diff --git a/src/el/sayid-magit.el b/src/el/sayid-magit.el
new file mode 100644
index 0000000..a70c2a9
--- /dev/null
+++ b/src/el/sayid-magit.el
@@ -0,0 +1,57 @@
+;;; sayid-magit.el --- Choose sayid tracing from magit -*- lexical-binding: t -*-
+
+;; Author: Mark Dawson
+;; Maintainer: Bill Piel <bill@billpiel.com>
+;; Version: 0.0.1
+;; URL: https://github.com/clojure-emacs/sayid
+;; Package-Requires: ((cider "0.21.0") (magit "2.90.1"))
+
+;; Licensed under the Apache License, Version 2.0 (the "License");
+;; you may not use this file except in compliance with the License.
+;; You may obtain a copy of the License at
+
+;;     http://www.apache.org/licenses/LICENSE-2.0
+
+;; Unless required by applicable law or agreed to in writing, software
+;; distributed under the License is distributed on an "AS IS" BASIS,
+;; WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+;; See the License for the specific language governing permissions and
+;; limitations under the License.
+
+;;; Commentary:
+
+;;; Code:
+
+;;;###autoload
+(defun sayid-magit--trace-ns-in-files (file-names)
+  "Trace namespace in FILE-NAMES."
+  (mapc (lambda (file-name)
+          (with-current-buffer (find-file-noselect
+                                file-name)
+            (nrepl-send-sync-request (list "op" "sayid-trace-ns-in-file"
+                                           "file" (buffer-file-name))
+                                     (cider-current-connection))))
+        file-names)
+  (sayid-show-traced))
+
+;;;###autoload
+(defun sayid-magit--changed-files ()
+  "Return the absolute paths to changed files which have a .clj \
+extension in the current .git directory."
+  (seq-filter
+   (apply-partially #'string-match ".clj$")
+   (mapcar
+    (lambda (file)
+      (expand-file-name file (locate-dominating-file file ".git")))
+    (magit-changed-files (magit-read-starting-point "Sayid trace" nil "HEAD")))))
+
+;;;###autoload
+(defun sayid-magit-trace-changed-ns ()
+  "Trace the changed namespaces in a git commit."
+  (interactive)
+  (sayid-magit--trace-ns-in-files
+   (sayid-magit--changed-files)))
+
+(provide 'sayid-magit)
+
+;;; sayid-magit.el ends here
diff --git a/src/el/sayid.el b/src/el/sayid.el
index 9806c92..6ecf848 100644
--- a/src/el/sayid.el
+++ b/src/el/sayid.el
@@ -564,12 +564,13 @@ Disable traces, load buffer, enable traces, clear log."
   (sayid-show-traced))
 
 ;;;###autoload
-(defun sayid-trace-ns-by-pattern ()
+(defun sayid-trace-ns-by-pattern (ns-pattern)
   "Trace all namespaces that match specified pattern."
-  (interactive)
+  (interactive (list
+                (read-string "Namespace to trace (*=wildcard) "
+                             (cider-current-ns))))
   (nrepl-send-sync-request (list "op" "sayid-trace-ns-by-pattern"
-                                 "ns-pattern" (read-string "Namespace to trace (*=wildcard) "
-                                                           (cider-current-ns))
+                                 "ns-pattern" ns-pattern
                                  "ref-ns" (cider-current-ns))
                            (cider-current-connection))
   (sayid-show-traced))
@@ -718,19 +719,30 @@ Disable traces, load buffer, enable traces, clear log."
         (setq paths (cdr paths)))
       (car paths))))
 
-;;;###autoload
-(defun sayid-buffer-nav-from-point ()
-  "Navigate from sayid buffer to function source."
+(defun sayid-buffer-file-at-point ()
+  "Return file path for function at point in sayid buffer."
   (interactive)
   (let* ((file (get-text-property (point) 'src-file))
-         (line (get-text-property (point) 'src-line))
          (xfile (sayid-find-existing-file file)))
     (if xfile
-        (progn
-          (pop-to-buffer (find-file-noselect xfile))
-          (goto-char (point-min))
-          (forward-line (- line 1)))
-      (message (concat "File not found: " file)))))
+        xfile
+      (user-error (concat "File not found: " file)))))
+
+(defun sayid-buffer-line-at-point ()
+  "Return line number for function at point in sayid buffer."
+  (get-text-property (point) 'src-line))
+
+;;;###autoload
+(defun sayid-buffer-nav-from-point ()
+  "Navigate from sayid buffer to function source."
+  (interactive)
+  (let ((line (sayid-buffer-line-at-point))
+        (file (sayid-buffer-file-at-point)))
+    (when file
+      (progn
+        (pop-to-buffer (find-file-noselect file))
+        (goto-char (point-min))
+        (forward-line (- line 1))))))
 
 ;;;###autoload
 (defun sayid-buffer-nav-to-prev ()
@@ -870,8 +882,8 @@ Disable traces, load buffer, enable traces, clear log."
   "Try to generate an expression that will reproduce traced call.
 Place expression in kill ring."
   (interactive)
-  (let ((expr (sayid-req-get-value (list "op" "sayid-gen-instance-expr"
-                                         "trace-id" (get-text-property (point) 'id)))))
+  (let ((expr (prin1-to-string (sayid-req-get-value (list "op" "sayid-gen-instance-expr"
+                                         "trace-id" (get-text-property (point) 'id))))))
     (kill-new expr)
     (message (concat "Written to kill ring: " expr))
     (sayid-buffer-nav-from-point)))