diff --git a/.github/workflows/publish.yml b/.github/workflows/publish.yml
index 4cddcb3..54e93c4 100644
--- a/.github/workflows/publish.yml
+++ b/.github/workflows/publish.yml
@@ -89,5 +89,5 @@ jobs:
       env:
         VSCE_PAT: ${{ secrets.VSCE_ACCESS_TOKEN }}
       run: |
-        make package
+        make CARGO_FLAGS=--release package
         just release ${{ steps.new_version.outputs.value }}
diff --git a/.gitignore b/.gitignore
index 9a22832..8f43650 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,6 +1,6 @@
 **/target
 **/node_modules
-**/out
+out
 yarn-error.log
 .vscode-test
 *.vsix
diff --git a/client/src/index.ts b/client/src/index.ts
index 38b6d67..9453560 100644
--- a/client/src/index.ts
+++ b/client/src/index.ts
@@ -157,6 +157,7 @@ class Extension implements Disposable {
           .getConfiguration()
           .get<string>('vscode-kanata.includesAndWorkspaces', ''),
         localKeysVariant: localKeysVariant as string,
+        format: getFormatterSettings(),
       },
     };
 
@@ -258,4 +259,26 @@ function getLocalKeysVariant(): LocalKeysVariant {
   }
 
   return localKeysVariant as LocalKeysVariant;
-}
\ No newline at end of file
+}
+
+
+interface FormatterSettings {
+  enable: boolean;
+}
+
+// Gets localkeys variant from config and when set to auto, detects it based on current OS.
+function getFormatterSettings(): FormatterSettings {
+  const formatSettings = workspace
+    .getConfiguration()
+    .get<FormatterSettings>('vscode-kanata.format');
+
+  if (formatSettings === undefined) {
+    throw new Error('should be defined')
+  }
+
+  console.log("formatSettings:", formatSettings)
+
+  return formatSettings;
+}
+
+
diff --git a/justfile b/justfile
index 6831966..cd9bfcd 100644
--- a/justfile
+++ b/justfile
@@ -4,7 +4,12 @@ _default:
 install:
     git submodule update
     make package
-    code --install-extension kanata.vsix
+    code --install-extension kanata.vsix --force
+
+install_release:
+    git submodule update
+    make CARGO_FLAGS=--release package
+    code --install-extension kanata.vsix --force
 
 # Creates a commit, that updates kanata to latest git and adds notice about it to CHANGELOG.md
 bump_kanata:
diff --git a/kls/.gitignore b/kls/.gitignore
index e69de29..1de5659 100644
--- a/kls/.gitignore
+++ b/kls/.gitignore
@@ -0,0 +1 @@
+target
\ No newline at end of file
diff --git a/kls/.vscode/extensions.json b/kls/.vscode/extensions.json
new file mode 100644
index 0000000..61ed5d4
--- /dev/null
+++ b/kls/.vscode/extensions.json
@@ -0,0 +1,5 @@
+{
+    "recommendations": [
+        "rust-lang.rust-analyzer"
+    ]
+}
\ No newline at end of file
diff --git a/kls/.vscode/settings.json b/kls/.vscode/settings.json
new file mode 100644
index 0000000..494f440
--- /dev/null
+++ b/kls/.vscode/settings.json
@@ -0,0 +1,5 @@
+{
+    // "rust-analyzer.cargo.target": "wasm32-unknown-unknown",
+    "rust-analyzer.cargo.features": "all",
+    "rust-analyzer.showUnlinkedFileNotification": false,
+}
\ No newline at end of file
diff --git a/kls/Cargo.lock b/kls/Cargo.lock
index e7b2157..b5036ae 100644
--- a/kls/Cargo.lock
+++ b/kls/Cargo.lock
@@ -4,9 +4,9 @@ version = 3
 
 [[package]]
 name = "addr2line"
-version = "0.20.0"
+version = "0.21.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f4fa78e18c64fce05e902adecd7a5eed15a5e0a3439f7b0e169f0252214865e3"
+checksum = "8a30b2e23b9e17a9f90641c7ab1549cd9b44f296d3ccbf309d2863cfe398a0cb"
 dependencies = [
  "gimli",
 ]
@@ -19,9 +19,9 @@ checksum = "f26201604c87b1e01bd3d98f8d5d9a8fcbb815e8cedb41ffccbeb4bf593a35fe"
 
 [[package]]
 name = "anyhow"
-version = "1.0.72"
+version = "1.0.79"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3b13c32d80ecc7ab747b80c3784bce54ee8a7a0cc4fbda9bf4cda2cf6fe90854"
+checksum = "080e9890a082662b09c1ad45f567faeeb47f22b5fb23895fbe1e651e718e25ca"
 
 [[package]]
 name = "arraydeque"
@@ -31,9 +31,9 @@ checksum = "f0ffd3d69bd89910509a5d31d1f1353f38ccffdd116dd0099bbd6627f7bd8ad8"
 
 [[package]]
 name = "atomic-polyfill"
-version = "0.1.11"
+version = "1.0.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e3ff7eb3f316534d83a8a2c3d1674ace8a5a71198eba31e2e2b597833f699b28"
+checksum = "8cf2bce30dfe09ef0bfaef228b9d414faaf7e563035494d7fe092dba54b300f4"
 dependencies = [
  "critical-section",
 ]
@@ -46,9 +46,9 @@ checksum = "d468802bab17cbc0cc575e9b053f41e72aa36bfa6b7f55e3529ffa43161b97fa"
 
 [[package]]
 name = "backtrace"
-version = "0.3.68"
+version = "0.3.69"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4319208da049c43661739c5fade2ba182f09d1dc2299b32298d3a31692b17e12"
+checksum = "2089b7e3f35b9dd2d0ed921ead4f6d318c27680d4a5bd167b3ee120edb105837"
 dependencies = [
  "addr2line",
  "cc",
@@ -76,27 +76,27 @@ checksum = "bef38d45163c2f1dde094a7dfd33ccf595c92905c8f8f4fdc18d06fb1037718a"
 
 [[package]]
 name = "bitflags"
-version = "2.3.3"
+version = "2.4.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "630be753d4e58660abd17930c71b647fe46c27ea6b63cc59e1e3851406972e42"
+checksum = "327762f6e5a765692301e5bb513e0d9fef63be86bbc14528052b1cd3e6f03e07"
 
 [[package]]
 name = "bumpalo"
-version = "3.13.0"
+version = "3.14.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a3e2c3daef883ecc1b5d58c15adae93470a91d425f3532ba1695849656af3fc1"
+checksum = "7f30e7476521f6f8af1a1c4c0b8cc94f0bee37d91763d0ca2665f299b6cd8aec"
 
 [[package]]
 name = "byteorder"
-version = "1.4.3"
+version = "1.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "14c189c53d098945499cdfa7ecc63567cf3886b3332b312a5b4585d8d3a6a610"
+checksum = "1fd0f2584146f6f2ef48085050886acf353beff7305ebd1ae69500e27c67f64b"
 
 [[package]]
 name = "cc"
-version = "1.0.81"
+version = "1.0.83"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6c6b2562119bf28c3439f7f02db99faf0aa1a8cdfe5772a2ee155d32227239f0"
+checksum = "f1174fb0b6ec23863f8b971027804a42614e347eafb0a95bf0b12cdae21fc4d0"
 dependencies = [
  "libc",
 ]
@@ -119,9 +119,9 @@ dependencies = [
 
 [[package]]
 name = "critical-section"
-version = "1.1.1"
+version = "1.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6548a0ad5d2549e111e1f6a11a6c2e2d00ce6a3dafe22948d67c2b443f775e52"
+checksum = "7059fff8937831a9ae6f0fe4d658ffabf58f2ca96aa9dec1c889f936f705f216"
 
 [[package]]
 name = "endian-type"
@@ -131,45 +131,28 @@ checksum = "c34f04666d835ff5d62e058c3995147c06f42fe86ff053337632bca83e42702d"
 
 [[package]]
 name = "errno"
-version = "0.3.2"
+version = "0.3.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6b30f669a7961ef1631673d2766cc92f52d64f7ef354d4fe0ddfd30ed52f0f4f"
+checksum = "a258e46cdc063eb8519c00b9fc845fc47bcfca4130e2f08e88665ceda8474245"
 dependencies = [
- "errno-dragonfly",
  "libc",
  "windows-sys",
 ]
 
-[[package]]
-name = "errno-dragonfly"
-version = "0.1.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "aa68f1b12764fab894d2755d2518754e71b4fd80ecfb822714a1206c2aab39bf"
-dependencies = [
- "cc",
- "libc",
-]
-
-[[package]]
-name = "fnv"
-version = "1.0.7"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3f9eec918d3f24069decb9af1554cad7c880e2da24a9afd88aca000531ab82c1"
-
 [[package]]
 name = "form_urlencoded"
-version = "1.2.0"
+version = "1.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a62bc1cf6f830c2ec14a513a9fb124d0a213a629668a4186f329db21fe045652"
+checksum = "e13624c2627564efccf4934284bdd98cbaa14e79b0b5a141218e507b3a823456"
 dependencies = [
  "percent-encoding",
 ]
 
 [[package]]
 name = "gimli"
-version = "0.27.3"
+version = "0.28.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b6c80984affa11d98d1b88b66ac8853f143217b399d3c74116778ff8fdb4ed2e"
+checksum = "4271d37baee1b8c7e4b708028c57d816cf9d2434acb33a549475f78c181f6253"
 
 [[package]]
 name = "hash32"
@@ -182,9 +165,9 @@ dependencies = [
 
 [[package]]
 name = "heapless"
-version = "0.7.16"
+version = "0.7.17"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "db04bc24a18b9ea980628ecf00e6c0264f3c1426dac36c00cb49b6fbad8b0743"
+checksum = "cdc6457c0eb62c71aac4bc17216026d8410337c4126773b9c5daba343f17964f"
 dependencies = [
  "atomic-polyfill",
  "hash32",
@@ -195,15 +178,15 @@ dependencies = [
 
 [[package]]
 name = "hermit-abi"
-version = "0.3.2"
+version = "0.3.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "443144c8cdadd93ebf52ddb4056d257f5b52c04d3c804e657d19eb73fc33668b"
+checksum = "d77f7ec81a6d05a3abb01ab6eb7590f6083d08449fe5a1c8b1e620283546ccb7"
 
 [[package]]
 name = "idna"
-version = "0.4.0"
+version = "0.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7d20d6b07bfbc108882d88ed8e37d39636dcc260e15e30c45e6ba089610b917c"
+checksum = "634d9b1461af396cad843f47fdba5597a4f9e6ddd4bfb6ff5d85028c25cb12f6"
 dependencies = [
  "unicode-bidi",
  "unicode-normalization",
@@ -211,9 +194,9 @@ dependencies = [
 
 [[package]]
 name = "is-terminal"
-version = "0.4.9"
+version = "0.4.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cb0889898416213fab133e1d33a0e5858a48177452750691bde3666d0fdbaf8b"
+checksum = "0bad00257d07be169d870ab665980b06cdb366d792ad690bf2e76876dc503455"
 dependencies = [
  "hermit-abi",
  "rustix",
@@ -228,15 +211,15 @@ checksum = "616cde7c720bb2bb5824a224687d8f77bfd38922027f01d825cd7453be5099fb"
 
 [[package]]
 name = "itoa"
-version = "1.0.9"
+version = "1.0.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "af150ab688ff2122fcef229be89cb50dd66af9e01a4ff320cc137eecc9bacc38"
+checksum = "b1a46d1a171d865aa5f83f92695765caa047a9b4cbae2cbf37dbd613a793fd4c"
 
 [[package]]
 name = "js-sys"
-version = "0.3.64"
+version = "0.3.66"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c5f195fe497f702db0f318b07fdd68edb16955aed830df8363d837542f8f935a"
+checksum = "cee9c64da59eae3b50095c18d3e74f8b73c0b86d2792824ff01bbce68ba229ca"
 dependencies = [
  "wasm-bindgen",
 ]
@@ -289,27 +272,26 @@ dependencies = [
  "serde-wasm-bindgen",
  "serde_json",
  "wasm-bindgen",
- "wasm-bindgen-test",
  "web-sys",
 ]
 
 [[package]]
 name = "libc"
-version = "0.2.147"
+version = "0.2.151"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b4668fb0ea861c1df094127ac5f1da3409a82116a4ba74fca2e58ef927159bb3"
+checksum = "302d7ab3130588088d277783b1e2d2e10c9e9e4a16dd9050e6ec93fb3e7048f4"
 
 [[package]]
 name = "linux-raw-sys"
-version = "0.4.5"
+version = "0.4.12"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "57bcfdad1b858c2db7c38303a6d2ad4dfaf5eb53dfeb0910128b2c26d6158503"
+checksum = "c4cd1a83af159aa67994778be9070f0ae1bd732942279cabb14f86f986a21456"
 
 [[package]]
 name = "lock_api"
-version = "0.4.10"
+version = "0.4.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c1cc9717a20b1bb222f333e6a92fd32f7d8a18ddc5a3191a11af45dcbf4dcd16"
+checksum = "3c168f8615b12bc01f9c17e2eb0cc07dcae1940121185446edc3744920e8ef45"
 dependencies = [
  "autocfg",
  "scopeguard",
@@ -317,15 +299,15 @@ dependencies = [
 
 [[package]]
 name = "log"
-version = "0.4.19"
+version = "0.4.20"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b06a4cde4c0f271a446782e3eff8de789548ce57dbc8eca9292c27f4a42004b4"
+checksum = "b5e6163cb8c49088c2c36f57875e58ccd8c87c7427f7fbd50ea6710b2f3f2e8f"
 
 [[package]]
 name = "lsp-types"
-version = "0.94.0"
+version = "0.95.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0b63735a13a1f9cd4f4835223d828ed9c2e35c8c5e61837774399f558b6a1237"
+checksum = "158c1911354ef73e8fe42da6b10c0484cb65c7f1007f28022e847706c1ab6984"
 dependencies = [
  "bitflags 1.3.2",
  "serde",
@@ -336,9 +318,9 @@ dependencies = [
 
 [[package]]
 name = "memchr"
-version = "2.5.0"
+version = "2.7.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2dffe52ecf27772e601905b7522cb4ef790d2cc203488bbd0e2fe85fcb74566d"
+checksum = "523dc4f511e55ab87b694dc30d0f820d60906ef06413f93d4d7a1385599cc149"
 
 [[package]]
 name = "miette"
@@ -392,18 +374,18 @@ dependencies = [
 
 [[package]]
 name = "object"
-version = "0.31.1"
+version = "0.32.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8bda667d9f2b5051b8833f59f3bf748b28ef54f850f4fcb389a252aa383866d1"
+checksum = "a6a622008b6e321afc04970976f62ee297fdbaa6f95318ca343e3eebb9648441"
 dependencies = [
  "memchr",
 ]
 
 [[package]]
 name = "once_cell"
-version = "1.18.0"
+version = "1.19.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dd8b5dd2ae5ed71462c540258bedcb51965123ad7e7ccf4b9a8cafaa4a63576d"
+checksum = "3fdb12b2476b595f9358c5161aa467c2438859caa136dec86c26fdd2efe17b92"
 
 [[package]]
 name = "owo-colors"
@@ -423,37 +405,37 @@ dependencies = [
 
 [[package]]
 name = "parking_lot_core"
-version = "0.9.8"
+version = "0.9.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "93f00c865fe7cabf650081affecd3871070f26767e7b2070a3ffae14c654b447"
+checksum = "4c42a9226546d68acdd9c0a280d17ce19bfe27a46bf68784e4066115788d008e"
 dependencies = [
  "cfg-if",
  "libc",
  "redox_syscall",
  "smallvec",
- "windows-targets",
+ "windows-targets 0.48.5",
 ]
 
 [[package]]
 name = "percent-encoding"
-version = "2.3.0"
+version = "2.3.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9b2a4787296e9989611394c33f193f676704af1686e70b8f8033ab5ba9a35a94"
+checksum = "e3148f5046208a5d56bcfc03053e3ca6334e51da8dfb19b6cdc8b306fae3283e"
 
 [[package]]
 name = "proc-macro2"
-version = "1.0.66"
+version = "1.0.75"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "18fb31db3f9bddb2ea821cde30a9f70117e3f119938b5ee630b7403aa6e2ead9"
+checksum = "907a61bd0f64c2f29cd1cf1dc34d05176426a3f504a78010f08416ddb7b13708"
 dependencies = [
  "unicode-ident",
 ]
 
 [[package]]
 name = "quote"
-version = "1.0.32"
+version = "1.0.35"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "50f3b39ccfb720540debaa0164757101c08ecb8d326b15358ce76a62c7e85965"
+checksum = "291ec9ab5efd934aaf503a6466c5d5251535d108ee747472c3977cc5acc868ef"
 dependencies = [
  "proc-macro2",
 ]
@@ -470,9 +452,9 @@ dependencies = [
 
 [[package]]
 name = "redox_syscall"
-version = "0.3.5"
+version = "0.4.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "567664f262709473930a4bf9e51bf2ebf3348f2e748ccc50dea20646858f8f29"
+checksum = "4722d768eff46b75989dd134e5c353f0d6296e5aaa3132e776cbdb56be7731aa"
 dependencies = [
  "bitflags 1.3.2",
 ]
@@ -500,11 +482,11 @@ dependencies = [
 
 [[package]]
 name = "rustix"
-version = "0.38.6"
+version = "0.38.28"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1ee020b1716f0a80e2ace9b03441a749e402e86712f15f16fe8a8f75afac732f"
+checksum = "72e572a5e8ca657d7366229cdde4bd14c4eb5499a9573d4d366fe1b599daa316"
 dependencies = [
- "bitflags 2.3.3",
+ "bitflags 2.4.1",
  "errno",
  "libc",
  "linux-raw-sys",
@@ -513,15 +495,9 @@ dependencies = [
 
 [[package]]
 name = "ryu"
-version = "1.0.15"
+version = "1.0.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1ad4cc8da4ef723ed60bced201181d83791ad433213d8c24efffda1eec85d741"
-
-[[package]]
-name = "scoped-tls"
-version = "1.0.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e1cf6437eb19a8f4a6cc0f7dca544973b0b78843adbfeb3683d1a94a0024a294"
+checksum = "f98d2aa92eebf49b69786be48e4477826b256916e84a57ff2a4f21923b48eb4c"
 
 [[package]]
 name = "scopeguard"
@@ -531,26 +507,25 @@ checksum = "94143f37725109f92c262ed2cf5e59bce7498c01bcc1502d7b9afe439a4e9f49"
 
 [[package]]
 name = "semver"
-version = "1.0.18"
+version = "1.0.21"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b0293b4b29daaf487284529cc2f5675b8e57c61f70167ba415a463651fd6a918"
+checksum = "b97ed7a9823b74f99c7742f5336af7be5ecd3eeafcb1507d1fa93347b1d589b0"
 
 [[package]]
 name = "serde"
-version = "1.0.181"
+version = "1.0.194"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6d3e73c93c3240c0bda063c239298e633114c69a888c3e37ca8bb33f343e9890"
+checksum = "0b114498256798c94a0689e1a15fec6005dee8ac1f41de56404b67afc2a4b773"
 dependencies = [
  "serde_derive",
 ]
 
 [[package]]
 name = "serde-wasm-bindgen"
-version = "0.3.1"
+version = "0.6.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "618365e8e586c22123d692b72a7d791d5ee697817b65a218cdf12a98870af0f7"
+checksum = "b9b713f70513ae1f8d92665bbbbda5c295c2cf1da5542881ae5eefe20c9af132"
 dependencies = [
- "fnv",
  "js-sys",
  "serde",
  "wasm-bindgen",
@@ -558,9 +533,9 @@ dependencies = [
 
 [[package]]
 name = "serde_derive"
-version = "1.0.181"
+version = "1.0.194"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "be02f6cb0cd3a5ec20bbcfbcbd749f57daddb1a0882dc2e46a6c236c90b977ed"
+checksum = "a3385e45322e8f9931410f01b3031ec534c3947d0e94c18049af4d9f9907d4e0"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -569,9 +544,9 @@ dependencies = [
 
 [[package]]
 name = "serde_json"
-version = "1.0.104"
+version = "1.0.111"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "076066c5f1078eac5b722a31827a8832fe108bed65dfa75e233c89f8206e976c"
+checksum = "176e46fa42316f18edd598015a5166857fc835ec732f5215eac6b7bdbf0a84f4"
 dependencies = [
  "itoa",
  "ryu",
@@ -580,9 +555,9 @@ dependencies = [
 
 [[package]]
 name = "serde_repr"
-version = "0.1.16"
+version = "0.1.18"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8725e1dfadb3a50f7e5ce0b1a540466f6ed3fe7a0fca2ac2b8b831d31316bd00"
+checksum = "0b2e6b945e9d3df726b65d6ee24060aff8e3533d431f677a9695db04eff9dfdb"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -591,15 +566,15 @@ dependencies = [
 
 [[package]]
 name = "smallvec"
-version = "1.11.0"
+version = "1.11.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "62bb4feee49fdd9f707ef802e22365a35de4b7b299de4763d44bfea899442ff9"
+checksum = "4dccd0940a2dcdf68d092b8cbab7dc0ad8fa938bf95787e1b916b0e3d0e8e970"
 
 [[package]]
 name = "smawk"
-version = "0.3.1"
+version = "0.3.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f67ad224767faa3c7d8b6d91985b78e70a1324408abcb1cfcc2be4c06bc06043"
+checksum = "b7c388c1b5e93756d0c740965c41e8822f866621d41acbdf6336a6a168f8840c"
 
 [[package]]
 name = "spin"
@@ -618,9 +593,9 @@ checksum = "a8f112729512f8e442d81f95a8a7ddf2b7c6b8a1a6f509a95864142b30cab2d3"
 
 [[package]]
 name = "supports-color"
-version = "2.0.0"
+version = "2.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4950e7174bffabe99455511c39707310e7e9b440364a2fcb1cc21521be57b354"
+checksum = "d6398cde53adc3c4557306a96ce67b302968513830a77a95b2b17305d9719a89"
 dependencies = [
  "is-terminal",
  "is_ci",
@@ -646,9 +621,9 @@ dependencies = [
 
 [[package]]
 name = "syn"
-version = "2.0.28"
+version = "2.0.48"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "04361975b3f5e348b2189d8dc55bc942f278b2d482a6a0365de5bdd62d351567"
+checksum = "0f3531638e407dfc0814761abb7c00a5b54992b849452a0646b7f65c9f770f3f"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -678,18 +653,18 @@ dependencies = [
 
 [[package]]
 name = "thiserror"
-version = "1.0.44"
+version = "1.0.56"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "611040a08a0439f8248d1990b111c95baa9c704c805fa1f62104b39655fd7f90"
+checksum = "d54378c645627613241d077a3a79db965db602882668f9136ac42af9ecb730ad"
 dependencies = [
  "thiserror-impl",
 ]
 
 [[package]]
 name = "thiserror-impl"
-version = "1.0.44"
+version = "1.0.56"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "090198534930841fab3a5d1bb637cde49e339654e606195f8d9c76eeb081dc96"
+checksum = "fa0faa943b50f3db30a20aa7e265dbc66076993efed8463e8de414e5d06d3471"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -713,15 +688,15 @@ checksum = "1f3ccbac311fea05f86f61904b462b55fb3df8837a366dfc601a0161d0532f20"
 
 [[package]]
 name = "unicode-bidi"
-version = "0.3.13"
+version = "0.3.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "92888ba5573ff080736b3648696b70cafad7d250551175acbaa4e0385b3e1460"
+checksum = "6f2528f27a9eb2b21e69c95319b30bd0efd85d09c379741b0f78ea1d86be2416"
 
 [[package]]
 name = "unicode-ident"
-version = "1.0.11"
+version = "1.0.12"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "301abaae475aa91687eb82514b328ab47a211a533026cb25fc3e519b86adfc3c"
+checksum = "3354b9ac3fae1ff6755cb6db53683adb661634f67557942dea4facebec0fee4b"
 
 [[package]]
 name = "unicode-linebreak"
@@ -740,15 +715,15 @@ dependencies = [
 
 [[package]]
 name = "unicode-width"
-version = "0.1.10"
+version = "0.1.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c0edd1e5b14653f783770bce4a4dabb4a5108a5370a5f5d8cfe8710c361f6c8b"
+checksum = "e51733f11c9c4f72aa0c160008246859e340b00807569a0da0e7a1079b27ba85"
 
 [[package]]
 name = "url"
-version = "2.4.0"
+version = "2.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "50bff7831e19200a85b17131d085c25d7811bc4e186efdaf54bbd132994a88cb"
+checksum = "31e6302e3bb753d46e83516cae55ae196fc0c309407cf11ab35cc51a4c2a4633"
 dependencies = [
  "form_urlencoded",
  "idna",
@@ -758,9 +733,9 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen"
-version = "0.2.87"
+version = "0.2.89"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7706a72ab36d8cb1f80ffbf0e071533974a60d0a308d01a5d0375bf60499a342"
+checksum = "0ed0d4f68a3015cc185aff4db9506a015f4b96f95303897bfa23f846db54064e"
 dependencies = [
  "cfg-if",
  "wasm-bindgen-macro",
@@ -768,9 +743,9 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-backend"
-version = "0.2.87"
+version = "0.2.89"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5ef2b6d3c510e9625e5fe6f509ab07d66a760f0885d858736483c32ed7809abd"
+checksum = "1b56f625e64f3a1084ded111c4d5f477df9f8c92df113852fa5a374dbda78826"
 dependencies = [
  "bumpalo",
  "log",
@@ -781,23 +756,11 @@ dependencies = [
  "wasm-bindgen-shared",
 ]
 
-[[package]]
-name = "wasm-bindgen-futures"
-version = "0.4.37"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c02dbc21516f9f1f04f187958890d7e6026df8d16540b7ad9492bc34a67cea03"
-dependencies = [
- "cfg-if",
- "js-sys",
- "wasm-bindgen",
- "web-sys",
-]
-
 [[package]]
 name = "wasm-bindgen-macro"
-version = "0.2.87"
+version = "0.2.89"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dee495e55982a3bd48105a7b947fd2a9b4a8ae3010041b9e0faab3f9cd028f1d"
+checksum = "0162dbf37223cd2afce98f3d0785506dcb8d266223983e4b5b525859e6e182b2"
 dependencies = [
  "quote",
  "wasm-bindgen-macro-support",
@@ -805,9 +768,9 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-macro-support"
-version = "0.2.87"
+version = "0.2.89"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "54681b18a46765f095758388f2d0cf16eb8d4169b639ab575a8f5693af210c7b"
+checksum = "f0eb82fcb7930ae6219a7ecfd55b217f5f0893484b7a13022ebb2b2bf20b5283"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -818,39 +781,15 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-shared"
-version = "0.2.87"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ca6ad05a4870b2bf5fe995117d3728437bd27d7cd5f06f13c17443ef369775a1"
-
-[[package]]
-name = "wasm-bindgen-test"
-version = "0.3.37"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6e6e302a7ea94f83a6d09e78e7dc7d9ca7b186bc2829c24a22d0753efd680671"
-dependencies = [
- "console_error_panic_hook",
- "js-sys",
- "scoped-tls",
- "wasm-bindgen",
- "wasm-bindgen-futures",
- "wasm-bindgen-test-macro",
-]
-
-[[package]]
-name = "wasm-bindgen-test-macro"
-version = "0.3.37"
+version = "0.2.89"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ecb993dd8c836930ed130e020e77d9b2e65dd0fbab1b67c790b0f5d80b11a575"
-dependencies = [
- "proc-macro2",
- "quote",
-]
+checksum = "7ab9b36309365056cd639da3134bf87fa8f3d86008abf99e612384a6eecd459f"
 
 [[package]]
 name = "web-sys"
-version = "0.3.64"
+version = "0.3.66"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9b85cbef8c220a6abc02aefd892dfc0fc23afb1c6a426316ec33253a3877249b"
+checksum = "50c24a44ec86bb68fbecd1b3efed7e85ea5621b39b35ef2766b66cd984f8010f"
 dependencies = [
  "js-sys",
  "wasm-bindgen",
@@ -880,66 +819,123 @@ checksum = "712e227841d057c1ee1cd2fb22fa7e5a5461ae8e48fa2ca79ec42cfc1931183f"
 
 [[package]]
 name = "windows-sys"
-version = "0.48.0"
+version = "0.52.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "282be5f36a8ce781fad8c8ae18fa3f9beff57ec1b52cb3de0789201425d9a33d"
+dependencies = [
+ "windows-targets 0.52.0",
+]
+
+[[package]]
+name = "windows-targets"
+version = "0.48.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "677d2418bec65e3338edb076e806bc1ec15693c5d0104683f2efe857f61056a9"
+checksum = "9a2fa6e2155d7247be68c096456083145c183cbbbc2764150dda45a87197940c"
 dependencies = [
- "windows-targets",
+ "windows_aarch64_gnullvm 0.48.5",
+ "windows_aarch64_msvc 0.48.5",
+ "windows_i686_gnu 0.48.5",
+ "windows_i686_msvc 0.48.5",
+ "windows_x86_64_gnu 0.48.5",
+ "windows_x86_64_gnullvm 0.48.5",
+ "windows_x86_64_msvc 0.48.5",
 ]
 
 [[package]]
 name = "windows-targets"
-version = "0.48.1"
+version = "0.52.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "05d4b17490f70499f20b9e791dcf6a299785ce8af4d709018206dc5b4953e95f"
+checksum = "8a18201040b24831fbb9e4eb208f8892e1f50a37feb53cc7ff887feb8f50e7cd"
 dependencies = [
- "windows_aarch64_gnullvm",
- "windows_aarch64_msvc",
- "windows_i686_gnu",
- "windows_i686_msvc",
- "windows_x86_64_gnu",
- "windows_x86_64_gnullvm",
- "windows_x86_64_msvc",
+ "windows_aarch64_gnullvm 0.52.0",
+ "windows_aarch64_msvc 0.52.0",
+ "windows_i686_gnu 0.52.0",
+ "windows_i686_msvc 0.52.0",
+ "windows_x86_64_gnu 0.52.0",
+ "windows_x86_64_gnullvm 0.52.0",
+ "windows_x86_64_msvc 0.52.0",
 ]
 
 [[package]]
 name = "windows_aarch64_gnullvm"
-version = "0.48.0"
+version = "0.48.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2b38e32f0abccf9987a4e3079dfb67dcd799fb61361e53e2882c3cbaf0d905d8"
+
+[[package]]
+name = "windows_aarch64_gnullvm"
+version = "0.52.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cb7764e35d4db8a7921e09562a0304bf2f93e0a51bfccee0bd0bb0b666b015ea"
+
+[[package]]
+name = "windows_aarch64_msvc"
+version = "0.48.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "91ae572e1b79dba883e0d315474df7305d12f569b400fcf90581b06062f7e1bc"
+checksum = "dc35310971f3b2dbbf3f0690a219f40e2d9afcf64f9ab7cc1be722937c26b4bc"
 
 [[package]]
 name = "windows_aarch64_msvc"
-version = "0.48.0"
+version = "0.52.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bbaa0368d4f1d2aaefc55b6fcfee13f41544ddf36801e793edbbfd7d7df075ef"
+
+[[package]]
+name = "windows_i686_gnu"
+version = "0.48.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b2ef27e0d7bdfcfc7b868b317c1d32c641a6fe4629c171b8928c7b08d98d7cf3"
+checksum = "a75915e7def60c94dcef72200b9a8e58e5091744960da64ec734a6c6e9b3743e"
 
 [[package]]
 name = "windows_i686_gnu"
-version = "0.48.0"
+version = "0.52.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "622a1962a7db830d6fd0a69683c80a18fda201879f0f447f065a3b7467daa241"
+checksum = "a28637cb1fa3560a16915793afb20081aba2c92ee8af57b4d5f28e4b3e7df313"
 
 [[package]]
 name = "windows_i686_msvc"
-version = "0.48.0"
+version = "0.48.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8f55c233f70c4b27f66c523580f78f1004e8b5a8b659e05a4eb49d4166cca406"
+
+[[package]]
+name = "windows_i686_msvc"
+version = "0.52.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ffe5e8e31046ce6230cc7215707b816e339ff4d4d67c65dffa206fd0f7aa7b9a"
+
+[[package]]
+name = "windows_x86_64_gnu"
+version = "0.48.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4542c6e364ce21bf45d69fdd2a8e455fa38d316158cfd43b3ac1c5b1b19f8e00"
+checksum = "53d40abd2583d23e4718fddf1ebec84dbff8381c07cae67ff7768bbf19c6718e"
 
 [[package]]
 name = "windows_x86_64_gnu"
-version = "0.48.0"
+version = "0.52.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ca2b8a661f7628cbd23440e50b05d705db3686f894fc9580820623656af974b1"
+checksum = "3d6fa32db2bc4a2f5abeacf2b69f7992cd09dca97498da74a151a3132c26befd"
 
 [[package]]
 name = "windows_x86_64_gnullvm"
-version = "0.48.0"
+version = "0.48.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0b7b52767868a23d5bab768e390dc5f5c55825b6d30b86c844ff2dc7414044cc"
+
+[[package]]
+name = "windows_x86_64_gnullvm"
+version = "0.52.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1a657e1e9d3f514745a572a6846d3c7aa7dbe1658c056ed9c3344c4109a6949e"
+
+[[package]]
+name = "windows_x86_64_msvc"
+version = "0.48.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7896dbc1f41e08872e9d5e8f8baa8fdd2677f29468c4e156210174edc7f7b953"
+checksum = "ed94fce61571a4006852b7389a063ab983c02eb1bb37b47f8272ce92d06d9538"
 
 [[package]]
 name = "windows_x86_64_msvc"
-version = "0.48.0"
+version = "0.52.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1a515f5799fe4961cb532f983ce2b23082366b898e52ffbce459c86f67c8378a"
+checksum = "dff9641d1cd4be8d1a070daf9e3773c5f67e78b4d9d42263020c057706765c04"
diff --git a/kls/Cargo.toml b/kls/Cargo.toml
index 2ac0944..342dd0c 100644
--- a/kls/Cargo.toml
+++ b/kls/Cargo.toml
@@ -16,18 +16,18 @@ crate-type = ["cdylib"]
 bench = false
 
 [dependencies]
-kanata-parser = { path = "../kanata/parser", features = ["cmd"]}
+kanata-parser = { path = "../kanata-local/parser", features = ["cmd"]}
 
-console_error_panic_hook = "0.1.6"
+console_error_panic_hook = "0.1.7"
 js-sys = "0.3.53"
-lsp-types = "0.94.0"
-serde = { version = "1.0", features = ["derive"] }
-serde-wasm-bindgen = "0.3.1"
-wasm-bindgen = "0.2.76"
+lsp-types = "0.95.0"
+serde = { version = "^1.0.194", features = ["derive"] }
+serde-wasm-bindgen = "0.6.3"
+wasm-bindgen = "0.2.88"
 web-sys = { version = "0.3.64", features = ["console"] }
-rustc-hash = "1.1.0"
-anyhow = "1.0.72"
-serde_json = "1.0.104"
+rustc-hash = "^1.1.0"
+anyhow = "^1.0.72"
+serde_json = "^1.0.104"
 
 [dev-dependencies]
-wasm-bindgen-test = "0.3.26"
+# wasm-bindgen-test = "0.3.39"
diff --git a/kls/justfile b/kls/justfile
new file mode 100644
index 0000000..e4985af
--- /dev/null
+++ b/kls/justfile
@@ -0,0 +1,5 @@
+# default:
+#     @just --list
+
+test:
+    cargo test
diff --git a/kls/src/formatter/ext_tree.rs b/kls/src/formatter/ext_tree.rs
new file mode 100644
index 0000000..d10654f
--- /dev/null
+++ b/kls/src/formatter/ext_tree.rs
@@ -0,0 +1,415 @@
+use kanata_parser::cfg::{
+    sexpr::{self, Position, SExpr, SExprMetaData, Span, Spanned},
+    ParseError,
+};
+use std::{borrow::BorrowMut, fmt::Display};
+
+/// Extended Parse Tree.
+/// Let's represent the whole config as a [`ParseTreeNode`].
+/// Root node should be [`ParseTreeNode::List`] containing other top level items.
+/// While [`sexpr::parse_`] can only return [`ParseTreeNode::List`]s as top-level items,
+/// this doesn't change anything in regard to how we use this struct later.
+#[derive(PartialEq, Eq, Debug)]
+pub struct ExtParseTree(pub ParseTreeNode);
+
+#[derive(PartialEq, Eq, Debug)]
+pub enum ParseTreeNode {
+    List(Vec<ParseTreeNode>),
+
+    Atom(String),
+    LineComment(String),
+    BlockComment(String),
+    Whitespace(String),
+}
+
+/// Parses config from text and combines both [`SExpr`] and [`SExprMetaData`] into [`ExtParseTree`].
+pub fn parse_into_ext_tree(src: &str) -> std::result::Result<ExtParseTree, ParseError> {
+    parse_into_ext_tree_and_root_span(src).map(|(x1, _)| x1)
+}
+
+/// Compared to [`kanata_parser::cfg::sexpr::Span`], this struct uses `&'a str`
+/// for `file_content` and String for `file_name` instead of using
+/// [`alloc::rc::Rc<str>`] for both.
+#[derive(Clone)]
+pub struct CustomSpan<'a> {
+    pub start: Position,
+    pub end: Position,
+    pub file_name: String,
+    pub file_content: &'a str,
+}
+
+impl<'a> From<CustomSpan<'a>> for Span {
+    fn from(val: CustomSpan<'a>) -> Self {
+        Span {
+            start: val.start,
+            end: val.end,
+            file_name: val.file_name.into(),
+            file_content: val.file_content.into(),
+        }
+    }
+}
+
+pub fn parse_into_ext_tree_and_root_span(
+    src: &str,
+) -> std::result::Result<(ExtParseTree, CustomSpan<'_>), ParseError> {
+    let filename = "";
+    let (exprs, exprs_ext) = sexpr::parse_(src, filename, false)?;
+    let exprs: Vec<SExpr> = exprs.into_iter().map(SExpr::List).collect();
+    let position_end = exprs.last().map(|x| x.span().end).unwrap_or_default();
+    let root_span = CustomSpan {
+        start: Position::default(),
+        end: position_end,
+        file_name: filename.to_string(),
+        file_content: src,
+    };
+    let exprs = {
+        let mut r = SExpr::List(Spanned::new(
+            Vec::with_capacity(exprs.len()),
+            root_span.clone().into(),
+        ));
+        for x in exprs {
+            if let SExpr::List(Spanned { t, .. }) = &mut r {
+                t.push(x)
+            }
+        }
+        r
+    };
+    let exprs: SExprCustom = SExprCustom(exprs);
+    // crate::log!("sexprs: {:?}", sexprs);
+
+    let mut metadata_iter = exprs_ext.into_iter().peekable();
+    let mut tree: ExtParseTree = ExtParseTree(ParseTreeNode::List(vec![]));
+    let mut tree_depth: u8 = 0; // currentdepth of the list we're currently appending to in `tree`.
+    let mut expr_path: Vec<usize> = vec![0]; // path to the current item in `exprs` tree.
+    loop {
+        match exprs.get_node(&expr_path) {
+            Some(expr) => {
+                while let Some(metadata) =
+                    metadata_iter.next_if(|m| m.span().start() < expr.span().start())
+                {
+                    tree.append(
+                        tree_depth,
+                        match metadata {
+                            SExprMetaData::LineComment(m) => ParseTreeNode::LineComment(m.t),
+                            SExprMetaData::BlockComment(m) => ParseTreeNode::BlockComment(m.t),
+                            SExprMetaData::Whitespace(m) => ParseTreeNode::Whitespace(m.t),
+                        },
+                    )
+                }
+
+                match expr {
+                    SExpr::Atom(x) => {
+                        tree.append(tree_depth, ParseTreeNode::Atom(x.t.clone()));
+                        match expr_path.last_mut() {
+                            Some(i) => *i += 1,
+                            None => unreachable!(),
+                        };
+                    }
+                    SExpr::List(_) => {
+                        tree.append(tree_depth, ParseTreeNode::List(vec![]));
+                        tree_depth += 1;
+                        expr_path.push(0);
+                    }
+                }
+            }
+            None => {
+                // Reached the end of the list.
+                expr_path.pop();
+
+                // Get the absolute position of the closing paren, and push all leftover metadata
+                // that's located before it.
+                let expr = exprs
+                    .get_node(&expr_path)
+                    .expect("should exist, we just iterated over it");
+                while let Some(metadata) =
+                    metadata_iter.next_if(|m| m.span().start() < expr.span().end())
+                {
+                    tree.append(
+                        tree_depth,
+                        match metadata {
+                            SExprMetaData::LineComment(m) => ParseTreeNode::LineComment(m.t),
+                            SExprMetaData::BlockComment(m) => ParseTreeNode::BlockComment(m.t),
+                            SExprMetaData::Whitespace(m) => ParseTreeNode::Whitespace(m.t),
+                        },
+                    )
+                }
+
+                match expr_path.last_mut() {
+                    Some(i) => *i += 1,
+                    None => break,
+                };
+                tree_depth -= 1;
+            }
+        };
+    }
+
+    // Add remaining metadata.
+    for metadata in metadata_iter {
+        tree.append(
+            tree_depth,
+            match metadata {
+                SExprMetaData::LineComment(m) => ParseTreeNode::LineComment(m.t),
+                SExprMetaData::BlockComment(m) => ParseTreeNode::BlockComment(m.t),
+                SExprMetaData::Whitespace(m) => ParseTreeNode::Whitespace(m.t),
+            },
+        )
+    }
+
+    Ok((tree, root_span))
+}
+
+impl ParseTreeNode {
+    /// If any step on path is not List, panic.
+    /// If any step is out-of-bounds, return None.
+    pub fn get_node(&self, at_path: &[usize]) -> Option<&ParseTreeNode> {
+        let mut head: &ParseTreeNode = self;
+        for i in at_path {
+            if let ParseTreeNode::List(l) = head {
+                head = match &l.get(*i) {
+                    Some(x) => x,
+                    None => return None,
+                };
+            } else {
+                panic!("invalid tree path")
+            }
+        }
+        Some(head)
+    }
+}
+
+impl ExtParseTree {
+    /// Appends `node` to the last node at given `depth`, which is expected
+    /// to be a list (otherwise panics).
+    fn append(&mut self, depth: u8, node: ParseTreeNode) {
+        let mut head: &mut ParseTreeNode = self.0.borrow_mut();
+        for _ in 0..depth {
+            if let ParseTreeNode::List(li) = head {
+                head = li.last_mut().expect("path is valid");
+            } else {
+                panic!("unexpected non-list item")
+            }
+        }
+        if let ParseTreeNode::List(ref mut l) = head {
+            l.push(node);
+        } else {
+            panic!("unexpected non-list item");
+        }
+    }
+
+    /// If any step on path is not List, panic.
+    /// If any step is out-of-bounds, return None.
+    pub fn get_node(&self, at_path: &[usize]) -> Option<&ParseTreeNode> {
+        return self.0.get_node(at_path);
+    }
+}
+
+struct SExprCustom(SExpr);
+
+impl<'a> SExprCustom {
+    /// If any step on path is not List, panic.
+    /// If any step is out-of-bounds, return None.
+    fn get_node(&'a self, at_path: &[usize]) -> Option<&'a SExpr> {
+        let mut head: &SExpr = &self.0; // is it ok to do this?
+        for i in at_path {
+            if let SExpr::List(Spanned { t, .. }) = head {
+                head = match &t.get(*i) {
+                    Some(x) => x,
+                    None => return None,
+                };
+            } else {
+                panic!("invalid tree path")
+            }
+        }
+        Some(head)
+    }
+}
+
+impl Display for ExtParseTree {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        if let ParseTreeNode::List(l) = &self.0 {
+            for expr in l {
+                write!(f, "{}", expr)?;
+            }
+        } else {
+            // root node must be a list.
+            return Err(std::fmt::Error);
+        }
+        Ok(())
+    }
+}
+
+impl Display for ParseTreeNode {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            ParseTreeNode::List(l) => {
+                write!(f, "(")?;
+                for expr in l {
+                    write!(f, "{}", expr)?;
+                }
+                write!(f, ")")?;
+            }
+            ParseTreeNode::Atom(x)
+            | ParseTreeNode::LineComment(x)
+            | ParseTreeNode::BlockComment(x)
+            | ParseTreeNode::Whitespace(x) => {
+                write!(f, "{}", x)?;
+            }
+        }
+        Ok(())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::log;
+
+    macro_rules! Tree {
+        ($($element:expr),*) => {{
+            ExtParseTree(ParseTreeNode::List(vec![$($element),*]))
+        }};
+    }
+
+    macro_rules! Atom {
+        ($text:expr) => {
+            ParseTreeNode::Atom($text.to_string())
+        };
+    }
+
+    macro_rules! LineComment {
+        ($text:expr) => {
+            ParseTreeNode::LineComment($text.to_string())
+        };
+    }
+
+    macro_rules! BlockComment {
+        ($text:expr) => {
+            ParseTreeNode::BlockComment($text.to_string())
+        };
+    }
+
+    macro_rules! Whitespace {
+        ($text:expr) => {
+            ParseTreeNode::Whitespace($text.to_string())
+        };
+    }
+
+    macro_rules! List {
+        ($($element:expr),*) => {{
+            ParseTreeNode::List(vec![$($element),*])
+        }};
+    }
+
+    #[test]
+    fn test_macros() {
+        use ParseTreeNode::*;
+        assert_eq!(Tree!(), ExtParseTree(List(vec![])));
+        assert_eq!(Tree!(List!()), ExtParseTree(List(vec![List(vec![])])));
+        assert_eq!(
+            Tree!(
+                Atom!("test"),
+                Whitespace!(" "),
+                LineComment!("# test"),
+                BlockComment!("#| test |#")
+            ),
+            ExtParseTree(List(vec![
+                Atom("test".to_string()),
+                Whitespace(" ".to_string()),
+                LineComment("# test".to_string()),
+                BlockComment("#| test |#".to_string())
+            ]))
+        );
+    }
+
+    #[test]
+    fn test_parse_into_ext_tree() {
+        let s = "";
+        assert_eq!(parse_into_ext_tree(s).expect("parses"), Tree!());
+
+        #[rustfmt::skip]
+        let cases = vec![
+            (
+                "",
+                Tree!()
+            ),
+            (
+                "()",
+                Tree!(List!())
+            ),
+            (
+                "(atom)",
+                Tree!(List!(Atom!("atom")))
+            ),
+            (
+                "( test)(1 \n\t 2)",
+                Tree!(
+                    List!(
+                        Whitespace!(" "),
+                        Atom!("test")
+                    ),
+                    List!(
+                        Atom!("1"),
+                        Whitespace!(" \n\t "),
+                        Atom!("2")
+                    )
+                )
+            ),
+            (
+                " \n\t \n",
+                Tree!(Whitespace!(" \n\t \n"))
+            ),
+            (
+                "(1 2 #|block|# 3)",
+                Tree!(
+                    List!(
+                        Atom!("1"),
+                        Whitespace!(" "),
+                        Atom!("2"),
+                        Whitespace!(" "),
+                        BlockComment!("#|block|#"),
+                        Whitespace!(" "),
+                        Atom!("3")
+                    )
+                )
+            ),
+            (
+                "(1\n)",
+                Tree!(
+                    List!(
+                        Atom!("1"),
+                        Whitespace!("\n")
+                    )
+                )
+            ),
+            (
+                "\n(1\n) \n ;; comment \n\t (2) ",
+                Tree!(
+                    Whitespace!("\n"),
+                    List!(
+                        Atom!("1"),
+                        Whitespace!("\n")
+                    ),
+                    Whitespace!(" \n "),
+                    LineComment!(";; comment \n"),
+                    Whitespace!("\t "),
+                    List!(
+                        Atom!("2")
+                    ),
+                    Whitespace!(" ")
+                )
+            ),
+        ];
+        for (case, expected_result) in cases {
+            log!("===========================");
+            let actual_result = parse_into_ext_tree(case).expect("parses");
+            log!("actual: {:#?}", actual_result);
+            log!("expected: {:#?}", expected_result);
+            assert_eq!(actual_result, expected_result, "parse_into_ext_tree(case)");
+            assert_eq!(
+                actual_result.to_string(),
+                case,
+                "<ExtParseTree>.to_string()"
+            );
+        }
+    }
+}
diff --git a/kls/src/formatter/mod.rs b/kls/src/formatter/mod.rs
new file mode 100644
index 0000000..bcb0d60
--- /dev/null
+++ b/kls/src/formatter/mod.rs
@@ -0,0 +1,42 @@
+use crate::log;
+use kanata_parser::cfg::{
+    sexpr::{self, Position, SExpr, SExprMetaData, Span, Spanned},
+    ParseError,
+};
+use std::{borrow::BorrowMut, collections::HashMap};
+use wasm_bindgen::prelude::*;
+
+pub mod ext_tree;
+use ext_tree::*;
+
+mod remove_excessive_newlines;
+
+pub struct Formatter {
+    // Additional options
+    pub extension_options: crate::ExtensionFormatterOptions,
+
+    pub remove_extra_empty_lines: bool,
+}
+
+impl Formatter {
+    /// Transforms [`ExtParseTree`] to another [`ExtParseTree`] in-place,
+    /// applying selected formatting funtions depending on [`FormatterOptions`].
+    pub fn format(&self, tree: &mut ExtParseTree) {
+        if !self.extension_options.enable {
+            return;
+        }
+        if self.remove_extra_empty_lines {
+            tree.0.remove_excessive_adjacent_newlines(2);
+        }
+    }
+
+    // VSCode normally sends formatting options along with
+    // every textDocument/formatting request.
+    pub fn format_with_options(
+        &self,
+        tree: &mut ExtParseTree,
+        _options: &lsp_types::FormattingOptions, // todo: we should probably handle these options
+    ) {
+        self.format(tree)
+    }
+}
diff --git a/kls/src/formatter/remove_excessive_newlines.rs b/kls/src/formatter/remove_excessive_newlines.rs
new file mode 100644
index 0000000..ee5256f
--- /dev/null
+++ b/kls/src/formatter/remove_excessive_newlines.rs
@@ -0,0 +1,99 @@
+use std::borrow::BorrowMut;
+
+use super::ext_tree::*;
+
+impl ParseTreeNode {
+    /// Removes excessive adjacent newlines after `max` number of newlines.
+    /// Depends on whitespace removal at ends of lines to work correctly.
+    /// Otherwise it might look like it didn't remove some excessive newlines.
+    pub fn remove_excessive_adjacent_newlines(&mut self, max: usize) {
+        match self.borrow_mut() {
+            ParseTreeNode::List(list) => {
+                for node in list {
+                    node.remove_excessive_adjacent_newlines(max);
+                }
+            }
+            ParseTreeNode::Whitespace(x) => loop {
+                let mut consecutive_newlines: usize = 0;
+                let mut replace_at_index: Option<usize> = None;
+                for (i, char) in x.chars().enumerate() {
+                    if char == '\n' {
+                        consecutive_newlines += 1;
+
+                        if consecutive_newlines > max {
+                            replace_at_index = Some(i);
+                        }
+                    } else {
+                        if consecutive_newlines > max {
+                            break;
+                        }
+                        consecutive_newlines = 0;
+                    }
+                }
+                if let Some(i) = replace_at_index {
+                    let newlines_to_remove = consecutive_newlines - max;
+                    x.drain((i + 1 - newlines_to_remove)..(i + 1));
+                    continue;
+                }
+                break;
+            },
+            _ => {}
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::log;
+
+    use super::*;
+
+    #[test]
+    fn test_remove_above_2_adjacent_newlines() {
+        #[rustfmt::skip]
+        let cases = vec![
+            (
+                1,
+                "(1 \n\n\n 2)",
+                "(1 \n 2)"
+            ),
+            (
+                0,
+                "(1 \n\n\n 2)",
+                "(1  2)"
+            ),
+            (
+                1,
+                "\n\n\n\n",
+                "\n"
+            ),
+            (
+                0,
+                "\n\n\n\n",
+                ""
+            ),
+            (
+                3,
+                "\n\n\n\n\n",
+                "\n\n\n"
+            ),
+            (
+                3,
+                "\n\n\n\n\n \n\n\n\n \n\n",
+                "\n\n\n \n\n\n \n\n"
+            ),
+            (
+                2,
+                "(\n(\n\n\n (1\n \n\n\n\n ))\n)\n \n(\n\n\n 2\n)\n",
+                "(\n(\n\n (1\n \n\n ))\n)\n \n(\n\n 2\n)\n",
+            ),
+        ];
+        for (max, case, expected_result) in cases {
+            log!("==============");
+            log!("max: {:?}", max);
+            let mut tree = parse_into_ext_tree(case).expect("parses");
+            tree.0.remove_excessive_adjacent_newlines(max);
+            assert_eq!(tree.to_string(), expected_result);
+        }
+    }
+}
diff --git a/kls/src/helpers.rs b/kls/src/helpers.rs
index 0ba809b..d363a4b 100644
--- a/kls/src/helpers.rs
+++ b/kls/src/helpers.rs
@@ -1,7 +1,5 @@
 use std::{collections::BTreeMap, path::Path, rc::Rc};
 
-use wasm_bindgen::JsValue;
-
 use kanata_parser::cfg::{sexpr::Span, FileContentProvider, ParseError};
 use lsp_types::{PublishDiagnosticsParams, TextDocumentItem, Url};
 
@@ -10,13 +8,22 @@ pub type HashSet<T> = rustc_hash::FxHashSet<T>;
 pub type Documents = BTreeMap<Url, TextDocumentItem>;
 pub type Diagnostics = BTreeMap<Url, PublishDiagnosticsParams>;
 
+#[cfg(target_os = "unknown")]
 #[macro_export]
 macro_rules! log {
     ($string:expr) => {
-        web_sys::console::log_1(&JsValue::from($string))
+        web_sys::console::log_1(&wasm_bindgen::JsValue::from($string))
+    };
+    ($($tokens:tt)*) => {
+        web_sys::console::log_1(&wasm_bindgen::JsValue::from(format!($($tokens)*)))
     };
+}
+
+#[cfg(not(target_os = "unknown"))]
+#[macro_export]
+macro_rules! log {
     ($($tokens:tt)*) => {
-        web_sys::console::log_1(&JsValue::from(format!($($tokens)*)))
+        println!($($tokens)*)
     };
 }
 
@@ -32,8 +39,8 @@ pub fn utf16_length(str: impl AsRef<str>) -> usize {
     utf16_encoded.len()
 }
 
-pub fn slice_rc_str(rc_str: &Rc<str>, start: usize, end: usize) -> String {
-    rc_str[start..end].to_string()
+pub fn slice_rc_str(rc_str: &Rc<str>, start: usize, end: usize) -> &str {
+    &rc_str[start..end]
 }
 
 #[derive(Debug, Clone)]
@@ -48,7 +55,7 @@ impl CustomParseError {
     pub fn from_parse_error(e: ParseError, main_cfg_file: &str) -> Self {
         Self {
             msg: e.msg,
-            span: e.span.unwrap_or_else(|| kanata_parser::cfg::sexpr::Span {
+            span: e.span.unwrap_or_else(|| Span {
                 file_name: main_cfg_file.into(),
                 ..Default::default()
             }),
@@ -56,30 +63,28 @@ impl CustomParseError {
     }
 }
 
-impl From<&CustomParseError> for lsp_types::Range {
-    fn from(val: &CustomParseError) -> Self {
-        lsp_types::Range {
-            start: lsp_types::Position::new(
-                val.span.start.line.try_into().unwrap(),
-                utf16_length(slice_rc_str(
-                    &val.span.file_content,
-                    val.span.start.line_beginning,
-                    val.span.start.absolute,
-                ))
-                .try_into()
-                .unwrap(),
-            ),
-            end: lsp_types::Position::new(
-                val.span.end.line.try_into().unwrap(),
-                utf16_length(slice_rc_str(
-                    &val.span.file_content,
-                    val.span.end.line_beginning,
-                    val.span.end.absolute,
-                ))
-                .try_into()
-                .unwrap(),
-            ),
-        }
+pub fn lsp_range_from_span(span: &Span) -> lsp_types::Range {
+    lsp_types::Range {
+        start: lsp_types::Position::new(
+            span.start.line.try_into().unwrap(),
+            utf16_length(slice_rc_str(
+                &span.file_content,
+                span.start.line_beginning,
+                span.start.absolute,
+            ))
+            .try_into()
+            .unwrap(),
+        ),
+        end: lsp_types::Position::new(
+            span.end.line.try_into().unwrap(),
+            utf16_length(slice_rc_str(
+                &span.file_content,
+                span.end.line_beginning,
+                span.end.absolute,
+            ))
+            .try_into()
+            .unwrap(),
+        ),
     }
 }
 
diff --git a/kls/src/lib.rs b/kls/src/lib.rs
index ffae9bf..e4f01de 100644
--- a/kls/src/lib.rs
+++ b/kls/src/lib.rs
@@ -1,29 +1,33 @@
-use std::{
-    collections::BTreeMap,
-    fmt::Display,
-    path::{self, Path, PathBuf},
-    str::{FromStr, Split},
-};
-
+use crate::helpers::{lsp_range_from_span, HashSet};
 use anyhow::{anyhow, bail};
+use formatter::Formatter;
+use kanata_parser::cfg::{FileContentProvider, ParseError};
 use lsp_types::{
     notification::{
         DidChangeTextDocument, DidChangeWatchedFiles, DidCloseTextDocument, DidDeleteFiles,
         DidOpenTextDocument, DidSaveTextDocument, Initialized, Notification,
     },
+    request::{Formatting, Request},
     DeleteFilesParams, Diagnostic, DiagnosticSeverity, DidChangeTextDocumentParams,
     DidChangeWatchedFilesParams, DidOpenTextDocumentParams, DidSaveTextDocumentParams,
     FileChangeType, FileDelete, FileEvent, InitializeParams, PublishDiagnosticsParams,
-    TextDocumentItem, Url, VersionedTextDocumentIdentifier,
+    TextDocumentItem, TextEdit, Url, VersionedTextDocumentIdentifier,
 };
+use serde::Deserialize;
 use serde_wasm_bindgen::{from_value, to_value};
+use std::{
+    collections::BTreeMap,
+    fmt::Display,
+    path::{self, Path, PathBuf},
+    str::{FromStr, Split},
+};
 use wasm_bindgen::prelude::*;
 
-use kanata_parser::cfg::{FileContentProvider, ParseError};
-
 mod helpers;
 use helpers::{empty_diagnostics_for_doc, parse_wrapper, CustomParseError, Diagnostics, Documents};
 
+mod formatter;
+
 struct Kanata {
     def_local_keys_variant_to_apply: String,
 }
@@ -39,14 +43,17 @@ const KANATA_PARSER_HELP: &str = r"For more info, see the configuration guide or
 
 impl Kanata {
     fn new(def_local_keys_variant_to_apply: DefLocalKeysVariant) -> Self {
-        *kanata_parser::keys::OSCODE_MAPPING_VARIANT.lock() = match def_local_keys_variant_to_apply
+        #[cfg(target_os = "unknown")] // todo: make this compilable for non-wasm too
         {
-            DefLocalKeysVariant::Win | DefLocalKeysVariant::Wintercept => {
-                kanata_parser::keys::Platform::Win
-            }
-            DefLocalKeysVariant::Linux => kanata_parser::keys::Platform::Linux,
-            DefLocalKeysVariant::MacOS => kanata_parser::keys::Platform::Macos,
-        };
+            *kanata_parser::keys::OSCODE_MAPPING_VARIANT.lock() =
+                match def_local_keys_variant_to_apply {
+                    DefLocalKeysVariant::Win | DefLocalKeysVariant::Wintercept => {
+                        kanata_parser::keys::Platform::Win
+                    }
+                    DefLocalKeysVariant::Linux => kanata_parser::keys::Platform::Linux,
+                    DefLocalKeysVariant::MacOS => kanata_parser::keys::Platform::Macos,
+                };
+        }
         Self {
             def_local_keys_variant_to_apply: def_local_keys_variant_to_apply.to_string(),
         }
@@ -138,10 +145,6 @@ impl Kanata {
     }
 }
 
-use serde::Deserialize;
-
-use crate::helpers::HashSet;
-
 #[derive(Debug, Deserialize, Clone)]
 struct Config {
     #[serde(rename = "includesAndWorkspaces")]
@@ -150,6 +153,7 @@ struct Config {
     main_config_file: String,
     #[serde(rename = "localKeysVariant")]
     def_local_keys_variant: DefLocalKeysVariant,
+    format: ExtensionFormatterOptions,
 }
 
 #[derive(Debug, Deserialize, Clone, Copy)]
@@ -200,6 +204,11 @@ impl From<Config> for WorkspaceOptions {
     }
 }
 
+#[derive(Debug, Deserialize, Clone, Copy)]
+pub struct ExtensionFormatterOptions {
+    enable: bool,
+}
+
 #[wasm_bindgen]
 pub struct KanataLanguageServer {
     documents: Documents,
@@ -207,6 +216,7 @@ pub struct KanataLanguageServer {
     workspace_options: WorkspaceOptions,
     root: Option<Url>,
     send_diagnostics_callback: js_sys::Function,
+    formatter: formatter::Formatter,
 }
 
 /// Public API exposed via WASM.
@@ -247,6 +257,10 @@ impl KanataLanguageServer {
         Self {
             documents: BTreeMap::new(),
             kanata: Kanata::new(config.def_local_keys_variant),
+            formatter: Formatter {
+                extension_options: config.format,
+                remove_extra_empty_lines: true,
+            },
             workspace_options: config.into(),
             root: root_uri,
             send_diagnostics_callback: send_diagnostics_callback.clone(),
@@ -266,7 +280,7 @@ impl KanataLanguageServer {
     #[allow(unused_variables)]
     #[wasm_bindgen(js_class = KanataLanguageServer, js_name = onNotification)]
     pub fn on_notification(&mut self, method: &str, params: JsValue) {
-        log!(method);
+        log!("notification: {}", method);
 
         match method {
             // Nothing to do when we receive the `Initialized` notification.
@@ -366,9 +380,47 @@ impl KanataLanguageServer {
                 self.send_diagnostics(&diagnostics);
             }
 
-            _ => log!("unexpected notification"),
+            _ => log!("unsupported notification"),
         }
     }
+
+    #[allow(unused_variables)]
+    #[wasm_bindgen(js_class = KanataLanguageServer, js_name = onDocumentFormatting)]
+    pub fn on_document_formatting(&mut self, params: JsValue) -> JsValue {
+        type Params = <Formatting as Request>::Params;
+        type Result = <Formatting as Request>::Result;
+
+        let Params {
+            text_document,
+            options, // vscode formatting options
+            ..
+        } = from_value(params).expect("deserializes");
+
+        let text = &self
+            .documents
+            .get(&text_document.uri)
+            .expect("document should be cached")
+            .text;
+
+        let (mut tree, root_span) =
+            match formatter::ext_tree::parse_into_ext_tree_and_root_span(text) {
+                Ok(x) => x,
+                Err(e) => {
+                    log!("failed to parse into tree");
+                    return to_value::<Result>(&None).expect("serializes");
+                }
+            };
+
+        let range = lsp_range_from_span(&root_span.into());
+
+        self.formatter.format_with_options(&mut tree, &options);
+
+        to_value::<Result>(&Some(vec![TextEdit {
+            range,
+            new_text: tree.to_string(),
+        }]))
+        .expect("no err")
+    }
 }
 
 /// Individual LSP notification handlers.
@@ -491,8 +543,10 @@ impl KanataLanguageServer {
 
         let mut diagnostics = vec![];
 
+        let range = lsp_range_from_span(&err.span);
+
         diagnostics.push(Diagnostic {
-            range: err.into(),
+            range,
             severity: Some(severity),
             source: if is_extension_the_error_source {
                 Some("vscode-kanata".to_string())
@@ -505,7 +559,7 @@ impl KanataLanguageServer {
 
         if !is_extension_the_error_source {
             diagnostics.push(Diagnostic {
-                range: err.into(),
+                range,
                 severity: Some(DiagnosticSeverity::INFORMATION),
                 message: KANATA_PARSER_HELP.to_string(),
                 ..Default::default()
diff --git a/package.json b/package.json
index e04da0d..03dda3b 100644
--- a/package.json
+++ b/package.json
@@ -14,7 +14,8 @@
   ],
   "categories": [
     "Programming Languages",
-    "Other"
+    "Other",
+    "Formatters"
   ],
   "repository": {
     "type": "git",
@@ -99,6 +100,11 @@
           ],
           "default": "auto",
           "markdownDescription": "Select which localkeys variant to use."
+        },
+        "vscode-kanata.format.enable": {
+          "type": "boolean",
+          "default": true,
+          "description": "Enable formatting feature"
         }
       }
     }
diff --git a/server/src/index.ts b/server/src/index.ts
index 7d04b6a..bc39748 100644
--- a/server/src/index.ts
+++ b/server/src/index.ts
@@ -18,6 +18,7 @@ connection.onInitialize((params: InitializeParams) => {
   const kls = new KanataLanguageServer(params, sendDiagnosticsCallback);
 
   connection.onNotification((...args) => kls.onNotification(...args));
+  connection.onDocumentFormatting((...args) => kls.onDocumentFormatting(...args));
 
   return {
     capabilities: {
@@ -29,6 +30,7 @@ connection.onInitialize((params: InitializeParams) => {
       // UTF-8 is not supported in vscode-languageserver/node. See:
       // https://github.com/microsoft/vscode-languageserver-node/issues/1224
       positionEncoding: PositionEncodingKind.UTF16,
+      documentFormattingProvider: true,
       workspace: {
         workspaceFolders: { supported: false },
         fileOperations: {