diff --git a/lua/sloth-flake/command/init.lua b/lua/sloth-flake/command/init.lua
index ada16a5..e44bf1e 100644
--- a/lua/sloth-flake/command/init.lua
+++ b/lua/sloth-flake/command/init.lua
@@ -8,13 +8,69 @@ local commands = {
   version = require 'sloth-flake.command.version',
 }
 
-function sloth_cmd(param)
+local function parse_line(line, cursor_pos)
+  local raw_args = vim.split(line, ' +', { trimempty = true })
+  local parse_pos = 1
+  local args = vim.iter(raw_args):map(function(arg)
+    local start, stop = string.find(line, arg, parse_pos, { plain = true })
+    parse_pos = stop
+    return {
+      arg = arg,
+      start = start,
+      stop = stop,
+    }
+  end):totable()
+  parse_pos = 1
+  local arg_idx = 1
+  vim.iter(args):find(function(arg)
+    if cursor_pos < arg.start then
+      arg_idx = arg_idx - 1
+      return true
+    elseif cursor_pos <= arg.stop then
+      return true
+    end
+    arg_idx = arg_idx + 1
+    return false
+  end)
+  arg_idx = arg_idx < 1 and 1 or arg_idx
+  if arg_idx > #args then
+    args[#args + 1] = {
+      arg = "",
+      start = line:len(),
+      stop = line:len(),
+    }
+  end
+  return {
+    line = line,
+    args = args,
+    arg_idx = arg_idx,
+    pos = cursor_pos,
+    in_arg_pos = args[arg_idx] and cursor_pos - args[arg_idx].start + 1,
+  }
+end
+-- print(vim.inspect(parse_line('Sloth ', 6)))
+
+local function sloth_cmd_complete(arg_lead, cmd_line, cursor_pos)
+  local parsed_line = parse_line(cmd_line, cursor_pos)
+  local arg = parsed_line.args[parsed_line.arg_idx]
+  if parsed_line.arg_idx == 2 then
+    return vim.iter(commands):map(function(name, command)
+      return vim.startswith(name, arg.arg) and name or nil
+    end):totable()
+  elseif parsed_line.arg_idx > 2 then
+    local cmd = parsed_line.args[2].arg
+    local command = commands[cmd]
+    return command and command.complete(parsed_line)
+  end
+end
+
+local function sloth_cmd(param)
   local args = param.fargs
   local cmd = args[1] or "list";
   table.remove(args, 1)
-  local fn = commands[cmd]
-  if fn then
-    fn(args)
+  local command = commands[cmd]
+  if command then
+    command.cmd(args)
   else
     vim.api.nvim_err_writeln(string.format([[No Sloth subcommand "%s"]], cmd))
   end
@@ -23,6 +79,7 @@ end
 function M.register()
   vim.api.nvim_create_user_command('Sloth', sloth_cmd, {
     nargs = '*',
+    complete = sloth_cmd_complete
   })
 end
 
diff --git a/lua/sloth-flake/command/list.lua b/lua/sloth-flake/command/list.lua
index a1eed0e..49d4552 100644
--- a/lua/sloth-flake/command/list.lua
+++ b/lua/sloth-flake/command/list.lua
@@ -1,29 +1,46 @@
 local Dep = require 'sloth-flake.dep'
 local utils = require 'sloth-flake.utils'
 
-return function(args)
-  local filter = args[1] or "all"
-  local deps = vim.iter(Dep.all()):map(function(_, dep)
-    return dep.name
-  end)
-  if filter == "all" then
-    -- Nothing to do
-  elseif filter == "loaded" then
-    deps = deps:filter(function(dep)
-      return Dep.get(dep).is_loaded
+local filters = {
+  all = {},
+  loaded = {},
+  notloaded = {},
+}
+
+return {
+  complete = function(line)
+    if line.arg_idx == 3 then
+      local prefix = line.args[3].arg
+      return vim.iter(vim.tbl_keys(filters)):filter(function(name)
+        return vim.startswith(name, prefix)
+      end):totable()
+    end
+  end,
+
+  cmd = function(args)
+    local filter = args[1] or "all"
+    local deps = vim.iter(Dep.all()):map(function(_, dep)
+      return dep.name
     end)
-  elseif filter == "notloaded" then
-    deps = deps:filter(function(dep)
-      return not Dep.get(dep).is_loaded
-    end)
-  else
-    utils.error([[No Sloth list filter "%s".]], cmd)
-    utils.error("Filters are: all, loaded, notloaded")
-    return
-  end
-  deps = deps:totable()
-  table.sort(deps)
-  for _, dep in ipairs(deps) do
-    print(string.format("- %s", dep))
-  end
-end
+    if filter == "all" then
+      -- Nothing to do
+    elseif filter == "loaded" then
+      deps = deps:filter(function(dep)
+        return Dep.get(dep).is_loaded
+      end)
+    elseif filter == "notloaded" then
+      deps = deps:filter(function(dep)
+        return not Dep.get(dep).is_loaded
+      end)
+    else
+      utils.error([[No Sloth list filter "%s".]], cmd)
+      utils.error("Filters are: all, loaded, notloaded")
+      return
+    end
+    deps = deps:totable()
+    table.sort(deps)
+    for _, dep in ipairs(deps) do
+      print(string.format("- %s", dep))
+    end
+  end,
+}
diff --git a/lua/sloth-flake/command/load.lua b/lua/sloth-flake/command/load.lua
index cd68ddf..599575a 100644
--- a/lua/sloth-flake/command/load.lua
+++ b/lua/sloth-flake/command/load.lua
@@ -1,15 +1,32 @@
 local Dep = require 'sloth-flake.dep'
 local utils = require 'sloth-flake.utils'
 
-return function(plugins)
-  if #plugins == 0 then
-    utils.error("You should at least give a plugin to load!")
-    return
-  end
-  for _, plugin in ipairs(plugins) do
-    local dep = Dep.get(plugin)
-    if dep ~= nil then
-      dep:load()
+return {
+  complete = function(line)
+    local previous_deps = vim.iter(line.args):enumerate():map(function(i, arg)
+      if i < 3 or i > line.arg_idx then return end
+      return arg.arg
+    end):totable()
+
+    local prefix = line.args[line.arg_idx].arg
+    return vim.iter(Dep.all()):filter(function(name, dep)
+      return vim.startswith(name, prefix) and not dep.is_loaded
+          and not vim.list_contains(previous_deps, name)
+    end):map(function(name)
+      return name
+    end):totable()
+  end,
+
+  cmd = function(plugins)
+    if #plugins == 0 then
+      utils.error("You should at least give a plugin to load!")
+      return
     end
-  end
-end
+    for _, plugin in ipairs(plugins) do
+      local dep = Dep.get(plugin)
+      if dep ~= nil then
+        dep:load()
+      end
+    end
+  end,
+}
diff --git a/lua/sloth-flake/command/version.lua b/lua/sloth-flake/command/version.lua
index f8a5689..c6f505f 100644
--- a/lua/sloth-flake/command/version.lua
+++ b/lua/sloth-flake/command/version.lua
@@ -1,4 +1,7 @@
-return function()
-  local version = require('sloth-flake.version')
-  print(string.format('Sloth v%s', version()))
-end
+return {
+  complete = function() end,
+  cmd = function()
+    local version = require('sloth-flake.version')
+    print(string.format('Sloth v%s', version()))
+  end,
+}