Support native completions

README.md

@@ -88,8 +88,8 @@ through `search` and `work`
                         -- exclude = { ".env", ".env.*", "node_modules", ".git", ... },
                     },
 
-                    --- What autocomplete you use.
-                    source = "cmp" | "blink",
+                    --- What autocomplete engine to use. Defaults to native (built-in) if not specified.
+                    source = "native", -- "native" (default), "cmp", or "blink"
                 },
 
                 --- WARNING: if you change cwd then this is likely broken
@@ -421,7 +421,7 @@ When prompting, you can reference rules and files to add context to your request
 - `#` references rules — type `#` in the prompt to autocomplete rule files from your configured rule directories
 - `@` references files — type `@` to fuzzy-search project files
 
-Referenced content is automatically resolved and injected into the AI context. Requires cmp (`source = "cmp"` in your completion config).
+Referenced content is automatically resolved and injected into the AI context. Native completions work by default. For nvim-cmp or blink.cmp, set `source = "cmp"` or `source = "blink"`.
 
 ## Providers
 99 supports multiple AI CLI backends. Set `provider` in your setup to switch. If you don't set `model`, the provider's default is used.

lua/99/extensions/cmp.lua

@@ -37,7 +37,7 @@ function CmpSource.complete(_, params, callback)
   -- Find which trigger is active
   local trigger = nil
   for _, char in ipairs(Completions.get_trigger_characters()) do
-    local pattern = char:gsub("([%%%^%$%(%)%.%[%]%*%+%-%?])", "%%%1") .. "%S*$"
+    local pattern = Completions.escape_pattern(char) .. "%S*$"
     if before:match(pattern) then
       trigger = char
       break

lua/99/extensions/completions.lua

@@ -14,6 +14,13 @@ local providers = {}
 
 local M = {}
 
+--- Escape special Lua pattern characters in a string
+--- @param str string The string to escape
+--- @return string The escaped string safe for use in Lua patterns
+function M.escape_pattern(str)
+  return str:gsub("([%%%^%$%(%)%.%[%]%*%+%-%?])", "%%%1")
+end
+
 --- @param provider _99.CompletionProvider
 function M.register(provider)
   for i, p in ipairs(providers) do
@@ -48,10 +55,7 @@ end
 function M.parse(prompt_text)
   local refs = {}
   for _, provider in ipairs(providers) do
-    local pattern = provider.trigger:gsub(
-      "([%%%^%$%(%)%.%[%]%*%+%-%?])",
-      "%%%1"
-    ) .. "%S+"
+    local pattern = M.escape_pattern(provider.trigger) .. "%S+"
     for word in prompt_text:gmatch(pattern) do
       local token = word:sub(#provider.trigger + 1)
       if provider.is_valid(token) then

lua/99/extensions/init.lua

@@ -8,15 +8,22 @@ local Files = require("99.extensions.files")
 --- @param completion _99.Completion | nil
 --- @return _99.Extensions.Source | nil
 local function get_source(completion)
-  if not completion or not completion.source then
-    return
+  local source = completion and completion.source or "native"
+
+  if source == "native" then
+    local ok, native = pcall(require, "99.extensions.native")
+    if not ok then
+      vim.notify("[99] Failed to load native completions", vim.log.levels.ERROR)
+      return
+    end
+    return native
   end
-  local source = completion.source
+
   if source == "cmp" then
     local ok, cmp = pcall(require, "99.extensions.cmp")
     if not ok then
       vim.notify(
-        '[99] nvim-cmp is not installed. Install hrsh7th/nvim-cmp or use source = "blink"',
+        '[99] nvim-cmp is not installed. Install hrsh7th/nvim-cmp or use source = "blink" or "native"',
         vim.log.levels.WARN
       )
       return

lua/99/extensions/native.lua

@@ -0,0 +1,162 @@
+local Agents = require("99.extensions.agents")
+local Files = require("99.extensions.files")
+local Completions = require("99.extensions.completions")
+
+local DEBOUNCE_MS = 100
+
+--- @param items CompletionItem[]
+--- @return table[]
+local function to_native_items(items)
+  local out = {}
+  for _, item in ipairs(items) do
+    local info = ""
+    if item.documentation then
+      if type(item.documentation) == "string" then
+        info = item.documentation
+      elseif item.documentation.value then
+        info = item.documentation.value
+      end
+    end
+    table.insert(out, {
+      word = item.insertText or item.label,
+      abbr = item.label,
+      info = info,
+      icase = 1,
+      dup = 0,
+    })
+  end
+  return out
+end
+
+--- @param _99 _99.State
+local function register_providers(_99)
+  Completions.register(Agents.completion_provider(_99))
+  Completions.register(Files.completion_provider())
+end
+
+--- @param buf number
+local function setup_completion_autocmd(buf)
+  local timer = vim.uv.new_timer()
+  local group = vim.api.nvim_create_augroup(
+    "99_native_completion_" .. buf,
+    { clear = true }
+  )
+
+  vim.api.nvim_create_autocmd("TextChangedI", {
+    group = group,
+    buffer = buf,
+    callback = function()
+      timer:stop()
+      timer:start(
+        DEBOUNCE_MS,
+        0,
+        vim.schedule_wrap(function()
+          if vim.fn.mode() ~= "i" then
+            return
+          end
+
+          if not vim.api.nvim_buf_is_valid(buf) then
+            timer:stop()
+            return
+          end
+
+          local line = vim.api.nvim_get_current_line()
+          local col = vim.fn.col(".")
+          local before = line:sub(1, col - 1)
+
+          local trigger = nil
+          local start_col = nil
+          for _, char in ipairs(Completions.get_trigger_characters()) do
+            local escaped = Completions.escape_pattern(char)
+            local pattern = escaped .. "%S*$"
+            local match_start = before:find(pattern)
+            if match_start then
+              trigger = char
+              start_col = match_start
+              break
+            end
+          end
+
+          if not trigger or not start_col then
+            return
+          end
+
+          local items = Completions.get_completions(trigger)
+          if #items == 0 then
+            return
+          end
+
+          local native_items = to_native_items(items)
+          vim.fn.complete(start_col, native_items)
+        end)
+      )
+    end,
+  })
+
+  vim.api.nvim_create_autocmd("BufWipeout", {
+    group = group,
+    buffer = buf,
+    callback = function()
+      timer:stop()
+      pcall(vim.api.nvim_del_augroup_by_id, group)
+    end,
+  })
+end
+
+--- @param buf number
+local function setup_keymaps(buf)
+  vim.keymap.set("i", "<Tab>", function()
+    if vim.fn.pumvisible() == 1 then
+      return "<C-n>"
+    end
+    return "<Tab>"
+  end, { buffer = buf, expr = true, noremap = true })
+
+  vim.keymap.set("i", "<S-Tab>", function()
+    if vim.fn.pumvisible() == 1 then
+      return "<C-p>"
+    end
+    return "<S-Tab>"
+  end, { buffer = buf, expr = true, noremap = true })
+end
+
+--- @param _ _99.State
+local function init_for_buffer(_)
+  local buf = vim.api.nvim_get_current_buf()
+
+  vim.bo[buf].filetype = "99prompt"
+  vim.opt_local.completeopt = "menuone,noinsert,noselect,popup,fuzzy"
+
+  setup_completion_autocmd(buf)
+  setup_keymaps(buf)
+end
+
+--- @param _99 _99.State
+local function init(_99)
+  local rule_dirs = {}
+  if _99.completion and _99.completion.custom_rules then
+    for _, dir in ipairs(_99.completion.custom_rules) do
+      table.insert(rule_dirs, dir)
+    end
+  end
+
+  if _99.completion and _99.completion.files then
+    Files.setup(_99.completion.files, rule_dirs)
+  else
+    Files.setup({ enabled = true }, rule_dirs)
+  end
+
+  register_providers(_99)
+end
+
+--- @param _99 _99.State
+local function refresh_state(_99)
+  register_providers(_99)
+end
+
+--- @type _99.Extensions.Source
+return {
+  init_for_buffer = init_for_buffer,
+  init = init,
+  refresh_state = refresh_state,
+}