diff --git a/bin/mnemosyne-bot b/bin/mnemosyne-bot
new file mode 100755
index 0000000..c5d08db
--- /dev/null
+++ b/bin/mnemosyne-bot
@@ -0,0 +1,13 @@
+#!/usr/bin/env perl
+use strict;
+use warnings;
+use FindBin qw($RealBin);
+use lib "$RealBin/../lib";
+
+# TODO: Parse --config flag (default: $RealBin/../config/mnemosyne.conf)
+# TODO: Load Mnemosyne::Config, Mnemosyne::DB
+# TODO: Build Mojolicious::Lite app:
+#         POST /<webhook_path> => validate secret token, route to Mnemosyne::Webhook
+# TODO: Start app on 127.0.0.1:<listen_port> (never bind 0.0.0.0)
+
+print "mnemosyne-bot: not yet implemented\n";
diff --git a/bin/mnemosyne-digest b/bin/mnemosyne-digest
new file mode 100755
index 0000000..e5b886a
--- /dev/null
+++ b/bin/mnemosyne-digest
@@ -0,0 +1,19 @@
+#!/usr/bin/env perl
+use strict;
+use warnings;
+use FindBin qw($RealBin);
+use lib "$RealBin/../lib";
+
+# Invoked by cron every N minutes (e.g. */5 * * * *).
+# Exits immediately unless:
+#   a) the current local time matches digest_time (within the cron granularity window), AND
+#   b) last_digest_sent (config table) is not today's date.
+# On success, records today's date in last_digest_sent to prevent duplicate sends.
+#
+# TODO: Load config + DB
+# TODO: Read digest_time and last_digest_sent from config table
+# TODO: Compare current local time against digest_time (allow ±(cron_interval/2) window)
+# TODO: If it's time and not already sent: call Mnemosyne::Digest::send(...)
+# TODO: On success: update last_digest_sent to today's ISO date
+
+print "mnemosyne-digest: not yet implemented\n";
diff --git a/bin/mnemosyne-webhook b/bin/mnemosyne-webhook
new file mode 100755
index 0000000..27bda32
--- /dev/null
+++ b/bin/mnemosyne-webhook
@@ -0,0 +1,19 @@
+#!/usr/bin/env perl
+use strict;
+use warnings;
+use FindBin qw($RealBin);
+use lib "$RealBin/../lib";
+
+# One-shot helper to register (or remove) the Telegram webhook.
+# Run once after install, and again whenever the webhook URL changes.
+# Only one webhook can be active per bot token at a time.
+#
+# Usage:
+#   mnemosyne-webhook [--config /path/to/mnemosyne.conf] [--delete]
+#
+# TODO: Load config
+# TODO: --delete: call Mnemosyne::Telegram::delete_webhook()
+# TODO: default:  call Mnemosyne::Telegram::set_webhook(webhook_url, webhook_secret)
+# TODO: Print result (registered URL, or confirmation of deletion)
+
+print "mnemosyne-webhook: not yet implemented\n";
diff --git a/config/mnemosyne.conf.example b/config/mnemosyne.conf.example
new file mode 100644
index 0000000..ced612c
--- /dev/null
+++ b/config/mnemosyne.conf.example
@@ -0,0 +1,35 @@
+# Mnemosyne configuration — copy to mnemosyne.conf and fill in real values.
+# This file is NOT committed to git. Keep it outside the repo or in config/
+# (which is .gitignored). Never commit secrets.
+
+[bot]
+# Telegram bot token from @BotFather
+token = YOUR_BOT_TOKEN_HERE
+
+# Secret token sent by Telegram on every webhook POST (X-Telegram-Bot-Api-Secret-Token).
+# Generate with:  openssl rand -hex 32
+webhook_secret = YOUR_WEBHOOK_SECRET_HERE
+
+# Full public HTTPS URL Telegram will POST updates to.
+# Include a hard-to-guess path segment as a second layer of obscurity.
+webhook_url = https://mnemosyne.example.com/hook/YOUR_RANDOM_PATH_HERE
+
+# Local port the Mojolicious app listens on (nginx proxies to this).
+listen_port = 8765
+
+# Comma-separated list of Telegram chat IDs allowed to use the bot.
+# Get your chat ID by messaging @userinfobot.
+allowed_chat_ids = 123456789
+
+[db]
+# Absolute path to the SQLite database file.
+path = /var/lib/mnemosyne/mnemosyne.db
+
+[app]
+# IANA timezone name used for all day-granular date calculations.
+timezone = America/New_York
+
+# Default morning digest time (HH:MM, 24-hour, local time).
+# Also stored in the config table and adjustable via /settime — the value here
+# is written to the DB on first run; subsequent /settime changes update the DB.
+digest_time = 06:30
diff --git a/cpanfile b/cpanfile
new file mode 100644
index 0000000..6e00b73
--- /dev/null
+++ b/cpanfile
@@ -0,0 +1,12 @@
+# Runtime dependencies
+requires 'Mojolicious',        '>= 9.0';
+requires 'DBI',                '>= 1.643';
+requires 'DBD::SQLite',        '>= 1.70';
+requires 'DateTime',           '>= 1.54';
+requires 'DateTime::TimeZone', '>= 2.20';
+
+# Test dependencies
+on test => sub {
+    requires 'Test::More',      '>= 1.302';
+    requires 'Test::Exception', '>= 0.43';
+};
diff --git a/lib/Mnemosyne/Config.pm b/lib/Mnemosyne/Config.pm
new file mode 100644
index 0000000..74f00af
--- /dev/null
+++ b/lib/Mnemosyne/Config.pm
@@ -0,0 +1,69 @@
+package Mnemosyne::Config;
+use strict;
+use warnings;
+
+# Loads mnemosyne.conf (INI-style) and exposes a simple accessor.
+# Usage:
+#   my $cfg = Mnemosyne::Config->new('/path/to/mnemosyne.conf');
+#   my $token = $cfg->get('bot', 'token');
+#   my $href  = $cfg->section('bot');   # all keys in [bot]
+
+sub new {
+    my ($class, $path) = @_;
+    die "Config file not specified\n"      unless defined $path;
+    die "Config file not found: $path\n"   unless -f $path;
+
+    my $self = bless { _path => $path, _data => {} }, $class;
+    $self->_parse;
+    return $self;
+}
+
+sub _parse {
+    my ($self) = @_;
+    open my $fh, '<', $self->{_path}
+        or die "Cannot open config '$self->{_path}': $!\n";
+
+    my $section = '_default';
+    while (my $line = <$fh>) {
+        chomp $line;
+        $line =~ s/\s*#.*$//;   # strip inline comments
+        $line =~ s/^\s+|\s+$//g; # trim
+        next unless length $line;
+
+        if ($line =~ /^\[(\w+)\]$/) {
+            $section = lc $1;
+        }
+        elsif ($line =~ /^([\w_]+)\s*=\s*(.*)$/) {
+            my ($key, $val) = (lc $1, $2);
+            $val =~ s/\s+$//;
+            $self->{_data}{$section}{$key} = $val;
+        }
+        else {
+            warn "Config: unrecognised line in $self->{_path}: $line\n";
+        }
+    }
+    close $fh;
+}
+
+sub get {
+    my ($self, $section, $key) = @_;
+    $section = lc $section;
+    $key     = lc $key;
+    return $self->{_data}{$section}{$key};
+}
+
+sub section {
+    my ($self, $section) = @_;
+    return { %{ $self->{_data}{lc $section} // {} } };
+}
+
+# Returns the list of allowed chat IDs as an array ref (parsed from the
+# comma-separated 'allowed_chat_ids' value in [bot]).
+sub allowed_chat_ids {
+    my ($self) = @_;
+    my $raw = $self->get('bot', 'allowed_chat_ids') // '';
+    my @ids = grep { /^\d+$/ } map { s/^\s+|\s+$//gr } split /,/, $raw;
+    return \@ids;
+}
+
+1;
diff --git a/lib/Mnemosyne/DB.pm b/lib/Mnemosyne/DB.pm
new file mode 100644
index 0000000..06de13a
--- /dev/null
+++ b/lib/Mnemosyne/DB.pm
@@ -0,0 +1,137 @@
+package Mnemosyne::DB;
+use strict;
+use warnings;
+use DBI;
+use File::Basename qw(dirname);
+use File::Spec;
+use Carp qw(croak);
+
+# Opens (and initialises if new) the Mnemosyne SQLite database.
+# Usage:
+#   my $db = Mnemosyne::DB->new('/var/lib/mnemosyne/mnemosyne.db');
+#   my $dbh = $db->dbh;
+
+sub new {
+    my ($class, $path) = @_;
+    croak "Database path required" unless defined $path;
+
+    # Ensure parent directory exists
+    my $dir = dirname($path);
+    unless (-d $dir) {
+        require File::Path;
+        File::Path::make_path($dir) or croak "Cannot create DB directory '$dir': $!";
+    }
+
+    my $dbh = DBI->connect(
+        "dbi:SQLite:dbname=$path", '', '',
+        {
+            RaiseError     => 1,
+            AutoCommit     => 1,
+            sqlite_unicode => 1,
+        }
+    ) or croak "Cannot connect to SQLite '$path': " . $DBI::errstr;
+
+    my $self = bless { _dbh => $dbh, _path => $path }, $class;
+    $self->_configure;
+    $self->_apply_schema;
+    return $self;
+}
+
+sub dbh { $_[0]->{_dbh} }
+
+sub _configure {
+    my ($self) = @_;
+    my $dbh = $self->{_dbh};
+    $dbh->do('PRAGMA foreign_keys = ON');
+    $dbh->do('PRAGMA journal_mode = WAL');
+    $dbh->do('PRAGMA synchronous  = NORMAL'); # safe with WAL, faster than FULL
+}
+
+sub _apply_schema {
+    my ($self) = @_;
+
+    # Schema DDL is kept here alongside the canonical share/schema.sql.
+    # share/schema.sql is the human-readable reference; this is what runs at startup.
+    # Both must be kept in sync when the schema changes.
+    my @statements = (
+        q{
+        CREATE TABLE IF NOT EXISTS tasks (
+            id           INTEGER PRIMARY KEY AUTOINCREMENT,
+            title        TEXT    NOT NULL,
+            notes        TEXT,
+            class        TEXT    NOT NULL
+                                 CHECK(class IN ('monthly_date','monthly_weekday',
+                                                 'every_n_period','interval','floating')),
+            active       INTEGER NOT NULL DEFAULT 1,
+            day_of_month   INTEGER,
+            weekday        INTEGER,
+            ordinal        INTEGER,
+            interval_n     INTEGER,
+            period_unit    TEXT CHECK(period_unit IN ('day','week','month') OR period_unit IS NULL),
+            anchor_date    TEXT,
+            interval_days  INTEGER,
+            priority       TEXT CHECK(priority IN ('high','medium','low') OR priority IS NULL),
+            created_at   TEXT NOT NULL DEFAULT (strftime('%Y-%m-%dT%H:%M:%SZ','now')),
+            updated_at   TEXT NOT NULL DEFAULT (strftime('%Y-%m-%dT%H:%M:%SZ','now'))
+        )},
+        q{
+        CREATE TABLE IF NOT EXISTS completions (
+            id           INTEGER PRIMARY KEY AUTOINCREMENT,
+            task_id      INTEGER NOT NULL REFERENCES tasks(id) ON DELETE CASCADE,
+            completed_at TEXT    NOT NULL DEFAULT (strftime('%Y-%m-%dT%H:%M:%SZ','now'))
+        )},
+        q{CREATE INDEX IF NOT EXISTS idx_completions_task_id ON completions(task_id)},
+        q{
+        CREATE TABLE IF NOT EXISTS config (
+            key   TEXT PRIMARY KEY,
+            value TEXT NOT NULL
+        )},
+    );
+
+    my @config_defaults = (
+        [ 'digest_time',       '06:30' ],
+        [ 'timezone',          'UTC'   ],
+        [ 'last_digest_sent',  ''      ],
+        [ 'upcoming_horizon',  '7'     ],
+        [ 'medium_float_days', '3'     ],
+    );
+
+    my $dbh = $self->{_dbh};
+    $dbh->begin_work;
+    eval {
+        $dbh->do($_) for @statements;
+        my $ins = $dbh->prepare('INSERT OR IGNORE INTO config (key, value) VALUES (?, ?)');
+        $ins->execute(@$_) for @config_defaults;
+        $dbh->commit;
+    };
+    if ($@) {
+        $dbh->rollback;
+        croak "Schema initialisation failed: $@";
+    }
+}
+
+# --- Config table helpers ---
+
+sub config_get {
+    my ($self, $key) = @_;
+    my ($val) = $self->{_dbh}->selectrow_array(
+        'SELECT value FROM config WHERE key = ?', undef, $key
+    );
+    return $val;
+}
+
+sub config_set {
+    my ($self, $key, $value) = @_;
+    $self->{_dbh}->do(
+        'INSERT INTO config (key, value) VALUES (?, ?)
+         ON CONFLICT(key) DO UPDATE SET value = excluded.value',
+        undef, $key, $value
+    );
+}
+
+sub DESTROY {
+    my ($self) = @_;
+    $self->{_dbh}->disconnect if $self->{_dbh};
+}
+
+1;
diff --git a/lib/Mnemosyne/Digest.pm b/lib/Mnemosyne/Digest.pm
new file mode 100644
index 0000000..51f75e9
--- /dev/null
+++ b/lib/Mnemosyne/Digest.pm
@@ -0,0 +1,27 @@
+package Mnemosyne::Digest;
+use strict;
+use warnings;
+
+# Assembles the "Day at a Glance" digest content and sends it via Telegram.
+# Also used by the /today and /glance commands for on-demand delivery.
+#
+# Sections (in order), each omitted when empty:
+#   1. Overdue   — dated tasks past their due date with no completion
+#   2. Today     — tasks due today
+#   3. Upcoming  — tasks due in the next upcoming_horizon days (default 7)
+#   4. Floating  — priority-driven selection per Schedule::_floating_show rules
+#
+# Each actionable line gets a Mark Done inline keyboard button.
+# A friendly "all clear" line is shown when all sections are empty.
+#
+# TODO: build($db, $config, $today_dt) — returns an arrayref of message segments
+#       (Telegram has a 4096-char limit; split into multiple messages if needed)
+#
+# TODO: send($db, $config, $telegram, $chat_id, $today_dt)
+#       — calls build(), sends via Telegram, records last_digest_sent in config table
+#
+# TODO: already_sent_today($db, $today_dt)
+#       — checks last_digest_sent config row; returns true if digest was sent today
+#       — used by mnemosyne-digest script to prevent duplicate sends
+
+1;
diff --git a/lib/Mnemosyne/Schedule.pm b/lib/Mnemosyne/Schedule.pm
new file mode 100644
index 0000000..9a5cc01
--- /dev/null
+++ b/lib/Mnemosyne/Schedule.pm
@@ -0,0 +1,36 @@
+package Mnemosyne::Schedule;
+use strict;
+use warnings;
+
+# Resolves whether a task is due/upcoming/overdue/irrelevant for a given date.
+# This module is the heart of the scheduling logic and must be well unit-tested.
+#
+# Public interface (all take a task hashref + a DateTime object for "today"):
+#
+# TODO: status($task, $today_dt) — returns one of: 'overdue', 'due', 'upcoming', 'inactive'
+#       Dispatches to the appropriate class handler below.
+#
+# TODO: next_due_date($task, $today_dt) — returns a DateTime of the next occurrence,
+#       or undef if the task has no upcoming date (e.g. inactive).
+#
+# --- Per-class handlers ---
+#
+# TODO: _monthly_date_due($task, $today_dt)
+#       Rule: fires on day_of_month each month.
+#       Short-month rule: if day_of_month > days-in-month, fire on last day of month.
+#
+# TODO: _monthly_weekday_due($task, $today_dt)
+#       Rule: fires on the Nth weekday (ordinal 1-4, or -1 for last) each month.
+#
+# TODO: _every_n_period_due($task, $today_dt)
+#       Rule: occurrences = anchor_date + k * (interval_n period_units), k=0,1,2,...
+#       Calendar-anchored; NOT reset by completion.
+#
+# TODO: _interval_due($task, $today_dt, $last_completion_dt)
+#       Rule: next_due = last_completion_dt + interval_days (or created_at if never done).
+#
+# TODO: _floating_show($task, $today_dt, $last_completion_dt)
+#       Rule: high → always; medium → every medium_float_days; low → weekly + randomised.
+#       Returns true/false (floating tasks are never "overdue", just shown or not).
+
+1;
diff --git a/lib/Mnemosyne/Task.pm b/lib/Mnemosyne/Task.pm
new file mode 100644
index 0000000..50ef18e
--- /dev/null
+++ b/lib/Mnemosyne/Task.pm
@@ -0,0 +1,17 @@
+package Mnemosyne::Task;
+use strict;
+use warnings;
+
+# CRUD operations for the tasks table, plus class-specific field validation.
+#
+# TODO: create($dbh, \%fields)   — insert a new task, validate class + required fields
+# TODO: get($dbh, $id)           — fetch one task by id (returns hashref or undef)
+# TODO: list($dbh, %filters)     — list tasks; filters: class, active, priority
+# TODO: update($dbh, $id, \%fields) — partial update; sets updated_at
+# TODO: delete($dbh, $id)        — hard delete (completions cascade)
+# TODO: disable($dbh, $id)       — set active=0
+# TODO: complete($dbh, $id)      — insert into completions; for floating, also sets active=0
+# TODO: undo_completion($dbh, $completion_id) — delete a completion row (misclick undo)
+# TODO: last_completion($dbh, $id) — returns the most recent completions row for a task
+
+1;
diff --git a/lib/Mnemosyne/Telegram.pm b/lib/Mnemosyne/Telegram.pm
new file mode 100644
index 0000000..9cda042
--- /dev/null
+++ b/lib/Mnemosyne/Telegram.pm
@@ -0,0 +1,35 @@
+package Mnemosyne::Telegram;
+use strict;
+use warnings;
+
+# Bot API client. All outbound calls use Mojo::UserAgent.
+# Never use Telegram::Bot or other heavyweight frameworks.
+#
+# Constructor:
+# TODO: new($token) — stores token; lazily creates Mojo::UserAgent
+#
+# Sending messages:
+# TODO: send_message($chat_id, $text, %opts)
+#       — opts: parse_mode (default 'HTML'), reply_markup (inline keyboard hashref)
+#       — returns the sent message's message_id (needed for later edits)
+#
+# TODO: edit_message($chat_id, $message_id, $text, %opts)
+#       — wraps editMessageText; used to replace "pending" with "✓ Done — [Undo]"
+#
+# TODO: edit_reply_markup($chat_id, $message_id, $reply_markup)
+#       — wraps editMessageReplyMarkup; strips buttons after undo window expires
+#
+# TODO: answer_callback_query($callback_query_id, %opts)
+#       — must be called promptly to stop the client spinner; opts: text, show_alert
+#
+# Keyboard helpers:
+# TODO: mark_done_keyboard($task_id) — returns inline_keyboard hashref with one
+#       "Mark Done" button; callback_data encodes action + task_id
+#
+# TODO: undo_keyboard($completion_id) — "Undo" button after a mark-done action
+#
+# Setup:
+# TODO: set_webhook($url, $secret_token) — calls setWebhook; idempotent
+# TODO: delete_webhook()                 — calls deleteWebhook
+
+1;
diff --git a/lib/Mnemosyne/Webhook.pm b/lib/Mnemosyne/Webhook.pm
new file mode 100644
index 0000000..17b1270
--- /dev/null
+++ b/lib/Mnemosyne/Webhook.pm
@@ -0,0 +1,37 @@
+package Mnemosyne::Webhook;
+use strict;
+use warnings;
+
+# Mojolicious controller / update router for inbound Telegram webhook POSTs.
+#
+# Security gates (must run in this order before any processing):
+#   1. Validate X-Telegram-Bot-Api-Secret-Token header matches config.
+#      Reject with 403 (not 200) — this is not a Telegram client, it's a rogue POST.
+#   2. Validate chat_id is in the allowed_chat_ids whitelist.
+#      Respond 200 (so Telegram stops retrying) but do not process the update.
+#
+# Update types handled:
+# TODO: handle_message($update, $db, $config, $telegram)
+#       — routes slash commands: /today /glance /list /add /done /edit /disable /delete
+#         /settime /help; plus free-text during multi-step flows (e.g. /add wizard)
+#
+# TODO: handle_callback_query($update, $db, $config, $telegram)
+#       — handles Mark Done and Undo button taps; calls answerCallbackQuery immediately
+#         then does DB work + message edit; idempotent (tolerate Telegram redelivery)
+#
+# Command handlers (each returns a Telegram reply or edits the original message):
+# TODO: cmd_today($chat_id, $db, $config, $telegram)
+# TODO: cmd_list($chat_id, $args, $db, $config, $telegram)
+# TODO: cmd_add($chat_id, $args, $db, $config, $telegram)   — starts guided flow
+# TODO: cmd_done($chat_id, $args, $db, $config, $telegram)
+# TODO: cmd_edit($chat_id, $args, $db, $config, $telegram)
+# TODO: cmd_disable($chat_id, $args, $db, $config, $telegram)
+# TODO: cmd_delete($chat_id, $args, $db, $config, $telegram) — confirmation required
+# TODO: cmd_settime($chat_id, $args, $db, $config, $telegram)
+# TODO: cmd_help($chat_id, $telegram)
+#
+# Conversation state for multi-step flows (e.g. /add wizard):
+# TODO: decide and document storage mechanism (in-memory hash keyed by chat_id,
+#       or a small 'sessions' table in SQLite for persistence across restarts)
+
+1;
diff --git a/nginx/mnemosyne.conf.example b/nginx/mnemosyne.conf.example
new file mode 100644
index 0000000..b13ad3f
--- /dev/null
+++ b/nginx/mnemosyne.conf.example
@@ -0,0 +1,37 @@
+# Nginx reverse-proxy config for Mnemosyne.
+# Place in /etc/nginx/conf.d/ (RHEL/AlmaLinux) or /etc/nginx/sites-available/ (Debian/Ubuntu).
+# Replace mnemosyne.example.com with your actual subdomain.
+# Assumes Let's Encrypt cert managed by certbot.
+
+server {
+    listen 80;
+    server_name mnemosyne.example.com;
+    # certbot will add a redirect here
+    return 301 https://$host$request_uri;
+}
+
+server {
+    listen 443 ssl;
+    server_name mnemosyne.example.com;
+
+    ssl_certificate     /etc/letsencrypt/live/mnemosyne.example.com/fullchain.pem;
+    ssl_certificate_key /etc/letsencrypt/live/mnemosyne.example.com/privkey.pem;
+    include             /etc/letsencrypt/options-ssl-nginx.conf;
+    ssl_dhparam         /etc/letsencrypt/ssl-dhparams.pem;
+
+    # Only expose the webhook path; deny everything else
+    location /hook/ {
+        proxy_pass         http://127.0.0.1:8765;
+        proxy_http_version 1.1;
+        proxy_set_header   Host              $host;
+        proxy_set_header   X-Real-IP         $remote_addr;
+        proxy_set_header   X-Forwarded-For   $proxy_add_x_forwarded_for;
+        proxy_set_header   X-Forwarded-Proto $scheme;
+        # Forward Telegram's secret-token header
+        proxy_pass_header  X-Telegram-Bot-Api-Secret-Token;
+    }
+
+    location / {
+        return 404;
+    }
+}
diff --git a/scripts/backup.sh b/scripts/backup.sh
new file mode 100755
index 0000000..bab5b5a
--- /dev/null
+++ b/scripts/backup.sh
@@ -0,0 +1,13 @@
+#!/usr/bin/env bash
+# Online SQLite backup using the .backup API (safe while the bot is running).
+# TODO: implement; outline below.
+set -euo pipefail
+
+# TODO: read DB_PATH from config or env
+# TODO: BACKUP_DIR default /var/backups/mnemosyne, override via $MNEMOSYNE_BACKUP_DIR
+# TODO: filename: mnemosyne-$(date +%Y%m%d-%H%M%S).db
+# TODO: sqlite3 "$DB_PATH" ".backup '$BACKUP_DIR/$FILENAME'"
+#       (uses the SQLite backup API — safe for concurrent access, no locks held)
+# TODO: optionally prune backups older than N days
+
+echo "TODO: backup.sh not yet implemented"
diff --git a/scripts/install.sh b/scripts/install.sh
new file mode 100755
index 0000000..84d1051
--- /dev/null
+++ b/scripts/install.sh
@@ -0,0 +1,44 @@
+#!/usr/bin/env bash
+# Mnemosyne install script — idempotent; safe to re-run.
+# Does NOT clobber an existing database or config file.
+# TODO: implement; outline below.
+
+set -euo pipefail
+
+# --- Detect distro family ---
+# TODO: detect RHEL/AlmaLinux (dnf/yum) vs Debian/Ubuntu (apt) vs other
+# TODO: on RHEL family: dnf install -y perl perl-App-cpanminus perl-DBI sqlite
+# TODO: on Debian family: apt-get install -y perl cpanminus libdbi-perl sqlite3
+# TODO: document: on either family, run `cpanm --installdeps .` after this step
+
+# --- System user ---
+# TODO: create 'mnemosyne' system user/group if not present (useradd -r -s /sbin/nologin)
+
+# --- Directories ---
+# TODO: /opt/mnemosyne  — app files (copy repo here or symlink)
+# TODO: /var/lib/mnemosyne — database directory, owned by mnemosyne user
+# TODO: /etc/mnemosyne — config directory (skip if already exists to avoid clobbering)
+
+# --- Config ---
+# TODO: if /etc/mnemosyne/mnemosyne.conf does not exist:
+#         copy config/mnemosyne.conf.example → /etc/mnemosyne/mnemosyne.conf
+#         chmod 640, chown root:mnemosyne
+#         print reminder to edit the file before starting the service
+
+# --- CPAN deps ---
+# TODO: cd /opt/mnemosyne && cpanm --installdeps .
+
+# --- Systemd ---
+# TODO: copy systemd/mnemosyne-bot.service → /etc/systemd/system/
+# TODO: systemctl daemon-reload
+# TODO: systemctl enable mnemosyne-bot (but do NOT start — user must configure first)
+
+# --- Cron for digest ---
+# TODO: install a cron entry for mnemosyne user:
+#         */5 * * * * /opt/mnemosyne/bin/mnemosyne-digest --config /etc/mnemosyne/mnemosyne.conf
+#       This fires every 5 minutes; the script itself checks against digest_time and exits early.
+
+# --- Nginx ---
+# TODO: remind user to copy nginx/mnemosyne.conf.example and adjust, then reload nginx
+
+echo "TODO: install.sh not yet implemented"
diff --git a/share/schema.sql b/share/schema.sql
new file mode 100644
index 0000000..056bfb4
--- /dev/null
+++ b/share/schema.sql
@@ -0,0 +1,68 @@
+-- Mnemosyne schema
+-- Apply once; all statements use IF NOT EXISTS so this is safe to re-run.
+
+PRAGMA foreign_keys = ON;
+PRAGMA journal_mode = WAL;
+
+CREATE TABLE IF NOT EXISTS tasks (
+    id           INTEGER PRIMARY KEY AUTOINCREMENT,
+    title        TEXT    NOT NULL,
+    notes        TEXT,
+    class        TEXT    NOT NULL
+                         CHECK(class IN ('monthly_date','monthly_weekday',
+                                         'every_n_period','interval','floating')),
+    active       INTEGER NOT NULL DEFAULT 1,
+
+    -- monthly_date: fires on this day of every month.
+    -- Short-month rule: if day_of_month > last day of month, fire on last day.
+    day_of_month   INTEGER,
+
+    -- monthly_weekday: fires on the Nth weekday of every month.
+    -- weekday: 0=Monday .. 6=Sunday (ISO weekday - 1)
+    -- ordinal:  1-4 for first-fourth; -1 for "last"
+    weekday        INTEGER,
+    ordinal        INTEGER,
+
+    -- every_n_period: fires every interval_n period_units after anchor_date.
+    -- Occurrences are calendar-anchored (not completion-driven).
+    interval_n     INTEGER,
+    period_unit    TEXT    CHECK(period_unit IN ('day','week','month') OR period_unit IS NULL),
+    anchor_date    TEXT,   -- ISO date YYYY-MM-DD
+
+    -- interval: next due = last_completed_at + interval_days.
+    -- If never completed, seeds from created_at (so it doesn't scream overdue on day one).
+    interval_days  INTEGER,
+
+    -- floating: no fixed date; reminder frequency driven by priority.
+    -- high   → appears every day
+    -- medium → appears every medium_float_days (see config table, default 3)
+    -- low    → appears roughly weekly; which low items show is randomised/rotated
+    -- Completing a floating task sets active=0 (archives it), since floating items
+    -- are typically one-and-done aspirations.
+    priority       TEXT    CHECK(priority IN ('high','medium','low') OR priority IS NULL),
+
+    created_at   TEXT    NOT NULL DEFAULT (strftime('%Y-%m-%dT%H:%M:%SZ','now')),
+    updated_at   TEXT    NOT NULL DEFAULT (strftime('%Y-%m-%dT%H:%M:%SZ','now'))
+);
+
+CREATE TABLE IF NOT EXISTS completions (
+    id           INTEGER PRIMARY KEY AUTOINCREMENT,
+    task_id      INTEGER NOT NULL REFERENCES tasks(id) ON DELETE CASCADE,
+    completed_at TEXT    NOT NULL DEFAULT (strftime('%Y-%m-%dT%H:%M:%SZ','now'))
+);
+
+CREATE INDEX IF NOT EXISTS idx_completions_task_id ON completions(task_id);
+
+-- Single-row key/value store for runtime-tunable settings.
+-- Populated with defaults below; /settime and future commands update rows here.
+CREATE TABLE IF NOT EXISTS config (
+    key   TEXT PRIMARY KEY,
+    value TEXT NOT NULL
+);
+
+INSERT OR IGNORE INTO config (key, value) VALUES
+    ('digest_time',       '06:30'),   -- local HH:MM, adjustable via /settime
+    ('timezone',          'UTC'),     -- overridden by mnemosyne.conf at startup
+    ('last_digest_sent',  ''),        -- ISO date of last successful digest; guards against dupes
+    ('upcoming_horizon',  '7'),       -- days forward shown in Upcoming section
+    ('medium_float_days', '3');       -- how often medium-priority floating items surface
diff --git a/systemd/mnemosyne-bot.service b/systemd/mnemosyne-bot.service
new file mode 100644
index 0000000..996e6c6
--- /dev/null
+++ b/systemd/mnemosyne-bot.service
@@ -0,0 +1,19 @@
+[Unit]
+Description=Mnemosyne Telegram bot (webhook receiver)
+After=network.target
+
+[Service]
+Type=simple
+User=mnemosyne
+Group=mnemosyne
+WorkingDirectory=/opt/mnemosyne
+ExecStart=/usr/bin/perl /opt/mnemosyne/bin/mnemosyne-bot --config /etc/mnemosyne/mnemosyne.conf
+Restart=always
+RestartSec=5
+# Keep logs in the journal
+StandardOutput=journal
+StandardError=journal
+SyslogIdentifier=mnemosyne-bot
+
+[Install]
+WantedBy=multi-user.target
diff --git a/t/config.t b/t/config.t
new file mode 100644
index 0000000..eae69e6
--- /dev/null
+++ b/t/config.t
@@ -0,0 +1,40 @@
+#!/usr/bin/env perl
+use strict;
+use warnings;
+use Test::More;
+use File::Temp qw(tempfile);
+use FindBin qw($RealBin);
+use lib "$RealBin/../lib";
+
+use_ok('Mnemosyne::Config');
+
+my (undef, $tmp) = tempfile(SUFFIX => '.conf', UNLINK => 1);
+open my $fh, '>', $tmp or die $!;
+print $fh <<'END';
+[bot]
+token = abc123
+webhook_secret = secret456
+allowed_chat_ids = 111, 222, 333
+listen_port = 8765
+
+[db]
+path = /var/lib/mnemosyne/mnemosyne.db
+
+[app]
+timezone = America/Chicago  # inline comment
+digest_time = 07:30
+END
+close $fh;
+
+my $cfg = Mnemosyne::Config->new($tmp);
+isa_ok($cfg, 'Mnemosyne::Config');
+
+is($cfg->get('bot', 'token'),          'abc123',  'bot.token');
+is($cfg->get('bot', 'listen_port'),    '8765',    'bot.listen_port');
+is($cfg->get('app', 'digest_time'),    '07:30',   'app.digest_time');
+is($cfg->get('app', 'timezone'),       'America/Chicago', 'inline comment stripped');
+is($cfg->get('db',  'path'),           '/var/lib/mnemosyne/mnemosyne.db', 'db.path');
+is_deeply($cfg->allowed_chat_ids,      [111, 222, 333], 'allowed_chat_ids parsed');
+is($cfg->get('bot', 'nonexistent'),    undef,     'missing key returns undef');
+
+done_testing;
diff --git a/t/db.t b/t/db.t
new file mode 100644
index 0000000..ac12a37
--- /dev/null
+++ b/t/db.t
@@ -0,0 +1,30 @@
+#!/usr/bin/env perl
+use strict;
+use warnings;
+use Test::More;
+use File::Temp qw(tempfile);
+use FindBin qw($RealBin);
+use lib "$RealBin/../lib";
+
+use_ok('Mnemosyne::DB');
+
+my (undef, $tmp) = tempfile(SUFFIX => '.db', UNLINK => 1);
+
+my $db = Mnemosyne::DB->new($tmp);
+isa_ok($db, 'Mnemosyne::DB');
+ok($db->dbh, 'dbh returns a handle');
+
+# Schema applied
+my @tables = map { $_->[0] }
+    @{ $db->dbh->selectall_arrayref("SELECT name FROM sqlite_master WHERE type='table' AND name NOT LIKE 'sqlite_%' ORDER BY name") };
+is_deeply(\@tables, [qw(completions config tasks)], 'expected tables created');
+
+# Config defaults
+is($db->config_get('digest_time'), '06:30', 'default digest_time');
+is($db->config_get('upcoming_horizon'), '7', 'default upcoming_horizon');
+
+# config_set round-trip
+$db->config_set('digest_time', '07:00');
+is($db->config_get('digest_time'), '07:00', 'config_set persists');
+
+done_testing;
diff --git a/t/schedule.t b/t/schedule.t
new file mode 100644
index 0000000..feba200
--- /dev/null
+++ b/t/schedule.t
@@ -0,0 +1,36 @@
+#!/usr/bin/env perl
+use strict;
+use warnings;
+use Test::More;
+
+# Schedule.pm unit tests — date math across all five task classes.
+# This file is a placeholder; tests will be added as Schedule.pm is implemented.
+#
+# Priority test cases to cover:
+#
+# monthly_date:
+#   - Normal case: day_of_month=15, today=2026-06-15 → due
+#   - Short-month clamp: day_of_month=31, today=2026-06-30 → due (last day of June)
+#   - Short-month clamp: day_of_month=31, today=2026-06-15 → upcoming
+#   - Overdue: day_of_month=1, today=2026-06-05, no completion → overdue
+#
+# monthly_weekday:
+#   - 4th Monday: 2026-06 → 2026-06-22
+#   - last Monday: 2026-06 → 2026-06-29
+#   - ordinal=1, weekday=0 (Mon): 2026-06 → 2026-06-01
+#
+# every_n_period:
+#   - every 2 weeks from 2026-01-01: check correct occurrence dates
+#   - every 3 months from 2026-01-15: Feb has 28 days — verify month arithmetic
+#
+# interval:
+#   - never completed: due = created_at + interval_days
+#   - completed yesterday: interval=30 → not due yet
+#   - completed 31 days ago: interval=30 → overdue
+#
+# floating:
+#   - high priority → always shown
+#   - medium: shown at day 0 and day 3, not at day 1 or 2
+
+plan skip_all => 'Schedule.pm not yet implemented';
+done_testing;