diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index d817250..20a865d 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -8,6 +8,10 @@ If you learn something useful, please add it to this file.
 python -m unittest
 ```
 
+# Formatting
+
+Blueprint uses [Black](https://github.com/psf/black) for code formatting.
+
 # Build the docs
 
 ```sh
diff --git a/blueprintcompiler/decompiler.py b/blueprintcompiler/decompiler.py
index 036c86f..1d9f4dd 100644
--- a/blueprintcompiler/decompiler.py
+++ b/blueprintcompiler/decompiler.py
@@ -22,7 +22,7 @@ from enum import Enum
 import typing as T
 from dataclasses import dataclass
 
-from .xml_reader import Element, parse
+from .xml_reader import Element, parse, parse_string
 from .gir import *
 from .utils import Colors
 
@@ -211,6 +211,15 @@ def decompile(data: str) -> str:
     return ctx.result
 
 
+def decompile_string(data):
+    ctx = DecompileCtx()
+
+    xml = parse_string(data)
+    _decompile_element(ctx, None, xml)
+
+    return ctx.result
+
+
 def canon(string: str) -> str:
     if string == "class":
         return "klass"
diff --git a/blueprintcompiler/lsp.py b/blueprintcompiler/lsp.py
index dd12905..b44d631 100644
--- a/blueprintcompiler/lsp.py
+++ b/blueprintcompiler/lsp.py
@@ -24,7 +24,8 @@ import json, sys, traceback
 from .completions import complete
 from .errors import PrintableError, CompileError, MultipleErrors
 from .lsp_utils import *
-from . import tokenizer, parser, utils, xml_reader
+from .outputs.xml import XmlOutput
+from . import tokenizer, parser, utils, xml_reader, decompiler
 
 
 def printerr(*args, **kwargs):
@@ -149,6 +150,18 @@ class LanguageServer:
         )
         sys.stdout.flush()
 
+    def _send_error(self, id, code, message, data=None):
+        self._send(
+            {
+                "id": id,
+                "error": {
+                    "code": code,
+                    "message": message,
+                    "data": data,
+                },
+            }
+        )
+
     def _send_response(self, id, result):
         self._send(
             {
@@ -169,7 +182,7 @@ class LanguageServer:
     def initialize(self, id, params):
         from . import main
 
-        self.client_capabilities = params.get("capabilities")
+        self.client_capabilities = params.get("capabilities", {})
         self._send_response(
             id,
             {
@@ -256,6 +269,41 @@ class LanguageServer:
             id, [completion.to_json(True) for completion in completions]
         )
 
+    @command("textDocument/x-blueprint-compile")
+    def compile(self, id, params):
+        open_file = self._open_files[params["textDocument"]["uri"]]
+
+        if open_file.ast is None:
+            self._send_error(id, ErrorCode.RequestFailed, "Document is not open")
+            return
+
+        xml = None
+        try:
+            output = XmlOutput()
+            xml = output.emit(open_file.ast)
+        except:
+            printerr(traceback.format_exc())
+            self._send_error(id, ErrorCode.RequestFailed, "Could not compile document")
+            return
+        self._send_response(id, {"xml": xml})
+
+    @command("x-blueprint/decompile")
+    def decompile(self, id, params):
+        text = params.get("text")
+        blp = None
+
+        try:
+            blp = decompiler.decompile_string(text)
+        except decompiler.UnsupportedError as e:
+            self._send_error(id, ErrorCode.RequestFailed, e.message)
+            return
+        except:
+            printerr(traceback.format_exc())
+            self._send_error(id, ErrorCode.RequestFailed, "Invalid input")
+            return
+
+        self._send_response(id, {"blp": blp})
+
     @command("textDocument/semanticTokens/full")
     def semantic_tokens(self, id, params):
         open_file = self._open_files[params["textDocument"]["uri"]]
diff --git a/blueprintcompiler/lsp_utils.py b/blueprintcompiler/lsp_utils.py
index 5e4ef89..219cade 100644
--- a/blueprintcompiler/lsp_utils.py
+++ b/blueprintcompiler/lsp_utils.py
@@ -69,6 +69,10 @@ class CompletionItemKind(enum.IntEnum):
     TypeParameter = 25
 
 
+class ErrorCode(enum.IntEnum):
+    RequestFailed = -32803
+
+
 @dataclass
 class Completion:
     label: str
diff --git a/blueprintcompiler/xml_reader.py b/blueprintcompiler/xml_reader.py
index 5e31773..b2d579b 100644
--- a/blueprintcompiler/xml_reader.py
+++ b/blueprintcompiler/xml_reader.py
@@ -92,3 +92,9 @@ def parse(filename):
     parser.setContentHandler(handler)
     parser.parse(filename)
     return handler.root
+
+
+def parse_string(xml):
+    handler = Handler()
+    parser = sax.parseString(xml, handler)
+    return handler.root