diff --git a/.github/workflows/rust.yml b/.github/workflows/rust.yml
index 6738b0b292..20cd48ddc4 100644
--- a/.github/workflows/rust.yml
+++ b/.github/workflows/rust.yml
@@ -13,7 +13,17 @@ jobs:
 
     steps:
     - uses: actions/checkout@v2
-    - name: Build
+
+    - name: setup
+      run: |
+        rustup install nightly
+        rustup component add rustfmt --toolchain nightly
+
+    - name: fmt
+      run: cargo +nightly fmt --all -- --check
+
+    - name: build
       run: cargo build --verbose
-    - name: Run tests
+
+    - name: test
       run: cargo test --verbose
diff --git a/LICENSE_TEMPLATE b/LICENSE_TEMPLATE
index 03419d93b9..a96085a478 100644
--- a/LICENSE_TEMPLATE
+++ b/LICENSE_TEMPLATE
@@ -1,4 +1,4 @@
-// Copyright 2019 Parity Technologies (UK) Ltd.
+// Copyright 2019-2020 Parity Technologies (UK) Ltd.
 // This file is part of substrate-subxt.
 //
 // subxt is free software: you can redistribute it and/or modify
diff --git a/examples/fetch_remote.rs b/examples/fetch_remote.rs
index 8454daf3cc..64dbac1097 100644
--- a/examples/fetch_remote.rs
+++ b/examples/fetch_remote.rs
@@ -1,4 +1,4 @@
-// Copyright 2020 Parity Technologies (UK) Ltd.
+// Copyright 2019-2020 Parity Technologies (UK) Ltd.
 // This file is part of substrate-subxt.
 //
 // subxt is free software: you can redistribute it and/or modify
diff --git a/examples/kusama_balance_transfer.rs b/examples/kusama_balance_transfer.rs
index b0ea53b17c..78076b7b87 100644
--- a/examples/kusama_balance_transfer.rs
+++ b/examples/kusama_balance_transfer.rs
@@ -1,4 +1,4 @@
-// Copyright 2020 Parity Technologies (UK) Ltd.
+// Copyright 2019-2020 Parity Technologies (UK) Ltd.
 // This file is part of substrate-subxt.
 //
 // subxt is free software: you can redistribute it and/or modify
diff --git a/examples/submit_and_watch.rs b/examples/submit_and_watch.rs
index 1bc2f476cc..b587c97f00 100644
--- a/examples/submit_and_watch.rs
+++ b/examples/submit_and_watch.rs
@@ -1,4 +1,4 @@
-// Copyright 2019 Parity Technologies (UK) Ltd.
+// Copyright 2019-2020 Parity Technologies (UK) Ltd.
 // This file is part of substrate-subxt.
 //
 // subxt is free software: you can redistribute it and/or modify
diff --git a/proc-macro/src/call.rs b/proc-macro/src/call.rs
index a01b2e5444..7c44772aaf 100644
--- a/proc-macro/src/call.rs
+++ b/proc-macro/src/call.rs
@@ -1,3 +1,19 @@
+// Copyright 2019-2020 Parity Technologies (UK) Ltd.
+// This file is part of substrate-subxt.
+//
+// subxt is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// subxt is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with substrate-subxt.  If not, see <http://www.gnu.org/licenses/>.
+
 use crate::utils;
 use heck::{
     CamelCase,
diff --git a/proc-macro/src/event.rs b/proc-macro/src/event.rs
index 59f64622fd..ce0c8abb15 100644
--- a/proc-macro/src/event.rs
+++ b/proc-macro/src/event.rs
@@ -1,3 +1,19 @@
+// Copyright 2019-2020 Parity Technologies (UK) Ltd.
+// This file is part of substrate-subxt.
+//
+// subxt is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// subxt is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with substrate-subxt.  If not, see <http://www.gnu.org/licenses/>.
+
 use crate::utils;
 use heck::{
     CamelCase,
diff --git a/proc-macro/src/lib.rs b/proc-macro/src/lib.rs
index ccecbe1c62..c42006f935 100644
--- a/proc-macro/src/lib.rs
+++ b/proc-macro/src/lib.rs
@@ -1,3 +1,19 @@
+// Copyright 2019-2020 Parity Technologies (UK) Ltd.
+// This file is part of substrate-subxt.
+//
+// subxt is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// subxt is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with substrate-subxt.  If not, see <http://www.gnu.org/licenses/>.
+
 extern crate proc_macro;
 
 mod call;
diff --git a/proc-macro/src/module.rs b/proc-macro/src/module.rs
index 3327b368c4..69bee65f3a 100644
--- a/proc-macro/src/module.rs
+++ b/proc-macro/src/module.rs
@@ -1,3 +1,19 @@
+// Copyright 2019-2020 Parity Technologies (UK) Ltd.
+// This file is part of substrate-subxt.
+//
+// subxt is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// subxt is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with substrate-subxt.  If not, see <http://www.gnu.org/licenses/>.
+
 use crate::utils;
 use heck::SnakeCase;
 use proc_macro2::TokenStream;
diff --git a/proc-macro/src/store.rs b/proc-macro/src/store.rs
index 865573d0d0..d5444f5357 100644
--- a/proc-macro/src/store.rs
+++ b/proc-macro/src/store.rs
@@ -1,3 +1,19 @@
+// Copyright 2019-2020 Parity Technologies (UK) Ltd.
+// This file is part of substrate-subxt.
+//
+// subxt is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// subxt is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with substrate-subxt.  If not, see <http://www.gnu.org/licenses/>.
+
 use crate::utils;
 use heck::SnakeCase;
 use proc_macro2::{
diff --git a/proc-macro/src/test.rs b/proc-macro/src/test.rs
index 3d270587d9..b3c2886001 100644
--- a/proc-macro/src/test.rs
+++ b/proc-macro/src/test.rs
@@ -1,3 +1,19 @@
+// Copyright 2019-2020 Parity Technologies (UK) Ltd.
+// This file is part of substrate-subxt.
+//
+// subxt is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// subxt is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with substrate-subxt.  If not, see <http://www.gnu.org/licenses/>.
+
 use crate::utils;
 use proc_macro2::TokenStream;
 use quote::{
diff --git a/proc-macro/src/utils.rs b/proc-macro/src/utils.rs
index 3e3aaea6d5..b8c0ce361e 100644
--- a/proc-macro/src/utils.rs
+++ b/proc-macro/src/utils.rs
@@ -1,3 +1,19 @@
+// Copyright 2019-2020 Parity Technologies (UK) Ltd.
+// This file is part of substrate-subxt.
+//
+// subxt is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// subxt is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with substrate-subxt.  If not, see <http://www.gnu.org/licenses/>.
+
 use proc_macro2::{
     Span,
     TokenStream,
diff --git a/proc-macro/tests/balances.rs b/proc-macro/tests/balances.rs
index b5b6f0b30c..3eb3321fe1 100644
--- a/proc-macro/tests/balances.rs
+++ b/proc-macro/tests/balances.rs
@@ -1,3 +1,19 @@
+// Copyright 2019-2020 Parity Technologies (UK) Ltd.
+// This file is part of substrate-subxt.
+//
+// subxt is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// subxt is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with substrate-subxt.  If not, see <http://www.gnu.org/licenses/>.
+
 use codec::{
     Decode,
     Encode,
diff --git a/src/error.rs b/src/error.rs
index 681b2d455c..bda8fbb527 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -1,4 +1,4 @@
-// Copyright 2019 Parity Technologies (UK) Ltd.
+// Copyright 2019-2020 Parity Technologies (UK) Ltd.
 // This file is part of substrate-subxt.
 //
 // subxt is free software: you can redistribute it and/or modify
diff --git a/src/events.rs b/src/events.rs
index b170e1ec48..991b66af5b 100644
--- a/src/events.rs
+++ b/src/events.rs
@@ -1,4 +1,4 @@
-// Copyright 2019 Parity Technologies (UK) Ltd.
+// Copyright 2019-2020 Parity Technologies (UK) Ltd.
 // This file is part of substrate-subxt.
 //
 // subxt is free software: you can redistribute it and/or modify
@@ -81,7 +81,7 @@ pub enum EventsError {
 
 /// Event decoder.
 pub struct EventsDecoder<T> {
-    metadata: Metadata, // todo: [AJ] borrow?
+    metadata: Metadata,
     type_sizes: HashMap<String, usize>,
     marker: PhantomData<fn() -> T>,
 }
diff --git a/src/extrinsic.rs b/src/extrinsic.rs
index c9c53dce8e..80aad5b8bd 100644
--- a/src/extrinsic.rs
+++ b/src/extrinsic.rs
@@ -1,4 +1,4 @@
-// Copyright 2019 Parity Technologies (UK) Ltd.
+// Copyright 2019-2020 Parity Technologies (UK) Ltd.
 // This file is part of substrate-subxt.
 //
 // subxt is free software: you can redistribute it and/or modify
diff --git a/src/frame/balances.rs b/src/frame/balances.rs
index c597f20b1b..373a500491 100644
--- a/src/frame/balances.rs
+++ b/src/frame/balances.rs
@@ -1,4 +1,4 @@
-// Copyright 2019 Parity Technologies (UK) Ltd.
+// Copyright 2019-2020 Parity Technologies (UK) Ltd.
 // This file is part of substrate-subxt.
 //
 // subxt is free software: you can redistribute it and/or modify
diff --git a/src/frame/contracts.rs b/src/frame/contracts.rs
index 7060749952..e4cd4ee61d 100644
--- a/src/frame/contracts.rs
+++ b/src/frame/contracts.rs
@@ -1,4 +1,4 @@
-// Copyright 2019 Parity Technologies (UK) Ltd.
+// Copyright 2019-2020 Parity Technologies (UK) Ltd.
 // This file is part of substrate-subxt.
 //
 // subxt is free software: you can redistribute it and/or modify
diff --git a/src/frame/mod.rs b/src/frame/mod.rs
index 898031f753..3fca355ee9 100644
--- a/src/frame/mod.rs
+++ b/src/frame/mod.rs
@@ -1,4 +1,4 @@
-// Copyright 2019 Parity Technologies (UK) Ltd.
+// Copyright 2019-2020 Parity Technologies (UK) Ltd.
 // This file is part of substrate-subxt.
 //
 // subxt is free software: you can redistribute it and/or modify
diff --git a/src/frame/system.rs b/src/frame/system.rs
index d3ed9005bc..ac3282931f 100644
--- a/src/frame/system.rs
+++ b/src/frame/system.rs
@@ -1,4 +1,4 @@
-// Copyright 2019 Parity Technologies (UK) Ltd.
+// Copyright 2019-2020 Parity Technologies (UK) Ltd.
 // This file is part of substrate-subxt.
 //
 // subxt is free software: you can redistribute it and/or modify
diff --git a/src/lib.rs b/src/lib.rs
index 61cbe38512..67b521f5a4 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,4 +1,4 @@
-// Copyright 2019 Parity Technologies (UK) Ltd.
+// Copyright 2019-2020 Parity Technologies (UK) Ltd.
 // This file is part of substrate-subxt.
 //
 // subxt is free software: you can redistribute it and/or modify
diff --git a/src/metadata.rs b/src/metadata.rs
index c4dc6c4562..ae0b67bf56 100644
--- a/src/metadata.rs
+++ b/src/metadata.rs
@@ -1,4 +1,4 @@
-// Copyright 2019 Parity Technologies (UK) Ltd.
+// Copyright 2019-2020 Parity Technologies (UK) Ltd.
 // This file is part of substrate-subxt.
 //
 // subxt is free software: you can redistribute it and/or modify
diff --git a/src/rpc.rs b/src/rpc.rs
index b2d7183710..a3c0661072 100644
--- a/src/rpc.rs
+++ b/src/rpc.rs
@@ -1,4 +1,4 @@
-// Copyright 2019 Parity Technologies (UK) Ltd.
+// Copyright 2019-2020 Parity Technologies (UK) Ltd.
 // This file is part of substrate-subxt.
 //
 // subxt is free software: you can redistribute it and/or modify
@@ -129,8 +129,6 @@ impl<T: System> Rpc<T> {
         key: StorageKey,
         hash: Option<T::Hash>,
     ) -> Result<Option<V>, Error> {
-        // todo: update jsonrpsee::rpc_api! macro to accept shared Client (currently only RawClient)
-        // until then we manually construct params here and in other methods
         let params = Params::Array(vec![to_json_value(key)?, to_json_value(hash)?]);
         let data: Option<StorageData> =
             self.client.request("state_getStorage", params).await?;
diff --git a/src/runtimes.rs b/src/runtimes.rs
index 793aeef2a6..3ced7ce0b5 100644
--- a/src/runtimes.rs
+++ b/src/runtimes.rs
@@ -1,4 +1,4 @@
-// Copyright 2019 Parity Technologies (UK) Ltd.
+// Copyright 2019-2020 Parity Technologies (UK) Ltd.
 // This file is part of substrate-subxt.
 //
 // subxt is free software: you can redistribute it and/or modify