diff --git a/master.js b/lib/master.js
similarity index 100%
rename from master.js
rename to lib/master.js
diff --git a/lib/sni-callback.js b/lib/sni-callback.js
deleted file mode 100644
index d70b879..0000000
--- a/lib/sni-callback.js
+++ /dev/null
@@ -1,114 +0,0 @@
-'use strict';
-
-// opts = { notBefore, notAfter, renew, register, httpsOptions }
-module.exports.create = function (opts) {
-
-  if (!opts.notBefore) { throw new Error("must supply options.notBefore (and options.notAfter)"); }
-  if (!opts.notAfter) { opts.notAfter = opts.notBefore - (3 * 24 * 60 * 60 * 1000); }
-  if (!opts.httpsOptions) { opts.httpOptions = {}; }
-
-
-
-
-  //opts.renewWithin = opts.notBefore;                    // i.e. 15 days
-  opts.renewWindow = opts.notBefore - opts.notAfter;      // i.e. 1 day
-  //opts.renewRatio = opts.notBefore = opts.renewWindow;  // i.e. 1/15 (6.67%)
-
-
-
-
-  var tls = require('tls');
-
-
-
-
-  var snicb = {
-
-
-
-
-    // in-process cache
-    _ipc: {}
-    // just to account for clock skew
-  , _fiveMin: 5 * 60 * 1000
-
-
-
-
-    // cache and format incoming certs
-  , cacheCerts: function (certs) {
-      var meta = {
-        certs: certs
-      , tlsContext: tls.createSecureContext({
-          key: certs.privkey
-        , cert: certs.cert + certs.chain
-        , rejectUnauthorized: opts.httpsOptions.rejectUnauthorized
-
-        , requestCert: opts.httpsOptions.requestCert  // request peer verification
-        , ca: opts.httpsOptions.ca                    // this chain is for incoming peer connctions
-        , crl: opts.httpsOptions.crl                  // this crl is for incoming peer connections
-        })
-
-      , subject: certs.subject
-        // stagger renewal time by a little bit of randomness
-      , renewAt: (certs.expiresAt - (opts.notBefore - (opts.renewWindow * Math.random())))
-        // err just barely on the side of safety
-      , expiresNear: certs.expiresAt - snicb._fiveMin
-      };
-
-      certs.altnames.forEach(function (domain) {
-        snicb._ipc[domain] = { subject: certs.subject };
-      });
-      snicb._ipc[certs.subject] = meta;
-
-      return meta;
-    }
-
-
-
-
-    // automate certificate registration on request
-  , sniCallback: function (domain, cb) {
-      var certMeta = snicb._ipc[domain];
-      var promise;
-      var now = Date.now();
-
-      if (certMeta && certMeta.subject !== domain) {
-        certMeta = snicb._ipc[domain];
-      }
-
-      if (!certMeta) {
-        // we don't have a cert and must get one
-        promise = opts.register(domain);
-      }
-      else if (now >= certMeta.expiresNear) {
-        // we have a cert, but it's no good for the average user
-        promise = opts.renew(domain, certMeta.certs);
-      } else {
-
-        // we could stand to try to renew the cert
-        if (now >= certMeta.renewAt) {
-          // give the cert some time to be validated and replaced before trying again
-          certMeta.renewAt = Date.now() + (2 * 60 * 60 * 1000) + (3 * 60 * 60 * 1000 * Math.random());
-          // let the update happen in the background
-          opts.renew(domain, certMeta.certs).then(snicb.cacheCerts);
-        }
-
-        // return the valid cert right away
-        cb(null, certMeta.certs);
-        return;
-      }
-
-      // promise the non-existent or expired cert
-      promise.then(snicb.cacheCerts).then(function (certMeta) {
-        cb(null, certMeta.tlsContext);
-      }, cb);
-    }
-
-
-
-
-  };
-
-  return snicb;
-};
diff --git a/lib/worker.js b/lib/worker.js
new file mode 100644
index 0000000..a62673a
--- /dev/null
+++ b/lib/worker.js
@@ -0,0 +1,20 @@
+'use strict';
+
+module.exports.create = function (opts) {
+
+  opts.workerSniCallback = require('le-sni-auto').create({
+    getCertificates: function (domain, certs, cb) {
+      opts.approveDomains(domain, certs, function (err, certs) {
+        process.send({ type: 'LE_REQUEST', domain: domain, certs: certs });
+
+        process.on('message', function (msg) {
+          if (msg.domain === domain) {
+            cb(msg.certs);
+          }
+        });
+      });
+    }
+  }).sniCallback;
+
+  return opts;
+};