diff --git a/slackronyms/.slack/.gitignore b/slackronyms/.slack/.gitignore
new file mode 100644
index 0000000..973ba60
--- /dev/null
+++ b/slackronyms/.slack/.gitignore
@@ -0,0 +1,2 @@
+apps.dev.json
+cache/
diff --git a/slackronyms/.slack/config.json b/slackronyms/.slack/config.json
new file mode 100644
index 0000000..fa7669f
--- /dev/null
+++ b/slackronyms/.slack/config.json
@@ -0,0 +1,6 @@
+{
+  "manifest": {
+    "source": "local"
+  },
+  "project_id": "725579d7-7881-4412-8090-c011a560fa42"
+}
diff --git a/slackronyms/.slack/hooks.json b/slackronyms/.slack/hooks.json
new file mode 100644
index 0000000..ce474c9
--- /dev/null
+++ b/slackronyms/.slack/hooks.json
@@ -0,0 +1,5 @@
+{
+  "hooks": {
+    "get-hooks": "python3 -m slack_cli_hooks.hooks.get_hooks"
+  }
+}
diff --git a/slackronyms/app.py b/slackronyms/app.py
new file mode 100644
index 0000000..4780df2
--- /dev/null
+++ b/slackronyms/app.py
@@ -0,0 +1,25 @@
+import logging
+import os
+
+from listeners import register_listeners
+from slack_bolt import App
+from slack_bolt.adapter.socket_mode import SocketModeHandler
+
+logging.basicConfig(level=logging.DEBUG)
+
+# From OAuth & Permissions tab
+bot_user_oauth_token = os.environ.get("SLACK_BOT_TOKEN")
+
+# From Basic Information tab's App-Level Tokens section
+app_token = os.environ.get("SLACK_APP_TOKEN")
+
+# Initialization
+app = App(token=bot_user_oauth_token)
+
+# Register Listeners
+register_listeners(app)
+
+# Start Bolt app
+if __name__ == "__main__":
+    # app.start(port=8080)
+    SocketModeHandler(app, app_token).start()
diff --git a/slackronyms/data/.gitkeep b/slackronyms/data/.gitkeep
new file mode 100644
index 0000000..e69de29
diff --git a/slackronyms/listeners/__init__.py b/slackronyms/listeners/__init__.py
new file mode 100644
index 0000000..b647612
--- /dev/null
+++ b/slackronyms/listeners/__init__.py
@@ -0,0 +1,5 @@
+from listeners import commands
+
+
+def register_listeners(app):
+    commands.register(app)
diff --git a/slackronyms/listeners/commands/__init__.py b/slackronyms/listeners/commands/__init__.py
new file mode 100644
index 0000000..204b0a6
--- /dev/null
+++ b/slackronyms/listeners/commands/__init__.py
@@ -0,0 +1,6 @@
+from slack_bolt import App
+
+from .define import define_callback
+
+def register(app: App):
+    app.command("/define")(define_callback)
diff --git a/slackronyms/listeners/commands/define.py b/slackronyms/listeners/commands/define.py
new file mode 100644
index 0000000..a49d9ee
--- /dev/null
+++ b/slackronyms/listeners/commands/define.py
@@ -0,0 +1,57 @@
+import json
+from datetime import datetime as dt
+from logging import Logger
+
+from slack_bolt import Ack, Respond
+
+
+def define_callback(command, ack: Ack, respond: Respond, logger: Logger):
+    logger.debug(command)
+
+    # TODO: DETERMINE HOW TO HANDLE REMOTE STORAGE OF THIS JSON FILE
+
+    # load the current list of terms into a dict
+    with open("data/terms.json", mode="r", encoding="utf-8") as read_file:
+        terms = json.load(read_file)
+
+    # split command text at the first colon (if any) and detemine whether we have a term
+    text = command["text"]
+    text = text.split(":", maxsplit=1)
+    term = text[0].strip()
+
+    # check whether the term we ened up with isn't just an empty string
+    if term:
+        try:
+            if len(text) == 2:
+                # the split resulted in the list `text` having two items, so this is a request to set a definition
+                definition = text[1].strip()
+                if definition:
+                    ack()
+                    terms[term] = {
+                        "definition": definition,
+                        "added_by": command["user_name"],
+                        "added_on": dt.now().strftime("%Y-%m-%d %H:%M:%S"),
+                    }
+                    with open("data/terms.json", mode="w", encoding="utf-8") as write_file:
+                        json.dump(terms, write_file, indent=2)
+                    respond(f'*{term}* is now defined as "{definition}"', response_type="ephemeral")
+                else:
+                    ack("Please specify a definition after the colon.")
+            else:
+                # the split resulted in the list `text` having only one item, so this is a request to output a definition
+                ack()
+
+                # TODO: MATCH TERMS CASE INSENSITIVELY
+
+                if term_dict := terms.get(term):
+                    # definition exists, so spit it out publicly
+                    respond(
+                        f"Someone asked what *{term}* means. It means: *{term_dict['definition']}*", response_type="in_channel"
+                    )
+                else:
+                    # definition doesn't exist, let the requester know that privately
+                    respond(f"*{term}* not found. Use `/define {term}: <definition>` to add it.", response_type="ephemeral")
+        except Exception as e:
+            logger.error(e)
+    else:
+        ack("You must specify a term.")
diff --git a/slackronyms/manifest.json b/slackronyms/manifest.json
new file mode 100644
index 0000000..470e2a9
--- /dev/null
+++ b/slackronyms/manifest.json
@@ -0,0 +1,58 @@
+{
+  "_metadata": {
+    "major_version": 1,
+    "minor_version": 1
+  },
+  "display_information": {
+    "name": "Slackronyms"
+  },
+  "features": {
+    "app_home": {
+      "home_tab_enabled": true,
+      "messages_tab_enabled": false,
+      "messages_tab_read_only_enabled": true
+    },
+    "bot_user": {
+      "display_name": "Slackronyms",
+      "always_online": false
+    },
+    "shortcuts": [
+      {
+        "name": "Run sample shortcut",
+        "type": "global",
+        "callback_id": "sample_shortcut_id",
+        "description": "Runs a sample shortcut"
+      }
+    ],
+    "slash_commands": [
+      {
+        "command": "/define",
+        "description": "Explain the given term. Add a colon and definition to set it.",
+        "usage_hint": "term[: definition]",
+        "should_escape": false
+      },
+      {
+        "command": "/sample-command",
+        "description": "Runs a sample command",
+        "should_escape": false
+      }
+    ]
+  },
+  "oauth_config": {
+    "scopes": {
+      "bot": ["chat:write", "chat:write.public", "commands"]
+    }
+  },
+  "settings": {
+    "event_subscriptions": {
+      "bot_events": ["app_home_opened", "message.channels"]
+    },
+    "interactivity": {
+      "is_enabled": true
+    },
+    "org_deploy_enabled": false,
+    "socket_mode_enabled": true,
+    "token_rotation_enabled": false,
+    "is_mcp_enabled": false
+  }
+}
diff --git a/slackronyms/requirements.txt b/slackronyms/requirements.txt
new file mode 100644
index 0000000..0b4fef7
--- /dev/null
+++ b/slackronyms/requirements.txt
@@ -0,0 +1,4 @@
+Flask==3.1.3
+slack-bolt==1.28.0
+slack-cli-hooks<1.0.0
+slack-sdk==3.42.0
diff --git a/slackronyms/tests/__init__.py b/slackronyms/tests/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/slackronyms/tests/listeners/__init__.py b/slackronyms/tests/listeners/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/slackronyms/tests/listeners/commands/__init__.py b/slackronyms/tests/listeners/commands/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/slackronyms/tests/listeners/commands/test_define.py b/slackronyms/tests/listeners/commands/test_define.py
new file mode 100644
index 0000000..4e25691
--- /dev/null
+++ b/slackronyms/tests/listeners/commands/test_define.py
@@ -0,0 +1,41 @@
+import logging
+from unittest.mock import Mock
+
+from listeners.commands.define import define_callback
+from slack_bolt import Ack, Respond
+
+test_logger = logging.getLogger(__name__)
+
+
+class TestDefine:
+    def setup_method(self):
+        self.fake_ack = Mock(Ack)
+        self.fake_respond = Mock(Respond)
+        self.fake_command = {"text": "TEST"}
+
+    def test_define_callback_definition(self):
+        command = {"text": "who"}
+        define_callback(
+            command,
+            ack=self.fake_ack,
+            respond=self.fake_respond,
+            logger=test_logger,
+        )
+
+        self.fake_ack.assert_called_once()
+
+        self.fake_respond.assert_called_once()
+        args = self.fake_respond.call_args.args
+        assert "he's on first" in args[0]
+
+    def test_ack_exception(self, caplog):
+        self.fake_ack.side_effect = Exception("test exception")
+        define_callback(
+            self.fake_command,
+            ack=self.fake_ack,
+            respond=self.fake_respond,
+            logger=test_logger,
+        )
+
+        self.fake_ack.assert_called_once()
+        assert str(self.fake_ack.side_effect) in caplog.text