diff --git a/clang-tools-extra/clangd/CMakeLists.txt b/clang-tools-extra/clangd/CMakeLists.txt
--- a/clang-tools-extra/clangd/CMakeLists.txt
+++ b/clang-tools-extra/clangd/CMakeLists.txt
@@ -75,6 +75,7 @@
   IncludeFixer.cpp
   JSONTransport.cpp
   PathMapping.cpp
+  Plugin.cpp
   Protocol.cpp
   Quality.cpp
   ParsedAST.cpp
diff --git a/clang-tools-extra/clangd/Plugin.h b/clang-tools-extra/clangd/Plugin.h
new file mode 100644
--- /dev/null
+++ b/clang-tools-extra/clangd/Plugin.h
@@ -0,0 +1,38 @@
+#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANGD_PLUGIN_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANGD_PLUGIN_H
+#include "Diagnostics.h"
+#include "support/Path.h"
+#include "clang/Basic/Diagnostic.h"
+#include "llvm/ADT/None.h"
+#include "llvm/ADT/Optional.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/Support/Registry.h"
+#include <vector>
+
+namespace clang {
+namespace clangd {
+
+/// Plugins enable augmenting clangd's behaviour in various places.
+class Plugin {
+public:
+  virtual ~Plugin() = default;
+
+  /// Identifier for the plugin, should be unique.
+  virtual llvm::StringLiteral id() = 0;
+
+  /// Returns an action that can be invoked to fix the diagnostic.
+  virtual llvm::Optional<CodeAction>
+  actOnDiagnostic(DiagnosticsEngine::Level L, const clang::Diagnostic &Diag) {
+    return llvm::None;
+  }
+
+  /// Convenience helper to collect fixes from all the plugins.
+  static std::vector<CodeAction> collectFixes(DiagnosticsEngine::Level L,
+                                              const clang::Diagnostic &Diag);
+};
+using PluginRegistry = llvm::Registry<Plugin>;
+
+} // namespace clangd
+} // namespace clang
+#endif
diff --git a/clang-tools-extra/clangd/Plugin.cpp b/clang-tools-extra/clangd/Plugin.cpp
new file mode 100644
--- /dev/null
+++ b/clang-tools-extra/clangd/Plugin.cpp
@@ -0,0 +1,24 @@
+#include "Plugin.h"
+#include "Diagnostics.h"
+#include "Protocol.h"
+#include "clang/Basic/Diagnostic.h"
+#include "llvm/Support/Registry.h"
+#include <utility>
+#include <vector>
+
+namespace clang {
+namespace clangd {
+
+std::vector<CodeAction> Plugin::collectFixes(DiagnosticsEngine::Level L,
+                                             const clang::Diagnostic &Diag) {
+  std::vector<CodeAction> Actions;
+  for (const auto &Entry : PluginRegistry::entries()) {
+    if (auto Action = Entry.instantiate()->actOnDiagnostic(L, Diag))
+      Actions.emplace_back(std::move(*Action));
+  }
+  return Actions;
+}
+} // namespace clangd
+} // namespace clang
+
+LLVM_INSTANTIATE_REGISTRY(clang::clangd::PluginRegistry);