diff --git a/README.md b/README.md
index 47339a4..98cf5a2 100644
--- a/README.md
+++ b/README.md
@@ -5,7 +5,7 @@
 > Latest version: ![GitHub tag (latest SemVer)](https://img.shields.io/github/v/tag/johnseth97/codex.nvim?sort=semver)
 
 ### Features:
-- ✅ Toggle Codex window or side-panel with `:CodexToggle`
+- ✅ Toggle Codex window, side-panel, or horizontal split with `:CodexToggle`
 - ✅ Optional keymap mapping via `setup` call
 - ✅ Background running when window hidden
 - ✅ Statusline integration via `require('codex').status()`
@@ -36,7 +36,7 @@ return {
     {
       '<leader>cc', -- Change this to your preferred keybinding
       function() require('codex').toggle() end,
-      desc = 'Toggle Codex popup or side-panel',
+      desc = 'Toggle Codex window',
       mode = { 'n', 't' }
     },
   },
@@ -46,19 +46,25 @@ return {
       quit = '<C-q>', -- Keybind to close the Codex window (default: Ctrl + q)
     },         -- Disable internal default keymap (<leader>cc -> :CodexToggle)
     border      = 'rounded',  -- Options: 'single', 'double', or 'rounded'
-    width       = 0.8,        -- Width of the floating window (0.0 to 1.0)
-    height      = 0.8,        -- Height of the floating window (0.0 to 1.0)
+    width       = 0.8,        -- Width of the floating window or split (0.0 to 1.0)
+    height      = 0.8,        -- Height of the floating window or split (0.0 to 1.0)
     model       = nil,        -- Optional: pass a string to use a specific model (e.g., 'o3-mini')
     autoinstall = true,       -- Automatically install the Codex CLI if not found
-    panel       = false,      -- Open Codex in a side-panel (vertical split) instead of floating window
+    panel       = false,      -- Open Codex in a panel (split) instead of floating window
+    layout      = 'vertical', -- 'vertical' or 'horizontal' (only applies when panel = true)
     use_buffer  = false,      -- Capture Codex stdout into a normal buffer instead of a terminal buffer
   },
 }```
 
 ### Usage:
-- Call `:Codex` (or `:CodexToggle`) to open or close the Codex popup or side-panel.
+- Call `:Codex` (or `:CodexToggle`) to open or close the Codex window.
 - Map your own keybindings via the `keymaps.toggle` setting.
-- To choose floating popup vs side-panel, set `panel = false` (popup) or `panel = true` (panel) in your setup options.
+- Configure the window display:
+  - Set `panel = false` for a floating window (default)
+  - Set `panel = true` for an in-place split panel
+  - When `panel = true`, use `layout` to choose split direction:
+    - `layout = 'vertical'` - Vertical split on the right (default)
+    - `layout = 'horizontal'` - Horizontal split at the bottom
 - To capture Codex output in an editable buffer instead of a terminal, set `use_buffer = true` (or `false` to keep terminal) in your setup options.
 - Add the following code to show backgrounded Codex window in lualine:
 
diff --git a/lua/codex/init.lua b/lua/codex/init.lua
index 4378b46..488f4af 100644
--- a/lua/codex/init.lua
+++ b/lua/codex/init.lua
@@ -15,8 +15,9 @@ local config = {
   cmd = 'codex',
   model = nil, -- Default to the latest model
   autoinstall = true,
-  panel     = false,   -- if true, open Codex in a side-panel instead of floating window
-  use_buffer = false,  -- if true, capture Codex stdout into a normal buffer instead of a terminal
+  panel     = false,      -- if true, open Codex in a panel instead of floating window
+  layout    = 'vertical', -- 'vertical' or 'horizontal' (only applies when panel = true)
+  use_buffer = false,     -- if true, capture Codex stdout into a normal buffer instead of a terminal
 }
 
 function M.setup(user_config)
@@ -100,6 +101,35 @@ local function open_panel()
   state.win = win
 end
 
+--- Open Codex in a horizontal split at the bottom
+local function open_horizontal_split()
+  -- Create a horizontal split at the bottom and show the buffer
+  vim.cmd('rightbelow split')
+  local win = vim.api.nvim_get_current_win()
+  vim.api.nvim_win_set_buf(win, state.buf)
+  -- Adjust height according to config (percentage of total lines)
+  local height = math.floor(vim.o.lines * config.height)
+  vim.api.nvim_win_set_height(win, height)
+  state.win = win
+end
+
+--- Open the window based on the configured panel and layout settings
+local function open_based_on_config()
+  if config.panel then
+    -- Panel mode: check layout to decide between vertical and horizontal
+    local layout = config.layout or 'vertical'
+    if layout == 'horizontal' then
+      open_horizontal_split()
+    else
+      -- Default to vertical split for backward compatibility
+      open_panel()
+    end
+  else
+    -- Floating window mode
+    open_window()
+  end
+end
+
 function M.open()
   local function create_clean_buf()
     local buf = vim.api.nvim_create_buf(false, false)
@@ -142,7 +172,7 @@ function M.open()
             'You can install manually with:',
             '  npm install -g @openai/codex',
           })
-          if config.panel then open_panel() else open_window() end
+          open_based_on_config()
         end
       end)
       return
@@ -159,7 +189,7 @@ function M.open()
         '',
         'Or enable autoinstall in setup: require("codex").setup{ autoinstall = true }',
       })
-      if config.panel then open_panel() else open_window() end
+      open_based_on_config()
       return
     end
   end
@@ -172,7 +202,7 @@ function M.open()
     state.buf = create_clean_buf()
   end
 
-  if config.panel then open_panel() else open_window() end
+  open_based_on_config()
 
   if not state.job then
     -- assemble command