diff --git a/lib/index.js b/lib/index.js
index c2bfaec..03c5f76 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -1,6 +1,201 @@
+var path = require('path');
+
+var Q = require('q');
+var wrench = require('wrench');
+var _ = require('lodash');
+var grunt = require('grunt');
+
+var pkg = require('../package.json');
+var git = require('./git');
+
+var copy = require('./util').copy;
+
+function getCacheDir() {
+  return '.gh-pages';
+}
+
+function getRemoteUrl(dir, remote) {
+  var repo;
+  return git(['config', '--get', 'remote.' + remote + '.url'], dir)
+      .progress(function(chunk) {
+        repo = String(chunk).split(/[\n\r]/).shift();
+      })
+      .then(function() {
+        if (repo) {
+          return Q.resolve(repo);
+        } else {
+          return Q.reject(new Error(
+              'Failed to get repo URL from options or current directory.'));
+        }
+      })
+      .fail(function(err) {
+        return Q.reject(new Error(
+            'Failed to get remote.origin.url (task must either be run in a ' +
+            'git repository with a configured origin remote or must be ' +
+            'configured with the "repo" option).'));
+      });
+}
+
+function getRepo(options) {
+  if (options.repo) {
+    return Q.resolve(options.repo);
+  } else {
+    return getRemoteUrl(process.cwd(), 'origin');
+  }
+}
 
 
-/**
- * Generate promises for spawned git commands.
- */
-exports.git = require('./git');
+exports.publish = function publish(config, done) {
+  var defaults = {
+    add: false,
+    git: 'git',
+    clone: getCacheDir(),
+    dotfiles: false,
+    branch: 'gh-pages',
+    remote: 'origin',
+    base: process.cwd(),
+    src: '**/*',
+    only: '.',
+    push: true,
+    message: 'Updates',
+    silent: false,
+    logger: function(){}
+  };
+
+  // override defaults with any task options
+  var options = _.extend({}, defaults, config);
+
+  if (!grunt.file.isDir(options.base)) {
+    return done(new Error('The "base" option must be an existing directory'));
+  }
+
+  var files = grunt.file.expand({
+    filter: 'isFile',
+    cwd: options.base,
+    dot: options.dotfiles
+  }, options.src);
+
+  if (!Array.isArray(files) || files.length === 0) {
+    return done(new Error('Files must be provided in the "src" property.'));
+  }
+
+  var only = grunt.file.expand({cwd: options.base}, options.only);
+
+  function log(message) {
+    if (!options.silent) {
+      options.logger(message);
+    }
+  }
+
+  git.exe(options.git);
+
+  var repoUrl;
+  getRepo(options)
+      .then(function(repo) {
+        repoUrl = repo;
+        log('Cloning ' + repo + ' into ' + options.clone);
+        return git.clone(repo, options.clone, options.branch, options);
+      })
+      .then(function() {
+        return getRemoteUrl(options.clone, options.remote)
+            .then(function(url) {
+              if (url !== repoUrl) {
+                var message = 'Remote url mismatch.  Got "' + url + '" ' +
+                    'but expected "' + repoUrl + '" in ' + options.clone +
+                    '.  If you have changed your "repo" option, try ' +
+                    'running `grunt gh-pages-clean` first.';
+                return Q.reject(new Error(message));
+              } else {
+                return Q.resolve();
+              }
+            });
+      })
+      .then(function() {
+        // only required if someone mucks with the checkout between builds
+        log('Cleaning');
+        return git.clean(options.clone);
+      })
+      .then(function() {
+        log('Fetching ' + options.remote);
+        return git.fetch(options.remote, options.clone);
+      })
+      .then(function() {
+        log('Checking out ' + options.remote + '/' +
+            options.branch);
+        return git.checkout(options.remote, options.branch,
+            options.clone);
+      })
+      .then(function() {
+        if (!options.add) {
+          log('Removing files');
+          return git.rm(only.join(' '), options.clone);
+        } else {
+          return Q.resolve();
+        }
+      })
+      .then(function() {
+        log('Copying files');
+        return copy(files, options.base, options.clone);
+      })
+      .then(function() {
+        log('Adding all');
+        return git.add('.', options.clone);
+      })
+      .then(function() {
+        if (options.user) {
+          return git(['config', 'user.email', options.user.email],
+              options.clone)
+              .then(function() {
+                return git(['config', 'user.name', options.user.name],
+                    options.clone);
+              });
+        } else {
+          return Q.resolve();
+        }
+      })
+      .then(function() {
+        log('Committing');
+        return git.commit(options.message, options.clone);
+      })
+      .then(function() {
+        if (options.tag) {
+          log('Tagging');
+          var deferred = Q.defer();
+          git.tag(options.tag, options.clone)
+            .then(function() {
+                return deferred.resolve();
+              })
+            .fail(function(error) {
+                // tagging failed probably because this tag alredy exists
+                log('Tagging failed, continuing');
+                options.logger(error);
+                return deferred.resolve();
+              });
+          return deferred.promise;
+        } else {
+          return Q.resolve();
+        }
+      })
+      .then(function() {
+        if (options.push) {
+          log('Pushing');
+          return git.push(options.remote, options.branch,
+              options.clone);
+        } else {
+          return Q.resolve();
+        }
+      })
+      .then(function() {
+        done();
+      }, function(error) {
+        if (options.silent) {
+          error = new Error(
+              'Unspecified error (run without silent option for detail)');
+        }
+        done(error);
+      });
+};
+
+exports.clean = function clean() {
+  wrench.rmdirSyncRecursive(getCacheDir(), true);
+};
diff --git a/lib/util.js b/lib/util.js
new file mode 100644
index 0000000..c3742dd
--- /dev/null
+++ b/lib/util.js
@@ -0,0 +1,164 @@
+var path = require('path');
+
+var async = require('async');
+var fs = require('graceful-fs');
+var Q = require('q');
+
+
+/**
+ * Generate a list of unique directory paths given a list of file paths.
+ * @param {Array.<string>} files List of file paths.
+ * @return {Array.<string>} List of directory paths.
+ */
+var uniqueDirs = exports.uniqueDirs = function(files) {
+  var dirs = {};
+  files.forEach(function(filepath) {
+    var parts = path.dirname(filepath).split(path.sep);
+    var partial = parts[0];
+    dirs[partial] = true;
+    for (var i = 1, ii = parts.length; i < ii; ++i) {
+      partial = path.join(partial, parts[i]);
+      dirs[partial] = true;
+    }
+  });
+  return Object.keys(dirs);
+};
+
+
+/**
+ * Sort function for paths.  Sorter paths come first.  Paths of equal length are
+ * sorted alphanumerically in path segment order.
+ * @param {string} a First path.
+ * @param {string} b Second path.
+ * @return {number} Comparison.
+ */
+var byShortPath = exports.byShortPath = function(a, b) {
+  var aParts = a.split(path.sep);
+  var bParts = b.split(path.sep);
+  var aLength = aParts.length;
+  var bLength = bParts.length;
+  var cmp = 0;
+  if (aLength < bLength) {
+    cmp = -1;
+  } else if (aLength > bLength) {
+    cmp = 1;
+  } else {
+    var aPart, bPart;
+    for (var i = 0; i < aLength; ++i) {
+      aPart = aParts[i];
+      bPart = bParts[i];
+      if (aPart < bPart) {
+        cmp = -1;
+        break;
+      } else if (aPart > bPart) {
+        cmp = 1;
+        break;
+      }
+    }
+  }
+  return cmp;
+};
+
+
+/**
+ * Generate a list of directories to create given a list of file paths.
+ * @param {Array.<string>} files List of file paths.
+ * @return {Array.<string>} List of directory paths ordered by path length.
+ */
+var dirsToCreate = exports.dirsToCreate = function(files) {
+  return uniqueDirs(files).sort(byShortPath);
+};
+
+
+/**
+ * Copy a file.
+ * @param {Object} obj Object with src and dest properties.
+ * @param {function(Error)} callback Callback
+ */
+var copyFile = exports.copyFile = function(obj, callback) {
+  var called = false;
+  function done(err) {
+    if (!called) {
+      called = true;
+      callback(err);
+    }
+  }
+
+  var read = fs.createReadStream(obj.src);
+  read.on('error', function(err) {
+    done(err);
+  });
+
+  var write = fs.createWriteStream(obj.dest);
+  write.on('error', function(err) {
+    done(err);
+  });
+  write.on('close', function(ex) {
+    done();
+  });
+
+  read.pipe(write);
+};
+
+
+/**
+ * Make directory, ignoring errors if directory already exists.
+ * @param {string} path Directory path.
+ * @param {function(Error)} callback Callback.
+ */
+function makeDir(path, callback) {
+  fs.mkdir(path, function(err) {
+    if (err) {
+      // check if directory exists
+      fs.stat(path, function(err2, stat) {
+        if (err2 || !stat.isDirectory()) {
+          callback(err);
+        } else {
+          callback();
+        }
+      });
+    } else {
+      callback();
+    }
+  });
+}
+
+
+/**
+ * Copy a list of files.
+ * @param {Array.<string>} files Files to copy.
+ * @param {string} base Base directory.
+ * @param {string} dest Destination directory.
+ * @return {Promise} A promise.
+ */
+var copy = exports.copy = function(files, base, dest) {
+  var deferred = Q.defer();
+
+  var pairs = [];
+  var destFiles = [];
+  files.forEach(function(file) {
+    var src = path.resolve(base, file);
+    var relative = path.relative(base, src);
+    var target = path.join(dest, relative);
+    pairs.push({
+      src: src,
+      dest: target
+    });
+    destFiles.push(target);
+  });
+
+  async.eachSeries(dirsToCreate(destFiles), makeDir, function(err) {
+    if (err) {
+      return deferred.reject(err);
+    }
+    async.each(pairs, copyFile, function(err) {
+      if (err) {
+        return deferred.reject(err);
+      } else {
+        return deferred.resolve();
+      }
+    });
+  });
+
+  return deferred.promise;
+};
diff --git a/package.json b/package.json
index 83d641f..bf0d5a1 100644
--- a/package.json
+++ b/package.json
@@ -31,7 +31,12 @@
   },
   "dependencies": {
     "q": "~1.0.1",
-    "q-io": "~1.11.0"
+    "q-io": "~1.11.0",
+    "graceful-fs": "2.0.1",
+    "async": "0.2.9",
+    "wrench": "1.5.1",
+    "lodash": "~2.4.1",
+    "grunt": "~0.4.5"
   },
   "devDependencies": {
     "glob": "~3.2.9",