diff --git a/functions/package-lock.json b/functions/package-lock.json
index e96e73b..9c8517c 100644
--- a/functions/package-lock.json
+++ b/functions/package-lock.json
@@ -896,6 +896,16 @@
         "qs": "6.5.2",
         "raw-body": "2.3.3",
         "type-is": "~1.6.16"
+      },
+      "dependencies": {
+        "debug": {
+          "version": "2.6.9",
+          "resolved": "https://registry.npmjs.org/debug/-/debug-2.6.9.tgz",
+          "integrity": "sha512-bC7ElrdJaJnPbAP+1EotYvqZsb3ecl5wi6Bfi6BJTUcNowp6cvspg0jXznRTKDjm/E7AdgFBVeAPVMNcKGsHMA==",
+          "requires": {
+            "ms": "2.0.0"
+          }
+        }
       }
     },
     "boolbase": {
@@ -1338,14 +1348,6 @@
       "resolved": "https://registry.npmjs.org/date-fns/-/date-fns-1.30.1.tgz",
       "integrity": "sha512-hBSVCvSmWC+QypYObzwGOd9wqdDpOt+0wl0KbU+R+uuZBS1jN8VsD1ss3irQDknRj5NvxiTF6oj/nDRnN/UQNw=="
     },
-    "debug": {
-      "version": "2.6.9",
-      "resolved": "https://registry.npmjs.org/debug/-/debug-2.6.9.tgz",
-      "integrity": "sha512-bC7ElrdJaJnPbAP+1EotYvqZsb3ecl5wi6Bfi6BJTUcNowp6cvspg0jXznRTKDjm/E7AdgFBVeAPVMNcKGsHMA==",
-      "requires": {
-        "ms": "2.0.0"
-      }
-    },
     "decamelize": {
       "version": "1.2.0",
       "resolved": "https://registry.npmjs.org/decamelize/-/decamelize-1.2.0.tgz",
@@ -1653,6 +1655,14 @@
         "to-regex": "^3.0.1"
       },
       "dependencies": {
+        "debug": {
+          "version": "2.6.9",
+          "resolved": "https://registry.npmjs.org/debug/-/debug-2.6.9.tgz",
+          "integrity": "sha512-bC7ElrdJaJnPbAP+1EotYvqZsb3ecl5wi6Bfi6BJTUcNowp6cvspg0jXznRTKDjm/E7AdgFBVeAPVMNcKGsHMA==",
+          "requires": {
+            "ms": "2.0.0"
+          }
+        },
         "define-property": {
           "version": "0.2.5",
           "resolved": "https://registry.npmjs.org/define-property/-/define-property-0.2.5.tgz",
@@ -1706,6 +1716,16 @@
         "type-is": "~1.6.16",
         "utils-merge": "1.0.1",
         "vary": "~1.1.2"
+      },
+      "dependencies": {
+        "debug": {
+          "version": "2.6.9",
+          "resolved": "https://registry.npmjs.org/debug/-/debug-2.6.9.tgz",
+          "integrity": "sha512-bC7ElrdJaJnPbAP+1EotYvqZsb3ecl5wi6Bfi6BJTUcNowp6cvspg0jXznRTKDjm/E7AdgFBVeAPVMNcKGsHMA==",
+          "requires": {
+            "ms": "2.0.0"
+          }
+        }
       }
     },
     "extend": {
@@ -1860,6 +1880,16 @@
         "parseurl": "~1.3.2",
         "statuses": "~1.4.0",
         "unpipe": "~1.0.0"
+      },
+      "dependencies": {
+        "debug": {
+          "version": "2.6.9",
+          "resolved": "https://registry.npmjs.org/debug/-/debug-2.6.9.tgz",
+          "integrity": "sha512-bC7ElrdJaJnPbAP+1EotYvqZsb3ecl5wi6Bfi6BJTUcNowp6cvspg0jXznRTKDjm/E7AdgFBVeAPVMNcKGsHMA==",
+          "requires": {
+            "ms": "2.0.0"
+          }
+        }
       }
     },
     "firebase-admin": {
@@ -3366,6 +3396,16 @@
         "depd": "~1.1.2",
         "on-finished": "~2.3.0",
         "on-headers": "~1.0.1"
+      },
+      "dependencies": {
+        "debug": {
+          "version": "2.6.9",
+          "resolved": "https://registry.npmjs.org/debug/-/debug-2.6.9.tgz",
+          "integrity": "sha512-bC7ElrdJaJnPbAP+1EotYvqZsb3ecl5wi6Bfi6BJTUcNowp6cvspg0jXznRTKDjm/E7AdgFBVeAPVMNcKGsHMA==",
+          "requires": {
+            "ms": "2.0.0"
+          }
+        }
       }
     },
     "ms": {
@@ -3975,6 +4015,14 @@
         "statuses": "~1.4.0"
       },
       "dependencies": {
+        "debug": {
+          "version": "2.6.9",
+          "resolved": "https://registry.npmjs.org/debug/-/debug-2.6.9.tgz",
+          "integrity": "sha512-bC7ElrdJaJnPbAP+1EotYvqZsb3ecl5wi6Bfi6BJTUcNowp6cvspg0jXznRTKDjm/E7AdgFBVeAPVMNcKGsHMA==",
+          "requires": {
+            "ms": "2.0.0"
+          }
+        },
         "mime": {
           "version": "1.4.1",
           "resolved": "https://registry.npmjs.org/mime/-/mime-1.4.1.tgz",
@@ -4051,6 +4099,14 @@
         "use": "^3.1.0"
       },
       "dependencies": {
+        "debug": {
+          "version": "2.6.9",
+          "resolved": "https://registry.npmjs.org/debug/-/debug-2.6.9.tgz",
+          "integrity": "sha512-bC7ElrdJaJnPbAP+1EotYvqZsb3ecl5wi6Bfi6BJTUcNowp6cvspg0jXznRTKDjm/E7AdgFBVeAPVMNcKGsHMA==",
+          "requires": {
+            "ms": "2.0.0"
+          }
+        },
         "define-property": {
           "version": "0.2.5",
           "resolved": "https://registry.npmjs.org/define-property/-/define-property-0.2.5.tgz",
diff --git a/functions/package.json b/functions/package.json
index 9c81af5..a7d6727 100644
--- a/functions/package.json
+++ b/functions/package.json
@@ -3,9 +3,8 @@
   "name": "functions",
   "description": "Cloud Functions for Firebase",
   "scripts": {
-    "serve": "firebase serve --only functions",
+    "start": "firebase serve --only functions",
     "shell": "firebase functions:shell",
-    "start": "npm run shell",
     "deploy": "firebase deploy --only functions",
     "logs": "firebase functions:log"
   },
diff --git a/modules/utils/debug.js b/modules/utils/debug.js
new file mode 100644
index 0000000..58ccf01
--- /dev/null
+++ b/modules/utils/debug.js
@@ -0,0 +1,2 @@
+const debug = process.env.DEBUG ? console.log.bind(console) : () => {};
+export default debug;
diff --git a/modules/utils/fetchNpmPackage.js b/modules/utils/fetchNpmPackage.js
index 46ead66..2a1913a 100644
--- a/modules/utils/fetchNpmPackage.js
+++ b/modules/utils/fetchNpmPackage.js
@@ -3,6 +3,7 @@ import https from 'https';
 import gunzip from 'gunzip-maybe';
 import tar from 'tar-stream';
 
+import debug from './debug';
 import bufferStream from './bufferStream';
 import agent from './registryAgent';
 
@@ -10,11 +11,7 @@ export default function fetchNpmPackage(packageConfig) {
   return new Promise((resolve, reject) => {
     const tarballURL = packageConfig.dist.tarball;
 
-    console.log(
-      'Fetching package for %s from %s',
-      packageConfig.name,
-      tarballURL
-    );
+    debug('Fetching package for %s from %s', packageConfig.name, tarballURL);
 
     const { hostname, pathname } = url.parse(tarballURL);
     const options = {
diff --git a/modules/utils/fetchNpmPackageInfo.js b/modules/utils/fetchNpmPackageInfo.js
index dd196ba..2762a23 100644
--- a/modules/utils/fetchNpmPackageInfo.js
+++ b/modules/utils/fetchNpmPackageInfo.js
@@ -3,6 +3,7 @@ import https from 'https';
 
 import { npmRegistryURL } from '../config';
 
+import debug from './debug';
 import bufferStream from './bufferStream';
 import agent from './registryAgent';
 
@@ -19,7 +20,7 @@ export default function fetchNpmPackageInfo(packageName) {
 
     const infoURL = `${npmRegistryURL}/${encodedPackageName}`;
 
-    console.log('Fetching package info for %s from %s', packageName, infoURL);
+    debug('Fetching package info for %s from %s', packageName, infoURL);
 
     const { hostname, pathname } = url.parse(infoURL);
     const options = {
diff --git a/rollup.config.js b/rollup.config.js
index abb6c3b..ea3c98f 100644
--- a/rollup.config.js
+++ b/rollup.config.js
@@ -108,13 +108,17 @@ const functions = [
           emitFiles: false
         }),
         replace({
-          'process.env.NODE_ENV': JSON.stringify(env),
           'process.env.CLOUDFLARE_EMAIL': JSON.stringify(
             process.env.CLOUDFLARE_EMAIL
           ),
           'process.env.CLOUDFLARE_KEY': JSON.stringify(
             process.env.CLOUDFLARE_KEY
           ),
+          'process.env.DEBUG': JSON.stringify(process.env.DEBUG),
+          'process.env.NODE_ENV': JSON.stringify(env),
+          'process.env.NPM_REGISTRY_URL': JSON.stringify(
+            process.env.NPM_REGISTRY_URL
+          ),
           'process.env.ORIGIN': JSON.stringify(process.env.ORIGIN),
           'process.env.SECRET_KEY': JSON.stringify(secretKey)
         })