diff --git a/Source/StringFilr.d.ts b/Source/StringFilr.d.ts
new file mode 100644
index 0000000..d6fe0f3
--- /dev/null
+++ b/Source/StringFilr.d.ts
@@ -0,0 +1,23 @@
+declare module StringFilr {
+    export interface IStringFilrSettings {
+        // An Object containing data stored as children of sub-Objects.
+        library: any;
+
+        // A String to use as a default key to rescue on, if provided.
+        normal?: string;
+
+        // Whether it's ok for the library to have Objects that don't contain the
+        // normal key (by default, false).
+        requireNormalKey?: boolean;
+    }
+
+    export interface IStringFilr {
+        getLibrary(): any;
+        getNormal(): string;
+        getCache(): any;
+        getCached(key: string): any;
+        clearCache(): void;
+        clearCached(key: string): void;
+        get(keyRaw: string): any;
+    }
+}
\ No newline at end of file
diff --git a/Source/StringFilr.ts b/Source/StringFilr.ts
index 073b79c..086a5ab 100644
--- a/Source/StringFilr.ts
+++ b/Source/StringFilr.ts
@@ -1,18 +1,8 @@
+/// <reference path="StringFilr.d.ts" />
+
 module StringFilr {
     "use strict";
 
-    export interface IStringFilrSettings {
-        // An Object containing data stored as children of sub-Objects.
-        library: any;
-
-        // A String to use as a default key to rescue on, if provided.
-        normal?: string;
-
-        // Whether it's ok for the library to have Objects that don't contain the
-        // normal key (by default, false).
-        requireNormalKey?: boolean;
-    }
-
     /**
      * A general utility for retrieving data from an Object based on nested class
      * names. You can think of the internal "library" Object as a tree structure,
@@ -21,7 +11,7 @@ module StringFilr {
      * 
      * @author "Josh Goldberg" <josh@fullscreenmario.com>
      */
-    export class StringFilr {
+    export class StringFilr implements IStringFilr {
         // The library of data.
         private library: any;
 
@@ -152,7 +142,7 @@ module StringFilr {
          *                           don't have a matching key.
          * @return {String[]} output
          */
-        findLackingNormal(current: any, path: string, output: string[]): string[] {
+        private findLackingNormal(current: any, path: string, output: string[]): string[] {
             var i: string;
 
             if (!current.hasOwnProperty(this.normal)) {