diff --git a/.env.example b/.env.example
index 766fc7d..398d62d 100644
--- a/.env.example
+++ b/.env.example
@@ -25,3 +25,6 @@ BACKUP_RETAIN=7
 BACKUP_REPLICA_DIR=
 # Optional public HTTPS health URL for the independent monitor.
 MONITOR_URL=
+# Discord Developer Portal > General Information > Public Key.
+# Interactions endpoint: https://YOUR_PRODUCTION_HOST/api/discord/interactions
+DISCORD_PUBLIC_KEY=
diff --git a/drizzle/0012_discord_commands.sql b/drizzle/0012_discord_commands.sql
new file mode 100644
index 0000000..9505867
--- /dev/null
+++ b/drizzle/0012_discord_commands.sql
@@ -0,0 +1,20 @@
+CREATE TABLE `discord_controls` (
+	`id` text PRIMARY KEY NOT NULL,
+	`user_id` text NOT NULL,
+	`action` text NOT NULL,
+	`payload` text NOT NULL,
+	`expires_at` integer NOT NULL,
+	`used` integer DEFAULT false NOT NULL,
+	FOREIGN KEY (`user_id`) REFERENCES `users`(`id`) ON UPDATE no action ON DELETE cascade
+);
+--> statement-breakpoint
+CREATE INDEX `discord_controls_expiry_idx` ON `discord_controls` (`expires_at`);--> statement-breakpoint
+CREATE TABLE `discord_receipts` (
+	`id` text PRIMARY KEY NOT NULL,
+	`user_id` text NOT NULL,
+	`response` text NOT NULL,
+	`expires_at` integer NOT NULL,
+	FOREIGN KEY (`user_id`) REFERENCES `users`(`id`) ON UPDATE no action ON DELETE cascade
+);
+--> statement-breakpoint
+CREATE INDEX `discord_receipts_expiry_idx` ON `discord_receipts` (`expires_at`);
\ No newline at end of file
diff --git a/drizzle/meta/0012_snapshot.json b/drizzle/meta/0012_snapshot.json
new file mode 100644
index 0000000..c85acee
--- /dev/null
+++ b/drizzle/meta/0012_snapshot.json
@@ -0,0 +1,1217 @@
+{
+  "version": "6",
+  "dialect": "sqlite",
+  "id": "39a7a2c2-c411-4e0a-ba41-9e4abdc8fbcf",
+  "prevId": "31d42afd-5a60-4cbe-8188-d9aff933e13e",
+  "tables": {
+    "combined_charts": {
+      "name": "combined_charts",
+      "columns": {
+        "id": {
+          "name": "id",
+          "type": "text",
+          "primaryKey": true,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "user_id": {
+          "name": "user_id",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "name": {
+          "name": "name",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "habit_ids": {
+          "name": "habit_ids",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "settings": {
+          "name": "settings",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "created_at": {
+          "name": "created_at",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "updated_at": {
+          "name": "updated_at",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        }
+      },
+      "indexes": {
+        "combined_charts_user_idx": {
+          "name": "combined_charts_user_idx",
+          "columns": [
+            "user_id"
+          ],
+          "isUnique": false
+        }
+      },
+      "foreignKeys": {
+        "combined_charts_user_id_users_id_fk": {
+          "name": "combined_charts_user_id_users_id_fk",
+          "tableFrom": "combined_charts",
+          "tableTo": "users",
+          "columnsFrom": [
+            "user_id"
+          ],
+          "columnsTo": [
+            "id"
+          ],
+          "onDelete": "no action",
+          "onUpdate": "no action"
+        }
+      },
+      "compositePrimaryKeys": {},
+      "uniqueConstraints": {},
+      "checkConstraints": {}
+    },
+    "discord_controls": {
+      "name": "discord_controls",
+      "columns": {
+        "id": {
+          "name": "id",
+          "type": "text",
+          "primaryKey": true,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "user_id": {
+          "name": "user_id",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "action": {
+          "name": "action",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "payload": {
+          "name": "payload",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "expires_at": {
+          "name": "expires_at",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "used": {
+          "name": "used",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false,
+          "default": false
+        }
+      },
+      "indexes": {
+        "discord_controls_expiry_idx": {
+          "name": "discord_controls_expiry_idx",
+          "columns": [
+            "expires_at"
+          ],
+          "isUnique": false
+        }
+      },
+      "foreignKeys": {
+        "discord_controls_user_id_users_id_fk": {
+          "name": "discord_controls_user_id_users_id_fk",
+          "tableFrom": "discord_controls",
+          "tableTo": "users",
+          "columnsFrom": [
+            "user_id"
+          ],
+          "columnsTo": [
+            "id"
+          ],
+          "onDelete": "cascade",
+          "onUpdate": "no action"
+        }
+      },
+      "compositePrimaryKeys": {},
+      "uniqueConstraints": {},
+      "checkConstraints": {}
+    },
+    "discord_deliveries": {
+      "name": "discord_deliveries",
+      "columns": {
+        "id": {
+          "name": "id",
+          "type": "text",
+          "primaryKey": true,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "user_id": {
+          "name": "user_id",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "image_hash": {
+          "name": "image_hash",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "status": {
+          "name": "status",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "message_url": {
+          "name": "message_url",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": false,
+          "autoincrement": false
+        },
+        "created_at": {
+          "name": "created_at",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        }
+      },
+      "indexes": {},
+      "foreignKeys": {
+        "discord_deliveries_user_id_users_id_fk": {
+          "name": "discord_deliveries_user_id_users_id_fk",
+          "tableFrom": "discord_deliveries",
+          "tableTo": "users",
+          "columnsFrom": [
+            "user_id"
+          ],
+          "columnsTo": [
+            "id"
+          ],
+          "onDelete": "cascade",
+          "onUpdate": "no action"
+        }
+      },
+      "compositePrimaryKeys": {},
+      "uniqueConstraints": {},
+      "checkConstraints": {}
+    },
+    "discord_receipts": {
+      "name": "discord_receipts",
+      "columns": {
+        "id": {
+          "name": "id",
+          "type": "text",
+          "primaryKey": true,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "user_id": {
+          "name": "user_id",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "response": {
+          "name": "response",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "expires_at": {
+          "name": "expires_at",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        }
+      },
+      "indexes": {
+        "discord_receipts_expiry_idx": {
+          "name": "discord_receipts_expiry_idx",
+          "columns": [
+            "expires_at"
+          ],
+          "isUnique": false
+        }
+      },
+      "foreignKeys": {
+        "discord_receipts_user_id_users_id_fk": {
+          "name": "discord_receipts_user_id_users_id_fk",
+          "tableFrom": "discord_receipts",
+          "tableTo": "users",
+          "columnsFrom": [
+            "user_id"
+          ],
+          "columnsTo": [
+            "id"
+          ],
+          "onDelete": "cascade",
+          "onUpdate": "no action"
+        }
+      },
+      "compositePrimaryKeys": {},
+      "uniqueConstraints": {},
+      "checkConstraints": {}
+    },
+    "habit_calendar_settings": {
+      "name": "habit_calendar_settings",
+      "columns": {
+        "habit_id": {
+          "name": "habit_id",
+          "type": "text",
+          "primaryKey": true,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "settings": {
+          "name": "settings",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        }
+      },
+      "indexes": {},
+      "foreignKeys": {
+        "habit_calendar_settings_habit_id_habits_id_fk": {
+          "name": "habit_calendar_settings_habit_id_habits_id_fk",
+          "tableFrom": "habit_calendar_settings",
+          "tableTo": "habits",
+          "columnsFrom": [
+            "habit_id"
+          ],
+          "columnsTo": [
+            "id"
+          ],
+          "onDelete": "no action",
+          "onUpdate": "no action"
+        }
+      },
+      "compositePrimaryKeys": {},
+      "uniqueConstraints": {},
+      "checkConstraints": {}
+    },
+    "habit_days": {
+      "name": "habit_days",
+      "columns": {
+        "id": {
+          "name": "id",
+          "type": "integer",
+          "primaryKey": true,
+          "notNull": true,
+          "autoincrement": true
+        },
+        "habit_id": {
+          "name": "habit_id",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "revision_id": {
+          "name": "revision_id",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "date": {
+          "name": "date",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "timezone": {
+          "name": "timezone",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "ends_at": {
+          "name": "ends_at",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "count_set": {
+          "name": "count_set",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false,
+          "default": false
+        },
+        "count": {
+          "name": "count",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false,
+          "default": 0
+        },
+        "done": {
+          "name": "done",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false,
+          "default": false
+        }
+      },
+      "indexes": {
+        "habit_days_lookup_idx": {
+          "name": "habit_days_lookup_idx",
+          "columns": [
+            "habit_id",
+            "date",
+            "revision_id"
+          ],
+          "isUnique": false
+        }
+      },
+      "foreignKeys": {
+        "habit_days_habit_id_habits_id_fk": {
+          "name": "habit_days_habit_id_habits_id_fk",
+          "tableFrom": "habit_days",
+          "tableTo": "habits",
+          "columnsFrom": [
+            "habit_id"
+          ],
+          "columnsTo": [
+            "id"
+          ],
+          "onDelete": "no action",
+          "onUpdate": "no action"
+        },
+        "habit_days_revision_id_habit_revisions_id_fk": {
+          "name": "habit_days_revision_id_habit_revisions_id_fk",
+          "tableFrom": "habit_days",
+          "tableTo": "habit_revisions",
+          "columnsFrom": [
+            "revision_id"
+          ],
+          "columnsTo": [
+            "id"
+          ],
+          "onDelete": "no action",
+          "onUpdate": "no action"
+        }
+      },
+      "compositePrimaryKeys": {},
+      "uniqueConstraints": {},
+      "checkConstraints": {}
+    },
+    "habit_revisions": {
+      "name": "habit_revisions",
+      "columns": {
+        "id": {
+          "name": "id",
+          "type": "integer",
+          "primaryKey": true,
+          "notNull": true,
+          "autoincrement": true
+        },
+        "habit_id": {
+          "name": "habit_id",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "effective_date": {
+          "name": "effective_date",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "config": {
+          "name": "config",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "created_at": {
+          "name": "created_at",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        }
+      },
+      "indexes": {
+        "habit_revisions_date_idx": {
+          "name": "habit_revisions_date_idx",
+          "columns": [
+            "habit_id",
+            "effective_date",
+            "id"
+          ],
+          "isUnique": false
+        }
+      },
+      "foreignKeys": {
+        "habit_revisions_habit_id_habits_id_fk": {
+          "name": "habit_revisions_habit_id_habits_id_fk",
+          "tableFrom": "habit_revisions",
+          "tableTo": "habits",
+          "columnsFrom": [
+            "habit_id"
+          ],
+          "columnsTo": [
+            "id"
+          ],
+          "onDelete": "no action",
+          "onUpdate": "no action"
+        }
+      },
+      "compositePrimaryKeys": {},
+      "uniqueConstraints": {},
+      "checkConstraints": {}
+    },
+    "habits": {
+      "name": "habits",
+      "columns": {
+        "id": {
+          "name": "id",
+          "type": "text",
+          "primaryKey": true,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "user_id": {
+          "name": "user_id",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "created_date": {
+          "name": "created_date",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "materialized_through": {
+          "name": "materialized_through",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": false,
+          "autoincrement": false
+        },
+        "created_at": {
+          "name": "created_at",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        }
+      },
+      "indexes": {
+        "habits_user_idx": {
+          "name": "habits_user_idx",
+          "columns": [
+            "user_id"
+          ],
+          "isUnique": false
+        }
+      },
+      "foreignKeys": {
+        "habits_user_id_users_id_fk": {
+          "name": "habits_user_id_users_id_fk",
+          "tableFrom": "habits",
+          "tableTo": "users",
+          "columnsFrom": [
+            "user_id"
+          ],
+          "columnsTo": [
+            "id"
+          ],
+          "onDelete": "no action",
+          "onUpdate": "no action"
+        }
+      },
+      "compositePrimaryKeys": {},
+      "uniqueConstraints": {},
+      "checkConstraints": {}
+    },
+    "live_discord_cards": {
+      "name": "live_discord_cards",
+      "columns": {
+        "user_id": {
+          "name": "user_id",
+          "type": "text",
+          "primaryKey": true,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "channel_id": {
+          "name": "channel_id",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "message_id": {
+          "name": "message_id",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": false,
+          "autoincrement": false
+        },
+        "message_url": {
+          "name": "message_url",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": false,
+          "autoincrement": false
+        },
+        "nonce": {
+          "name": "nonce",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "theme": {
+          "name": "theme",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "status": {
+          "name": "status",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "image_hash": {
+          "name": "image_hash",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": false,
+          "autoincrement": false
+        },
+        "dirty": {
+          "name": "dirty",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false,
+          "default": true
+        },
+        "error": {
+          "name": "error",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": false,
+          "autoincrement": false
+        },
+        "retry_at": {
+          "name": "retry_at",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": false,
+          "autoincrement": false
+        },
+        "updated_at": {
+          "name": "updated_at",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        }
+      },
+      "indexes": {},
+      "foreignKeys": {
+        "live_discord_cards_user_id_users_id_fk": {
+          "name": "live_discord_cards_user_id_users_id_fk",
+          "tableFrom": "live_discord_cards",
+          "tableTo": "users",
+          "columnsFrom": [
+            "user_id"
+          ],
+          "columnsTo": [
+            "id"
+          ],
+          "onDelete": "cascade",
+          "onUpdate": "no action"
+        }
+      },
+      "compositePrimaryKeys": {},
+      "uniqueConstraints": {},
+      "checkConstraints": {}
+    },
+    "progress_events": {
+      "name": "progress_events",
+      "columns": {
+        "id": {
+          "name": "id",
+          "type": "integer",
+          "primaryKey": true,
+          "notNull": true,
+          "autoincrement": true
+        },
+        "day_id": {
+          "name": "day_id",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "occurrence_id": {
+          "name": "occurrence_id",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": false,
+          "autoincrement": false
+        },
+        "before": {
+          "name": "before",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "after": {
+          "name": "after",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "created_at": {
+          "name": "created_at",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        }
+      },
+      "indexes": {
+        "progress_events_day_idx": {
+          "name": "progress_events_day_idx",
+          "columns": [
+            "day_id"
+          ],
+          "isUnique": false
+        }
+      },
+      "foreignKeys": {
+        "progress_events_day_id_habit_days_id_fk": {
+          "name": "progress_events_day_id_habit_days_id_fk",
+          "tableFrom": "progress_events",
+          "tableTo": "habit_days",
+          "columnsFrom": [
+            "day_id"
+          ],
+          "columnsTo": [
+            "id"
+          ],
+          "onDelete": "no action",
+          "onUpdate": "no action"
+        }
+      },
+      "compositePrimaryKeys": {},
+      "uniqueConstraints": {},
+      "checkConstraints": {}
+    },
+    "reminder_deliveries": {
+      "name": "reminder_deliveries",
+      "columns": {
+        "id": {
+          "name": "id",
+          "type": "text",
+          "primaryKey": true,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "user_id": {
+          "name": "user_id",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "slot": {
+          "name": "slot",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false,
+          "default": "'*'"
+        },
+        "date": {
+          "name": "date",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "status": {
+          "name": "status",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "retry_at": {
+          "name": "retry_at",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": false,
+          "autoincrement": false
+        },
+        "updated_at": {
+          "name": "updated_at",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        }
+      },
+      "indexes": {
+        "reminder_deliveries_user_date_slot_idx": {
+          "name": "reminder_deliveries_user_date_slot_idx",
+          "columns": [
+            "user_id",
+            "date",
+            "slot"
+          ],
+          "isUnique": true
+        }
+      },
+      "foreignKeys": {
+        "reminder_deliveries_user_id_users_id_fk": {
+          "name": "reminder_deliveries_user_id_users_id_fk",
+          "tableFrom": "reminder_deliveries",
+          "tableTo": "users",
+          "columnsFrom": [
+            "user_id"
+          ],
+          "columnsTo": [
+            "id"
+          ],
+          "onDelete": "cascade",
+          "onUpdate": "no action"
+        }
+      },
+      "compositePrimaryKeys": {},
+      "uniqueConstraints": {},
+      "checkConstraints": {}
+    },
+    "reminder_settings": {
+      "name": "reminder_settings",
+      "columns": {
+        "user_id": {
+          "name": "user_id",
+          "type": "text",
+          "primaryKey": true,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "enabled": {
+          "name": "enabled",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false,
+          "default": false
+        },
+        "time": {
+          "name": "time",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false,
+          "default": "'20:00'"
+        },
+        "reminders": {
+          "name": "reminders",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": false,
+          "autoincrement": false
+        },
+        "quiet_start": {
+          "name": "quiet_start",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false,
+          "default": "'22:00'"
+        },
+        "quiet_end": {
+          "name": "quiet_end",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false,
+          "default": "'08:00'"
+        },
+        "updated_at": {
+          "name": "updated_at",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        }
+      },
+      "indexes": {},
+      "foreignKeys": {
+        "reminder_settings_user_id_users_id_fk": {
+          "name": "reminder_settings_user_id_users_id_fk",
+          "tableFrom": "reminder_settings",
+          "tableTo": "users",
+          "columnsFrom": [
+            "user_id"
+          ],
+          "columnsTo": [
+            "id"
+          ],
+          "onDelete": "cascade",
+          "onUpdate": "no action"
+        }
+      },
+      "compositePrimaryKeys": {},
+      "uniqueConstraints": {},
+      "checkConstraints": {}
+    },
+    "reminder_worker_state": {
+      "name": "reminder_worker_state",
+      "columns": {
+        "id": {
+          "name": "id",
+          "type": "text",
+          "primaryKey": true,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "blocked_until": {
+          "name": "blocked_until",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        }
+      },
+      "indexes": {},
+      "foreignKeys": {},
+      "compositePrimaryKeys": {},
+      "uniqueConstraints": {},
+      "checkConstraints": {}
+    },
+    "sessions": {
+      "name": "sessions",
+      "columns": {
+        "token_hash": {
+          "name": "token_hash",
+          "type": "text",
+          "primaryKey": true,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "user_id": {
+          "name": "user_id",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "created_at": {
+          "name": "created_at",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "expires_at": {
+          "name": "expires_at",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        }
+      },
+      "indexes": {
+        "sessions_user_id_idx": {
+          "name": "sessions_user_id_idx",
+          "columns": [
+            "user_id"
+          ],
+          "isUnique": false
+        },
+        "sessions_expires_at_idx": {
+          "name": "sessions_expires_at_idx",
+          "columns": [
+            "expires_at"
+          ],
+          "isUnique": false
+        }
+      },
+      "foreignKeys": {
+        "sessions_user_id_users_id_fk": {
+          "name": "sessions_user_id_users_id_fk",
+          "tableFrom": "sessions",
+          "tableTo": "users",
+          "columnsFrom": [
+            "user_id"
+          ],
+          "columnsTo": [
+            "id"
+          ],
+          "onDelete": "cascade",
+          "onUpdate": "no action"
+        }
+      },
+      "compositePrimaryKeys": {},
+      "uniqueConstraints": {},
+      "checkConstraints": {}
+    },
+    "sharing_limits": {
+      "name": "sharing_limits",
+      "columns": {
+        "key": {
+          "name": "key",
+          "type": "text",
+          "primaryKey": true,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "started_at": {
+          "name": "started_at",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "count": {
+          "name": "count",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        }
+      },
+      "indexes": {},
+      "foreignKeys": {},
+      "compositePrimaryKeys": {},
+      "uniqueConstraints": {},
+      "checkConstraints": {}
+    },
+    "task_occurrences": {
+      "name": "task_occurrences",
+      "columns": {
+        "id": {
+          "name": "id",
+          "type": "text",
+          "primaryKey": true,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "day_id": {
+          "name": "day_id",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "task_id": {
+          "name": "task_id",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "name": {
+          "name": "name",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "done": {
+          "name": "done",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false,
+          "default": false
+        },
+        "expired_at": {
+          "name": "expired_at",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": false,
+          "autoincrement": false
+        },
+        "closed_at": {
+          "name": "closed_at",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": false,
+          "autoincrement": false
+        },
+        "updated_at": {
+          "name": "updated_at",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        }
+      },
+      "indexes": {
+        "task_occurrences_day_idx": {
+          "name": "task_occurrences_day_idx",
+          "columns": [
+            "day_id"
+          ],
+          "isUnique": false
+        }
+      },
+      "foreignKeys": {
+        "task_occurrences_day_id_habit_days_id_fk": {
+          "name": "task_occurrences_day_id_habit_days_id_fk",
+          "tableFrom": "task_occurrences",
+          "tableTo": "habit_days",
+          "columnsFrom": [
+            "day_id"
+          ],
+          "columnsTo": [
+            "id"
+          ],
+          "onDelete": "no action",
+          "onUpdate": "no action"
+        }
+      },
+      "compositePrimaryKeys": {},
+      "uniqueConstraints": {},
+      "checkConstraints": {}
+    },
+    "users": {
+      "name": "users",
+      "columns": {
+        "id": {
+          "name": "id",
+          "type": "text",
+          "primaryKey": true,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "discord_id": {
+          "name": "discord_id",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "username": {
+          "name": "username",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "global_name": {
+          "name": "global_name",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": false,
+          "autoincrement": false
+        },
+        "avatar_hash": {
+          "name": "avatar_hash",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": false,
+          "autoincrement": false
+        },
+        "timezone": {
+          "name": "timezone",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false,
+          "default": "'UTC'"
+        },
+        "created_at": {
+          "name": "created_at",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "updated_at": {
+          "name": "updated_at",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        }
+      },
+      "indexes": {
+        "users_discord_id_unique": {
+          "name": "users_discord_id_unique",
+          "columns": [
+            "discord_id"
+          ],
+          "isUnique": true
+        }
+      },
+      "foreignKeys": {},
+      "compositePrimaryKeys": {},
+      "uniqueConstraints": {},
+      "checkConstraints": {}
+    }
+  },
+  "views": {},
+  "enums": {},
+  "_meta": {
+    "schemas": {},
+    "tables": {},
+    "columns": {}
+  },
+  "internal": {
+    "indexes": {}
+  }
+}
\ No newline at end of file
diff --git a/drizzle/meta/_journal.json b/drizzle/meta/_journal.json
index e89ed83..4dde595 100644
--- a/drizzle/meta/_journal.json
+++ b/drizzle/meta/_journal.json
@@ -85,6 +85,13 @@
       "when": 1788845281801,
       "tag": "0011_multiple_reminders",
       "breakpoints": true
+    },
+    {
+      "idx": 12,
+      "version": "6",
+      "when": 1788847978168,
+      "tag": "0012_discord_commands",
+      "breakpoints": true
     }
   ]
 }
\ No newline at end of file
diff --git a/src/api.ts b/src/api.ts
index aa6a06e..a45c815 100644
--- a/src/api.ts
+++ b/src/api.ts
@@ -1,3 +1,4 @@
+import { createDiscordRoutes, type CommandConfig } from "./discord/routes";
 import { createLiveDiscord } from "./sharing/live-discord";
 import { createReminderRoutes } from "./reminders/routes";
 import { errorDetails } from "./ops/monitor";
@@ -12,7 +13,7 @@ import type { FetchDiscord } from "./auth/discord";
 import { createSharingRoutes, type DiscordFetch } from "./sharing/routes";
 import type { DiscordSharingConfig } from "./sharing/config";
 
-export function createApi(db: AppDatabase, config: AuthConfig, request?: FetchDiscord, now?: () => number, discordRequest?: DiscordFetch, sharingConfig: DiscordSharingConfig = { token: "", channelId: "" }, operations: { healthy?: () => boolean; log?: (event: Record<string, unknown>) => void } = {}) {
+export function createApi(db: AppDatabase, config: AuthConfig, request?: FetchDiscord, now?: () => number, discordRequest?: DiscordFetch, sharingConfig: DiscordSharingConfig = { token: "", channelId: "" }, operations: { healthy?: () => boolean; log?: (event: Record<string, unknown>) => void; discord?: CommandConfig } = {}) {
   const app = new Hono<AuthEnv>();
   app.use("*", async (c, next) => {
     const requestId = crypto.randomUUID();
@@ -32,6 +33,7 @@ export function createApi(db: AppDatabase, config: AuthConfig, request?: FetchDi
     if (operations.healthy && !operations.healthy()) return c.json({ status: "degraded" }, 503);
     return c.json({ status: "ok" });
   });
+  app.route("/api/discord/interactions", createDiscordRoutes(db, operations.discord ?? { publicKey: "", applicationId: config.clientId, origin: config.origin }, now ?? Date.now, liveSharing.changed));
   app.route("/api/sharing/live", liveSharing.routes);
   app.route("/api/auth", auth.routes);
   app.route("/api/reminders", createReminderRoutes(db, auth, Boolean(sharingConfig.token), now ?? Date.now));
diff --git a/src/auth/index.ts b/src/auth/index.ts
index 0477dda..b50e523 100644
--- a/src/auth/index.ts
+++ b/src/auth/index.ts
@@ -26,7 +26,7 @@ export function normalizeTimezone(value: unknown): string {
   }
 }
 
-function publicUser(user: typeof users.$inferSelect): PublicUser {
+export function publicUser(user: typeof users.$inferSelect): PublicUser {
   return {
     id: user.id,
     discordId: user.discordId,
diff --git a/src/db/schema.ts b/src/db/schema.ts
index 5c90b1b..7e2cd37 100644
--- a/src/db/schema.ts
+++ b/src/db/schema.ts
@@ -101,3 +101,15 @@ export const liveDiscordCards = sqliteTable('live_discord_cards', {
   retryAt: integer('retry_at'),
   updatedAt: integer('updated_at').notNull(),
 });
+
+// Short-lived UI state and replay receipts; no Discord interaction tokens are persisted.
+export const discordControls = sqliteTable('discord_controls', {
+  id: text('id').primaryKey(), userId: text('user_id').notNull().references(() => users.id, { onDelete: 'cascade' }),
+  action: text('action').notNull(), payload: text('payload', { mode: 'json' }).$type<import('../discord/types').ControlData>().notNull(),
+  expiresAt: integer('expires_at').notNull(), used: integer('used', { mode: 'boolean' }).notNull().default(false),
+}, t => [index('discord_controls_expiry_idx').on(t.expiresAt)]);
+export const discordReceipts = sqliteTable('discord_receipts', {
+  id: text('id').primaryKey(), userId: text('user_id').notNull().references(() => users.id, { onDelete: 'cascade' }),
+  response: text('response', { mode: 'json' }).$type<import('../discord/types').Reply>().notNull(),
+  expiresAt: integer('expires_at').notNull(),
+}, t => [index('discord_receipts_expiry_idx').on(t.expiresAt)]);
diff --git a/src/discord/README.md b/src/discord/README.md
new file mode 100644
index 0000000..a59823b
--- /dev/null
+++ b/src/discord/README.md
@@ -0,0 +1,21 @@
+# Discord interface
+
+Signed HTTP interactions enter `/api/discord/interactions`. The raw request body
+is verified with the application's Ed25519 public key and a five-minute timestamp
+window. `DISCORD_PUBLIC_KEY` enables the endpoint; `DISCORD_CLIENT_ID` identifies
+the application. Commands are global with contexts `[0, 1]` (server and bot DM).
+
+`HabitService` remains the shared domain implementation. Verified Discord user IDs
+resolve the same account as website OAuth; new accounts start in UTC. Server
+responses are ephemeral. Buttons/forms carry opaque persisted owner-bound state,
+expire after 15 minutes, and mutation controls are consumed after successful use.
+Interaction IDs retain replay receipts for 24 hours. Neither table stores tokens.
+
+`daily.ts` implements the initial `/today` workflow. `types.ts`, `ui.ts`, and
+`state.ts` provide the shared feature building blocks. Feature tasks extend command
+registration and route dispatch while keeping their behavior in separate modules.
+
+Tests use real Ed25519 signatures and disposable migrated SQLite databases. The
+foundation tests cover server/DM privacy, replay after restart, stale progress,
+cross-account controls, and matching website state. Command registration and live
+Discord validation will be completed during integration.
diff --git a/src/discord/commands.ts b/src/discord/commands.ts
new file mode 100644
index 0000000..e198f31
--- /dev/null
+++ b/src/discord/commands.ts
@@ -0,0 +1,4 @@
+// Global commands are required for bot DMs; guild-only registrations cannot run there.
+export const commands = [
+  { name: 'today', description: 'View and complete today’s habits' },
+].map(command => ({ ...command, type: 1, integration_types: [0], contexts: [0, 1] }));
diff --git a/src/discord/daily.ts b/src/discord/daily.ts
new file mode 100644
index 0000000..0ee1a0b
--- /dev/null
+++ b/src/discord/daily.ts
@@ -0,0 +1,50 @@
+import { ApiError } from '../habits/service';
+import { progressInput } from '../habits/contracts';
+import type { Context, ControlData, Reply } from './types';
+import { fields } from './types';
+import { button, message, modal, pages, row, select, text } from './ui';
+export function today(c: Context, data: ControlData = {}): Reply {
+  if (data.date && data.date !== c.service.today) throw new ApiError(409, 'That reminder is from an earlier day. Run /today for a fresh check-in.');
+  const all = c.service.list().map(h => c.service.day(h.id, c.service.today)).filter(d => d.due);
+  const page = data.page ?? 0, visible = all.slice(page * 10, page * 10 + 10);
+  return message(c, `**Today · ${c.service.today}** · ${text(c.service.user.timezone)}\n${all.filter(h => h.complete).length}/${all.length} complete\n\n${visible.map(h => `${h.complete ? '✓' : '○'} ${text(h.name ?? 'Habit')} — ${h.value}/${h.target} ${text(h.unit ?? '')}`).join('\n') || 'No habits due. Use /habits to create or manage your habits.'}`,
+    [...(visible.length ? [select(c, 'Choose a habit', 'daily.select', { date: c.service.today, today: true }, visible.map(h => ({ id: h.habitId, name: h.name ?? 'Habit' })))] : []), ...pages(c, 'today', data, all.length), row(button(c, 'Refresh', 'today'))], c.interaction.data?.custom_id?.startsWith('mina:') && data.mode !== 'reminder');
+}
+export function detail(c: Context, data: ControlData): Reply {
+  const date = data.date ?? c.service.today;
+  if (data.today && date !== c.service.today) throw new ApiError(409, 'The day changed. Run /today to check in.');
+  const d = c.service.day(data.habitId!, date);
+  const state: ControlData = { ...data, date, expected: JSON.stringify([d.value, d.revisionId, d.tasks.map(t => [t.taskId, t.done])]) };
+  const controls = [];
+  if (d.due && !d.future) {
+    if (d.method === 'manual') controls.push(row(button(c, d.complete ? 'Mark incomplete' : 'Mark complete', 'daily.save', { ...state, done: !d.complete }, 1)));
+    if (d.method === 'count') controls.push(row(button(c, '+1', 'daily.save', { ...state, value: d.value + 1 }, 1), button(c, 'Enter amount', 'daily.amount', state)));
+    if (d.method === 'tasks') {
+      const visible = d.tasks.slice((data.page ?? 0) * 10, ((data.page ?? 0) + 1) * 10);
+      controls.push(select(c, 'Choose a task to change its completion', 'daily.task', state, visible.map(t => ({ id: t.taskId, name: `${t.done ? '✓ ' : '○ '}${t.name}` }))));
+      controls.push(...pages(c, 'daily.detail', data, d.tasks.length));
+    }
+  }
+  controls.push(row(button(c, 'Refresh', 'daily.detail', data), button(c, 'Today', 'today')));
+  return message(c, `**${text(d.name ?? 'Not tracked')} · ${date}**\n${d.due ? `${d.value}/${d.target} ${text(d.unit ?? '')} · ${d.complete ? 'Complete' : 'Incomplete'}` : 'Not scheduled'}${d.future ? ' · Future dates are read-only' : ''}${d.method === 'tasks' ? '\n\n' + d.tasks.slice((data.page ?? 0) * 10, ((data.page ?? 0) + 1) * 10).map(t => `${t.done ? '✓' : '○'} ${text(t.name)}`).join('\n') : ''}`, controls);
+}
+export function dailyAction(c: Context, action: string, data: ControlData): Reply | undefined {
+  if (action === 'today') return today(c, data);
+  if (action === 'daily.select') return detail(c, { ...data, habitId: c.interaction.data?.values?.[0] });
+  if (action === 'daily.detail') return detail(c, data);
+  if (action === 'daily.amount') return modal(c, 'Record amount', 'daily.save', data, [{ id: 'amount', label: 'Total for this date', value: String(c.service.day(data.habitId!, data.date!).value), max: 10 }]);
+  if (action === 'daily.save' || action === 'daily.task') {
+    if (data.today && data.date !== c.service.today) throw new ApiError(409, 'The day changed. Run /today again.');
+    const d = c.service.day(data.habitId!, data.date!);
+    if (data.expected !== JSON.stringify([d.value, d.revisionId, d.tasks.map(t => [t.taskId, t.done])])) throw new ApiError(409, 'Progress changed since this message was opened. Refresh it before saving.');
+    if (action === 'daily.task') {
+      const task = d.tasks.find(t => t.taskId === c.interaction.data?.values?.[0]);
+      if (!task) throw new ApiError(404, 'Task not found.');
+      c.service.completeTask(data.habitId!, data.date!, task.taskId, !task.done);
+    } else {
+      const amount = fields(c.interaction).amount;
+      c.service.progress(data.habitId!, data.date!, progressInput.parse(data.done !== undefined ? { done: data.done } : { count: amount === undefined ? data.value : /^\d+$/.test(amount) ? Number(amount) : NaN }));
+    }
+    c.controls.consume(c.interaction.data!.custom_id!); c.changed(); return detail(c, data);
+  }
+}
diff --git a/src/discord/routes.test.ts b/src/discord/routes.test.ts
new file mode 100644
index 0000000..5a9f56d
--- /dev/null
+++ b/src/discord/routes.test.ts
@@ -0,0 +1,47 @@
+import { afterEach, describe, expect, test } from 'bun:test';
+import { discordFixture, control, submit } from './test-fixture';
+import { commands } from './commands';
+let f: ReturnType<typeof discordFixture>;
+afterEach(() => f?.close());
+describe('signed Discord interactions', () => {
+  test('registers commands globally for servers and bot DMs', () => {
+    for (const c of commands) { expect(c.contexts).toEqual([0, 1]); expect(c.integration_types).toEqual([0]); }
+  });
+  test('rejects forged and old signatures and answers Discord PING', async () => {
+    f = discordFixture();
+    expect((await f.requestDiscord(f.payload({ type: 1 }), { 'X-Signature-Ed25519': '0'.repeat(128) })).status).toBe(401);
+    expect((await f.requestDiscord(f.payload({ type: 1 }), { 'X-Signature-Timestamp': '1000000000' })).status).toBe(401);
+    expect(await f.run({ type: 1 })).toEqual({ type: 1 });
+    expect((await f.requestDiscord(f.payload({ application_id: 'wrong' }))).status).toBe(400);
+  });
+  for (const guild of [false, true]) test(`records progress from ${guild ? 'server' : 'DM'} and shares website state`, async () => {
+    f = discordFixture(); const h = await f.json('/habits', 'POST', { name: 'Reading', method: 'count', target: 10, unit: 'pages' }, 201);
+    const today = await f.run({ data: { name: 'today' } }, guild);
+    expect(today.data.flags).toBe(guild ? 64 : undefined);
+    const detail = await f.run({ type: 3, message: { id: '123' }, data: { custom_id: control(today, 'Choose a habit'), values: [h.id] } }, guild);
+    const click = f.payload({ type: 3, message: { id: '123' }, data: { custom_id: control(detail, '+1') } }, guild);
+    expect((await (await f.requestDiscord(click)).json()).type).toBe(7);
+    f.restart(); await f.requestDiscord(click);
+    expect((await f.json(`/habits/${h.id}/days/2026-09-04`)).value).toBe(1);
+    expect(f.changed).toEqual(['alice']);
+    const stale = await f.run({ type: 3, data: { custom_id: control(detail, 'Enter amount') } }, guild);
+    const failed = await f.run(submit(stale.data.custom_id, { amount: '7' }), guild);
+    expect(failed.data.content).toContain('Progress changed');
+  });
+  test('owner-bound buttons and habit IDs prevent cross-account access', async () => {
+    f = discordFixture(); const h = await f.json('/habits', 'POST', { name: 'Private', method: 'manual' }, 201);
+    const a = await f.run({ data: { name: 'today' } });
+    const blocked = await f.run({ type: 3, data: { custom_id: control(a, 'Choose a habit'), values: [h.id] } }, true, f.bob);
+    expect(blocked.data.content).toContain('belongs to another user'); expect(blocked.data.flags).toBe(64);
+    const b = await f.run({ data: { name: 'today' } }, false, f.bob);
+    expect(b.data.content).not.toContain('Private');
+  });
+  test('old daily buttons cannot correct history accidentally', async () => {
+    f = discordFixture(); const h = await f.json('/habits', 'POST', { name: 'Read', method: 'manual' }, 201);
+    const t = await f.run({ data: { name: 'today' } });
+    const d = await f.run({ type: 3, data: { custom_id: control(t, 'Choose a habit'), values: [h.id] } });
+    f.setDiscordTime('2026-09-05T12:00:00Z');
+    expect((await f.run({ type: 3, data: { custom_id: control(d, 'Mark complete') } })).data.content).toContain('expired');
+    expect((await f.json(`/habits/${h.id}/days/2026-09-04`)).value).toBe(0);
+  });
+});
diff --git a/src/discord/routes.ts b/src/discord/routes.ts
new file mode 100644
index 0000000..89b077c
--- /dev/null
+++ b/src/discord/routes.ts
@@ -0,0 +1,62 @@
+import { createPublicKey, verify } from 'node:crypto';
+import { eq } from 'drizzle-orm';
+import { Hono } from 'hono';
+import { bodyLimit } from 'hono/body-limit';
+import { ZodError } from 'zod';
+import { publicUser, type AppDatabase } from '../auth';
+import { users, discordReceipts } from '../db/schema';
+import { ApiError, HabitService } from '../habits/service';
+import { ControlStore } from './state';
+import { interactionSchema, type Context, type Reply } from './types';
+import { dailyAction, today } from './daily';
+import { message } from './ui';
+
+export type CommandConfig = { publicKey: string; applicationId: string; origin: string };
+export function createDiscordRoutes(db: AppDatabase, config: CommandConfig, now = Date.now, changed: (userId: string) => void = () => {}) {
+  const app = new Hono();
+  const key = /^[a-f\d]{64}$/i.test(config.publicKey) ? createPublicKey({ key: Buffer.concat([Buffer.from('302a300506032b6570032100', 'hex'), Buffer.from(config.publicKey, 'hex')]), format: 'der', type: 'spki' }) : null;
+  app.use('*', bodyLimit({ maxSize: 64 * 1024 }));
+  app.post('/', async c => {
+    c.header('Cache-Control', 'no-store');
+    if (!key) return c.json({ error: 'Discord commands are not configured.' }, 503);
+    const signature = c.req.header('X-Signature-Ed25519') ?? '', timestamp = c.req.header('X-Signature-Timestamp') ?? '';
+    const body = await c.req.text();
+    if (!/^\d{10,12}$/.test(timestamp) || Math.abs(now() - Number(timestamp) * 1000) > 300000 || !/^[a-f\d]{128}$/i.test(signature) || !verify(null, Buffer.from(timestamp + body), key, Buffer.from(signature, 'hex')))
+      return c.json({ error: 'Invalid request signature.' }, 401);
+    let value: unknown;
+    try { value = JSON.parse(body); } catch { return c.json({ error: "Malformed JSON." }, 400); }
+    const parsed = interactionSchema.safeParse(value);
+    if (!parsed.success || parsed.data.application_id !== config.applicationId) return c.json({ error: 'Invalid interaction.' }, 400);
+    const i = parsed.data;
+    if (i.type === 1) return c.json({ type: 1 });
+    const profile = i.guild_id ? i.member?.user : i.user;
+    if (!profile || ![2, 3, 4, 5].includes(i.type)) return c.json({ error: 'Unsupported interaction.' }, 400);
+    const reply = db.transaction((): Reply => {
+      const existing = db.select().from(users).where(eq(users.discordId, profile.id)).get();
+      const userId = existing?.id ?? crypto.randomUUID();
+      if (!existing) db.insert(users).values({ id: userId, discordId: profile.id, username: profile.username, globalName: profile.global_name, avatarHash: profile.avatar, createdAt: now(), updatedAt: now() }).run();
+      const receipt = db.select().from(discordReceipts).where(eq(discordReceipts.id, i.id)).get();
+      if (receipt && receipt.expiresAt > now()) return receipt.response;
+      const user = publicUser(db.select().from(users).where(eq(users.id, userId)).get()!);
+      const controls = new ControlStore(db, userId, now()); controls.prune();
+      const service = new HabitService(db, user, now()); service.sync();
+      const ctx: Context = { db, service, controls, interaction: i, now: now(), origin: config.origin, changed: () => changed(userId) };
+      let result: Reply;
+      try {
+        if (i.type === 4) result = { type: 8, data: { choices: [] } };
+        else if (i.type === 2 && i.data?.name === 'today') result = today(ctx);
+        else if ([3, 5].includes(i.type)) {
+          const state = controls.read(i.data?.custom_id ?? '');
+          result = dailyAction(ctx, state.action, state.payload) ?? message(ctx, 'Run /today to get started.', [], false);
+        } else result = message(ctx, 'Run /today to get started.', [], false);
+      } catch (error) {
+        if (!(error instanceof ApiError) && !(error instanceof ZodError)) throw error;
+        result = message(ctx, error instanceof ApiError ? error.message : 'Check the entered values and try again.', [], false);
+      }
+      db.insert(discordReceipts).values({ id: i.id, userId, response: result, expiresAt: now() + 86400000 }).run();
+      return result;
+    });
+    return c.json(reply);
+  });
+  return app;
+}
diff --git a/src/discord/state.ts b/src/discord/state.ts
new file mode 100644
index 0000000..35b9895
--- /dev/null
+++ b/src/discord/state.ts
@@ -0,0 +1,29 @@
+import { randomBytes } from 'node:crypto';
+import { eq, lt } from 'drizzle-orm';
+import type { AppDatabase } from '../auth';
+import { discordControls, discordReceipts } from '../db/schema';
+import { ApiError } from '../habits/service';
+import type { ControlData } from './types';
+
+export class ControlStore {
+  constructor(readonly db: AppDatabase, readonly userId: string, readonly now: number) {}
+  create(action: string, payload: ControlData = {}, lifetime = 15 * 60000) {
+    const id = randomBytes(18).toString('base64url');
+    this.db.insert(discordControls).values({ id, userId: this.userId, action, payload, expiresAt: this.now + lifetime }).run();
+    return `mina:${id}`;
+  }
+  read(customId: string) {
+    const row = this.db.select().from(discordControls).where(eq(discordControls.id, customId.replace(/^mina:/, ''))).get();
+    if (!customId.startsWith('mina:') || !row || row.userId !== this.userId || row.expiresAt <= this.now || row.used)
+      throw new ApiError(409, 'This control expired or belongs to another user. Run the command again.');
+    return row;
+  }
+  consume(customId: string) {
+    const row = this.read(customId);
+    this.db.update(discordControls).set({ used: true }).where(eq(discordControls.id, row.id)).run();
+  }
+  prune() {
+    this.db.delete(discordControls).where(lt(discordControls.expiresAt, this.now)).run();
+    this.db.delete(discordReceipts).where(lt(discordReceipts.expiresAt, this.now)).run();
+  }
+}
diff --git a/src/discord/test-fixture.ts b/src/discord/test-fixture.ts
new file mode 100644
index 0000000..252ab5d
--- /dev/null
+++ b/src/discord/test-fixture.ts
@@ -0,0 +1,35 @@
+import { generateKeyPairSync, sign } from 'node:crypto';
+import { eq } from 'drizzle-orm';
+import { fixture } from '../habits/test-fixture';
+import { users } from '../db/schema';
+import { createDiscordRoutes } from './routes';
+import type { Interaction } from './types';
+export function discordFixture() {
+  const f = fixture();
+  const { publicKey, privateKey } = generateKeyPairSync('ed25519');
+  const key = publicKey.export({ format: 'der', type: 'spki' }).subarray(-32).toString('hex');
+  let time = Date.parse('2026-09-04T12:00:00Z'), sequence = 10000000000000000n;
+  const alice = '111111111111111111', bob = '222222222222222222', applicationId = '333333333333333333';
+  f.db.update(users).set({ discordId: alice }).where(eq(users.id, 'alice')).run();
+  f.db.update(users).set({ discordId: bob }).where(eq(users.id, 'bob')).run();
+  const changed: string[] = [];
+  let app = createDiscordRoutes(f.db, { publicKey: key, applicationId, origin: f.origin }, () => time, id => changed.push(id));
+  function payload(data: Partial<Interaction>, guild = false, user = alice): Interaction {
+    const profile = { id: user, username: user === alice ? 'alice' : 'bob' };
+    return { id: String(++sequence), application_id: applicationId, type: 2, ...(guild ? { guild_id: '444444444444444444', member: { user: profile } } : { user: profile }), ...data };
+  }
+  async function request(i: Interaction, headers: Record<string, string> = {}) {
+    const body = JSON.stringify(i), timestamp = String(time / 1000);
+    return app.request('http://localhost/', { method: 'POST', headers: { 'Content-Type': 'application/json', 'X-Signature-Timestamp': timestamp, 'X-Signature-Ed25519': sign(null, Buffer.from(timestamp + body), privateKey).toString('hex'), ...headers }, body });
+  }
+  async function run(data: Partial<Interaction>, guild = false, user = alice): Promise<any> { return (await request(payload(data, guild, user))).json(); }
+  return { ...f, alice, bob, changed, payload, requestDiscord: request, run, restart: () => { app = createDiscordRoutes(f.db, { publicKey: key, applicationId, origin: f.origin }, () => time, id => changed.push(id)); }, setDiscordTime: (value: string) => { time = Date.parse(value); f.setTime(value); } };
+}
+export function control(reply: any, label: string): string {
+  const item = reply.data.components.flatMap((r: any) => r.components ?? []).find((c: any) => c.label === label || c.placeholder === label);
+  if (!item) throw new Error(`Missing control ${label}: ${JSON.stringify(reply)}`);
+  return item.custom_id;
+}
+export function submit(custom_id: string, values: Record<string, string>) {
+  return { type: 5, message: { id: '123' }, data: { custom_id, components: Object.entries(values).map(([custom_id, value]) => ({ type: 1, components: [{ type: 4, custom_id, value }] })) } };
+}
diff --git a/src/discord/types.ts b/src/discord/types.ts
new file mode 100644
index 0000000..ccf381f
--- /dev/null
+++ b/src/discord/types.ts
@@ -0,0 +1,23 @@
+import { z } from 'zod';
+import type { AppDatabase } from '../auth';
+import type { HabitService } from '../habits/service';
+import type { ControlStore } from './state';
+
+const option: z.ZodType<Option> = z.lazy(() => z.object({ name: z.string(), type: z.number(), value: z.union([z.string(), z.number(), z.boolean()]).optional(), focused: z.boolean().optional(), options: z.array(option).optional() }));
+export type Option = { name: string; type: number; value?: string | number | boolean; focused?: boolean; options?: Option[] };
+const profile = z.object({ id: z.string().regex(/^\d{17,20}$/), username: z.string().max(100), global_name: z.string().max(100).nullish(), avatar: z.string().max(100).nullish() });
+const component: z.ZodType<ComponentInput> = z.lazy(() => z.object({ type: z.number(), custom_id: z.string().optional(), value: z.string().optional(), values: z.array(z.string()).optional(), components: z.array(component).optional() }));
+type ComponentInput = { type: number; custom_id?: string; value?: string; values?: string[]; components?: ComponentInput[] };
+export const interactionSchema = z.object({ id: z.string().regex(/^\d{17,20}$/), application_id: z.string(), type: z.number(), token: z.string().max(2048).optional(), guild_id: z.string().optional(), user: profile.optional(), member: z.object({ user: profile }).optional(), message: z.object({ id: z.string() }).optional(), data: z.object({ name: z.string().optional(), custom_id: z.string().max(100).optional(), values: z.array(z.string()).optional(), options: z.array(option).optional(), components: z.array(component).optional() }).optional() });
+export type Interaction = z.infer<typeof interactionSchema>;
+export type DiscordComponent = { type: number; [key: string]: unknown };
+export type Message = { content?: string; components?: DiscordComponent[]; flags?: number; allowed_mentions?: { parse: string[] }; attachments?: unknown[]; embeds?: unknown[] };
+export type Reply = { type: number; data?: Message | { custom_id: string; title: string; components: DiscordComponent[] } | { choices: { name: string; value: string }[] } };
+export type ControlData = { habitId?: string; taskId?: string; date?: string; today?: boolean; page?: number; mode?: string; method?: string; expected?: string; value?: number; done?: boolean; revision?: number; index?: number; theme?: 'light' | 'dark'; deliveryId?: string };
+export type Context = { db: AppDatabase; service: HabitService; controls: ControlStore; interaction: Interaction; now: number; origin: string; changed: () => void };
+export function fields(i: Interaction) {
+  const result: Record<string, string> = {};
+  const walk = (parts: ComponentInput[]) => parts.forEach(c => { if (c.custom_id && c.value !== undefined) result[c.custom_id] = c.value; if (c.components) walk(c.components); });
+  walk(i.data?.components ?? []); return result;
+}
+export const options = (i: Interaction) => Object.fromEntries((i.data?.options ?? []).map(o => [o.name, o.value]));
diff --git a/src/discord/ui.ts b/src/discord/ui.ts
new file mode 100644
index 0000000..b285bec
--- /dev/null
+++ b/src/discord/ui.ts
@@ -0,0 +1,21 @@
+import type { Context, ControlData, DiscordComponent, Reply } from './types';
+export const text = (s: string) => s.replace(/([\\`*_~|>])/g, '\\$1').replace(/@/g, '@\u200b');
+export const row = (...components: DiscordComponent[]): DiscordComponent => ({ type: 1, components });
+export const button = (c: Context, label: string, action: string, payload: ControlData = {}, style = 2): DiscordComponent => ({ type: 2, label, style, custom_id: c.controls.create(action, payload) });
+export function message(c: Context, content: string, components: DiscordComponent[] = [], update = true): Reply {
+  const edit = update && !!c.interaction.message && [3, 5].includes(c.interaction.type);
+  return { type: edit ? 7 : 4, data: { content: content.slice(0, 2000), components, allowed_mentions: { parse: [] }, ...(!edit && c.interaction.guild_id ? { flags: 64 } : {}) } };
+}
+export type Field = { id: string; label: string; value?: string; placeholder?: string; required?: boolean; max?: number };
+export function modal(c: Context, title: string, action: string, data: ControlData, fields: Field[]): Reply {
+  return { type: 9, data: { custom_id: c.controls.create(action, data), title: title.slice(0, 45), components: fields.map(f => row({ type: 4, custom_id: f.id, label: f.label.slice(0, 45), style: 1, required: f.required ?? true, max_length: f.max ?? 200, ...(f.value !== undefined ? { value: f.value } : {}), ...(f.placeholder ? { placeholder: f.placeholder.slice(0, 100) } : {}) })) } };
+}
+export function select(c: Context, placeholder: string, action: string, data: ControlData, items: { id: string; name: string; description?: string }[]) {
+  return row({ type: 3, custom_id: c.controls.create(action, data), placeholder, options: items.slice(0, 25).map(i => ({ label: i.name.slice(0, 100) || 'Untitled', value: i.id, ...(i.description ? { description: i.description.slice(0, 100) } : {}) })) });
+}
+export function pages(c: Context, action: string, data: ControlData, total: number, size = 10) {
+  const page = data.page ?? 0, buttons: DiscordComponent[] = [];
+  if (page > 0) buttons.push(button(c, 'Previous', action, { ...data, page: page - 1 }));
+  if ((page + 1) * size < total) buttons.push(button(c, 'Next', action, { ...data, page: page + 1 }));
+  return buttons.length ? [row(...buttons)] : [];
+}
diff --git a/src/index.ts b/src/index.ts
index f3684a4..8f52df0 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -20,7 +20,7 @@ if (import.meta.hot) import.meta.hot.dispose(() => backups?.stop());
 const reminders = process.env.NODE_ENV === "production" ? startReminders(db, { token: readDiscordSharingConfig().token, origin: readAuthConfig().origin }) : undefined;
 if (import.meta.hot) import.meta.hot.dispose(() => reminders?.stop());
 
-const app = createApi(db, readAuthConfig(), undefined, undefined, undefined, readDiscordSharingConfig(), { healthy: () => !backups?.state.enabled || (!backups.state.failed && backups.state.lastSuccess > 0) });
+const app = createApi(db, readAuthConfig(), undefined, undefined, undefined, readDiscordSharingConfig(), { discord: { publicKey: process.env.DISCORD_PUBLIC_KEY ?? "", applicationId: readAuthConfig().clientId, origin: readAuthConfig().origin }, healthy: () => !backups?.state.enabled || (!backups.state.failed && backups.state.lastSuccess > 0) });
 
 if (import.meta.hot) import.meta.hot.dispose(() => app.stopLiveSharing());