diff --git a/.emmyrc.json b/.emmyrc.json
index 4c6df27e51..758dd8ecf9 100644
--- a/.emmyrc.json
+++ b/.emmyrc.json
@@ -28,29 +28,27 @@
     "disable": [
       "annotation-usage-error",
       "assign-type-mismatch",
-      "await-in-sync",
       "code-style-check",
-      "deprecated",
-      "global-in-non-module",
       "incomplete-signature-doc",
-      "invert-if",
       "iter-variable-reassign",
-      "missing-global-doc",
       "need-check-nil",
-      "non-literal-expressions-in-assert",
       "param-type-mismatch",
-      "preferred-local-alias",
-      "return-type-mismatch",
-      "unknown-doc-tag",
       "unnecessary-assert",
-      "unnecessary-if",
-      "unused"
+      "unnecessary-if"
     ],
     "severity": {
+      "deprecated": "warning",
       "duplicate-require": "warning",
+      "preferred-local-alias": "warning",
       "redefined-local": "warning",
-      "unreachable-code": "warning"
-    }
+      "unreachable-code": "warning",
+      "unused": "warning"
+    },
+    "enables": [
+      "missing-global-doc",
+      "non-literal-expressions-in-assert",
+      "unknown-doc-tag"
+    ]
   },
   "codeAction": {
     "insertSpace": true
@@ -58,5 +56,14 @@
   "strict": {
     "typeCall": true,
     "arrayIndex": true
+  },
+  "doc": {
+    "knownTags": [
+      "brief",
+      "inlinedoc",
+      "nodoc",
+      "note",
+      "since"
+    ]
   }
 }
diff --git a/runtime/doc/lsp.txt b/runtime/doc/lsp.txt
index 854222650f..ceb1212967 100644
--- a/runtime/doc/lsp.txt
+++ b/runtime/doc/lsp.txt
@@ -2187,6 +2187,9 @@ get({filter})                                         *vim.lsp.codelens.get()*
                   • {client_id}? (`integer`, default: all) Client ID, or nil
                     for all.
 
+    Overloads: ~
+      • `fun(filter: integer): lsp.CodeLens[]`
+
     Return: ~
         (`table[]`) A list of objects with the following fields:
         • {client_id} (`integer`)
diff --git a/runtime/lua/coxpcall.lua b/runtime/lua/coxpcall.lua
index 23ea023f0c..bdd57095e7 100644
--- a/runtime/lua/coxpcall.lua
+++ b/runtime/lua/coxpcall.lua
@@ -48,6 +48,7 @@ local running = coroutine.running
 --- @type table<thread,thread>
 local coromap = setmetatable({}, { __mode = "k" })
 
+--- @async
 local function handleReturnValue(err, co, status, ...)
     if not status then
         return false, err(debug.traceback(co, (...)), ...)
@@ -59,6 +60,7 @@ local function handleReturnValue(err, co, status, ...)
     end
 end
 
+--- @async
 function performResume(err, co, ...)
     return handleReturnValue(err, co, coroutine.resume(co, ...))
 end
@@ -68,6 +70,10 @@ local function id(trace, ...)
     return trace
 end
 
+--- @param f function
+--- @param err function
+--- @param ... any
+--- @return boolean, any...
 function _G.coxpcall(f, err, ...)
     local current = running()
     if not current then
@@ -87,6 +93,8 @@ function _G.coxpcall(f, err, ...)
             co = coroutine.create(newf)
         end
         coromap[co] = current
+        -- This branch only runs inside a coroutine.
+        --- @diagnostic disable-next-line: await-in-sync
         return performResume(err, co, ...)
     end
 end
@@ -109,7 +117,12 @@ end
 -- Implements pcall with coroutines
 -------------------------------------------------------------------------------
 
+--- @param f function
+--- @param ... any
+--- @return boolean, any...
 function _G.copcall(f, ...)
+    -- EmmyLua does not distribute the union of xpcall return tuples.
+    --- @diagnostic disable-next-line: return-type-mismatch
     return coxpcall(f, id, ...)
 end
 
diff --git a/runtime/lua/man.lua b/runtime/lua/man.lua
index 84dfd0e7f4..f07c1dfe46 100644
--- a/runtime/lua/man.lua
+++ b/runtime/lua/man.lua
@@ -385,8 +385,8 @@ end
 --- (try `:Man 3 App::CLI`). Also on linux, name seems to be case-insensitive.
 --- So for `:Man PRIntf`, we still want the name of the buffer to be 'printf'.
 --- @param path string
---- @return string name
---- @return string sect
+--- @return string? name
+--- @return string? sect
 local function parse_path(path)
   local tail = vim.fs.basename(path)
   if
diff --git a/runtime/lua/vim/_core/editor.lua b/runtime/lua/vim/_core/editor.lua
index 12b772d047..7d44718785 100644
--- a/runtime/lua/vim/_core/editor.lua
+++ b/runtime/lua/vim/_core/editor.lua
@@ -535,10 +535,10 @@ do
   local function make_dict_accessor(scope, handle)
     vim.validate('scope', scope, 'string')
     local mt = {}
-    function mt:__newindex(k, v)
+    function mt.__newindex(_, k, v)
       return vim._setvar(scope, handle or 0, k, v)
     end
-    function mt:__index(k)
+    function mt.__index(_, k)
       if handle == nil and type(k) == 'number' then
         return make_dict_accessor(scope, k)
       end
@@ -926,7 +926,7 @@ function vim.str_utfindex(s, encoding, index, strict_indexing)
 
   if encoding == 'utf-8' then
     local len = #s
-    return index <= len and index or (strict_indexing and error('index out of range') or len)
+    return (index <= len and index or (strict_indexing and error('index out of range') or len)) --[[@as integer]]
   end
   local col32, col16 = vim._str_utfindex(s, index) --[[@as integer?,integer?]]
   local col = encoding == 'utf-16' and col16 or col32
diff --git a/runtime/lua/vim/_core/ex_cmd.lua b/runtime/lua/vim/_core/ex_cmd.lua
index 5187dade61..695e6affa2 100644
--- a/runtime/lua/vim/_core/ex_cmd.lua
+++ b/runtime/lua/vim/_core/ex_cmd.lua
@@ -216,7 +216,7 @@ function M.ex_log(eap)
     else
       path = fs.joinpath(log_dir, filename .. '.log')
     end
-    if not vim.uv.fs_stat(path) then
+    if not uv.fs_stat(path) then
       util.echo_err(N_('E5200: No such log file: %s'):format(path))
       return
     end
@@ -229,7 +229,7 @@ end
 --- @return string[] completions
 function M.log_complete()
   local names = { 'nvim' } --- @type string[]
-  for file, type in vim.fs.dir(log_dir, { depth = math.huge }) do
+  for file, type in fs.dir(log_dir, { depth = math.huge }) do
     local name, matches = file:gsub('%.log$', '')
     if matches ~= 0 and type == 'file' and name ~= 'nvim' then
       names[#names + 1] = name
diff --git a/runtime/lua/vim/_core/help.lua b/runtime/lua/vim/_core/help.lua
index 7223959352..b957621244 100644
--- a/runtime/lua/vim/_core/help.lua
+++ b/runtime/lua/vim/_core/help.lua
@@ -249,7 +249,7 @@ end
 ---
 ---@return string? resolved The resolved help tag, or nil if no match found
 function M.resolve_tag()
-  local tag = vim.fn.expand('<cWORD>')
+  local tag = vim.fn.expand('<cWORD>') --[[@as string]]
   if not tag or tag == '' then
     return nil
   end
diff --git a/runtime/lua/vim/_core/options.lua b/runtime/lua/vim/_core/options.lua
index 3bcf54ffd5..75e71aaf3c 100644
--- a/runtime/lua/vim/_core/options.lua
+++ b/runtime/lua/vim/_core/options.lua
@@ -295,7 +295,7 @@ local function create_option_accessor(scope)
     end,
 
     append = function(self, right)
-      vim.api.nvim_set_option_value(self._name, right, { operation = 'append', scope = scope })
+      api.nvim_set_option_value(self._name, right, { operation = 'append', scope = scope })
     end,
 
     __infix = function(self, right, operation)
@@ -315,7 +315,7 @@ local function create_option_accessor(scope)
       end
       return make_option(
         self._name,
-        vim.api.nvim_set_option_value(
+        api.nvim_set_option_value(
           self._name,
           right,
           { operation = operation, scope = scope, dry_run = true }
@@ -329,7 +329,7 @@ local function create_option_accessor(scope)
     end,
 
     prepend = function(self, right)
-      vim.api.nvim_set_option_value(self._name, right, { operation = 'prepend', scope = scope })
+      api.nvim_set_option_value(self._name, right, { operation = 'prepend', scope = scope })
     end,
 
     __pow = function(self, right)
@@ -337,7 +337,7 @@ local function create_option_accessor(scope)
     end,
 
     remove = function(self, right)
-      vim.api.nvim_set_option_value(self._name, right, { operation = 'remove', scope = scope })
+      api.nvim_set_option_value(self._name, right, { operation = 'remove', scope = scope })
     end,
 
     __sub = function(self, right)
@@ -479,6 +479,7 @@ local Option = {} -- luacheck: no unused
 --- end
 --- ```
 ---@return string|integer|boolean|nil value of option
+---@diagnostic disable-next-line: unused used for gen_vimdoc
 function Option:get() end
 
 --- Append a value to string-style options. See |:set+=|
@@ -490,7 +491,7 @@ function Option:get() end
 --- vim.opt.formatoptions = vim.opt.formatoptions + 'j'
 --- ```
 ---@param value string Value to append
----@diagnostic disable-next-line:unused-local used for gen_vimdoc
+---@diagnostic disable-next-line:unused used for gen_vimdoc
 function Option:append(value) end -- luacheck: no unused
 
 --- Prepend a value to string-style options. See |:set^=|
@@ -502,7 +503,7 @@ function Option:append(value) end -- luacheck: no unused
 --- vim.opt.wildignore = vim.opt.wildignore ^ '*.o'
 --- ```
 ---@param value string Value to prepend
----@diagnostic disable-next-line:unused-local used for gen_vimdoc
+---@diagnostic disable-next-line:unused used for gen_vimdoc
 function Option:prepend(value) end -- luacheck: no unused
 
 --- Remove a value from string-style options. See |:set-=|
@@ -514,7 +515,7 @@ function Option:prepend(value) end -- luacheck: no unused
 --- vim.opt.wildignore = vim.opt.wildignore - '*.pyc'
 --- ```
 ---@param value string Value to remove
----@diagnostic disable-next-line:unused-local used for gen_vimdoc
+---@diagnostic disable-next-line:unused used for gen_vimdoc
 function Option:remove(value) end -- luacheck: no unused
 
 --- @nodoc
diff --git a/runtime/lua/vim/_core/shared.lua b/runtime/lua/vim/_core/shared.lua
index d4c33d4b8a..4be64e2373 100644
--- a/runtime/lua/vim/_core/shared.lua
+++ b/runtime/lua/vim/_core/shared.lua
@@ -1680,6 +1680,7 @@ end
 --- @return T[]
 function vim._ensure_list(x)
   if type(x) == 'table' then
+    --- @cast x T[]
     return x
   end
   return { x }
diff --git a/runtime/lua/vim/_core/system.lua b/runtime/lua/vim/_core/system.lua
index d804b04dfe..a1e44e0408 100644
--- a/runtime/lua/vim/_core/system.lua
+++ b/runtime/lua/vim/_core/system.lua
@@ -147,6 +147,8 @@ function SystemObj:wait(timeout)
     end, nil, true)
   end
 
+  -- TODO: A short timeout can leave result nil even after sending SIGKILL.
+  ---@diagnostic disable-next-line: return-type-mismatch
   return state.result
 end
 
diff --git a/runtime/lua/vim/_core/table.lua b/runtime/lua/vim/_core/table.lua
index d039a25e41..4fb16d7cb5 100644
--- a/runtime/lua/vim/_core/table.lua
+++ b/runtime/lua/vim/_core/table.lua
@@ -5,17 +5,14 @@ local has_clear, clear = pcall(require, 'table.clear')
 local M = {}
 
 if not has_new then
-  ---@diagnostic disable-next-line: unused-local
-  new = function(narr, nrec)
+  new = function(_narr, _nrec)
     return {}
   end
 end
 
 if not has_clear then
   clear = function(tab)
-    ---@diagnostic disable-next-line: no-unknown
     for k in pairs(tab) do
-      ---@diagnostic disable-next-line: no-unknown
       tab[k] = nil
     end
   end
diff --git a/runtime/lua/vim/_core/ui2.lua b/runtime/lua/vim/_core/ui2.lua
index 219a703fe8..699490dd98 100644
--- a/runtime/lua/vim/_core/ui2.lua
+++ b/runtime/lua/vim/_core/ui2.lua
@@ -195,7 +195,7 @@ function M.enable(opts)
   M.cfg.msg.targets = type(M.cfg.msg.targets) == 'table' and M.cfg.msg.targets
     or { default = M.cfg.msg.targets }
   M.cfg.msg.targets.default = M.cfg.msg.targets.default or 'cmd'
-  if #vim.api.nvim_list_uis() == 0 then
+  if #api.nvim_list_uis() == 0 then
     return -- Don't prevent stdout messaging when no UIs are attached.
   end
 
diff --git a/runtime/lua/vim/_inspector.lua b/runtime/lua/vim/_inspector.lua
index 2ae357a700..5e0a518acb 100644
--- a/runtime/lua/vim/_inspector.lua
+++ b/runtime/lua/vim/_inspector.lua
@@ -56,6 +56,8 @@ function vim.inspect_pos(buf, row, col, filter)
     row, col = cursor[1] - 1, cursor[2]
   end
   buf = vim._resolve_bufnr(buf)
+  ---@cast row integer
+  ---@cast col integer
 
   local results = {
     treesitter = {}, --- @type table[]
diff --git a/runtime/lua/vim/diagnostic/_float.lua b/runtime/lua/vim/diagnostic/_float.lua
index aa41cdd38e..f7331b3c56 100644
--- a/runtime/lua/vim/diagnostic/_float.lua
+++ b/runtime/lua/vim/diagnostic/_float.lua
@@ -5,6 +5,8 @@ local store = require('vim.diagnostic._store')
 --- @class (private) vim.diagnostic._float
 local M = {}
 
+local float_ns = api.nvim_create_namespace('nvim.diagnostic.float')
+
 local severity = vim.diagnostic.severity
 
 --- @type table<vim.diagnostic.Severity, string>
@@ -263,19 +265,31 @@ function M.open(opts, ...)
     end
   end, { buf = float_bufnr, remap = false })
 
-  --- @diagnostic disable-next-line: deprecated
-  local add_highlight = api.nvim_buf_add_highlight
-
+  -- The preview may trim empty lines or reuse an older buffer, so highlight ranges
+  -- can extend past its contents. Use strict = false to tolerate this.
   for i, hl in ipairs(highlights) do
     local line = lines[i]
     local prefix_len = hl.prefix and hl.prefix.length or 0
     local suffix_len = hl.suffix and hl.suffix.length or 0
     if prefix_len > 0 then
-      add_highlight(float_bufnr, -1, hl.prefix.hlname, i - 1, 0, prefix_len)
+      api.nvim_buf_set_extmark(float_bufnr, float_ns, i - 1, 0, {
+        hl_group = hl.prefix.hlname,
+        end_col = prefix_len,
+        strict = false,
+      })
     end
-    add_highlight(float_bufnr, -1, hl.hlname, i - 1, prefix_len, #line - suffix_len)
+    api.nvim_buf_set_extmark(float_bufnr, float_ns, i - 1, prefix_len, {
+      hl_group = hl.hlname,
+      end_col = #line - suffix_len,
+      strict = false,
+    })
     if suffix_len > 0 then
-      add_highlight(float_bufnr, -1, hl.suffix.hlname, i - 1, #line - suffix_len, -1)
+      api.nvim_buf_set_extmark(float_bufnr, float_ns, i - 1, #line - suffix_len, {
+        hl_group = hl.suffix.hlname,
+        end_row = i,
+        end_col = 0,
+        strict = false,
+      })
     end
   end
 
diff --git a/runtime/lua/vim/diagnostic/_shared.lua b/runtime/lua/vim/diagnostic/_shared.lua
index 177cc61b32..2e504d5d68 100644
--- a/runtime/lua/vim/diagnostic/_shared.lua
+++ b/runtime/lua/vim/diagnostic/_shared.lua
@@ -58,6 +58,8 @@ function M.get_logical_pos(diagnostic)
     return diagnostic.lnum, diagnostic.col, diagnostic.end_lnum, diagnostic.end_col, true
   end
 
+  -- Diagnostic extmarks always have an end position.
+  ---@cast extmark [integer, integer, {end_row: integer, end_col: integer, invalid?: boolean}]
   return extmark[1], extmark[2], extmark[3].end_row, extmark[3].end_col, not extmark[3].invalid
 end
 
diff --git a/runtime/lua/vim/filetype.lua b/runtime/lua/vim/filetype.lua
index 2ba238085e..80af785617 100644
--- a/runtime/lua/vim/filetype.lua
+++ b/runtime/lua/vim/filetype.lua
@@ -109,7 +109,7 @@ end
 --- @return table<string,true>
 function M._get_known_filetypes()
   local known = {} --- @type table<string,true>
-  for _, ft in ipairs(vim.fn.getcompletion('', 'filetype')) do
+  for _, ft in ipairs(fn.getcompletion('', 'filetype')) do
     known[ft] = true
   end
   local registry = vim.filetype.inspect()
diff --git a/runtime/lua/vim/fs.lua b/runtime/lua/vim/fs.lua
index c412e9d714..7af6825bff 100644
--- a/runtime/lua/vim/fs.lua
+++ b/runtime/lua/vim/fs.lua
@@ -276,7 +276,7 @@ local function fs_scandir_next(fs, path)
   end
 
   if etype == nil then
-    local stat = vim.uv.fs_lstat(M.joinpath(path, name))
+    local stat = uv.fs_lstat(M.joinpath(path, name))
     -- Workaround #39612 https://github.com/luvit/luv/issues/660
     etype = stat and stat.type or 'unknown'
   end
diff --git a/runtime/lua/vim/health/health.lua b/runtime/lua/vim/health/health.lua
index 8ba44a748a..969b1e06aa 100644
--- a/runtime/lua/vim/health/health.lua
+++ b/runtime/lua/vim/health/health.lua
@@ -801,6 +801,8 @@ local function check_sysinfo()
     local encoded_body = vim.uri_encode(body) --- @type string
     local issue_url = 'https://github.com/neovim/neovim/issues/new?type=Bug&body=' .. encoded_body
 
+    --- Opens the prefilled issue from the checkhealth winbar.
+    ---@diagnostic disable-next-line: global-in-non-module
     _G.nvim_health_bugreport_open = function()
       vim.ui.open(issue_url)
     end
diff --git a/runtime/lua/vim/iter.lua b/runtime/lua/vim/iter.lua
index f81c43b3bf..9a195307c8 100644
--- a/runtime/lua/vim/iter.lua
+++ b/runtime/lua/vim/iter.lua
@@ -276,7 +276,7 @@ function Iter:unique(key)
 end
 
 --- @nodoc
---- @diagnostic disable-next-line:unused-local
+--- @diagnostic disable-next-line:unused
 function Iter:flatten(depth)
   error('flatten() requires an array-like table')
 end
@@ -629,7 +629,7 @@ function IterArray:next()
 end
 
 --- @nodoc
---- @diagnostic disable-next-line: unused-local
+--- @diagnostic disable-next-line: unused
 function Iter:rev()
   error('rev() requires an array-like table')
 end
@@ -743,7 +743,7 @@ function Iter:find(f)
 end
 
 --- @nodoc
---- @diagnostic disable-next-line:unused-local
+--- @diagnostic disable-next-line:unused
 function Iter:rfind(f)
   error('rfind() requires an array-like table')
 end
@@ -866,7 +866,7 @@ function IterArray:take(n)
 end
 
 --- @nodoc
---- @diagnostic disable-next-line: unused-local
+--- @diagnostic disable-next-line: unused
 function Iter:pop()
   error('pop() requires an array-like table')
 end
@@ -894,7 +894,7 @@ function IterArray:pop()
 end
 
 --- @nodoc
---- @diagnostic disable-next-line: unused-local
+--- @diagnostic disable-next-line: unused
 function Iter:rpeek()
   error('rpeek() requires an array-like table')
 end
@@ -1003,7 +1003,7 @@ function IterArray:skip(n)
 end
 
 --- @nodoc
---- @diagnostic disable-next-line:unused-local
+--- @diagnostic disable-next-line:unused
 function Iter:rskip(n)
   error('rskip() requires an array-like table')
 end
@@ -1064,7 +1064,7 @@ function Iter:nth(n)
 end
 
 --- @nodoc
---- @diagnostic disable-next-line:unused-local
+--- @diagnostic disable-next-line:unused
 function Iter:slice(first, last)
   error('slice() requires an array-like table')
 end
diff --git a/runtime/lua/vim/loader.lua b/runtime/lua/vim/loader.lua
index 2ab8d451a2..e819229583 100644
--- a/runtime/lua/vim/loader.lua
+++ b/runtime/lua/vim/loader.lua
@@ -437,7 +437,8 @@ function M.enable(enable)
   M.enabled = enable
 
   if enable then
-    vim.fn.mkdir(vim.fs.abspath(M.path), 'p')
+    vim.fn.mkdir(fs.abspath(M.path), 'p')
+    ---@diagnostic disable-next-line: global-in-non-module
     _G.loadfile = loadfile_cached
     -- add Lua loader
     table.insert(loaders, 2, loader_cached)
@@ -451,6 +452,7 @@ function M.enable(enable)
       end
     end
   else
+    ---@diagnostic disable-next-line: global-in-non-module
     _G.loadfile = _loadfile
     for l = #loaders, 1, -1 do
       local loader = loaders[l]
diff --git a/runtime/lua/vim/lsp/_capability.lua b/runtime/lua/vim/lsp/_capability.lua
index 977c1ab355..55f83e5ba5 100644
--- a/runtime/lua/vim/lsp/_capability.lua
+++ b/runtime/lua/vim/lsp/_capability.lua
@@ -118,18 +118,18 @@ end
 
 --- Callback invoked when textDocument/didClose is sent for a client.
 ---@param client_id integer
----@diagnostic disable-next-line: unused-local
+---@diagnostic disable-next-line: unused
 function M:on_close(client_id) end
 
 --- Callback invoked when textDocument/didChange or textDocument/didOpen is sent for a client.
 ---@param client_id integer
----@diagnostic disable-next-line: unused-local
+---@diagnostic disable-next-line: unused
 function M:on_change(client_id) end
 
 --- Callback invoked on every redraw.
 ---@param topline integer
 ---@param botline integer
----@diagnostic disable-next-line: unused-local
+---@diagnostic disable-next-line: unused
 function M:on_win(topline, botline) end
 
 ---@param name vim.lsp.capability.Name
diff --git a/runtime/lua/vim/lsp/_folding_range.lua b/runtime/lua/vim/lsp/_folding_range.lua
index 9f85be9eae..e1d9042ba9 100644
--- a/runtime/lua/vim/lsp/_folding_range.lua
+++ b/runtime/lua/vim/lsp/_folding_range.lua
@@ -254,7 +254,7 @@ function State:on_attach(client_id)
   self:refresh(client_id)
 end
 
----@params client_id integer
+---@param client_id integer
 function State:on_detach(client_id)
   self.client_state[client_id] = nil
   self:evaluate()
@@ -275,7 +275,7 @@ end
 
 ---@param kind lsp.FoldingRangeKind
 ---@param winid integer
-function State:foldclose(kind, winid)
+function State.foldclose(_, kind, winid)
   vim._with({ win = winid }, function()
     local bufnr = api.nvim_win_get_buf(winid)
     local row_kinds = State.active[bufnr].row_kinds
@@ -395,7 +395,7 @@ function M.foldtext(lnum)
   local row = lnum - 1
   local state = State.active[bufnr]
   local lang = state and state.lang
-  local line = vim.fn.getline(lnum)
+  local line = vim.fn.getline(lnum) --[[@as string]]
   if not lang then
     return line
   end ---@cast state -nil
diff --git a/runtime/lua/vim/lsp/buf.lua b/runtime/lua/vim/lsp/buf.lua
index 0eca0bc420..c6b44ab0cd 100644
--- a/runtime/lua/vim/lsp/buf.lua
+++ b/runtime/lua/vim/lsp/buf.lua
@@ -36,7 +36,7 @@ local function ctx_is_valid(ctx)
     not bufnr
     or not api.nvim_buf_is_valid(bufnr)
     or api.nvim_get_current_buf() ~= bufnr
-    or vim.lsp.util.buf_versions[bufnr] ~= ctx.version
+    or lsp.util.buf_versions[bufnr] ~= ctx.version
   then
     return false
   end
diff --git a/runtime/lua/vim/lsp/client.lua b/runtime/lua/vim/lsp/client.lua
index 984447720c..401d39042c 100644
--- a/runtime/lua/vim/lsp/client.lua
+++ b/runtime/lua/vim/lsp/client.lua
@@ -989,7 +989,7 @@ end
 
 --- Get provider for a method to be registered dynamically.
 --- @param method vim.lsp.protocol.Method | vim.lsp.protocol.Method.Registration
-function Client:_registration_provider(method)
+function Client._registration_provider(_, method)
   return lsp.protocol._request_name_to_registration_provider[method] or method
 end
 
@@ -1224,7 +1224,7 @@ function Client:on_attach(bufnr)
   -- schedule the initialization of capabilities to give the above on_attach and LspAttach callbacks
   -- the ability to enable or disable them
   vim.schedule(function()
-    if not vim.api.nvim_buf_is_valid(bufnr) then
+    if not api.nvim_buf_is_valid(bufnr) then
       return
     end
     for _, Capability in pairs(lsp._capability.all) do
@@ -1456,7 +1456,7 @@ function Client:_on_detach(bufnr)
     end
   end
 
-  vim.diagnostic.reset(vim.lsp.diagnostic.get_namespace(self.id, false), bufnr)
+  vim.diagnostic.reset(lsp.diagnostic.get_namespace(self.id, false), bufnr)
 
   changetracking.reset_buf(self, bufnr)
 
@@ -1468,10 +1468,10 @@ end
 --- Reset defaults set by `set_defaults`.
 --- Must only be called if the last client attached to a buffer exits.
 local function reset_defaults(bufnr)
-  if vim.bo[bufnr].tagfunc == vim.lsp.tagfunc then
+  if vim.bo[bufnr].tagfunc == lsp.tagfunc then
     vim.bo[bufnr].tagfunc = nil
   end
-  if vim.bo[bufnr].omnifunc == vim.lsp.omnifunc then
+  if vim.bo[bufnr].omnifunc == lsp.omnifunc then
     vim.bo[bufnr].omnifunc = nil
   end
   if vim.bo[bufnr].formatexpr == 'v:lua.vim.lsp.formatexpr()' then
diff --git a/runtime/lua/vim/lsp/codelens.lua b/runtime/lua/vim/lsp/codelens.lua
index ebcdef0b1e..89c8877b2d 100644
--- a/runtime/lua/vim/lsp/codelens.lua
+++ b/runtime/lua/vim/lsp/codelens.lua
@@ -297,6 +297,7 @@ end
 ---
 ---@param filter? vim.lsp.codelens.get.Filter
 ---@return vim.lsp.codelens.get.Result[]
+---@overload fun(filter: integer): lsp.CodeLens[]
 function M.get(filter)
   if type(filter) == 'number' then
     vim.deprecate(
@@ -316,6 +317,7 @@ function M.get(filter)
         result = vim.list_extend(result, row_lenses.lenses)
       end
     end
+    ---@diagnostic disable-next-line: return-type-mismatch
     return result
   end
 
diff --git a/runtime/lua/vim/lsp/completion.lua b/runtime/lua/vim/lsp/completion.lua
index 00f224b590..b092a71120 100644
--- a/runtime/lua/vim/lsp/completion.lua
+++ b/runtime/lua/vim/lsp/completion.lua
@@ -145,7 +145,7 @@ local compute_new_average = exp_avg(10, 10)
 ---
 --- @param last_request_time integer?
 --- @param current_rtt_ms number
---- @return integer
+--- @return number
 local function adaptive_debounce(last_request_time, current_rtt_ms)
   if not last_request_time then
     return current_rtt_ms
@@ -298,6 +298,7 @@ local function get_items(result)
     return result.items
   else
     -- Else just return the items as they are.
+    ---@cast result lsp.CompletionItem[]
     return result
   end
 end
@@ -308,7 +309,7 @@ end
 ---@return lsp.MarkupKind
 local function get_doc(item)
   local doc = item.documentation
-  local default_kind = vim.lsp.protocol.MarkupKind.Markdown
+  local default_kind = protocol.MarkupKind.Markdown
   if not doc then
     return '', default_kind
   end
@@ -349,11 +350,11 @@ end
 ---@return string? kind text or "■" for colors
 ---@return string? highlight group for colors
 local function generate_kind(item)
-  if not lsp.protocol.CompletionItemKind[item.kind] then
+  if not protocol.CompletionItemKind[item.kind] then
     return 'Unknown'
   end
-  if item.kind ~= lsp.protocol.CompletionItemKind.Color then
-    return lsp.protocol.CompletionItemKind[item.kind]
+  if item.kind ~= protocol.CompletionItemKind.Color then
+    return protocol.CompletionItemKind[item.kind] --[[@as string]]
   end
   local doc = get_doc(item)
   if #doc == 0 then
@@ -575,6 +576,7 @@ function M._lsp_to_complete_items(
 
       local hl_group = ''
       if
+        ---@diagnostic disable-next-line: deprecated
         item.deprecated
         or vim.list_contains((item.tags or {}), protocol.CompletionTag.Deprecated)
       then
@@ -786,7 +788,7 @@ end
 --- @param kind? string
 local function update_popup_window(winid, bufnr, kind)
   if winid and api.nvim_win_is_valid(winid) and bufnr and api.nvim_buf_is_valid(bufnr) then
-    if kind == lsp.protocol.MarkupKind.Markdown then
+    if kind == protocol.MarkupKind.Markdown then
       vim.wo[winid].conceallevel = 2
       vim.treesitter.start(bufnr, kind)
     end
@@ -856,9 +858,9 @@ end
 --- @return boolean, table Validity of the request and the completion info
 function CompletionResolver:is_valid()
   local cmp_info = vim.fn.complete_info({ 'selected', 'completed' })
-  return vim.api.nvim_buf_is_valid(self.bufnr)
-    and vim.api.nvim_get_current_buf() == self.bufnr
-    and vim.startswith(vim.api.nvim_get_mode().mode, 'i')
+  return api.nvim_buf_is_valid(self.bufnr)
+    and api.nvim_get_current_buf() == self.bufnr
+    and vim.startswith(api.nvim_get_mode().mode, 'i')
     and vim.fn.pumvisible() ~= 0
     and (vim.tbl_get(cmp_info, 'completed', 'word') or '') == self.word,
     cmp_info
@@ -887,7 +889,7 @@ function CompletionResolver:request(bufnr, param, selected_word)
     self:cancel_pending_requests()
 
     local client_id = vim.tbl_get(cmp_info.completed, 'user_data', 'nvim', 'lsp', 'client_id')
-    local client = client_id and vim.lsp.get_client_by_id(client_id)
+    local client = client_id and lsp.get_client_by_id(client_id)
     -- completionItem/resolve is not registrable, so supports_method() would
     -- only see the static capability.
     if not client or not completion_options(client, bufnr).resolveProvider then
@@ -917,7 +919,7 @@ function CompletionResolver:request(bufnr, param, selected_word)
 
       local info, kind = complete_item_info(result)
       if info ~= '' and info ~= cmp_info.completed.info then
-        local windata = vim.api.nvim__complete_set(cmp_info.selected, { info = info })
+        local windata = api.nvim__complete_set(cmp_info.selected, { info = info })
         update_popup_window(windata.winid, windata.bufnr, kind)
       end
     end, bufnr)
diff --git a/runtime/lua/vim/lsp/diagnostic.lua b/runtime/lua/vim/lsp/diagnostic.lua
index 6f4cdbc693..388c632285 100644
--- a/runtime/lua/vim/lsp/diagnostic.lua
+++ b/runtime/lua/vim/lsp/diagnostic.lua
@@ -295,12 +295,12 @@ function M.on_diagnostic(error, result, ctx)
   if error ~= nil then
     if error.code == protocol.ErrorCodes.ServerCancelled then
       if error.data == nil or error.data.retriggerRequest ~= false then
-        local client = assert(lsp.get_client_by_id(ctx.client_id))
+        local client = assert(lsp.get_client_by_id(client_id))
         ---@diagnostic disable-next-line: param-type-mismatch
         client:request(ctx.method, ctx.params, nil, ctx.bufnr)
       end
     else
-      vim.lsp.log.error('diagnostics', error)
+      lsp.log.error('diagnostics', error)
     end
     return
   end
@@ -354,7 +354,7 @@ end
 ---@package
 ---@param client_id integer Client ID to refresh
 function Diagnostics:refresh(client_id)
-  local client = vim.lsp.get_client_by_id(client_id)
+  local client = lsp.get_client_by_id(client_id)
 
   local method = 'textDocument/diagnostic'
   local clients = { client }
@@ -389,7 +389,7 @@ function M.on_refresh(err, _, ctx)
   if err then
     return vim.NIL
   end
-  local client = vim.lsp.get_client_by_id(ctx.client_id)
+  local client = lsp.get_client_by_id(ctx.client_id)
   if client == nil then
     return vim.NIL
   end
diff --git a/runtime/lua/vim/lsp/handlers.lua b/runtime/lua/vim/lsp/handlers.lua
index 5bdd8cc01f..3163b1bc85 100644
--- a/runtime/lua/vim/lsp/handlers.lua
+++ b/runtime/lua/vim/lsp/handlers.lua
@@ -44,6 +44,7 @@ local function show_message_notification(params, ctx)
 end
 
 --- @see # https://microsoft.github.io/language-server-protocol/specifications/specification-current/#workspace_executeCommand
+---@diagnostic disable-next-line: deprecated
 RCS['workspace/executeCommand'] = function(_, _, _)
   -- Error handling is done implicitly by wrapping all handlers; see end of this file
 end
@@ -120,6 +121,8 @@ RSC['window/showMessageRequest'] = function(_, params, ctx)
           coroutine.resume(co, choice or vim.NIL)
         end)
       end)
+      -- The coroutine.running() check above guards this yield.
+      ---@diagnostic disable-next-line: await-in-sync
       return coroutine.yield()
     else
       local option_strings = { params.message, '\nRequest Actions:' }
@@ -259,11 +262,13 @@ NSC['textDocument/publishDiagnostics'] = function(...)
 end
 
 --- @private
+---@diagnostic disable-next-line: deprecated
 RCS['textDocument/diagnostic'] = function(...)
   return vim.lsp.diagnostic.on_diagnostic(...)
 end
 
 --- @private
+---@diagnostic disable-next-line: deprecated
 RCS['textDocument/inlayHint'] = function(...)
   return vim.lsp.inlay_hint.on_inlayhint(...)
 end
@@ -304,6 +309,7 @@ end
 
 --- @deprecated remove in 0.13
 --- @see # https://microsoft.github.io/language-server-protocol/specifications/specification-current/#textDocument_documentSymbol
+---@diagnostic disable-next-line: deprecated
 RCS['textDocument/documentSymbol'] = response_to_list(
   util.symbols_to_items,
   'document symbols',
@@ -315,12 +321,14 @@ RCS['textDocument/documentSymbol'] = response_to_list(
 
 --- @deprecated remove in 0.13
 --- @see # https://microsoft.github.io/language-server-protocol/specifications/specification-current/#workspace_symbol
+---@diagnostic disable-next-line: deprecated
 RCS['workspace/symbol'] = response_to_list(util.symbols_to_items, 'symbols', function(ctx)
   return string.format("Symbols matching '%s'", ctx.params.query)
 end)
 
 --- @deprecated remove in 0.13
 --- @see # https://microsoft.github.io/language-server-protocol/specifications/specification-current/#textDocument_rename
+---@diagnostic disable-next-line: deprecated
 RCS['textDocument/rename'] = function(_, result, ctx)
   if not result then
     vim.notify("Language server couldn't provide rename result", vim.log.levels.INFO)
@@ -332,6 +340,7 @@ end
 
 --- @deprecated remove in 0.13
 --- @see # https://microsoft.github.io/language-server-protocol/specifications/specification-current/#textDocument_rangeFormatting
+---@diagnostic disable-next-line: deprecated
 RCS['textDocument/rangeFormatting'] = function(_, result, ctx)
   if not result then
     return
@@ -342,6 +351,7 @@ end
 
 --- @deprecated remove in 0.13
 --- @see # https://microsoft.github.io/language-server-protocol/specifications/specification-current/#textDocument_formatting
+---@diagnostic disable-next-line: deprecated
 RCS['textDocument/formatting'] = function(_, result, ctx)
   if not result then
     return
@@ -352,6 +362,7 @@ end
 
 --- @deprecated remove in 0.13
 --- @see # https://microsoft.github.io/language-server-protocol/specifications/specification-current/#textDocument_completion
+---@diagnostic disable-next-line: deprecated
 RCS['textDocument/completion'] = function(_, result, _)
   if vim.tbl_isempty(result or {}) then
     return
@@ -495,6 +506,7 @@ RCS['textDocument/signatureHelp'] = M.signature_help
 
 --- @deprecated remove in 0.13
 --- @see # https://microsoft.github.io/language-server-protocol/specifications/specification-current/#textDocument_documentHighlight
+---@diagnostic disable-next-line: deprecated
 RCS['textDocument/documentHighlight'] = function(_, result, ctx)
   if not result then
     return
@@ -547,10 +559,12 @@ end
 
 --- @deprecated remove in 0.13
 --- @see # https://microsoft.github.io/language-server-protocol/specifications/specification-current/#callHierarchy_incomingCalls
+---@diagnostic disable-next-line: deprecated
 RCS['callHierarchy/incomingCalls'] = make_call_hierarchy_handler('from')
 
 --- @deprecated remove in 0.13
 --- @see # https://microsoft.github.io/language-server-protocol/specifications/specification-current/#callHierarchy_outgoingCalls
+---@diagnostic disable-next-line: deprecated
 RCS['callHierarchy/outgoingCalls'] = make_call_hierarchy_handler('to')
 
 --- Displays type hierarchy in the quickfix window.
@@ -584,10 +598,12 @@ end
 
 --- @deprecated remove in 0.13
 --- @see # https://microsoft.github.io/language-server-protocol/specifications/specification-current/#typeHierarchy_incomingCalls
+---@diagnostic disable-next-line: deprecated
 RCS['typeHierarchy/subtypes'] = make_type_hierarchy_handler()
 
 --- @deprecated remove in 0.13
 --- @see # https://microsoft.github.io/language-server-protocol/specifications/specification-current/#typeHierarchy_outgoingCalls
+---@diagnostic disable-next-line: deprecated
 RCS['typeHierarchy/supertypes'] = make_type_hierarchy_handler()
 
 --- @see: https://microsoft.github.io/language-server-protocol/specifications/specification-current/#window_logMessage
@@ -690,6 +706,7 @@ end
 
 --- @nodoc
 --- @type table<string, lsp.Handler>
+---@diagnostic disable-next-line: deprecated
 M = vim.tbl_extend('force', M, RSC, NSC, RCS)
 
 -- Add boilerplate error validation and logging for all of these.
diff --git a/runtime/lua/vim/lsp/linked_editing_range.lua b/runtime/lua/vim/lsp/linked_editing_range.lua
index 8d37c074dd..6b66caed0d 100644
--- a/runtime/lua/vim/lsp/linked_editing_range.lua
+++ b/runtime/lua/vim/lsp/linked_editing_range.lua
@@ -227,7 +227,7 @@ end
 ---@param enable boolean? `true` or `nil` to enable, `false` to disable.
 ---@param filter vim.lsp.capability.enable.Filter?
 function M.enable(enable, filter)
-  vim.lsp._capability.enable('linked_editing_range', enable, filter)
+  lsp._capability.enable('linked_editing_range', enable, filter)
 end
 
 return M
diff --git a/runtime/lua/vim/lsp/on_type_formatting.lua b/runtime/lua/vim/lsp/on_type_formatting.lua
index 67c6d012af..5221d62640 100644
--- a/runtime/lua/vim/lsp/on_type_formatting.lua
+++ b/runtime/lua/vim/lsp/on_type_formatting.lua
@@ -37,7 +37,7 @@ local function on_type_formatting(err, result, ctx)
     return
   end
 
-  local client = assert(vim.lsp.get_client_by_id(ctx.client_id))
+  local client = assert(lsp.get_client_by_id(ctx.client_id))
 
   util.apply_text_edits(result, ctx.bufnr, client.offset_encoding)
 end
@@ -246,8 +246,10 @@ function M.enable(enable, filter)
   filter = filter or {}
 
   if filter.client_id then
-    local client =
-      assert(lsp.get_client_by_id(filter.client_id), 'Client not found for id ' .. filter.client_id)
+    local client = lsp.get_client_by_id(filter.client_id)
+    if not client then
+      error('Client not found for id ' .. filter.client_id)
+    end
     toggle_for_client(enable, client)
   else
     toggle_globally(enable)
diff --git a/runtime/lua/vim/lsp/semantic_tokens.lua b/runtime/lua/vim/lsp/semantic_tokens.lua
index 9951d39f25..4f50ebf27a 100644
--- a/runtime/lua/vim/lsp/semantic_tokens.lua
+++ b/runtime/lua/vim/lsp/semantic_tokens.lua
@@ -111,6 +111,7 @@ local function tokens_to_ranges(data, bufnr, client, request, ranges)
           -- If it's stale, we don't resume the coroutine so it'll be garbage collected.
           if
             version == util.buf_versions[bufnr]
+            ---@diagnostic disable-next-line: preferred-local-alias
             and request_id == request.request_id
             and api.nvim_buf_is_valid(bufnr)
           then
@@ -457,7 +458,7 @@ end
 --- @return lsp.Range
 function STHighlighter:get_overscan_range()
   local wins = vim.fn.win_findbuf(self.bufnr)
-  local num_lines = vim.api.nvim_buf_line_count(self.bufnr)
+  local num_lines = api.nvim_buf_line_count(self.bufnr)
   local min_start, max_end = nil, nil
 
   for _, win in ipairs(wins) do
@@ -775,7 +776,7 @@ end
 
 ---@private
 ---@param state STClientState
-function STHighlighter:reset_timer(state)
+function STHighlighter.reset_timer(_, state)
   local timer = state.timer
   if timer then
     state.timer = nil
diff --git a/runtime/lua/vim/lsp/sync.lua b/runtime/lua/vim/lsp/sync.lua
index 24a23183f8..7d3beef106 100644
--- a/runtime/lua/vim/lsp/sync.lua
+++ b/runtime/lua/vim/lsp/sync.lua
@@ -106,8 +106,8 @@ local function compute_start_range(
 )
   position_encoding = position_encoding or 'utf-8'
 
-  local char_idx --- @type integer?
-  local byte_idx --- @type integer?
+  local char_idx --- @type integer
+  local byte_idx --- @type integer
   -- If firstline == lastline, no existing text is changed. All edit operations
   -- occur on a new line pointed to by lastline. This occurs during insertion of
   -- new lines(O), the new newline is inserted at the line indicated by
diff --git a/runtime/lua/vim/lsp/util.lua b/runtime/lua/vim/lsp/util.lua
index 7a8e8d6812..8abf66d4a8 100644
--- a/runtime/lua/vim/lsp/util.lua
+++ b/runtime/lua/vim/lsp/util.lua
@@ -70,6 +70,8 @@ local function get_border_size(opts)
       -- border specified as a list of border characters
       return e
     end
+    -- EmmyLua rejects `never` as a subtype of the declared string result.
+    ---@diagnostic disable-next-line: return-type-mismatch
     return border_error(border)
   end
 
@@ -280,10 +282,10 @@ function M.apply_text_edits(text_edits, bufnr, position_encoding, change_annotat
         'change_annotations must be provided for annotated text edits'
       )
 
-      local annotation = assert(
-        change_annotations[text_edit.annotationId],
-        string.format('No change annotation found for ID: %s', text_edit.annotationId)
-      )
+      local annotation = change_annotations[text_edit.annotationId]
+      if not annotation then
+        error(string.format('No change annotation found for ID: %s', text_edit.annotationId))
+      end
 
       if annotation.needsConfirmation then
         confirmations[text_edit.annotationId] = (confirmations[text_edit.annotationId] or 0) + 1
@@ -365,7 +367,7 @@ function M.apply_text_document_edit(
   position_encoding,
   change_annotations
 )
-  vim.validate('position_encoding', position_encoding, 'string')
+  validate('position_encoding', position_encoding, 'string')
 
   local text_document = text_document_edit.textDocument
   local bufnr = vim.uri_to_bufnr(text_document.uri)
@@ -548,8 +550,8 @@ end
 ---@param position_encoding 'utf-8'|'utf-16'|'utf-32' (required)
 ---@see https://microsoft.github.io/language-server-protocol/specifications/specification-current/#workspace_applyEdit
 function M.apply_workspace_edit(workspace_edit, position_encoding)
-  vim.validate('workspace_edit', workspace_edit, 'table')
-  vim.validate('position_encoding', position_encoding, 'string')
+  validate('workspace_edit', workspace_edit, 'table')
+  validate('position_encoding', position_encoding, 'string')
 
   if workspace_edit.documentChanges then
     for idx, change in ipairs(workspace_edit.documentChanges) do
@@ -597,6 +599,7 @@ end
 --- Note that if the input is of type `MarkupContent` and its kind is `plaintext`,
 --- then the corresponding value is returned without further modifications.
 ---
+---@diagnostic disable-next-line: deprecated
 ---@param input lsp.MarkedString|lsp.MarkedString[]|lsp.MarkupContent
 ---@param contents string[]? List of strings to extend with converted lines. Defaults to {}.
 ---@return string[] extended with lines of converted markdown.
@@ -867,7 +870,7 @@ end
 ---@param opts? vim.lsp.util.show_document.Opts
 ---@return boolean `true` if succeeded
 function M.show_document(location, position_encoding, opts)
-  vim.validate('position_encoding', position_encoding, 'string')
+  validate('position_encoding', position_encoding, 'string')
 
   -- location may be Location or LocationLink
   local uri = location.uri or location.targetUri
@@ -919,10 +922,10 @@ function M.show_document(location, position_encoding, opts)
 
     -- nvim_win_set_cursor clamps to last char at EOL. In insert mode the cursor
     -- should be past the last char (append position).
-    if vim.api.nvim_get_mode().mode == 'i' then
+    if api.nvim_get_mode().mode == 'i' then
       local line = api.nvim_buf_get_lines(bufnr, row, row + 1, false)[1] or ''
       if col >= #line then
-        vim.api.nvim_feedkeys(vim.keycode('<End>'), 'n', false)
+        api.nvim_feedkeys(vim.keycode('<End>'), 'n', false)
       end
     end
   end
@@ -979,10 +982,10 @@ local function is_float(winnr)
 end
 
 ---Returns true if the line is empty or only contains whitespace.
----@param line string
+---@param line string?
 ---@return boolean
 local function is_blank_line(line)
-  return line and line:match('^%s*$')
+  return line ~= nil and line:match('^%s*$') ~= nil
 end
 
 ---Returns true if the line corresponds to a Markdown thematic break.
@@ -1131,7 +1134,7 @@ function M.stylize_markdown(bufnr, contents, opts)
 
   --- @param line string
   --- @param match {type:string,ft:string}
-  --- @return string
+  --- @return string?
   local function match_end(line, match)
     local pattern = matchers[match.type]
     return line:match(string.format('^%%s*%s%%s*$', pattern[3]))
@@ -1733,7 +1736,7 @@ end)
 ---@param position_encoding 'utf-8'|'utf-16'|'utf-32'
 ---@return vim.quickfix.entry[] # See |setqflist()| for the format
 function M.locations_to_items(locations, position_encoding)
-  vim.validate('position_encoding', position_encoding, 'string')
+  validate('position_encoding', position_encoding, 'string')
 
   local items = {} --- @type vim.quickfix.entry[]
 
@@ -1793,7 +1796,7 @@ end
 ---@param position_encoding 'utf-8'|'utf-16'|'utf-32'
 ---@return vim.quickfix.entry[] # See |setqflist()| for the format
 function M.symbols_to_items(symbols, bufnr, position_encoding)
-  vim.validate('position_encoding', position_encoding, 'string')
+  validate('position_encoding', position_encoding, 'string')
 
   bufnr = vim._resolve_bufnr(bufnr)
 
@@ -1814,6 +1817,7 @@ function M.symbols_to_items(symbols, bufnr, position_encoding)
 
     if filename and range then
       local kind = protocol.SymbolKind[symbol.kind] or 'Unknown'
+      ---@diagnostic disable-next-line: deprecated
       local is_deprecated = not vim.isnil(symbol.deprecated or nil)
         or (
           not vim.isnil(symbol.tags)
@@ -1958,7 +1962,7 @@ end
 ---@return integer `position_encoding` index of the character in line {row} column {col} in buffer {buf}
 function M.character_offset(buf, row, col, position_encoding)
   vim.deprecate('vim.lsp.util.character_offset', 'vim.str_utfindex', '0.14')
-  vim.validate('position_encoding', position_encoding, 'string')
+  validate('position_encoding', position_encoding, 'string')
 
   local line = get_line(buf, row)
   return vim.str_utfindex(line, position_encoding, col, false)
diff --git a/runtime/lua/vim/pack.lua b/runtime/lua/vim/pack.lua
index 754224ec31..93832427b8 100644
--- a/runtime/lua/vim/pack.lua
+++ b/runtime/lua/vim/pack.lua
@@ -878,7 +878,7 @@ local function install_list(plug_list, confirm)
     trigger_events(plug_list, 'PackChangedPre', 'install')
     run_list(plug_list, do_install, 'Installing plugins')
     local installed = vim.tbl_filter(function(p) --- @param p vim.pack.Plug
-      return p.info.installed
+      return p.info.installed == true
     end, plug_list)
     trigger_events(installed, 'PackChanged', 'install')
   end
@@ -1023,7 +1023,7 @@ local function lock_sync(confirm, specs)
 
   -- Compute installed plugins
   local plug_dir = get_plug_dir()
-  if vim.uv.fs_stat(plug_dir) == nil then
+  if uv.fs_stat(plug_dir) == nil then
     vim.fn.mkdir(plug_dir, 'p')
   end
 
@@ -1351,7 +1351,7 @@ end
 --- @param bufnr integer
 --- @return table<string,boolean>
 local function get_update_map(bufnr)
-  local lines = vim.api.nvim_buf_get_lines(bufnr, 0, -1, false)
+  local lines = api.nvim_buf_get_lines(bufnr, 0, -1, false)
   --- @type table<string,boolean>, boolean
   local res, is_in_update = {}, false
   for _, l in ipairs(lines) do
@@ -1383,7 +1383,7 @@ local function update_list(plug_list)
   run_list(plug_list, do_update, 'Applying updates')
 
   local updated = vim.tbl_filter(function(p) --- @param p vim.pack.Plug
-    return p.info.updated
+    return p.info.updated == true
   end, plug_list)
   trigger_events(updated, 'PackChanged', 'update')
 end
diff --git a/runtime/lua/vim/pack/_lsp.lua b/runtime/lua/vim/pack/_lsp.lua
index 223ede8197..3a289f8114 100644
--- a/runtime/lua/vim/pack/_lsp.lua
+++ b/runtime/lua/vim/pack/_lsp.lua
@@ -79,11 +79,11 @@ end
 --- @param line string Buffer line to find a link in
 --- @param pattern string Pattern matching link location and contents, like `'^Path: +()(.+)()$'`
 --- @param link_type "commit"|"path"|"src"|"tag"
---- @param lnum number Line number in a buffer
+--- @param lnum integer Line number in a buffer
 --- @param src string Plugin source
 --- @return vim.pack.lsp.DocumentLink? # A link structure according to the LSP specification
 local function match_link(line, pattern, link_type, lnum, src)
-  --- @type number?, string?, number?
+  --- @type integer?, string?, integer?
   local from, match, to = line:match(pattern)
   if not (from and match and to) then
     return nil
diff --git a/runtime/lua/vim/pos/_util.lua b/runtime/lua/vim/pos/_util.lua
index 00bcce7654..c21a876145 100644
--- a/runtime/lua/vim/pos/_util.lua
+++ b/runtime/lua/vim/pos/_util.lua
@@ -94,7 +94,7 @@ function M.get_lines(buf, rows)
   end
 
   -- Get the data from the file.
-  local success, data = pcall(vim.fn.readblob, vim.api.nvim_buf_get_name(buf))
+  local success, data = pcall(vim.fn.readblob, api.nvim_buf_get_name(buf))
   if not success then
     return row_line
   end
diff --git a/runtime/lua/vim/treesitter.lua b/runtime/lua/vim/treesitter.lua
index ff9d903589..3df65f7f5e 100644
--- a/runtime/lua/vim/treesitter.lua
+++ b/runtime/lua/vim/treesitter.lua
@@ -199,7 +199,7 @@ end
 
 ---@param buf integer
 ---@param range Range
----@returns string
+---@return string
 local function buf_range_get_text(buf, range)
   local start_row, start_col, end_row, end_col = M._range.unpack4(range)
   local append_newline = end_col == 0 and start_row ~= end_row
diff --git a/runtime/lua/vim/treesitter/_range.lua b/runtime/lua/vim/treesitter/_range.lua
index e6ee89d19e..ab322e8188 100644
--- a/runtime/lua/vim/treesitter/_range.lua
+++ b/runtime/lua/vim/treesitter/_range.lua
@@ -80,6 +80,8 @@ function M.intersection(r1, r2)
   if #r1 == 4 or #r2 == 4 then
     local rs = M.cmp_pos.le(r1[1], r1[2], r2[1], r2[2]) and r2 or r1
     local re = M.cmp_pos.ge(r1[3], r1[4], r2[3], r2[4]) and r2 or r1
+    -- This branch implements the Range4 overload.
+    ---@diagnostic disable-next-line: return-type-mismatch
     return { rs[1], rs[2], re[3], re[4] }
   end
 
@@ -95,6 +97,8 @@ function M.unpack4(r)
     return r[1], 0, r[2], 0
   end
   local off_1 = #r == 6 and 1 or 0
+  -- EmmyLua does not narrow tuple fields from the range length.
+  ---@diagnostic disable-next-line: return-type-mismatch
   return r[1], r[2], r[3 + off_1], r[4 + off_1]
 end
 
diff --git a/runtime/lua/vim/treesitter/dev.lua b/runtime/lua/vim/treesitter/dev.lua
index aa50696238..228d434cdc 100644
--- a/runtime/lua/vim/treesitter/dev.lua
+++ b/runtime/lua/vim/treesitter/dev.lua
@@ -148,9 +148,8 @@ function TSTreeView:new(buf, lang)
     },
   }
 
-  setmetatable(t, self)
   self.__index = self
-  return t
+  return setmetatable(t, self)
 end
 
 local decor_ns = api.nvim_create_namespace('nvim.treesitter.dev')
diff --git a/runtime/lua/vim/treesitter/language.lua b/runtime/lua/vim/treesitter/language.lua
index 2bf4d1048f..236cf1a6cb 100644
--- a/runtime/lua/vim/treesitter/language.lua
+++ b/runtime/lua/vim/treesitter/language.lua
@@ -2,7 +2,7 @@ local api = vim.api
 
 local M = {}
 
----@type table<string,string>
+---@type table<string,string?>
 local ft_to_lang = {
   help = 'vimdoc',
   checkhealth = 'vimdoc',
diff --git a/runtime/lua/vim/treesitter/languagetree.lua b/runtime/lua/vim/treesitter/languagetree.lua
index a956fc155f..765487bc05 100644
--- a/runtime/lua/vim/treesitter/languagetree.lua
+++ b/runtime/lua/vim/treesitter/languagetree.lua
@@ -412,6 +412,7 @@ end
 --- @return Range6[] changes
 --- @return integer no_regions_parsed
 --- @return number total_parse_time
+--- @async
 function LanguageTree:_parse_regions(range, thread_state)
   local changes = {}
   local no_regions_parsed = 0
@@ -636,12 +637,15 @@ function LanguageTree:parse(range, on_parse)
   if on_parse then
     return self:_async_parse(range, on_parse)
   end
+  -- Without a timeout, parsing never yields.
+  ---@diagnostic disable-next-line: await-in-sync
   local trees, _ = self:_parse(range, {})
   return trees
 end
 
 ---@param thread_state ParserThreadState
 ---@param time integer
+---@async
 function LanguageTree:_subtract_time(thread_state, time)
   thread_state.timeout = thread_state.timeout and math.max(thread_state.timeout - time, 0)
   if thread_state.timeout == 0 then
@@ -654,6 +658,7 @@ end
 --- @param thread_state ParserThreadState
 --- @return table<integer, TSTree> trees
 --- @return boolean finished
+--- @async
 function LanguageTree:_parse(range, thread_state)
   if self:is_valid(nil, type(range) == 'table' and range or nil) then
     self:_log('valid')
@@ -1088,6 +1093,7 @@ end
 --- @param range Range|Range[]|true
 --- @param thread_state ParserThreadState
 --- @return table<string, Range6[][]>
+--- @async
 function LanguageTree:_get_injections(range, thread_state)
   if not self._injection_query or #self._injection_query.captures == 0 then
     self._processed_injection_region = entire_document_range
diff --git a/runtime/lua/vim/treesitter/query.lua b/runtime/lua/vim/treesitter/query.lua
index 73d4ee7991..7e91baea9d 100644
--- a/runtime/lua/vim/treesitter/query.lua
+++ b/runtime/lua/vim/treesitter/query.lua
@@ -830,7 +830,7 @@ end
 ---@param captures table<integer, TSNode[]>
 ---@param source integer|string
 ---@return boolean whether the predicates match
-function Query:_match_predicates(predicates, pattern_i, captures, source)
+function Query._match_predicates(predicates, pattern_i, captures, source)
   for _, predicate in ipairs(predicates) do
     local processed_name = predicate[1]
     local should_match = predicate[2]
@@ -856,7 +856,7 @@ end
 ---@param source integer|string
 ---@param captures table<integer, TSNode[]>
 ---@return vim.treesitter.query.TSMetadata metadata
-function Query:_apply_directives(directives, pattern_i, captures, source)
+function Query._apply_directives(_, directives, pattern_i, captures, source)
   ---@type vim.treesitter.query.TSMetadata
   local metadata = {}
 
@@ -979,7 +979,7 @@ function Query:iter_captures(node, source, start_row, end_row, opts)
         local captures = match:captures()
 
         local predicates = processed_pattern.predicates
-        if not self:_match_predicates(predicates, pattern_i, captures, source) then
+        if not self._match_predicates(predicates, pattern_i, captures, source) then
           cursor:remove_match(match_id)
 
           local row, col = captured_node:range()
@@ -1081,7 +1081,7 @@ function Query:iter_matches(node, source, start, stop, opts)
     local metadata = {}
     if processed_pattern then
       local predicates = processed_pattern.predicates
-      if not self:_match_predicates(predicates, pattern_i, captures, source) then
+      if not self._match_predicates(predicates, pattern_i, captures, source) then
         cursor:remove_match(match_id)
         return iter() -- tail call: try next match
       end
diff --git a/runtime/pack/dist/opt/nvim.tohtml/lua/tohtml.lua b/runtime/pack/dist/opt/nvim.tohtml/lua/tohtml.lua
index 09c9a24fa0..ef0e8eb504 100644
--- a/runtime/pack/dist/opt/nvim.tohtml/lua/tohtml.lua
+++ b/runtime/pack/dist/opt/nvim.tohtml/lua/tohtml.lua
@@ -243,6 +243,8 @@ local function cterm_to_hex(colorstr)
       cterm_color_cache = cterm_16_to_hex
     end
   end
+  -- EmmyLua retains the failed lookup narrowing after the cache is updated.
+  ---@diagnostic disable-next-line: return-type-mismatch
   return cterm_color_cache[color]
 end
 
diff --git a/test/functional/treesitter/query_spec.lua b/test/functional/treesitter/query_spec.lua
index f5de261d17..7aac113670 100644
--- a/test/functional/treesitter/query_spec.lua
+++ b/test/functional/treesitter/query_spec.lua
@@ -883,9 +883,9 @@ void ui_refresh(void)
         local query0 = vim.treesitter.query.parse('c', query)
         local match_preds = query0._match_predicates
         local called = 0
-        function query0:_match_predicates(...)
+        function query0._match_predicates(...)
           called = called + 1
-          return match_preds(self, ...)
+          return match_preds(...)
         end
         local parser = vim.treesitter.get_parser(0, 'c')
         local root = parser:parse()[1]:root()