diff --git a/priv/static/ws-test-echo.html b/priv/static/echo.html
similarity index 100%
rename from priv/static/ws-test-echo.html
rename to priv/static/echo.html
diff --git a/priv/static/index.html b/priv/static/index.html
index 91952c7..3501522 100644
--- a/priv/static/index.html
+++ b/priv/static/index.html
@@ -17,7 +17,7 @@
 
         <ul>
             <li><a href="/chat.html">Chatroom</a></li>
-            <li><a href="/ws-test-echo.html">Echo</a></li>
+            <li><a href="/echo.html">Echo</a></li>
             <li><a href="/tetris.html">Tetris</a></li>
             <li><a href="/wfc.html">WFC</a></li>
         </ul>
diff --git a/priv/static/js/dist/index.d.ts b/priv/static/js/dist/index.d.ts
deleted file mode 100644
index e1bf407..0000000
--- a/priv/static/js/dist/index.d.ts
+++ /dev/null
@@ -1,22 +0,0 @@
-/**
- * Home page ts/js
- *
- * @module
- */
-declare function main(): void;
-declare function on_input_key(evt: KeyboardEvent, ielt: HTMLInputElement, oelt: HTMLTextAreaElement, cb_resize: HTMLInputElement, cb_scroll: HTMLInputElement, max_height: number): Promise<void>;
-declare function auto_resize_output(checkbox_element: HTMLInputElement, target_element: HTMLTextAreaElement, max_height: number): void;
-declare function auto_scroll_to_bottom(checkbox_element: HTMLInputElement, target_element: HTMLTextAreaElement): void;
-type ok_err<t> = {
-    ok: true;
-    result: t;
-} | {
-    ok: false;
-    error: string;
-};
-type wfcin = {
-    wfcin: string;
-};
-type wfcout = ok_err<string>;
-declare function assert(condition: boolean, fail_msg: string): void;
-declare function fetch_wfcin(user_line: string): Promise<wfcout>;
diff --git a/priv/static/js/dist/index.js.map b/priv/static/js/dist/index.js.map
deleted file mode 100644
index fa2c502..0000000
--- a/priv/static/js/dist/index.js.map
+++ /dev/null
@@ -1 +0,0 @@
-{"version":3,"file":"index.js","sourceRoot":"","sources":["../ts/index.ts"],"names":[],"mappings":";AAAA;;;;GAIG;AAGH,oEAAoE;AACpE,qBAAqB;AACrB,oEAAoE;AAEpE,IAAI,EAAE,CAAC;AAEP,SACA,IAAI;IAIA,IAAI,IAAI,GAAoC,QAAQ,CAAC,cAAc,CAAC,WAAW,CAA8B,CAAK;IAClH,IAAI,IAAI,GAAoC,QAAQ,CAAC,cAAc,CAAC,YAAY,CAAgC,CAAE;IAClH,IAAI,SAAS,GAA+B,QAAQ,CAAC,cAAc,CAAC,oBAAoB,CAAqB,CAAK;IAClH,IAAI,SAAS,GAA+B,QAAQ,CAAC,cAAc,CAAC,aAAa,CAA4B,CAAK;IAClH,IAAI,eAAe,GAAyB,GAAG,CAAC;IAGhD,IAAI,CAAC,gBAAgB,CAAC,SAAS,EAC3B,UAAS,CAAgB;QACrB,YAAY,CAAC,CAAC,EAAE,IAAI,EAAE,IAAI,EAAE,SAAS,EAAE,SAAS,EAAE,eAAe,CAAC,CAAC;IACvE,CAAC,CACJ,CAAC;AACN,CAAC;AAGD,yBAAyB;AACzB,KAAK,UACL,YAAY,CACP,GAA0B,EAC1B,IAA6B,EAC7B,IAAgC,EAChC,SAA6B,EAC7B,SAA6B,EAC7B,UAAmB;IAGpB,IAAI,GAAG,CAAC,GAAG,KAAK,OAAO,EAAE,CAAC;QACtB,yBAAyB;QACzB,GAAG,CAAC,cAAc,EAAE,CAAC;QACrB,gBAAgB;QAChB,IAAI,QAAQ,GAAa,IAAI,CAAC,KAAK,CAAC;QACpC,IAAI,OAAO,GAAc,QAAQ,CAAC,IAAI,EAAE,CAAC;QACzC,IAAI,QAAQ,GAAa,OAAO,CAAC,MAAM,GAAG,CAAC,CAAC;QAC5C,2BAA2B;QAC3B,IAAI,QAAQ,EAAE,CAAC;YACX,cAAc;YACd,IAAI,CAAC,KAAK,GAAG,EAAE,CAAC;YAEhB,gBAAgB;YAChB,IAAI,CAAC,KAAK,IAAI,IAAI,GAAG,OAAO,GAAG,IAAI,CAAC;YACpC,IAAI,CAAC,MAAM,GAAG,KAAK,CAAC;YAEpB,2BAA2B;YAC3B,IAAI,MAAM,GAAY,MAAM,WAAW,CAAC,OAAO,CAAC,CAAC;YAEjD,IAAI,MAAM,CAAC,EAAE;gBACT,IAAI,CAAC,KAAK,IAAI,MAAM,CAAC,MAAM,CAAC;;gBAE5B,IAAI,CAAC,KAAK,IAAI,MAAM,CAAC,KAAK,CAAC;YAC/B,IAAI,CAAC,KAAK,IAAI,IAAI,CAAC;YAEnB,cAAc;YACd,kBAAkB,CAAC,SAAS,EAAE,IAAI,EAAE,UAAU,CAAC,CAAC;YAChD,qBAAqB,CAAC,SAAS,EAAE,IAAI,CAAC,CAAC;QAC3C,CAAC;IACL,CAAC;AACL,CAAC;AAID,SACA,kBAAkB,CACb,gBAAmC,EACnC,cAAsC,EACtC,UAAyB;IAG1B,+DAA+D;IAC/D,IAAI,gBAAgB,CAAC,OAAO,EAAE,CAAC;QAC3B,IAAI,aAAa,GAAW,cAAc,CAAC,YAAY,CAAC;QACxD,sCAAsC;QACtC,IAAI,aAAa,GAAG,UAAU;YAC1B,cAAc,CAAC,KAAK,CAAC,MAAM,GAAG,MAAM,CAAC,aAAa,CAAC,GAAG,IAAI,CAAC;;YAE3D,cAAc,CAAC,KAAK,CAAC,MAAM,GAAG,MAAM,CAAC,UAAU,CAAC,GAAG,IAAI,CAAC;IAChE,CAAC;AACL,CAAC;AAGD,SACA,qBAAqB,CAChB,gBAAmC,EACnC,cAAsC;IAGvC,IAAI,gBAAgB,CAAC,OAAO,EAAE,CAAC;QAC3B,mBAAmB;QACnB,cAAc,CAAC,SAAS,GAAG,cAAc,CAAC,YAAY,CAAC;IAC3D,CAAC;AACL,CAAC;AAcD,SACA,MAAM,CACD,SAAmB,EACnB,QAAkB;IAGnB,IAAG,CAAC,SAAS;QACT,MAAM,IAAI,KAAK,CAAC,QAAQ,CAAC,CAAC;AAClC,CAAC;AAGD,KAAK,UACL,WAAW,CACN,SAAkB;IAGnB,IAAI,YAAY,GAAG,EAAC,KAAK,EAAE,SAAS,EAAC,CAAC;IACtC,IAAI,YAAY,GAAG,IAAI,CAAC,SAAS,CAAC,YAAY,CAAC,CAAC;IAEhD,IAAI,WAAW,GAAI,EAAC,MAAM,EAAG,MAAM;QACf,OAAO,EAAE,EAAC,cAAc,EAAE,kBAAkB,EAAC;QAC7C,IAAI,EAAK,YAAY,EAAC,CAAC;IAE3C,mEAAmE;IACnE,4CAA4C;IAC5C,IAAI,MAAM,GAAW,EAAC,EAAE,EAAM,KAAK;QACb,KAAK,EAAG,kCAAkC,EAAC,CAAC;IAElE,IAAI,CAAC;QACD,IAAI,QAAQ,GAAc,MAAM,KAAK,CAAC,QAAQ,EAAE,WAAW,CAAC,CAAC;QAC7D,IAAI,QAAQ,CAAC,EAAE;YACX,MAAM,GAAG,MAAM,QAAQ,CAAC,IAAI,EAAY,CAAC;aACxC,CAAC;YACF,OAAO,CAAC,GAAG,CAAC,oBAAoB,EAAE,QAAQ,CAAC,CAAC;YAC5C,MAAM,GAAG,EAAC,EAAE,EAAE,KAAK,EAAE,KAAK,EAAE,mBAAmB,EAAC,CAAC;QACrD,CAAC;IACL,CAAC;IACD,OAAO,CAAM,EAAE,CAAC;QACZ,OAAO,CAAC,GAAG,CAAC,gBAAgB,EAAE,CAAC,CAAC,CAAC;QACjC,MAAM,GAAG,EAAC,EAAE,EAAE,KAAK,EAAE,KAAK,EAAE,eAAe,EAAC,CAAC;IACjD,CAAC;IAED,OAAO,MAAM,CAAC;AAClB,CAAC"}
\ No newline at end of file
diff --git a/priv/static/js/dist/wfc.d.ts b/priv/static/js/dist/wfc.d.ts
new file mode 100644
index 0000000..6aae126
--- /dev/null
+++ b/priv/static/js/dist/wfc.d.ts
@@ -0,0 +1,6 @@
+/**
+ * Home page ts/js
+ *
+ * @module
+ */
+export {};
diff --git a/priv/static/js/dist/index.js b/priv/static/js/dist/wfc.js
similarity index 74%
rename from priv/static/js/dist/index.js
rename to priv/static/js/dist/wfc.js
index ce687d3..ab8c2c5 100644
--- a/priv/static/js/dist/index.js
+++ b/priv/static/js/dist/wfc.js
@@ -1,9 +1,9 @@
-"use strict";
 /**
  * Home page ts/js
  *
  * @module
  */
+import * as libfewd from './libfewd.js';
 //------------------------------------------------------------------
 // page element stuff
 //------------------------------------------------------------------
@@ -42,28 +42,11 @@ async function on_input_key(evt, ielt, oelt, cb_resize, cb_scroll, max_height) {
                 oelt.value += result.error;
             oelt.value += '\n';
             // auto-resize
-            auto_resize_output(cb_resize, oelt, max_height);
-            auto_scroll_to_bottom(cb_scroll, oelt);
+            libfewd.auto_resize(cb_resize, oelt, max_height);
+            libfewd.auto_scroll_to_bottom(cb_scroll, oelt);
         }
     }
 }
-function auto_resize_output(checkbox_element, target_element, max_height) {
-    // if the user has manually resized their output, we do nothing
-    if (checkbox_element.checked) {
-        let target_height = target_element.scrollHeight;
-        // resize it automagically up to 500px
-        if (target_height < max_height)
-            target_element.style.height = String(target_height) + 'px';
-        else
-            target_element.style.height = String(max_height) + 'px';
-    }
-}
-function auto_scroll_to_bottom(checkbox_element, target_element) {
-    if (checkbox_element.checked) {
-        // scroll to bottom
-        target_element.scrollTop = target_element.scrollHeight;
-    }
-}
 function assert(condition, fail_msg) {
     if (!condition)
         throw new Error(fail_msg);
@@ -93,4 +76,4 @@ async function fetch_wfcin(user_line) {
     }
     return result;
 }
-//# sourceMappingURL=index.js.map
\ No newline at end of file
+//# sourceMappingURL=wfc.js.map
\ No newline at end of file
diff --git a/priv/static/js/dist/wfc.js.map b/priv/static/js/dist/wfc.js.map
new file mode 100644
index 0000000..ca3d152
--- /dev/null
+++ b/priv/static/js/dist/wfc.js.map
@@ -0,0 +1 @@
+{"version":3,"file":"wfc.js","sourceRoot":"","sources":["../ts/wfc.ts"],"names":[],"mappings":"AAAA;;;;GAIG;AAEH,OAAO,KAAK,OAAO,MAAM,cAAc,CAAA;AAEvC,oEAAoE;AACpE,qBAAqB;AACrB,oEAAoE;AAEpE,IAAI,EAAE,CAAC;AAEP,SACA,IAAI;IAIA,IAAI,IAAI,GAAoC,QAAQ,CAAC,cAAc,CAAC,WAAW,CAA8B,CAAK;IAClH,IAAI,IAAI,GAAoC,QAAQ,CAAC,cAAc,CAAC,YAAY,CAAgC,CAAE;IAClH,IAAI,SAAS,GAA+B,QAAQ,CAAC,cAAc,CAAC,oBAAoB,CAAqB,CAAK;IAClH,IAAI,SAAS,GAA+B,QAAQ,CAAC,cAAc,CAAC,aAAa,CAA4B,CAAK;IAClH,IAAI,eAAe,GAAyB,GAAG,CAAC;IAGhD,IAAI,CAAC,gBAAgB,CAAC,SAAS,EAC3B,UAAS,CAAgB;QACrB,YAAY,CAAC,CAAC,EAAE,IAAI,EAAE,IAAI,EAAE,SAAS,EAAE,SAAS,EAAE,eAAe,CAAC,CAAC;IACvE,CAAC,CACJ,CAAC;AACN,CAAC;AAGD,yBAAyB;AACzB,KAAK,UACL,YAAY,CACP,GAA0B,EAC1B,IAA6B,EAC7B,IAAgC,EAChC,SAA6B,EAC7B,SAA6B,EAC7B,UAAmB;IAGpB,IAAI,GAAG,CAAC,GAAG,KAAK,OAAO,EAAE,CAAC;QACtB,yBAAyB;QACzB,GAAG,CAAC,cAAc,EAAE,CAAC;QACrB,gBAAgB;QAChB,IAAI,QAAQ,GAAa,IAAI,CAAC,KAAK,CAAC;QACpC,IAAI,OAAO,GAAc,QAAQ,CAAC,IAAI,EAAE,CAAC;QACzC,IAAI,QAAQ,GAAa,OAAO,CAAC,MAAM,GAAG,CAAC,CAAC;QAC5C,2BAA2B;QAC3B,IAAI,QAAQ,EAAE,CAAC;YACX,cAAc;YACd,IAAI,CAAC,KAAK,GAAG,EAAE,CAAC;YAEhB,gBAAgB;YAChB,IAAI,CAAC,KAAK,IAAI,IAAI,GAAG,OAAO,GAAG,IAAI,CAAC;YACpC,IAAI,CAAC,MAAM,GAAG,KAAK,CAAC;YAEpB,2BAA2B;YAC3B,IAAI,MAAM,GAAY,MAAM,WAAW,CAAC,OAAO,CAAC,CAAC;YAEjD,IAAI,MAAM,CAAC,EAAE;gBACT,IAAI,CAAC,KAAK,IAAI,MAAM,CAAC,MAAM,CAAC;;gBAE5B,IAAI,CAAC,KAAK,IAAI,MAAM,CAAC,KAAK,CAAC;YAC/B,IAAI,CAAC,KAAK,IAAI,IAAI,CAAC;YAEnB,cAAc;YACd,OAAO,CAAC,WAAW,CAAC,SAAS,EAAE,IAAI,EAAE,UAAU,CAAC,CAAC;YACjD,OAAO,CAAC,qBAAqB,CAAC,SAAS,EAAE,IAAI,CAAC,CAAC;QACnD,CAAC;IACL,CAAC;AACL,CAAC;AAaD,SACA,MAAM,CACD,SAAmB,EACnB,QAAkB;IAGnB,IAAG,CAAC,SAAS;QACT,MAAM,IAAI,KAAK,CAAC,QAAQ,CAAC,CAAC;AAClC,CAAC;AAGD,KAAK,UACL,WAAW,CACN,SAAkB;IAGnB,IAAI,YAAY,GAAG,EAAC,KAAK,EAAE,SAAS,EAAC,CAAC;IACtC,IAAI,YAAY,GAAG,IAAI,CAAC,SAAS,CAAC,YAAY,CAAC,CAAC;IAEhD,IAAI,WAAW,GAAI,EAAC,MAAM,EAAG,MAAM;QACf,OAAO,EAAE,EAAC,cAAc,EAAE,kBAAkB,EAAC;QAC7C,IAAI,EAAK,YAAY,EAAC,CAAC;IAE3C,mEAAmE;IACnE,4CAA4C;IAC5C,IAAI,MAAM,GAAW,EAAC,EAAE,EAAM,KAAK;QACb,KAAK,EAAG,kCAAkC,EAAC,CAAC;IAElE,IAAI,CAAC;QACD,IAAI,QAAQ,GAAc,MAAM,KAAK,CAAC,QAAQ,EAAE,WAAW,CAAC,CAAC;QAC7D,IAAI,QAAQ,CAAC,EAAE;YACX,MAAM,GAAG,MAAM,QAAQ,CAAC,IAAI,EAAY,CAAC;aACxC,CAAC;YACF,OAAO,CAAC,GAAG,CAAC,oBAAoB,EAAE,QAAQ,CAAC,CAAC;YAC5C,MAAM,GAAG,EAAC,EAAE,EAAE,KAAK,EAAE,KAAK,EAAE,mBAAmB,EAAC,CAAC;QACrD,CAAC;IACL,CAAC;IACD,OAAO,CAAM,EAAE,CAAC;QACZ,OAAO,CAAC,GAAG,CAAC,gBAAgB,EAAE,CAAC,CAAC,CAAC;QACjC,MAAM,GAAG,EAAC,EAAE,EAAE,KAAK,EAAE,KAAK,EAAE,eAAe,EAAC,CAAC;IACjD,CAAC;IAED,OAAO,MAAM,CAAC;AAClB,CAAC"}
\ No newline at end of file
diff --git a/priv/static/js/ts/index.ts b/priv/static/js/ts/wfc.ts
similarity index 78%
rename from priv/static/js/ts/index.ts
rename to priv/static/js/ts/wfc.ts
index 2b535c0..2871143 100644
--- a/priv/static/js/ts/index.ts
+++ b/priv/static/js/ts/wfc.ts
@@ -4,6 +4,7 @@
  * @module
  */
 
+import * as libfewd from './libfewd.js'
 
 //------------------------------------------------------------------
 // page element stuff
@@ -68,47 +69,13 @@ on_input_key
             oelt.value += '\n';
 
             // auto-resize
-            auto_resize_output(cb_resize, oelt, max_height);
-            auto_scroll_to_bottom(cb_scroll, oelt);
+            libfewd.auto_resize(cb_resize, oelt, max_height);
+            libfewd.auto_scroll_to_bottom(cb_scroll, oelt);
         }
     }
 }
 
 
-
-function
-auto_resize_output
-    (checkbox_element : HTMLInputElement,
-     target_element   : HTMLTextAreaElement,
-     max_height       : number)
-    : void
-{
-    // if the user has manually resized their output, we do nothing
-    if (checkbox_element.checked) {
-        let target_height: number = target_element.scrollHeight;
-        // resize it automagically up to 500px
-        if (target_height < max_height)
-            target_element.style.height = String(target_height) + 'px';
-        else
-            target_element.style.height = String(max_height) + 'px';
-    }
-}
-
-
-function
-auto_scroll_to_bottom
-    (checkbox_element : HTMLInputElement,
-     target_element   : HTMLTextAreaElement)
-    : void
-{
-    if (checkbox_element.checked) {
-        // scroll to bottom
-        target_element.scrollTop = target_element.scrollHeight;
-    }
-}
-
-
-
 //------------------------------------------------------------------
 // wfc api
 //------------------------------------------------------------------
diff --git a/priv/static/wfc.html b/priv/static/wfc.html
index 72ac544..1ae26d1 100644
--- a/priv/static/wfc.html
+++ b/priv/static/wfc.html
@@ -25,6 +25,6 @@
         </div>
     </div>
 
-    <script type="module" src="./js/dist/index.js"></script>
+    <script type="module" src="./js/dist/wfc.js"></script>
 </body>
 </html>