diff --git a/.travis.yml b/.travis.yml
index 67f98c7..7bf6b81 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -6,6 +6,7 @@ matrix:
   include:
     - php: "7.0"
     - php: "7.1"
+    - php: "7.2"
     - php: "nightly"
   allow_failures:
     - php: "nightly"
diff --git a/bin/create-client.php b/bin/create-client.php
index 582c752..ff0f5a4 100644
--- a/bin/create-client.php
+++ b/bin/create-client.php
@@ -10,6 +10,7 @@
 };
 
 $root = \dirname(__DIR__);
+/** @psalm-suppress UnresolvableInclude */
 require_once $root . '/cli-autoload.php';
 
 if (!\is_readable($root . '/local/settings.json')) {
diff --git a/bin/cross-sign.php b/bin/cross-sign.php
index 09b1612..a1c280c 100644
--- a/bin/cross-sign.php
+++ b/bin/cross-sign.php
@@ -14,6 +14,7 @@
 };
 
 $root = \dirname(__DIR__);
+/** @psalm-suppress UnresolvableInclude */
 require_once $root . '/cli-autoload.php';
 
 if (!\is_readable($root . '/local/settings.json')) {
diff --git a/bin/fix-nulls.php b/bin/fix-nulls.php
index 49e519d..2d51362 100644
--- a/bin/fix-nulls.php
+++ b/bin/fix-nulls.php
@@ -8,6 +8,7 @@
 use ParagonIE\Chronicle\Chronicle;
 
 $root = \dirname(__DIR__);
+/** @psalm-suppress UnresolvableInclude */
 require_once $root . '/cli-autoload.php';
 
 if (!\is_readable($root . '/local/settings.json')) {
diff --git a/bin/install.php b/bin/install.php
index 7f55dcc..0a5cc07 100644
--- a/bin/install.php
+++ b/bin/install.php
@@ -2,6 +2,7 @@
 declare(strict_types=1);
 
 $root = \dirname(__DIR__);
+/** @psalm-suppress UnresolvableInclude */
 require_once $root . '/cli-autoload.php';
 
 // Generate a signing key.
diff --git a/bin/keygen.php b/bin/keygen.php
index 623c031..37476d4 100644
--- a/bin/keygen.php
+++ b/bin/keygen.php
@@ -4,12 +4,13 @@
 use ParagonIE\Sapient\CryptographyKeys\SigningSecretKey;
 
 $root = \dirname(__DIR__);
+/** @psalm-suppress UnresolvableInclude */
 require_once $root . '/cli-autoload.php';
 
 /* This generates a new secret key from your kernel's CSPRNG */
 $signingSecretKey = SigningSecretKey::generate();
 
-echo json_encode(
+echo (string) json_encode(
     [
         'secret-key' => $signingSecretKey->getString(),
         'public-key' => $signingSecretKey->getPublicKey()->getString()
diff --git a/bin/make-tables.php b/bin/make-tables.php
index 7db9bef..df90868 100644
--- a/bin/make-tables.php
+++ b/bin/make-tables.php
@@ -2,7 +2,9 @@
 declare(strict_types=1);
 
 $root = \dirname(__DIR__);
+/** @psalm-suppress UnresolvableInclude */
 require_once $root . '/cli-autoload.php';
+/** @psalm-suppress UnresolvableInclude */
 require_once $root . '/src/settings.php';
 
 /**
@@ -29,7 +31,7 @@
 
 if (empty($settings['database'])) {
     echo "Please defined a database in local/settings.json. For example:\n\n";
-    echo \json_encode(
+    echo (string) \json_encode(
         [
             'database' => [
                 'dsn' => 'pgsql:rest-of-dsn-goes-here',
diff --git a/bin/replicate.php b/bin/replicate.php
index a6e9f36..15f0099 100644
--- a/bin/replicate.php
+++ b/bin/replicate.php
@@ -14,6 +14,7 @@
 };
 
 $root = \dirname(__DIR__);
+/** @psalm-suppress UnresolvableInclude */
 require_once $root . '/cli-autoload.php';
 
 if (!\is_readable($root . '/local/settings.json')) {
diff --git a/bin/scheduled-tasks.php b/bin/scheduled-tasks.php
index 0db7305..b83e957 100644
--- a/bin/scheduled-tasks.php
+++ b/bin/scheduled-tasks.php
@@ -8,6 +8,7 @@
 use ParagonIE\Chronicle\Chronicle;
 
 $root = \dirname(__DIR__);
+/** @psalm-suppress UnresolvableInclude */
 require_once $root . '/cli-autoload.php';
 
 if (!\is_readable($root . '/local/settings.json')) {
diff --git a/composer.json b/composer.json
index 279b7ce..e31dcf0 100644
--- a/composer.json
+++ b/composer.json
@@ -28,7 +28,7 @@
     },
     "require-dev": {
         "phpunit/phpunit": "^6",
-        "vimeo/psalm": "^0.3"
+        "vimeo/psalm": "^0"
     },
     "autoload-dev": {
         "psr-4": {
@@ -37,7 +37,7 @@
         }
     },
 	"scripts": {
-        "start": "php -S 0.0.0.0:8080 -t public public/index.php",
+        "start": "php -S 0.0.0.0:8080 -t public index.php",
         "static-analysis": "psalm",
         "test": "phpunit"
 	}
diff --git a/src/Chronicle/Handlers/Register.php b/src/Chronicle/Handlers/Register.php
index 1674725..39f2b87 100644
--- a/src/Chronicle/Handlers/Register.php
+++ b/src/Chronicle/Handlers/Register.php
@@ -3,8 +3,8 @@
 
 use ParagonIE\Chronicle\{
     Chronicle,
-    Exception\AccessDenied,
-    Exception\HTTPException,
+    Exception\ChainAppendException,
+    Exception\FilesystemException,
     Exception\SecurityViolation,
     HandlerInterface,
     Scheduled
@@ -32,9 +32,9 @@ class Register implements HandlerInterface
      * @param array $args
      * @return ResponseInterface
      *
-     * @throws AccessDenied
-     * @throws HTTPException
-     * @throws SecurityViolation
+     * @throws ChainAppendException
+     * @throws FilesystemException
+     * @throws \SodiumException
      * @throws \TypeError
      */
     public function __invoke(
@@ -105,6 +105,7 @@ public function __invoke(
         $settings = Chronicle::getSettings();
         if (!empty($settings['publish-new-clients'])) {
             $serverKey = Chronicle::getSigningKey();
+            /** @var string $message */
             $message = \json_encode(
                 [
                     'server-action' => 'New Client Registration',
@@ -114,6 +115,9 @@ public function __invoke(
                 ],
                 JSON_PRETTY_PRINT
             );
+            if (!\is_string($message)) {
+                throw new \TypeError('Invalid messsage');
+            }
             $signature = Base64UrlSafe::encode(
                 \ParagonIE_Sodium_Compat::crypto_sign_detached(
                     $message,
diff --git a/src/Chronicle/Handlers/Replica.php b/src/Chronicle/Handlers/Replica.php
index 93907b1..3d33d19 100644
--- a/src/Chronicle/Handlers/Replica.php
+++ b/src/Chronicle/Handlers/Replica.php
@@ -4,6 +4,7 @@
 
 use ParagonIE\Chronicle\{
     Chronicle,
+    Exception\FilesystemException,
     Exception\ReplicationSourceNotFound,
     Exception\HashNotFound,
     HandlerInterface
@@ -93,6 +94,7 @@ public function __invoke(
      * Gets the entire Blakechain.
      *
      * @return ResponseInterface
+     * @throws FilesystemException
      */
     public function exportChain(): ResponseInterface
     {
@@ -115,6 +117,7 @@ public function exportChain(): ResponseInterface
      * @param array $args
      * @return ResponseInterface
      * @throws HashNotFound
+     * @throws FilesystemException
      */
     public function getByHash(array $args = []): ResponseInterface
     {
@@ -159,6 +162,7 @@ public function getByHash(array $args = []): ResponseInterface
      * List the latest current hash and summary hash for this replica
      *
      * @return ResponseInterface
+     * @throws FilesystemException
      */
     public function getLastHash(): ResponseInterface
     {
@@ -197,6 +201,7 @@ public function getLastHash(): ResponseInterface
      * List all replicated Chronicles and their respective URIs
      *
      * @return ResponseInterface
+     * @throws FilesystemException
      */
     protected function getIndex(): ResponseInterface
     {
@@ -243,6 +248,7 @@ protected function getIndex(): ResponseInterface
      *
      * @param array $args
      * @return ResponseInterface
+     * @throws FilesystemException
      * @throws HashNotFound
      */
     public function getSince(array $args = []): ResponseInterface
diff --git a/src/Chronicle/Handlers/Revoke.php b/src/Chronicle/Handlers/Revoke.php
index 9ba22ad..d46ac3a 100644
--- a/src/Chronicle/Handlers/Revoke.php
+++ b/src/Chronicle/Handlers/Revoke.php
@@ -4,8 +4,8 @@
 use ParagonIE\Chronicle\{
     Chronicle,
     Exception\AccessDenied,
-    Exception\ClientNotFound,
-    Exception\HTTPException,
+    Exception\ChainAppendException,
+    Exception\FilesystemException,
     HandlerInterface,
     Scheduled
 };
@@ -32,8 +32,9 @@ class Revoke implements HandlerInterface
      * @return ResponseInterface
      *
      * @throws AccessDenied
-     * @throws ClientNotFound
-     * @throws HTTPException
+     * @throws ChainAppendException
+     * @throws FilesystemException
+     * @throws \SodiumException
      * @throws \TypeError
      */
     public function __invoke(
@@ -115,7 +116,7 @@ public function __invoke(
             ];
 
             if (!$result['deleted']) {
-                $result['reason'] = 'Delete operatio nwas unsuccessful due to unknown reasons.';
+                $result['reason'] = 'Delete operation was unsuccessful due to unknown reasons.';
             }
             $now = (new \DateTime())->format(\DateTime::ATOM);
 
@@ -126,11 +127,14 @@ public function __invoke(
                     [
                         'server-action' => 'Client Access Revocation',
                         'now' => $now,
-                        'clientid' => $result['client-id'],
+                        'clientid' => $post['clientid'],
                         'publickey' => $post['publickey']
                     ],
                     JSON_PRETTY_PRINT
                 );
+                if (!\is_string($message)) {
+                    throw new \TypeError('Invalid messsage');
+                }
                 $signature = Base64UrlSafe::encode(
                     \ParagonIE_Sodium_Compat::crypto_sign_detached(
                         $message,
diff --git a/src/Chronicle/Process/Attest.php b/src/Chronicle/Process/Attest.php
index 3221ddc..e8dade5 100644
--- a/src/Chronicle/Process/Attest.php
+++ b/src/Chronicle/Process/Attest.php
@@ -77,6 +77,10 @@ public function run()
 
     /**
      * @return array
+     * @throws FilesystemException
+     * @throws \ParagonIE\Chronicle\Exception\ChainAppendException
+     * @throws \SodiumException
+     * @throws \TypeError
      */
     public function attestAll(): array
     {
@@ -91,6 +95,7 @@ public function attestAll(): array
         }
 
         // Build the message
+        /** @var string $message */
         $message = \json_encode(
             [
                 'version' => Chronicle::VERSION,
@@ -99,6 +104,9 @@ public function attestAll(): array
             ],
             JSON_PRETTY_PRINT
         );
+        if (!\is_string($message)) {
+            throw new \TypeError('Invalid messsage');
+        }
 
         // Sign the message:
         $signature = Base64UrlSafe::encode(
diff --git a/src/routes.php b/src/routes.php
index 40bd452..d348371 100644
--- a/src/routes.php
+++ b/src/routes.php
@@ -15,6 +15,7 @@
     CheckClientSignature
 };
 use Psr\Http\Message\{
+    RequestInterface,
     ResponseInterface
 };
 
@@ -58,7 +59,7 @@
     $this->get('', Index::class);
 });
 
-$app->get('/', function ($request, $response, $args): ResponseInterface {
+$app->get('/', function (RequestInterface $request, ResponseInterface $response, array $args = []): ResponseInterface {
     /* UX enhancement: Automatically redirect to chronicle URI if client header is present: */
     if ($request instanceof \Slim\Http\Request && $response instanceof \Slim\Http\Response) {
         if ($request->hasHeader(Chronicle::CLIENT_IDENTIFIER_HEADER)) {