From 7818704cfc3b7decfacb8f30b9d8e530eb9c98cc Mon Sep 17 00:00:00 2001
From: Francis Belanger <francis.belanger@gmail.com>
Date: Tue, 24 Feb 2026 09:13:39 -0500
Subject: [PATCH] feat(ui): add enable_treesitter_markdown config for markdown
 rendering in output window

This should help with #293
---
 README.md               |  2 ++
 lua/opencode/config.lua |  1 +
 lua/opencode/types.lua  |  1 +
 lua/opencode/ui/ui.lua  | 25 +++++++++++++++++--------
 4 files changed, 21 insertions(+), 8 deletions(-)

diff --git a/README.md b/README.md
index bf895cbf..d41f4353 100644
--- a/README.md
+++ b/README.md
@@ -201,6 +201,7 @@ require('opencode').setup({
     },
   },
   ui = {
+    enable_treesitter_markdown = true, -- Use Treesitter for markdown rendering in the output window (default: true).
     position = 'right', -- 'right' (default), 'left' or 'current'. Position of the UI split. 'current' uses the current window for the output.
     input_position = 'bottom', -- 'bottom' (default) or 'top'. Position of the input window
     window_width = 0.40, -- Width as percentage of editor width
@@ -636,6 +637,7 @@ The plugin provides the following actions that can be triggered via keymaps, com
 - `open_input` (boolean, default: `true`): Whether to open the input window after adding the selection. Set to `false` to add selection silently without changing focus.
 
 Example keymap for silent add:
+
 ```lua
 ['<leader>oY'] = { 'add_visual_selection', { open_input = false }, mode = {'v'} }
 ```
diff --git a/lua/opencode/config.lua b/lua/opencode/config.lua
index 573e888d..c930a233 100644
--- a/lua/opencode/config.lua
+++ b/lua/opencode/config.lua
@@ -107,6 +107,7 @@ M.defaults = {
     },
   },
   ui = {
+    enable_treesitter_markdown = true,
     position = 'right',
     input_position = 'bottom',
     window_width = 0.40,
diff --git a/lua/opencode/types.lua b/lua/opencode/types.lua
index b52d085c..cd29fcc9 100644
--- a/lua/opencode/types.lua
+++ b/lua/opencode/types.lua
@@ -112,6 +112,7 @@
 ---@field frames string[]
 
 ---@class OpencodeUIConfig
+---@field enable_treesitter_markdown boolean
 ---@field position 'right'|'left'|'current' # Position of the UI (default: 'right')
 ---@field input_position 'bottom'|'top' # Position of the input window (default: 'bottom')
 ---@field window_width number
diff --git a/lua/opencode/ui/ui.lua b/lua/opencode/ui/ui.lua
index fd69d6ee..887afccc 100644
--- a/lua/opencode/ui/ui.lua
+++ b/lua/opencode/ui/ui.lua
@@ -76,8 +76,7 @@ local function capture_hidden_snapshot(windows)
     output_view = ok and type(view) == 'table' and view or nil,
     focused_window = focused,
     position = config.ui.position,
-    owner_tab = state.are_windows_in_current_tab()
-      and vim.api.nvim_get_current_tabpage() or nil,
+    owner_tab = state.are_windows_in_current_tab() and vim.api.nvim_get_current_tabpage() or nil,
   }
 end
 
@@ -92,8 +91,12 @@ function M.close_windows(windows, persist)
 end
 
 local function prepare_window_close()
-  if M.is_opencode_focused() then M.return_to_last_code_win() end
-  if state.display_route then state.display_route = nil end
+  if M.is_opencode_focused() then
+    M.return_to_last_code_win()
+  end
+  if state.display_route then
+    state.display_route = nil
+  end
 
   pcall(vim.api.nvim_del_augroup_by_name, 'OpencodeResize')
   pcall(vim.api.nvim_del_augroup_by_name, 'OpencodeWindows')
@@ -145,7 +148,9 @@ function M.hide_visible_windows(windows)
   end
   if windows.input_buf and vim.api.nvim_buf_is_valid(windows.input_buf) then
     local ok, lines = pcall(vim.api.nvim_buf_get_lines, windows.input_buf, 0, -1, false)
-    if ok then state.input_content = lines end
+    if ok then
+      state.input_content = lines
+    end
   end
   state.stash_hidden_buffers(snapshot)
   if state.windows == windows then
@@ -242,7 +247,9 @@ function M.restore_hidden_windows()
 
   vim.schedule(function()
     local w = state.windows
-    if not w then return end
+    if not w then
+      return
+    end
 
     if hidden.output_was_at_bottom then
       renderer.scroll_to_bottom(true)
@@ -323,8 +330,10 @@ function M.create_split_windows(input_buf, output_buf)
 end
 
 function M.create_windows()
-  vim.treesitter.language.register('markdown', 'opencode_output')
-  vim.treesitter.language.register('markdown', 'opencode')
+  if config.ui.enable_treesitter_markdown then
+    vim.treesitter.language.register('markdown', 'opencode_output')
+    vim.treesitter.language.register('markdown', 'opencode')
+  end
 
   local autocmds = require('opencode.ui.autocmds')