+
+  -- 3. Create selected_code container (conditional)
   if selected_code_height > 0 then
     self.containers.selected_code = Split({
       relative = {
@@ -316,7 +329,7 @@ function M:_create_containers()
     Logger.debug("Mounted container: selected_code (winid: " .. current_winid .. ")")
   end
 
-  -- 3. Create todos container (conditional)
+  -- 4. Create todos container (conditional)
   if todos_height > 0 then
     self.containers.todos = Split({
       relative = {
@@ -338,27 +351,7 @@ function M:_create_containers()
     Logger.debug("Mounted container: todos (winid: " .. current_winid .. ")")
   end
 
-  -- 4. Create status container (always present) - for processing messages
-  self.containers.status = Split({
-    relative = {
-      type = "win",
-      winid = current_winid,
-    },
-    position = "bottom",
-    size = { height = status_height },
-    buf_options = vim.tbl_deep_extend("force", base_buf_options, {
-      modifiable = false,
-    }),
-    win_options = vim.tbl_deep_extend("force", base_win_options, {
-      winhighlight = "Normal:WarningMsg",
-    }),
-  })
-  self.containers.status:mount()
-  self:_setup_container_events(self.containers.status, "status")
-  current_winid = self.containers.status.winid
-  Logger.debug("Mounted container: status (winid: " .. current_winid .. ")")
-
-  -- 5. Create contexts container between status and input
+  -- 5. Create contexts container between chat and input
   self.containers.contexts = Split({
     relative = {
       type = "win",
@@ -378,7 +371,7 @@ function M:_create_containers()
   current_winid = self.containers.contexts.winid
   Logger.debug("Mounted container: contexts (winid: " .. current_winid .. ")")
 
-  -- 6. Create input container (always present)
+  --6. Create input container (always present)
   self.containers.input = Split({
     relative = {
       type = "win",
@@ -405,13 +398,14 @@ function M:_create_containers()
       type = "win",
       winid = current_winid,
     },
+    enter = false,
     position = "bottom",
     size = { height = usage_height },
     buf_options = vim.tbl_deep_extend("force", base_buf_options, {
       modifiable = false,
     }),
     win_options = vim.tbl_deep_extend("force", base_win_options, {
-      winhighlight = "Normal:StatusLine",
+      winhighlight = "Normal:Comment",
       statusline = " ",
     }),
   })
@@ -421,14 +415,15 @@ function M:_create_containers()
 
   Logger.debug(
     string.format(
-      "Created containers: contexts=%d, chat=%d, selected_code=%s, todos=%s, status=%d, input=%d, usage=%d",
+      "Created containers: contexts=%d, chat=%d, selected_code=%s, todos=%s, status=%d, input=%d, usage=%d, config=%d",
       contexts_height,
       chat_height,
       selected_code_height > 0 and tostring(selected_code_height) or "hidden",
       todos_height > 0 and tostring(todos_height) or "hidden",
       status_height,
       input_height,
-      usage_height
+      usage_height,
+      config_height
     )
   )
 end
@@ -567,17 +562,12 @@ function M:get_chat_height()
   local contexts_height = self:get_contexts_height()
   local selected_code_height = self:get_selected_code_height()
   local todos_height = self:get_todos_height()
+  local config_height = 1
 
   return math.max(
     MIN_CHAT_HEIGHT,
     total_height
-      - input_height
-      - usage_height
-      - status_height
-      - contexts_height
-      - selected_code_height
-      - todos_height
-      - WINDOW_MARGIN
+      - config_height
   )
 end
 
@@ -696,7 +686,7 @@ function M:_setup_containers()
     self:_setup_todos_container()
   end
 
-  self:_setup_status_container()
+  self:_update_config_display()
   self:_setup_input_container()
   self:_setup_usage_container()
 
@@ -713,6 +703,10 @@ function M:_refresh_container_content()
     self:_set_welcome_content()
   end
 
+  if self.containers.config then
+    self:_update_config_display()
+  end
+
   if self.containers.selected_code then
     self:_update_selected_code_display()
   end
@@ -721,16 +715,22 @@ function M:_refresh_container_content()
     self:_update_todos_display()
   end
 
-  if self.containers.status then
-    self:_update_status_display()
-  end
-
   if self.containers.input then
     self:_add_input_line()
   end
 
   if self.containers.usage then
-    self:_update_usage_info(self._usage_info)
+    self:_update_usage_info()
+  end
+end
+
+function M:_handle_state_updated(state)
+  if state.usage or state.status then
+    self:_update_usage_info()
+  end
+
+  if state.config or state.tools then
+    self:_update_config_display()
   end
 end
 
@@ -799,16 +799,6 @@ function M:_setup_contexts_container()
   self:_update_contexts_display()
 end
 
-function M:_setup_status_container()
-  local status = self.containers.status
-  if not status then
-    return
-  end
-
-  -- Set initial status display
-  self:_update_status_display()
-end
-
 function M:_setup_usage_container()
   local usage = self.containers.usage
   if not usage then
@@ -816,9 +806,7 @@ function M:_setup_usage_container()
   end
 
   -- Set initial usage info
-  vim.api.nvim_set_option_value("modifiable", true, { buf = usage.bufnr })
-  vim.api.nvim_buf_set_lines(usage.bufnr, 0, -1, false, { "Usage: Tokens | Cost" })
-  vim.api.nvim_set_option_value("modifiable", false, { buf = usage.bufnr })
+  self:_update_usage_info()
 end
 
 function M:_setup_input_container()
@@ -1074,6 +1062,41 @@ function M:_update_todos_display()
   vim.api.nvim_set_option_value("modifiable", false, { buf = container.bufnr })
 end
 
+function M:_update_config_display()
+  local config = self.containers.config
+  if not config or not vim.api.nvim_buf_is_valid(config.bufnr) then
+    return
+  end
+
+  local model = self.mediator:selected_model() or "unknown"
+  local behavior = self.mediator:selected_behavior() or "unknown"
+  local mcps = vim.tbl_count(self.mediator:mcps())
+
+  local texts = {
+    { "model:",    "Comment" }, { model, "Normal" }, { "\t" },
+    { "behavior:", "Comment" }, { behavior, "Normal" }, { " " },
+    { "mcps:", "Comment" }, { tostring(mcps), "Exception" },
+  }
+
+  local virt_opts = { virt_text = texts, hl_mode = "combine" }
+
+  self.extmarks = self.extmarks or {}
+
+  if not self.extmarks.config then
+    self.extmarks.config = {
+      _ns = vim.api.nvim_create_namespace('extmarks_config'),
+    }
+  end
+
+  self.extmarks.config._id = vim.api.nvim_buf_set_extmark(
+    config.bufnr,
+    self.extmarks.config._ns,
+    0,
+    -1,
+    vim.tbl_extend("force", virt_opts, { id = self.extmarks.config._id })
+  )
+end
+
 function M:_update_contexts_display()
   -- Similar implementation for contexts...
   local contexts = self.containers.contexts
@@ -1106,40 +1129,65 @@ function M:_update_contexts_display()
   vim.api.nvim_set_option_value("modifiable", false, { buf = contexts.bufnr })
 end
 
-function M:_update_status_display()
-  local status = self.containers.status
-  if not status or not vim.api.nvim_buf_is_valid(status.bufnr) then
+function M:_update_usage_info()
+  local usage = self.containers.usage
+  if not usage or not vim.api.nvim_buf_is_valid(usage.bufnr) then
     return
   end
 
-  local status_text = self._current_status or ""
-  if status_text == "" then
-    status_text = "💤 Ready"
+  local status_state = self.mediator:status_state()
+  local status_text = self.mediator:status_text()
+
+  if status_state == "finished" then
+    status_text = "Idle"
   end
 
-  -- Update the buffer
-  vim.api.nvim_set_option_value("modifiable", true, { buf = status.bufnr })
-  vim.api.nvim_buf_set_lines(status.bufnr, 0, -1, false, { status_text })
-  vim.api.nvim_set_option_value("modifiable", false, { buf = status.bufnr })
-end
+  local tokens = self.mediator:tokens_session() or 0
+  local limit = self.mediator:tokens_limit() or 0
+  local costs = self.mediator:costs_session() or "0.00"
 
----@param status_text string
-function M:set_status(status_text)
-  self._current_status = status_text or ""
-  self:_update_status_display()
-end
+  self._current_status = string.format("%s", status_text)
+  self._usage_info = string.format("%d / %d (%s)", tokens, limit, costs)
 
-function M:_update_usage_info(usage_text)
-  local usage = self.containers.usage
-  if not usage or not vim.api.nvim_buf_is_valid(usage.bufnr) then
-    return
-  end
+  self.extmarks = self.extmarks or {}
 
-  self._usage_info = usage_text or "Usage: Tokens | Cost"
+  if not self.extmarks.usage then
+    self.extmarks.usage = {
+      _ns = vim.api.nvim_create_namespace('extmarks_usage'),
+    }
+  end
 
   vim.api.nvim_set_option_value("modifiable", true, { buf = usage.bufnr })
-  vim.api.nvim_buf_set_lines(usage.bufnr, 0, -1, false, { self._usage_info })
+  vim.api.nvim_buf_set_lines(usage.bufnr, 0, -1, false, { "" })
   vim.api.nvim_set_option_value("modifiable", false, { buf = usage.bufnr })
+
+  self.extmarks.usage._id_status = vim.api.nvim_buf_set_extmark(
+    usage.bufnr,
+    self.extmarks.usage._ns,
+    0,
+    -1,
+    vim.tbl_extend("force",
+      {
+        virt_text = { { self._current_status, (status_text ~= "Idle") and "Question" or "Normal" } },
+        virt_text_pos = 'eol',
+        hl_mode = 'combine',
+      },
+      { id = self.extmarks.config._id_status })
+  )
+
+  self.extmarks.usage._id_usage = vim.api.nvim_buf_set_extmark(
+    usage.bufnr,
+    self.extmarks.usage._ns,
+    0,
+    -1,
+    vim.tbl_extend("force",
+      {
+        virt_text = { { self._usage_info } },
+        virt_text_pos = 'right_align',
+        hl_mode = 'combine',
+      },
+      { id = self.extmarks.config._id_usage })
+  )
 end
 
 function M:_render_header(container_name, header_text)
@@ -1195,6 +1243,10 @@ function M:handle_chat_content(message)
   if message.params then
     self:handle_chat_content_received(message.params)
   end
+
+  if message.type == "state/updated" then
+    self:_handle_state_updated(message.content)
+  end
 end
 
 ---@param params table Server content notification
@@ -1210,26 +1262,10 @@ function M:handle_chat_content_received(params)
     -- Handle streaming text content
     self:_handle_streaming_text(content.text)
   elseif content.type == "progress" then
-    if content.state == "running" then
-      -- Show progress in status container instead of chat
-      self:set_status("⏳ " .. (content.text or "Processing..."))
-    elseif content.state == "finished" then
-      -- Clear status and finalize any streaming response
-      self:set_status("💤 Ready")
+    if content.state == "finished" then
       self:_finalize_streaming_response()
       self:_add_input_line()
     end
-  elseif content.type == "usage" then
-    -- Finalize streaming before adding usage info
-    self:_finalize_streaming_response()
-
-    -- Update usage container only (remove duplication in chat)
-    local usage_text =
-      string.format("Usage: Tokens %d in, %d out", content.messageInputTokens or 0, content.messageOutputTokens or 0)
-    if content.messageCost then
-      usage_text = usage_text .. " | Cost: " .. content.messageCost
-    end
-    self:_update_usage_info(usage_text)
   elseif content.type == "toolCallPrepare" then
     self:_finalize_streaming_response()
     self:_handle_tool_call_prepare(content)
@@ -1406,12 +1442,6 @@ function M:_add_message(role, content)
 
     -- Check if content looks like code (starts with common programming patterns)
     local is_code = content:match("^%s*function")
-      or content:match("^%s*class")
-      or content:match("^%s*def ")
-      or content:match("^%s*import")
-      or content:match("^%s*#include")
-      or content:match("^%s*<%?")
-      or content:match("^%s*<html")
 
     if is_code then
       -- Wrap in code block with auto-detection
diff --git a/lua/eca/state.lua b/lua/eca/state.lua
new file mode 100644
index 0000000..2da885c
--- /dev/null
+++ b/lua/eca/state.lua
@@ -0,0 +1,201 @@
+---@class eca.StateStatus
+---@field state string
+---@field text string
+
+---@class eca.StateConfig
+---@field welcome_message string?
+---@field behaviors { list: string[], default: string?, selected: string? }
+---@field models { list: string[], default: string?, selected: string? }
+
+---@class eca.StateUsage
+---@field tokens { limit: number, session: number }
+---@field costs { last_message: string, session: string }
+
+---@class eca.StateTool
+---@field type string
+---@field name string
+---@field status string
+---
+---@class eca.State
+---@field status eca.StateStatus
+---@field config eca.StateConfig
+---@field usage eca.StateUsage
+---@field tools table<string, eca.StateTool>
+local State = {}
+
+---@return eca.State
+function State._new()
+  local instance = setmetatable({
+    status = {
+      state = "idle",
+      text = "Idle",
+    },
+    config = {
+      welcome_message = nil,
+      behaviors = {
+        list = {},
+        default = nil,
+        selected = nil,
+      },
+      models = {
+        list = {},
+        default = nil,
+        selected = nil,
+      },
+    },
+    usage = {
+      tokens = {
+        limit = 0,
+        session = 0,
+      },
+      costs = {
+        last_message = "0.00",
+        session = "0.00",
+      },
+    },
+    tools = {},
+  }, { __index = State })
+
+  local handlers = {
+    ["chat/contentReceived"] = function(message) instance:_chat_content_received(message) end,
+    ["config/updated"] = function(message) instance:_config_updated(message) end,
+    ["tool/serverUpdated"] = function(message) instance:_tool_server_updated(message) end,
+  }
+
+  require("eca.observer").subscribe("state-1", function(message)
+    if not message or not message.method then
+      return
+    end
+
+    local handler = handlers[message.method]
+
+    if not handler or type(handler) ~= 'function' then
+      return
+    end
+
+    handler(message)
+  end)
+
+  return instance
+end
+
+local _instance
+
+---@return eca.State
+function State.new()
+  if not _instance then
+    _instance = State._new()
+  end
+
+  return _instance
+end
+
+function State:_chat_content_received(message)
+  if not message or not message.params then
+    return
+  end
+
+  if not message.params.content or not message.params.content.type then
+    return
+  end
+
+  local content = message.params.content
+
+  if content.type == "progress" then
+    self:_update_status(content)
+  end
+
+  if content.type == "usage" then
+    self:_update_usage(content)
+  end
+end
+
+function State:_config_updated(message)
+  if not message or not message.params then
+    return
+  end
+
+  if not message.params.chat or type(message.params.chat) ~= "table" then
+    return
+  end
+
+  self:_update_config({ chat = vim.deepcopy(message.params.chat) })
+end
+
+function State:_tool_server_updated(message)
+  if not message or not message.params then
+    return
+  end
+
+  self:_update_tools(message.params)
+end
+
+function State:_update_config(config)
+  local chat = config.chat
+
+  if not chat or type(chat) ~= "table" then
+    return
+  end
+
+  self.config.behaviors = {
+    list = (chat.behaviors and vim.deepcopy(chat.behaviors)) or self.config.behaviors.list,
+    default = (chat.defaultBehavior) or self.config.behaviors.default,
+    selected = (chat.selectBehavior) or self.config.behaviors.selected,
+  }
+
+  self.config.models = {
+    list = (chat.models and vim.deepcopy(chat.models)) or self.config.models.list,
+    default = (chat.defaultModel) or self.config.models.default,
+    selected = (chat.selectModel) or self.config.models.selected,
+  }
+
+  self.config.welcome_message = (chat and chat.welcomeMessage) or self.config.welcome_message
+
+  vim.schedule(function()
+    require("eca.observer").notify({ type = "state/updated", content = { config = vim.deepcopy(self.config) } })
+  end)
+end
+
+function State:_update_status(status)
+  self.status.state = status.state or self.status.state
+  self.status.text = status.text or self.status.text
+
+  vim.schedule(function()
+    require("eca.observer").notify({ type = "state/updated", content = { status = vim.deepcopy(self.status) } })
+  end)
+end
+
+function State:_update_usage(usage)
+  self.usage = {
+    tokens = {
+      limit = (usage.limit and usage.limit.output) or self.usage.tokens.limit,
+      session = usage.sessionTokens or self.usage.tokens.session,
+    },
+    costs = {
+      last_message = usage.lastMessageCost or self.usage.costs.last_message,
+      session = usage.sessionCost or self.usage.costs.session,
+    },
+  }
+
+  vim.schedule(function()
+    require("eca.observer").notify({ type = "state/updated", content = { usage = vim.deepcopy(self.usage) } })
+  end)
+end
+
+function State:_update_tools(tool)
+  if not tool.name then
+    return
+  end
+
+  self.tools[tool.name] = {
+    name = tool.name,
+    type = tool.type or (self.tools[tool.name] and self.tools[tool.name].type) or "unknown",
+    status = tool.status or (self.tools[tool.name] and self.tools[tool.name].status) or "unknown",
+  }
+
+  vim.schedule(function()
+    require("eca.observer").notify({ type = "state/updated", content = { tools = vim.deepcopy(self.tools) } })
+  end)
+end
+
+return State

From 61adc15a7c74c93c18b89c2f6a9372cee7d61938 Mon Sep 17 00:00:00 2001
From: joaopluigi <joao.luigi@nubank.com.br>
Date: Thu, 25 Sep 2025 11:45:58 -0300
Subject: [PATCH 02/10] add EcaServerMessages command

---
 lua/eca/commands.lua | 46 ++++++++++++++++++++++++++++++++++++++++++++
 lua/eca/server.lua   | 11 ++++-------
 2 files changed, 50 insertions(+), 7 deletions(-)

diff --git a/lua/eca/commands.lua b/lua/eca/commands.lua
index 898763d..5c14c60 100644
--- a/lua/eca/commands.lua
+++ b/lua/eca/commands.lua
@@ -157,6 +157,52 @@ function M.setup()
     desc = "Restart ECA server",
   })
 
+  vim.api.nvim_create_user_command("EcaServerMessages", function()
+    local has_snacks, snacks = pcall(require, "snacks")
+    if not has_snacks then
+      Logger.notify("snacks.nvim is not available", vim.log.levels.ERROR)
+      return
+    end
+
+    snacks.picker(
+      ---@type snacks.picker.Config
+      {
+        source = "eca messages",
+        finder = function(opts, ctx)
+          ---@type snacks.picker.finder.Item[]
+          local items = {}
+          local eca = require("eca")
+          if not eca or not eca.server then
+            Logger.notify("ECA plugin is not available", vim.log.levels.ERROR)
+            return items
+          end
+
+          for msg in vim.iter(eca.server.messages) do
+            print(msg)
+            local decoded = vim.json.decode(msg.content)
+            table.insert(items, {
+              text = decoded.method,
+              idx = decoded.id,
+              preview = {
+                text = vim.inspect(decoded),
+                ft = "lua",
+              },
+            })
+          end
+          return items
+        end,
+        preview = "preview",
+        format = "text",
+        confirm = function(self, item, _)
+          vim.fn.setreg("", item.preview.text)
+          self:close()
+        end,
+      }
+    )
+  end, {
+    desc = "Display Messages Sent to and Received by ECA server",
+  })
+
   vim.api.nvim_create_user_command("EcaLogs", function(opts)
     local Api = require("eca.api")
     local subcommand = opts.args and opts.args:match("%S+") or "show"
diff --git a/lua/eca/server.lua b/lua/eca/server.lua
index c1f2154..babe87e 100644
--- a/lua/eca/server.lua
+++ b/lua/eca/server.lua
@@ -13,7 +13,6 @@ local Logger = require("eca.logger")
 ---@field on_stop function Callback when the server stops
 ---Called when a notification is received(message without an ID)
 ---@field on_notification fun(server: eca.Server, message: table)
----@field capabilities eca.ServerCapabilities Server capabilities
 ---@field private path_finder eca.PathFinder Server path finder
 ---@field pending_requests {id: fun(err, data)} -- outgoing requests with callbacks
 local M = {}
@@ -50,7 +49,6 @@ function M.new(opts)
     path_finder = opts.path_finder,
     messages = {},
     pending_requests = {},
-    capabilities = {},
     initialized = false,
     next_id = 0,
   }, { __index = M })
@@ -67,7 +65,7 @@ local function on_stdout(server)
         if #message.content ~= message.content_length then
           return
         end
-        table.insert(messages, message)
+        table.insert(server.messages, message)
         local msg = vim.json.decode(message.content)
         server:handle_message(msg)
       end)
@@ -171,20 +169,18 @@ function M:initialize()
       },
     },
     workspaceFolders = workspace_folders,
-  }, function(err, result)
+  }, function(err, _)
     if err then
       Logger.notify("Could not initialize server: " .. err, vim.log.levels.ERROR)
       return
     end
-    if result then
-      self.capabilities = result
-    end
 
     self:send_notification("initialized", {})
 
     if self.on_initialize then
       self.on_initialize()
     end
+    self.initialized = true
   end)
 end
 
@@ -259,6 +255,7 @@ function M:send_request(method, params, callback)
   end
 
   local json = vim.json.encode(message)
+  table.insert(self.messages, { content = json, content_length = #json })
   local content = string.format("Content-Length: %d\r\n\r\n%s", #json, json)
   self.process:write(content)
 end

From 223db652ef8017c78f49ee1dbd7c4c035aafd9ad Mon Sep 17 00:00:00 2001
From: joaopluigi <joao.luigi@nubank.com.br>
Date: Thu, 25 Sep 2025 11:51:39 -0300
Subject: [PATCH 03/10] revert some unwanted changes

---
 lua/eca/sidebar.lua | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/lua/eca/sidebar.lua b/lua/eca/sidebar.lua
index 09e2fbc..aafc5d7 100644
--- a/lua/eca/sidebar.lua
+++ b/lua/eca/sidebar.lua
@@ -31,7 +31,10 @@ local M = {}
 M.__index = M
 
 -- Height calculation constants
+local MIN_CHAT_HEIGHT = 10 -- Minimum lines for chat container to remain usable
+local WINDOW_MARGIN = 3 -- Additional margin for window borders and spacing
 local UI_ELEMENTS_HEIGHT = 2 -- Reserve space for statusline and tabline
+local SAFETY_MARGIN = 2 -- Extra margin to prevent "Not enough room" errors
 
 ---@param id integer Tab ID
 ---@param mediator eca.Mediator
@@ -230,6 +233,12 @@ function M:_create_containers()
 
   -- Validate total height to prevent "Not enough room" error
   local total_height = chat_height
+    + selected_code_height
+    + todos_height
+    + status_height
+    + contexts_height
+    + input_height
+    + usage_height
     + config_height
 
   -- Always calculate from total screen minus UI elements (more accurate than current window)
@@ -567,6 +576,13 @@ function M:get_chat_height()
   return math.max(
     MIN_CHAT_HEIGHT,
     total_height
+      - input_height
+      - usage_height
+      - status_height
+      - contexts_height
+      - selected_code_height
+      - todos_height
+      - WINDOW_MARGIN
       - config_height
   )
 end
@@ -1442,6 +1458,12 @@ function M:_add_message(role, content)
 
     -- Check if content looks like code (starts with common programming patterns)
     local is_code = content:match("^%s*function")
+      or content:match("^%s*class")
+      or content:match("^%s*def ")
+      or content:match("^%s*import")
+      or content:match("^%s*#include")
+      or content:match("^%s*<%?")
+      or content:match("^%s*<html")
 
     if is_code then
       -- Wrap in code block with auto-detection

From 7db609daeea788fd02bd3b1f0b21147964235ea3 Mon Sep 17 00:00:00 2001
From: joaopluigi <joao.luigi@nubank.com.br>
Date: Thu, 25 Sep 2025 11:52:00 -0300
Subject: [PATCH 04/10] clear config buffer on update

---
 lua/eca/sidebar.lua | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/lua/eca/sidebar.lua b/lua/eca/sidebar.lua
index aafc5d7..5e0b76c 100644
--- a/lua/eca/sidebar.lua
+++ b/lua/eca/sidebar.lua
@@ -1104,6 +1104,10 @@ function M:_update_config_display()
     }
   end
 
+  vim.api.nvim_set_option_value("modifiable", true, { buf = config.bufnr })
+  vim.api.nvim_buf_set_lines(config.bufnr, 0, -1, false, { "" })
+  vim.api.nvim_set_option_value("modifiable", false, { buf = config.bufnr })
+
   self.extmarks.config._id = vim.api.nvim_buf_set_extmark(
     config.bufnr,
     self.extmarks.config._ns,

From ffd68e292698b4d6487e38d6c2c724d6fd9950cf Mon Sep 17 00:00:00 2001
From: joaopluigi <joao.luigi@nubank.com.br>
Date: Thu, 25 Sep 2025 12:00:23 -0300
Subject: [PATCH 05/10] change mcp count highlight based on mcp status

---
 lua/eca/sidebar.lua | 20 +++++++++++++++++---
 1 file changed, 17 insertions(+), 3 deletions(-)

diff --git a/lua/eca/sidebar.lua b/lua/eca/sidebar.lua
index 5e0b76c..bec7c5c 100644
--- a/lua/eca/sidebar.lua
+++ b/lua/eca/sidebar.lua
@@ -1086,12 +1086,26 @@ function M:_update_config_display()
 
   local model = self.mediator:selected_model() or "unknown"
   local behavior = self.mediator:selected_behavior() or "unknown"
-  local mcps = vim.tbl_count(self.mediator:mcps())
+  local mcps = self.mediator:mcps()
+
+  local mcps_hl = "Normal"
+
+  for _, mcp in pairs(mcps) do
+    if mcp.status == "starting" then
+      mcps_hl = "Comment"
+      break
+    end
+
+    if mcp.status == "failed" then
+      mcps_hl = "Exception"
+      break
+    end
+  end
 
   local texts = {
     { "model:",    "Comment" }, { model, "Normal" }, { "\t" },
     { "behavior:", "Comment" }, { behavior, "Normal" }, { " " },
-    { "mcps:", "Comment" }, { tostring(mcps), "Exception" },
+    { "mcps:", "Comment" }, { tostring(vim.tbl_count(mcps)), mcps_hl },
   }
 
   local virt_opts = { virt_text = texts, hl_mode = "combine" }
@@ -1188,7 +1202,7 @@ function M:_update_usage_info()
     -1,
     vim.tbl_extend("force",
       {
-        virt_text = { { self._current_status, (status_text ~= "Idle") and "Question" or "Normal" } },
+        virt_text = { { self._current_status, (status_text ~= "Idle") and "Debug" or "Normal" } },
         virt_text_pos = 'eol',
         hl_mode = 'combine',
       },

From d01f46536282e2fff5a50dc3e41fbbca1e0aa585 Mon Sep 17 00:00:00 2001
From: joaopluigi <joao.luigi@nubank.com.br>
Date: Thu, 25 Sep 2025 12:25:03 -0300
Subject: [PATCH 06/10] change server status hl to match previous
 implementation

---
 lua/eca/sidebar.lua | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lua/eca/sidebar.lua b/lua/eca/sidebar.lua
index bec7c5c..6b00f00 100644
--- a/lua/eca/sidebar.lua
+++ b/lua/eca/sidebar.lua
@@ -1202,7 +1202,7 @@ function M:_update_usage_info()
     -1,
     vim.tbl_extend("force",
       {
-        virt_text = { { self._current_status, (status_text ~= "Idle") and "Debug" or "Normal" } },
+        virt_text = { { self._current_status, (status_text ~= "Idle") and "WarningMsg" or "Normal" } },
         virt_text_pos = 'eol',
         hl_mode = 'combine',
       },

From 669c69410f5621fc37f73df906ccd5a449fe378b Mon Sep 17 00:00:00 2001
From: joaopluigi <joao.luigi@nubank.com.br>
Date: Thu, 25 Sep 2025 12:26:36 -0300
Subject: [PATCH 07/10] rm leftover print

---
 lua/eca/commands.lua | 1 -
 1 file changed, 1 deletion(-)

diff --git a/lua/eca/commands.lua b/lua/eca/commands.lua
index 5c14c60..6a245e6 100644
--- a/lua/eca/commands.lua
+++ b/lua/eca/commands.lua
@@ -178,7 +178,6 @@ function M.setup()
           end
 
           for msg in vim.iter(eca.server.messages) do
-            print(msg)
             local decoded = vim.json.decode(msg.content)
             table.insert(items, {
               text = decoded.method,

From 22b032bffdaf3eddd08a093b839898c2afcdf71b Mon Sep 17 00:00:00 2001
From: joaopluigi <joao.luigi@nubank.com.br>
Date: Thu, 25 Sep 2025 12:28:39 -0300
Subject: [PATCH 08/10] fix usage buffer extmarks id

---
 lua/eca/sidebar.lua | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lua/eca/sidebar.lua b/lua/eca/sidebar.lua
index 6b00f00..a5cdee6 100644
--- a/lua/eca/sidebar.lua
+++ b/lua/eca/sidebar.lua
@@ -1206,7 +1206,7 @@ function M:_update_usage_info()
         virt_text_pos = 'eol',
         hl_mode = 'combine',
       },
-      { id = self.extmarks.config._id_status })
+      { id = self.extmarks.usage._id_status })
   )
 
   self.extmarks.usage._id_usage = vim.api.nvim_buf_set_extmark(
@@ -1220,7 +1220,7 @@ function M:_update_usage_info()
         virt_text_pos = 'right_align',
         hl_mode = 'combine',
       },
-      { id = self.extmarks.config._id_usage })
+      { id = self.extmarks.usage._id_usage })
   )
 end
 

From d36ede9128f686402ec2e88de51d87a08c39757b Mon Sep 17 00:00:00 2001
From: joaopluigi <joao.luigi@nubank.com.br>
Date: Thu, 25 Sep 2025 14:35:26 -0300
Subject: [PATCH 09/10] add tests for state.lua

---
 tests/test_state.lua | 187 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 187 insertions(+)
 create mode 100644 tests/test_state.lua

diff --git a/tests/test_state.lua b/tests/test_state.lua
new file mode 100644
index 0000000..66a6d11
--- /dev/null
+++ b/tests/test_state.lua
@@ -0,0 +1,187 @@
+local MiniTest = require("mini.test")
+local eq = MiniTest.expect.equality
+local child = MiniTest.new_child_neovim()
+
+local T = MiniTest.new_set({
+  hooks = {
+    pre_case = function()
+      child.restart({ "-u", "scripts/minimal_init.lua" })
+      child.lua([[
+        _G.captured = {}
+        local Observer = require('eca.observer')
+        -- Clear any prior subscriptions by reloading the module (defensive)
+        package.loaded['eca.observer'] = nil
+        Observer = require('eca.observer')
+
+        -- Subscribe to capture all notifications
+        Observer.subscribe('test-capture', function(message)
+          table.insert(_G.captured, message)
+        end)
+
+        -- Instantiate state singleton
+        _G.State = require('eca.state').new()
+
+        -- Helper to filter captured messages by a predicate
+        _G.filter_msgs = function(pred)
+          local out = {}
+          for _, m in ipairs(_G.captured) do
+            if pred(m) then table.insert(out, m) end
+          end
+          return out
+        end
+      ]])
+    end,
+    post_case = function()
+      child.lua([[require('eca.observer').unsubscribe('test-capture')]])
+    end,
+    post_once = child.stop,
+  },
+})
+
+-- Ensure scheduled callbacks run (vim.schedule)
+local function flush(ms)
+  vim.uv.sleep(ms or 50)
+  -- Force at least one main loop iteration
+  child.api.nvim_eval("1")
+end
+
+T["singleton and defaults"] = MiniTest.new_set()
+
+T["singleton and defaults"]["returns same instance"] = function()
+  eq(child.lua_get("require('eca.state').new() == require('eca.state').new()"), true)
+end
+
+T["singleton and defaults"]["has expected default values"] = function()
+  eq(child.lua_get("_G.State.status.state"), "idle")
+  eq(child.lua_get("_G.State.status.text"), "Idle")
+
+  eq(child.lua_get("vim.tbl_isempty(_G.State.config.behaviors.list)"), true)
+  eq(child.lua_get("_G.State.config.behaviors.default"), vim.NIL)
+  eq(child.lua_get("_G.State.config.behaviors.selected"), vim.NIL)
+
+  eq(child.lua_get("vim.tbl_isempty(_G.State.config.models.list)"), true)
+  eq(child.lua_get("_G.State.config.models.default"), vim.NIL)
+  eq(child.lua_get("_G.State.config.models.selected"), vim.NIL)
+
+  eq(child.lua_get("_G.State.config.welcome_message"), vim.NIL)
+
+  eq(child.lua_get("_G.State.usage.tokens.limit"), 0)
+  eq(child.lua_get("_G.State.usage.tokens.session"), 0)
+  eq(child.lua_get("_G.State.usage.costs.last_message"), "0.00")
+  eq(child.lua_get("_G.State.usage.costs.session"), "0.00")
+
+  eq(child.lua_get("type(_G.State.tools)"), "table")
+end
+
+T["updates via observer notifications"] = MiniTest.new_set()
+
+T["updates via observer notifications"]["updates status on progress content"] = function()
+  child.lua([[require('eca.observer').notify({
+    method = 'chat/contentReceived',
+    params = { content = { type = 'progress', state = 'responding', text = 'Respondendo...' } },
+  })]])
+  flush()
+
+  eq(child.lua_get("_G.State.status.state"), "responding")
+  eq(child.lua_get("_G.State.status.text"), "Respondendo...")
+
+  -- Verify a state/updated notification was emitted for status
+  local updates = child.lua_get([[ _G.filter_msgs(function(m)
+    return type(m) == 'table' and m.type == 'state/updated' and type(m.content) == 'table' and m.content.status ~= nil
+  end) ]])
+  eq(#updates >= 1, true)
+end
+
+T["updates via observer notifications"]["updates usage on usage content"] = function()
+  child.lua([[require('eca.observer').notify({
+    method = 'chat/contentReceived',
+    params = { content = {
+      type = 'usage',
+      limit = { output = 1024 },
+      sessionTokens = 256,
+      lastMessageCost = '0.42',
+      sessionCost = '3.14',
+    } },
+  })]])
+  flush()
+
+  eq(child.lua_get("_G.State.usage.tokens.limit"), 1024)
+  eq(child.lua_get("_G.State.usage.tokens.session"), 256)
+  eq(child.lua_get("_G.State.usage.costs.last_message"), "0.42")
+  eq(child.lua_get("_G.State.usage.costs.session"), "3.14")
+
+  local updates = child.lua_get([[ _G.filter_msgs(function(m)
+    return type(m) == 'table' and m.type == 'state/updated' and type(m.content) == 'table' and m.content.usage ~= nil
+  end) ]])
+  eq(#updates >= 1, true)
+end
+
+T["updates via observer notifications"]["updates config on config/updated"] = function()
+  child.lua([[require('eca.observer').notify({
+    method = 'config/updated',
+    params = { chat = {
+      behaviors = { 'agent', 'plan' },
+      defaultBehavior = 'agent',
+      selectBehavior = 'plan',
+      models = { 'openai/gpt-5-mini', 'anthropic/claude' },
+      defaultModel = 'openai/gpt-5-mini',
+      selectModel = 'anthropic/claude',
+      welcomeMessage = 'Bem-vindo ao ECA!',
+    } },
+  })]])
+  flush()
+
+  eq(child.lua_get("_G.State.config.behaviors.list[1]"), "agent")
+  eq(child.lua_get("_G.State.config.behaviors.list[2]"), "plan")
+  eq(child.lua_get("_G.State.config.behaviors.default"), "agent")
+  eq(child.lua_get("_G.State.config.behaviors.selected"), "plan")
+
+  eq(child.lua_get("_G.State.config.models.list[1]"), "openai/gpt-5-mini")
+  eq(child.lua_get("_G.State.config.models.list[2]"), "anthropic/claude")
+  eq(child.lua_get("_G.State.config.models.default"), "openai/gpt-5-mini")
+  eq(child.lua_get("_G.State.config.models.selected"), "anthropic/claude")
+
+  eq(child.lua_get("_G.State.config.welcome_message"), "Bem-vindo ao ECA!")
+
+  local updates = child.lua_get([[ _G.filter_msgs(function(m)
+    return type(m) == 'table' and m.type == 'state/updated' and type(m.content) == 'table' and m.content.config ~= nil
+  end) ]])
+  eq(#updates >= 1, true)
+end
+
+T["updates via observer notifications"]["updates tools on tool/serverUpdated"] = function()
+  -- Initial add
+  child.lua([[require('eca.observer').notify({
+    method = 'tool/serverUpdated',
+    params = { name = 'server-1', type = 'mcp', status = 'connected' },
+  })]])
+  flush()
+
+  eq(child.lua_get("_G.State.tools['server-1'].name"), "server-1")
+  eq(child.lua_get("_G.State.tools['server-1'].type"), "mcp")
+  eq(child.lua_get("_G.State.tools['server-1'].status"), "connected")
+
+  -- Update only status, keep type
+  child.lua([[require('eca.observer').notify({
+    method = 'tool/serverUpdated',
+    params = { name = 'server-1', status = 'disconnected' },
+  })]])
+  flush()
+
+  eq(child.lua_get("_G.State.tools['server-1'].type"), "mcp")
+  eq(child.lua_get("_G.State.tools['server-1'].status"), "disconnected")
+
+  -- Invalid: missing name should be ignored (no errors, no new entries)
+  local before = child.lua_get("vim.tbl_count(_G.State.tools)")
+  child.lua([[require('eca.observer').notify({ method = 'tool/serverUpdated', params = { status = 'x' } })]])
+  flush()
+  local after = child.lua_get("vim.tbl_count(_G.State.tools)")
+  eq(after, before)
+
+  local updates = child.lua_get([[ _G.filter_msgs(function(m)
+    return type(m) == 'table' and m.type == 'state/updated' and type(m.content) == 'table' and m.content.tools ~= nil
+  end) ]])
+  eq(#updates >= 1, true)
+end
+
+return T

From db32bc3f487ca465b10d87b6b51fac7e6905c94a Mon Sep 17 00:00:00 2001
From: joaopluigi <joao.luigi@nubank.com.br>
Date: Fri, 26 Sep 2025 09:40:21 -0300
Subject: [PATCH 10/10] fix bufnr nil when config/tool updated message arrives
 and chat is not open

---
 lua/eca/sidebar.lua | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/lua/eca/sidebar.lua b/lua/eca/sidebar.lua
index a5cdee6..d779313 100644
--- a/lua/eca/sidebar.lua
+++ b/lua/eca/sidebar.lua
@@ -179,6 +179,7 @@ function M:reset()
 
   -- Reset all state
   self.containers = {}
+  self.extmarks = {}
   self._initialized = false
   self._is_streaming = false
   self._current_response_buffer = ""
@@ -1080,7 +1081,7 @@ end
 
 function M:_update_config_display()
   local config = self.containers.config
-  if not config or not vim.api.nvim_buf_is_valid(config.bufnr) then
+  if not config or not config.bufnr or not vim.api.nvim_buf_is_valid(config.bufnr) then
     return
   end
 
@@ -1165,7 +1166,7 @@ end
 
 function M:_update_usage_info()
   local usage = self.containers.usage
-  if not usage or not vim.api.nvim_buf_is_valid(usage.bufnr) then
+  if not usage or not usage.bufnr or not vim.api.nvim_buf_is_valid(usage.bufnr) then
     return
   end