diff --git a/src/fennel-ls/analyzer.fnl b/src/fennel-ls/analyzer.fnl
index 87be246..b62c4d1 100644
--- a/src/fennel-ls/analyzer.fnl
+++ b/src/fennel-ls/analyzer.fnl
@@ -221,12 +221,13 @@ find the definition `10`, but if `opts.stop-early?` is set, it would find
   (assert (= (type name) :string) "search-name-and-scope needs a string")
   (let [split (utils.multi-sym-split name)
         stack (stack-add-split! [] split)
+        base-name (. split 1)
         opts (or ?opts {})]
-    (case (docs.get-builtin server (. split 1))
+    (case (docs.get-builtin server base-name)
       metadata (search-document server metadata stack opts)
-      _ (case (find-local-definition file name scope)
+      _ (case (find-local-definition file base-name scope)
           def (search-val server file def.definition (stack-add-keys! stack def.keys) opts)
-          _ (case (docs.get-global server (. split 1))
+          _ (case (docs.get-global server base-name)
               metadata (search-document server metadata stack opts))))))
 
 (λ past? [?ast byte]
diff --git a/src/fennel-ls/completions.fnl b/src/fennel-ls/completions.fnl
index 2bd3245..c6d3544 100644
--- a/src/fennel-ls/completions.fnl
+++ b/src/fennel-ls/completions.fnl
@@ -26,7 +26,7 @@
         seen {}]
 
     (fn add-completion! [name definition ?kind]
-      (table.insert results (format.completion-item-format name definition range ?kind)))
+      (table.insert results (format.completion-item-format server name definition range ?kind)))
 
     (fn add-completion-recursively! [name definition]
       "add the completion. also recursively adds the fields' completions"
@@ -101,6 +101,20 @@
                  (io.stderr:write "BAD!!!! undocumented special: " (tostring special) "\n")
                  {:label special}))))
       (set scope scope.parent))
-    results))
+    (if server.can-do-good-completions?
+      {:itemDefaults {:editRange range :data {: uri : byte}}
+       :items results}
+      results)))
 
-{: textDocument/completion}
+(fn completionItem/resolve [server _send completion-item]
+  (let [{: uri : byte} completion-item.data
+        file (files.get-by-uri server uri)
+        (_symbol parents) (analyzer.find-symbol file.ast byte)
+        scope (or (accumulate [?find nil _ parent (ipairs parents) &until ?find]
+                    (. file.scopes parent))
+                  file.scope)]
+    (case (analyzer.search-name-and-scope server file completion-item.label scope)
+      result (doto completion-item (tset :documentation (format.hover-format result))))))
+
+{: textDocument/completion
+ : completionItem/resolve}
diff --git a/src/fennel-ls/config.fnl b/src/fennel-ls/config.fnl
index 55b5659..83096da 100644
--- a/src/fennel-ls/config.fnl
+++ b/src/fennel-ls/config.fnl
@@ -96,6 +96,12 @@ However, when not an option, fennel-ls will fall back to positionEncoding=\"utf-
   (set server.macro-modules {})
   (set server.root-uri params.rootUri)
   (set server.position-encoding (choose-position-encoding params))
+  (set server.can-do-good-completions?
+       ;; if client supports CompletionClientCapabilites.completionList.itemDefaults.editRange
+       ;;                and CompletionClientCapabilites.completionList.itemDefaults.data
+       (case (?. params :capabilities :textDocument :completion :completionList :itemDefaults)
+          completion-item-defaults  (and (accumulate [found nil _ v (ipairs completion-item-defaults) &until found] (= v :editRange))
+                                         (accumulate [found nil _ v (ipairs completion-item-defaults) &until found] (= v :data)))))
   (reload server))
 
 (λ validate [{: configuration} invalid]
diff --git a/src/fennel-ls/formatter.fnl b/src/fennel-ls/formatter.fnl
index 430bd5b..3b1cd4c 100644
--- a/src/fennel-ls/formatter.fnl
+++ b/src/fennel-ls/formatter.fnl
@@ -172,17 +172,16 @@ fntype is one of fn or λ or lambda"
   :Snippet 15 :Color 16 :File 17 :Reference 18 :Folder 19 :EnumMember 20
   :Constant 21 :Struct 22 :Event 23 :Operator 24 :TypeParameter 25})
 
-(λ completion-item-format [name definition range ?kind]
+(λ completion-item-format [server name definition range ?kind]
   "Makes a completion item"
   {:label name
-   :documentation (hover-format definition)
-   :filterText name
-   :textEdit {:newText name : range}
-   :kind (or (if ?kind (. kinds ?kind))
+   :documentation (when (not server.can-do-good-completions?) (hover-format definition))
+   :textEdit (when (not server.can-do-good-completions?) {:newText name : range})
+   :kind (or (when ?kind (. kinds ?kind))
              (. kinds (?. definition :metadata :fls/itemKind))
-             (if (or (?. definition :metadata :fnl/arglist)
-                     (?. (analyze-fn definition.definition)) :fntype)
-               (if (name:find ":") kinds.Method kinds.Function)))})
+             (when (or (?. definition :metadata :fnl/arglist)
+                       (?. (analyze-fn definition.definition)) :fntype)
+                 (if (name:find ":") kinds.Method kinds.Function)))})
 
 {: signature-help-format
  : hover-format
diff --git a/src/fennel-ls/handlers.fnl b/src/fennel-ls/handlers.fnl
index 683e97f..3fb6d37 100644
--- a/src/fennel-ls/handlers.fnl
+++ b/src/fennel-ls/handlers.fnl
@@ -35,7 +35,7 @@ Every time the client sends a message, it gets handled by a function in the corr
          :textDocumentSync {:openClose true :change 2}
          ;; :notebookDocumentSync nil
          :completionProvider {:workDoneProgress false
-                              :resolveProvider false
+                              :resolveProvider server.can-do-good-completions?
                               :triggerCharacters ["(" "[" "{"]
                               :completionItem {:labelDetailsSupport false}}
          :hoverProvider {:workDoneProgress false}
@@ -162,7 +162,9 @@ Every time the client sends a message, it gets handled by a function in the corr
                                                                   symbol)}
       (catch _ nil))))
 
-(set requests.textDocument/completion (. (require :fennel-ls.completions) :textDocument/completion))
+(set {:textDocument/completion requests.textDocument/completion
+      :completionItem/resolve requests.completionItem/resolve}
+     (require :fennel-ls.completions))
 
 (λ requests.textDocument/rename [server _send {: position :textDocument {: uri} :newName new-name}]
   (let [file (files.get-by-uri server uri)