diff --git a/bin/creature-start b/bin/creature-start
index 1edd6aa..516b88f 100755
--- a/bin/creature-start
+++ b/bin/creature-start
@@ -3,36 +3,10 @@
 const _ = require("lodash");
 
 const path = x => require("../" + x);
-const immutable = path("js/immutable");
 const git = path("js/git");
 const shell = path("js/shell");
 const commander = path("js/commander");
-const branch = path("js/branch");
-
-function validateCurrentBranch(dp) {
-  if (branch.isNonStandard(dp.branch.current)) {
-    throw `invalid base branch: ${dp.branch.current}`;
-  } else {
-    return dp;
-  }
-}
-
-function validateFeatureName(dp) {
-  if (branch.isStandard(commander.featureName())) {
-    throw `invalid feature branch: ${commander.featureName()}`;
-  } else {
-    return dp;
-  }
-}
-
-function setFeatureBranch(dp) {
-  const fb = [
-    commander.prefix(),
-    dp.branch.current,
-    commander.featureName()
-  ].join("-");
-  return immutable.set(dp, "branch.feature", fb);
-}
+const validate = path("js/validate");
 
 function createFeatureBranch(dp) {
   return shell.pipeline([
@@ -44,14 +18,11 @@ function createFeatureBranch(dp) {
   ]);
 }
 
-function toPromise(dp) {
-  return Promise.resolve(dp);
-}
-
-const x = toPromise(commander.parse())
-  .then(validateFeatureName)
+commander
+  .start()
   .then(git.setCurrentBranch)
-  .then(validateCurrentBranch)
-  .then(setFeatureBranch)
+  .then(validate.currentIsStandardBranch)
+  .then(git.setFeatureBranch)
+  .then(validate.featureIsNotStandardBranch)
   .then(createFeatureBranch)
   .catch(err => console.error(err));
diff --git a/js/commander.js b/js/commander.js
index 11aea3b..fb018eb 100644
--- a/js/commander.js
+++ b/js/commander.js
@@ -20,11 +20,25 @@ function prefix() {
   return process.env.FEATURE_USER || process.env.USER;
 }
 
+function toPromise(dp) {
+  return Promise.resolve(dp);
+}
+
+function echo(dp) {
+  console.log(JSON.stringify(dp));
+  return dp;
+}
+
+function start() {
+  return toPromise(parse());
+}
+
 lib = {
   args,
   parse,
   featureName,
-  prefix
+  prefix,
+  start
 };
 
 module.exports = lib;
diff --git a/js/git.js b/js/git.js
index abe701b..1742ac1 100644
--- a/js/git.js
+++ b/js/git.js
@@ -1,6 +1,7 @@
 const _ = require("lodash");
 
 const path = x => require("../" + x);
+const commander = path("js/commander");
 const immutable = path("js/immutable");
 const shell = path("js/shell");
 
@@ -12,8 +13,18 @@ function setCurrentBranch(dp) {
   return shell.capture(cmd).then(x => immutable.set(dp, "branch.current", x));
 }
 
+function setFeatureBranch(dp) {
+  const fb = [
+    commander.prefix(),
+    dp.branch.current,
+    commander.featureName()
+  ].join("-");
+  return immutable.set(dp, "branch.feature", fb);
+}
+
 lib = {
-  setCurrentBranch
+  setCurrentBranch,
+  setFeatureBranch
 };
 
 module.exports = lib;
diff --git a/js/validate.js b/js/validate.js
index e14ed0d..25c879f 100644
--- a/js/validate.js
+++ b/js/validate.js
@@ -1,23 +1,33 @@
+const path = x => require("../" + x);
 const branch = path("js/branch");
+const commander = path("js/commander");
 
 let lib;
 
-function validateCurrentBranch(dp) {
+function currentIsStandardBranch(dp) {
   if (branch.isNonStandard(dp.branch.current)) {
-    throw `invalid base branch: ${dp.branch.current}`;
+    const branches = branch
+      .standard()
+      .sort()
+      .join(", ");
+    throw `ERROR: starting branch must be one of: ${branches}`;
   } else {
     return dp;
   }
 }
 
-function validateFeatureName(dp) {
+function featureIsNotStandardBranch(dp) {
   if (branch.isStandard(commander.featureName())) {
-    throw `invalid feature branch: ${commander.featureName()}`;
+    const branches = branch
+      .standard()
+      .sort()
+      .join(", ");
+    throw `ERROR: feature branch cannot be any of: ${branches}`;
   } else {
     return dp;
   }
 }
 
-lib = { validateCurrentBranch, validateFeatureName };
+lib = { currentIsStandardBranch, featureIsNotStandardBranch };
 
 module.exports = lib;