diff --git a/Gemfile b/Gemfile
index 75a49ba7..2b5631d7 100644
--- a/Gemfile
+++ b/Gemfile
@@ -36,6 +36,7 @@ group :development do
   gem "spring"
   gem "spring-watcher-listen"
   gem "pry-rails"
+  gem "seedbank"
 end
 
 group :test do
diff --git a/Gemfile.lock b/Gemfile.lock
index a5a4083f..68f3d5d1 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -228,6 +228,8 @@ GEM
       sprockets (> 3.0)
       sprockets-rails
       tilt
+    seedbank (0.5.0)
+      rake (>= 10.0)
     semantic_range (3.0.0)
     sentry-raven (3.1.2)
       faraday (>= 1.0)
@@ -300,6 +302,7 @@ DEPENDENCIES
   rinku
   rspec-rails
   sass-rails (>= 6)
+  seedbank
   sentry-raven
   shoulda-matchers
   simplecov
diff --git a/config/application.yml b/config/application.yml
index 0329afe3..297363f1 100644
--- a/config/application.yml
+++ b/config/application.yml
@@ -6,7 +6,7 @@ auth_user: bob
 auth_password: password
 
 development:
-  todo_file: /home/bob/src/tmp/test/foo.todo
+  todo_file: tmp/todo_repo/todo.txt
   git_email: bob.whitelock1+todotxt-dev@gmail.com
 
 test:
diff --git a/db/seeds/development/deltas.seeds.rb b/db/seeds/development/deltas.seeds.rb
new file mode 100644
index 00000000..bd42fb05
--- /dev/null
+++ b/db/seeds/development/deltas.seeds.rb
@@ -0,0 +1,18 @@
+after "development:repo" do
+  new_task = "a new task"
+  today = Date.today.to_s
+  applied_new_task = "#{today} #{new_task}"
+
+  seed_deltas = [
+    {type: Delta::ADD, arguments: [new_task]},
+    {type: Delta::UPDATE, arguments: [applied_new_task, "#{applied_new_task} - now updated"]},
+    {type: Delta::DELETE, arguments: [TASK_TO_BE_DELETED]},
+    {type: Delta::COMPLETE, arguments: [TASK_TO_BE_COMPLETED]},
+    {type: Delta::SCHEDULE, arguments: [TASK_TO_BE_SCHEDULED]},
+    {type: Delta::UNSCHEDULE, arguments: [TASK_TO_BE_UNSCHEDULED]}
+  ]
+
+  seed_deltas.each do |args|
+    Delta.create!(args)
+  end
+end
diff --git a/db/seeds/development/repo.seeds.rb b/db/seeds/development/repo.seeds.rb
new file mode 100644
index 00000000..b5cea291
--- /dev/null
+++ b/db/seeds/development/repo.seeds.rb
@@ -0,0 +1,76 @@
+TODO_REPO = Rails.root.join("tmp/todo_repo")
+
+TASK_TO_BE_DELETED = "task to be deleted"
+TASK_TO_BE_COMPLETED = "task to be completed"
+TASK_TO_BE_SCHEDULED = "task to be scheduled"
+TASK_TO_BE_UNSCHEDULED = "task to be unscheduled @today"
+
+def system!(*args)
+  Kernel.system(*args, exception: true)
+end
+
+def in_todo_repo(command)
+  system! "cd #{TODO_REPO} && #{command}"
+end
+
+seed_tasks = [
+  "2021-03-22 simple task 1",
+  "2021-03-23 simple task 2",
+  "2021-03-24 simple task 3",
+  "2021-03-25 task with some tags +todotxt-ui @work @code @home key:value",
+  "2021-03-26 another task with some tags @work @code key:value2",
+  "2021-03-27 short",
+  "2021-03-28 very long context @pneumonoultramicroscopicsilicovolcanoconiosis",
+  "2021-03-29 very long project +pneumonoultramicroscopicsilicovolcanoconiosis",
+  "2021-03-30 very long metadata disease:pneumonoultramicroscopicsilicovolcanoconiosis",
+  "2021-03-31 task with a due date due:2021-08-13",
+  "2021-04-01 another task with a due date due:2021-08-11",
+  "2021-04-02 task that has previously been scheduled scheduled:3",
+  "2021-04-03 task from yesterday @yesterday scheduled:1",
+  "2021-04-04 task for today @today",
+  "2021-04-05 task for tomorrow @tomorrow",
+  "2021-04-06 task for Monday @monday",
+  "2021-04-07 task with URL: https://github.com/bobwhitelock/todotxt-ui",
+  "2021-04-08 task with backticks `@work` `+todotxt-ui`",
+  "x 2021-04-13 2021-04-09 complete task",
+  "(A) 2021-04-10 highest priority task",
+  "(B) 2021-04-11 high priority task",
+  "(C) 2021-04-12 lower priority task",
+  "(Z) 2021-04-13 lowest priority task",
+  "task without date",
+  TASK_TO_BE_DELETED,
+  TASK_TO_BE_COMPLETED,
+  TASK_TO_BE_SCHEDULED,
+  TASK_TO_BE_UNSCHEDULED,
+  <<~TODOTXT.squish
+    2021-04-14 a very long task that takes up lots of space -
+
+    In a hole in the ground there lived a hobbit. Not a nasty, dirty, wet hole,
+    filled with the ends of worms and an oozy smell, nor yet a dry, bare, sandy
+    hole with nothing in it to sit down on or to eat: it was a hobbit-hole, and
+    that means comfort.
+
+    It had a perfectly round door like a porthole, painted green, with a shiny
+    yellow brass knob in the exact middle. The door opened on to a tube-shaped
+    hall like a tunnel: a very comfortable tunnel without smoke, with panelled
+    walls, and floors tiled and carpeted, provided with polished chairs, and lots
+    and lots of pegs for hats and coats - the hobbit was fond of visitors.
+  TODOTXT
+]
+
+# Recreate repo.
+TODO_REPO.rmtree
+TODO_REPO.mkpath
+in_todo_repo "git init"
+in_todo_repo "git remote add origin git@github.com:bobwhitelock/todotxt-ui_test-repo.git"
+
+# Create todo file.
+#
+# Also set as the `TODO_FILE` to use in development in
+# `config/application.yml`.
+todo_file = TODO_REPO.join("todo.txt").to_s
+todo_file_content = seed_tasks.join("\n") + "\n"
+IO.write(todo_file, todo_file_content)
+in_todo_repo "git add ."
+in_todo_repo "git commit -m 'Initial commit'"
+in_todo_repo "git push --force"