--- /dev/null
+<?php
+
+namespace Drush\Boot;
+
+/**
+ * Defines the interface for a Boot classes. Any CMS that wishes
+ * to work with Drush should extend BaseBoot. If the CMS has a
+ * Drupal-Compatibility layer, then it should extend DrupalBoot.
+ *
+ * @todo Doc these methods.
+ */
+interface Boot
+{
+ /**
+ * Select the best URI for the provided cwd. Only called
+ * if the user did not explicitly specify a URI.
+ */
+ public function findUri($root, $uri);
+
+ /**
+ * Inject the uri for the specific site to be bootstrapped
+ *
+ * @param string $uri Site to bootstrap
+ */
+ public function setUri($uri);
+
+ /**
+ * This function determines if the specified path points to
+ * the root directory of a CMS that can be bootstrapped by
+ * the specific subclass that implements it.
+ *
+ * These functions should be written such that one and only
+ * one class will return TRUE for any given $path.
+ *
+ * @param $path to a directory to test
+ *
+ * @return TRUE if $path is a valid root directory
+ */
+ public function validRoot($path);
+
+ /**
+ * Given a site root directory, determine the exact version of the software.
+ *
+ * @param string $root
+ * The full path to the site installation, with no trailing slash.
+ * @return string|NULL
+ * The version string for the current version of the software, e.g. 8.1.3
+ */
+ public function getVersion($root);
+
+ /**
+ * Returns an array that determines what bootstrap phases
+ * are necessary to bootstrap this CMS. This array
+ * should map from a numeric phase to the name of a method
+ * (string) in the Boot class that handles the bootstrap
+ * phase.
+ *
+ * @see \Drush\Boot\DrupalBoot::bootstrapPhases()
+ *
+ * @return array of PHASE index => method name.
+ */
+ public function bootstrapPhases();
+
+ /**
+ * Return an array mapping from bootstrap phase shorthand
+ * strings (e.g. "full") to the corresponding bootstrap
+ * phase index constant (e.g. DRUSH_BOOTSTRAP_DRUPAL_FULL).
+ */
+ public function bootstrapPhaseMap();
+
+ /**
+ * Convert from a phase shorthand or constant to a phase index.
+ */
+ public function lookUpPhaseIndex($phase);
+
+ /**
+ * Called by Drush if a command is not found, or if the
+ * command was found, but did not meet requirements.
+ *
+ * The implementation in BaseBoot should be sufficient
+ * for most cases, so this method typically will not need
+ * to be overridden.
+ */
+ public function reportCommandError($command);
+
+ /**
+ * This method is called during the shutdown of drush.
+ *
+ * @return void
+ */
+ public function terminate();
+}