diff --git a/proto/code_analysis.proto b/proto/code_analysis.proto
new file mode 100644
index 000000000..fc8d81408
--- /dev/null
+++ b/proto/code_analysis.proto
@@ -0,0 +1,77 @@
+syntax = "proto3";
+import "types.proto";
+package github.semantic.v1alpha1;
+
+// Semanic's CodeAnalysis service provides endpoints for parsing, analyzing, and
+// comparing source code.
+service CodeAnalysis {
+  // Parsing
+  //
+  // Parse source code and return abstract syntax trees.
+  rpc Parse (ParseTreeRequest) returns (ParseTreeResponse);
+
+  // Diffing
+  //
+  // Summary of an AST diff of two source blobs.
+  rpc SummarizeDiff (SummarizeDiffRequest) returns (SummarizeDiffResponse);
+  // AST diff of two source blobs
+  // rpc Diff (DiffRequest) returns (DiffResponse) {}
+
+  // Analyzing
+  //
+  // Calculate an import graph for a project.
+  // rpc GraphImports (ImportGraphRequest) returns (ImportGraphResponse);
+  // rpc GraphCalls (CallGraphRequest) returns (CallGraphResponse);
+
+  // Basic server health status check.
+  rpc CheckHealth (HealthCheckRequest) returns (HealthCheckResponse);
+}
+
+message ParseTreeRequest {
+  repeated Blob blobs = 1;
+}
+
+message ParseTreeResponse {
+  bytes json_tree = 1;
+  repeated ParseError errors = 2;
+}
+
+message SummarizeDiffRequest  {
+  repeated BlobPair blobPairs = 1;
+}
+
+message SummarizeDiffResponse {
+  repeated DiffSummary changes = 1;
+  repeated ParseError errors = 2;
+}
+
+message BlobPair {
+  Blob before = 1;
+  Blob after = 2;
+}
+
+message DiffSummary {
+  string term = 1;
+  string name = 2;
+  Span span = 3;
+  string change = 4;
+}
+
+message ParseError {
+  string error = 1;
+  Span span = 2;
+  string language = 3;
+}
+
+message HealthCheckRequest {
+  string service = 1;
+}
+
+message HealthCheckResponse {
+  enum ServingStatus {
+    UNKNOWN = 0;
+    SERVING = 1;
+    NOT_SERVING = 2;
+  }
+  ServingStatus status = 1;
+}
diff --git a/types.proto b/proto/types.proto
similarity index 91%
rename from types.proto
rename to proto/types.proto
index 7d586835e..8ed05d5bc 100644
--- a/types.proto
+++ b/proto/types.proto
@@ -1,5 +1,5 @@
 syntax = "proto3";
-package semantic;
+package github.semantic.v1alpha1;
 enum Language {Unknown = 0;
                Go = 1;
                Haskell = 2;
@@ -28,14 +28,14 @@ message Boolean { bool booleanContent = 1;
                 }
 message Hash { repeated Term hashElements = 1;
              }
-message Float { bytes floatContent = 1;
+message Float { string floatContent = 1;
               }
 message KeyValue { Term key = 1;
                    Term value = 2;
                  }
 message Null {
              }
-message TextElement { bytes textElementContent = 1;
+message TextElement { string textElementContent = 1;
                     }
 message Term { oneof syntax {Array array = 1;
                              Boolean boolean = 2;
diff --git a/semantic.proto b/semantic.proto
deleted file mode 100644
index 68bad2620..000000000
--- a/semantic.proto
+++ /dev/null
@@ -1,58 +0,0 @@
-syntax = "proto3";
-import "types.proto";
-package semantic;
-
-message HealthCheckRequest {
-  string service = 1;
-}
-
-message HealthCheckResponse {
-  enum ServingStatus {
-    UNKNOWN = 0;
-    SERVING = 1;
-    NOT_SERVING = 2;
-  }
-  ServingStatus status = 1;
-}
-
-service SemanticAPI {
-  rpc HealthCheck(HealthCheckRequest) returns (HealthCheckResponse);
-  rpc FetchSummaries (SummariesRequest) returns (SummariesResponse) {}
-  rpc ParseBlobs (ParseRequest) returns (ParseResponse) {}
-}
-
-message SummariesRequest  {
-  repeated BlobPair blobPairs = 1;
-}
-
-message ParseRequest {
-  repeated Blob source = 1;
-}
-
-message BlobPair {
-  Blob before = 1;
-  Blob after = 2;
-}
-
-message SummariesResponse {
-  repeated Summary changes = 1;
-  repeated Error errors = 2;
-}
-
-message ParseResponse {
-  bytes json_tree = 1;
-  repeated Error errors = 2;
-}
-
-message Summary {
-  string categoryName = 1;
-  string termName = 2;
-  Span span = 3;
-  string changeType = 4;
-}
-
-message Error {
-  string error = 1;
-  Span span = 2;
-  string language = 3;
-}