diff --git a/infer/man/man1/infer-full.txt b/infer/man/man1/infer-full.txt
index 97ae4bed2..fff337b99 100644
--- a/infer/man/man1/infer-full.txt
+++ b/infer/man/man1/infer-full.txt
@@ -1538,6 +1538,14 @@ INTERNAL OPTIONS
            Activates: Warn when containers are used with nullable keys or
            values (Conversely: --no-nullsafe-strict-containers)
 
+       --nullsafe-third-party-signatures string
+           Path to a folder with annotated signatures of third-party methods
+           to be taken into account by nullsafe. Path is relative to
+           .inferconfig folder.
+
+       --nullsafe-third-party-signatures-reset
+           Cancel the effect of --nullsafe-third-party-signatures.
+
        --no-only-cheap-debug
            Deactivates: Disable expensive debugging output (Conversely:
            --only-cheap-debug)
diff --git a/infer/src/base/Config.ml b/infer/src/base/Config.ml
index a5f65435e..2f5a75242 100644
--- a/infer/src/base/Config.ml
+++ b/infer/src/base/Config.ml
@@ -1758,6 +1758,12 @@ and nullable_annotation =
   CLOpt.mk_string_opt ~long:"nullable-annotation-name" "Specify custom nullable annotation name"
 
 
+and nullsafe_third_party_signatures =
+  CLOpt.mk_string_opt ~long:"nullsafe-third-party-signatures"
+    "Path to a folder with annotated signatures of third-party methods to be taken into account \
+     by nullsafe. Path is relative to .inferconfig folder."
+
+
 and nullsafe_strict_containers =
   CLOpt.mk_bool ~long:"nullsafe-strict-containers" ~default:false
     "Warn when containers are used with nullable keys or values"
@@ -2516,7 +2522,7 @@ and (_ : bool ref) =
 
 (** Parse Command Line Args *)
 
-let inferconfig_file =
+let inferconfig_dir =
   let rec find dir =
     match Sys.file_exists ~follow_symlinks:false (dir ^/ CommandDoc.inferconfig_file) with
     | `Yes ->
@@ -2526,11 +2532,15 @@ let inferconfig_file =
         let is_root = String.equal dir parent in
         if is_root then None else find parent
   in
+  find (Sys.getcwd ())
+
+
+let inferconfig_file =
   match Sys.getenv CommandDoc.inferconfig_env_var with
   | Some _ as env_path ->
       env_path
   | None ->
-      find (Sys.getcwd ()) |> Option.map ~f:(fun dir -> dir ^/ CommandDoc.inferconfig_file)
+      Option.map inferconfig_dir ~f:(fun dir -> dir ^/ CommandDoc.inferconfig_file)
 
 
 let post_parsing_initialization command_opt =
@@ -2999,6 +3009,8 @@ and nelseg = !nelseg
 
 and nullable_annotation = !nullable_annotation
 
+and nullsafe_third_party_signatures = !nullsafe_third_party_signatures
+
 and nullsafe_strict_containers = !nullsafe_strict_containers
 
 and no_translate_libs = not !headers
diff --git a/infer/src/base/Config.mli b/infer/src/base/Config.mli
index 0428aa6e2..fce55ac49 100644
--- a/infer/src/base/Config.mli
+++ b/infer/src/base/Config.mli
@@ -404,6 +404,8 @@ val implicit_sdk_root : string option
 
 val inferconfig_file : string option
 
+val inferconfig_dir : string option
+
 val iphoneos_target_sdk_version : string option
 
 val iphoneos_target_sdk_version_path_regex : iphoneos_target_sdk_version_path_regex list
@@ -496,6 +498,8 @@ val nullable_annotation : string option
 
 val nullsafe : bool
 
+val nullsafe_third_party_signatures : string option
+
 val nullsafe_strict_containers : bool
 
 val oom_threshold : int option
diff --git a/infer/src/infer.ml b/infer/src/infer.ml
index 47fd86f1a..e49ae3965 100644
--- a/infer/src/infer.ml
+++ b/infer/src/infer.ml
@@ -63,6 +63,7 @@ let setup () =
   | Events ->
       ResultsDir.assert_results_dir "have you run infer before?" ) ;
   db_start () ;
+  NullsafeInit.init () ;
   if CLOpt.is_originator then ( RunState.add_run_to_sequence () ; RunState.store () ) ;
   ()
 
diff --git a/infer/src/nullsafe/NullsafeInit.ml b/infer/src/nullsafe/NullsafeInit.ml
new file mode 100644
index 000000000..ce5f01a3d
--- /dev/null
+++ b/infer/src/nullsafe/NullsafeInit.ml
@@ -0,0 +1,45 @@
+(*
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *)
+open! IStd
+
+let load_third_party_repo ~absolute_path_to_repo_dir =
+  match Sys.is_directory absolute_path_to_repo_dir with
+  | `Yes -> (
+    match ThirdPartyAnnotationInfoLoader.load ~path_to_repo_dir:absolute_path_to_repo_dir with
+    | Ok storage ->
+        storage
+    | Error error ->
+        Logging.die Logging.InternalError "Error while reading 3rd party annotation repo: %a"
+          ThirdPartyAnnotationInfoLoader.pp_load_error error )
+  | _ ->
+      Logging.die Logging.InternalError
+        "Could not locate 3rd party annotation repository: expected location %s"
+        absolute_path_to_repo_dir
+
+
+let get_absolute_path_to_repo_dir relative_path_to_repo_dir =
+  match Config.inferconfig_dir with
+  | None ->
+      Logging.die Logging.InternalError
+        "Could not locate .inferconfig directory, which is required for resolving the path to \
+         third party annotation repository"
+  | Some inferconfig_dir ->
+      inferconfig_dir ^/ relative_path_to_repo_dir
+
+
+let create_global_storage () =
+  match Config.nullsafe_third_party_signatures with
+  | Some dir ->
+      load_third_party_repo ~absolute_path_to_repo_dir:(get_absolute_path_to_repo_dir dir)
+  (* Create empty *)
+  | None ->
+      ThirdPartyAnnotationInfo.create_storage ()
+
+
+let init () =
+  let global_storage = create_global_storage () in
+  ThirdPartyAnnotationGlobalRepo.initialize global_storage
diff --git a/infer/src/nullsafe/NullsafeInit.mli b/infer/src/nullsafe/NullsafeInit.mli
new file mode 100644
index 000000000..91a1c4624
--- /dev/null
+++ b/infer/src/nullsafe/NullsafeInit.mli
@@ -0,0 +1,10 @@
+(*
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *)
+open! IStd
+
+val init : unit -> unit
+(** This function should be called once before nullsafe checker is called *)
diff --git a/infer/src/nullsafe/ThirdPartyAnnotationGlobalRepo.ml b/infer/src/nullsafe/ThirdPartyAnnotationGlobalRepo.ml
new file mode 100644
index 000000000..f2bdc5481
--- /dev/null
+++ b/infer/src/nullsafe/ThirdPartyAnnotationGlobalRepo.ml
@@ -0,0 +1,25 @@
+(*
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *)
+
+open! IStd
+
+let repo = ref None
+
+let initialize storage =
+  match !repo with
+  | None ->
+      repo := Some storage
+  | Some _ ->
+      Logging.die Logging.InternalError "Attempt to initialize global 3rd party repository twice"
+
+
+let get_repo () =
+  match !repo with
+  | None ->
+      Logging.die Logging.InternalError "Attempt to access not initialized 3rd party repository"
+  | Some repo ->
+      repo
diff --git a/infer/src/nullsafe/ThirdPartyAnnotationGlobalRepo.mli b/infer/src/nullsafe/ThirdPartyAnnotationGlobalRepo.mli
new file mode 100644
index 000000000..ed0c872a4
--- /dev/null
+++ b/infer/src/nullsafe/ThirdPartyAnnotationGlobalRepo.mli
@@ -0,0 +1,16 @@
+(*
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *)
+
+open! IStd
+
+(** A singleton. Should be initialized once prior to start of nullsafe. *)
+
+val initialize : ThirdPartyAnnotationInfo.storage -> unit
+(** Should be initialized exactly once before access. *)
+
+val get_repo : unit -> ThirdPartyAnnotationInfo.storage
+(** Can be accessed only when initialization was done *)
diff --git a/infer/src/nullsafe/ThirdPartyAnnotationInfoLoader.ml b/infer/src/nullsafe/ThirdPartyAnnotationInfoLoader.ml
new file mode 100644
index 000000000..670ae8a57
--- /dev/null
+++ b/infer/src/nullsafe/ThirdPartyAnnotationInfoLoader.ml
@@ -0,0 +1,29 @@
+(*
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *)
+open! IStd
+
+type load_error = {filename: string; parsing_error: ThirdPartyAnnotationInfo.file_parsing_error}
+
+let pp_load_error fmt {filename; parsing_error} =
+  Format.fprintf fmt "Could not parse %s: %a" filename ThirdPartyAnnotationInfo.pp_parsing_error
+    parsing_error
+
+
+let add_from_file storage ~path_to_repo_dir ~sig_file =
+  let lines = In_channel.read_lines (path_to_repo_dir ^ "/" ^ sig_file) in
+  ThirdPartyAnnotationInfo.add_from_signature_file storage ~lines
+  |> Result.map_error ~f:(fun parsing_error -> {filename= sig_file; parsing_error})
+  |> Result.bind ~f:(fun _ -> Ok storage)
+
+
+let load ~path_to_repo_dir =
+  (* Sequentally load information from all .sig files *)
+  Sys.ls_dir path_to_repo_dir
+  |> List.filter ~f:(String.is_suffix ~suffix:".sig")
+  |> List.fold_result ~init:(ThirdPartyAnnotationInfo.create_storage ())
+       ~f:(fun accumulated_storage sig_file ->
+         add_from_file accumulated_storage ~path_to_repo_dir ~sig_file )
diff --git a/infer/src/nullsafe/ThirdPartyAnnotationInfoLoader.mli b/infer/src/nullsafe/ThirdPartyAnnotationInfoLoader.mli
new file mode 100644
index 000000000..018cc08cb
--- /dev/null
+++ b/infer/src/nullsafe/ThirdPartyAnnotationInfoLoader.mli
@@ -0,0 +1,17 @@
+(*
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *)
+open! IStd
+
+type load_error
+
+val pp_load_error : Format.formatter -> load_error -> unit
+
+val load : path_to_repo_dir:string -> (ThirdPartyAnnotationInfo.storage, load_error) result
+(** Given a path to a repo with 3rd annotation info, loads it from a disk to
+    in-memory representation.
+    After this is done, information can be requested via [ThirdPartyAnnotationInfo].
+ *)
diff --git a/infer/tests/codetoanalyze/java/nullsafe-default/.inferconfig b/infer/tests/codetoanalyze/java/nullsafe-default/.inferconfig
index 9914a46a4..61cf77b67 100644
--- a/infer/tests/codetoanalyze/java/nullsafe-default/.inferconfig
+++ b/infer/tests/codetoanalyze/java/nullsafe-default/.inferconfig
@@ -2,5 +2,6 @@
   "external-java-packages": [
     "external."
   ],
-  "nullsafe-strict-containers": true
+  "nullsafe-strict-containers": true,
+  "nullsafe-third-party-signatures": "third-party-annots"
 }
diff --git a/infer/tests/codetoanalyze/java/nullsafe-default/third-party-annots/other.test.pckg.sig b/infer/tests/codetoanalyze/java/nullsafe-default/third-party-annots/other.test.pckg.sig
new file mode 100644
index 000000000..e69de29bb
diff --git a/infer/tests/codetoanalyze/java/nullsafe-default/third-party-annots/some.test.pckg.sig b/infer/tests/codetoanalyze/java/nullsafe-default/third-party-annots/some.test.pckg.sig
new file mode 100644
index 000000000..c50e04614
--- /dev/null
+++ b/infer/tests/codetoanalyze/java/nullsafe-default/third-party-annots/some.test.pckg.sig
@@ -0,0 +1,2 @@
+some.test.pckg.SomeClass#getNullable() @Nullable
+some.test.pckg.SomeClass#getNonnull()