shd.build/docs/architecture.md

SHD.build architecture

This project is intentionally being built in vertical slices.

Planned stack

• SvelteKit 2 / Svelte 5 with TypeScript
• Embedded Turso Database via @tursodatabase/database for durable application data
• Auth.js-compatible server authentication with Discord OAuth and credentials providers
• Argon2id password hashing, server-side sessions, CSRF protection, and role checks
• Browser localStorage only for anonymous build drafts

Product boundaries

• Public: browse, sort, and view published builds and guides.
• Anonymous: create and edit local drafts.
• Authenticated: publish, rate, comment, favorite, copy, and manage owned builds.
• Editor: manage builder source data.
• Admin: manage users, roles, source data, and audit history.

Authorization must be checked on the server for every mutation. Hiding an admin link is not authorization.

Local credentials are stored as Argon2id PHC strings with a unique random salt per password. Current work factors follow OWASP's 19 MiB / 2 iteration / single-lane minimum profile and can be increased over time; successful login will eventually rehash credentials whose parameters are outdated.

Database runtime

The application uses Turso Database in-process through its native Node package. It opens a local SQLite-compatible database file and does not use Turso Cloud, libSQL HTTP, remote replicas, auth tokens, or synchronization.

The database defaults to ./data/shd-build.db. Production deployments must provide a persistent writable filesystem and can override the location with TDR_DATABASE_PATH. This rules out ephemeral serverless filesystems unless a persistent volume is attached.

Increment plan

1. Product shell and anonymous local-draft builder.
2. Embedded Turso migrations, repositories, and seed data.
3. Credentials and Discord authentication.
4. Full equipment/stat builder driven by database definitions.
5. Publishing, discovery, ratings, comments, favorites, and copy flow.
6. Rich build guides and moderation.
7. Admin editors, validation, audit log, and data import/export.

Administrator bootstrap

The first successfully authenticated user is promoted to admin if the database does not contain an administrator. Promotion uses one conditional database update so concurrent first sign-ins cannot both become administrators. Once an administrator exists, later sign-ins never alter roles.

Database backup and restore

Embedded Turso databases contain contributor-entered source data and must be preserved across development changes.

Create a timestamped development backup:

npm run db:backup

Create a production backup:

npm run db:backup:production

The scripts write versioned JSON documents beneath data/backups/ by default. That directory is ignored by Git because backups contain private user data, including password hashes.

To restore, first create an empty database and apply the schema. Then run:

npm run db:restore -- data/backups/<backup-file>.json

The restore operation refuses to import into any database containing records. This guard prevents accidental merging or overwriting of contributor data. Stop the application before backup or restore so the embedded database file is not locked by another process.

ISAC audit and compensating reversals

Every successful ISAC mutation appends an event to audit_log through the shared server audit utility. Events identify the operator, operational category, specific action, target entity, timestamp, and useful before/after evidence. The audit registry is read-only and requires audit.view; the seeded Auditor role grants that permission without granting mutation capabilities.

Audit history is immutable. “Revert” is implemented as a new compensating mutation rather than deletion or modification of the original event:

1. The operator must independently hold audit.revert.
2. The original action must be explicitly supported and contain a usable before-snapshot.
3. The UI requires a second, explicit confirmation.
4. The server reloads the target and compares it with the original after-snapshot, ignoring bookkeeping timestamps. A mismatch means newer work exists and blocks automatic compensation.
5. Referenced roles, permissions, and relationships are revalidated before restoration. Restoring administrator authority additionally requires full administrative access.
6. The server restores the previous state and appends an audit.reverted event whose target is the original audit-event ID.
7. A successfully reverted event cannot be reverted again.

Unsupported destructive identity operations, account deletion, incomplete snapshots, stale targets, and events whose dependencies no longer exist are marked non-reversible or rejected. Recovery for those cases requires a specialized workflow rather than inferred database writes.

System metrics

The read-only /admin/metrics route requires metrics.view and collects a point-in-time process-local health snapshot. Node and operating-system APIs provide process CPU and memory, event-loop utilization and delay, host memory, load average, core count, platform, and uptime. Embedded Turso pragmas provide page allocation, page size, and free-page information; aggregate SQL queries provide application record volumes.

The interface refreshes on demand and may poll every ten seconds while the operator keeps auto-refresh enabled. CPU and event-loop values are deltas from the previous server-side sample, so the first or infrequently requested sample is directional rather than a monitoring-grade time series. Production alerting and historical analysis should eventually use a dedicated external telemetry system. This surface deliberately omits secrets, environment-variable values, and full database paths.

Weapon-owned exotic talents

Standard weapon talent pools remain globally reusable and classified by Talent 1 / Top or Talent 2 / Bottom. An exotic talent is different: one exotic weapon owns one dedicated talent, referenced by weapons.exotic_talent_id.

The weapon editor creates and updates the underlying normalized talents, talent_tiers, trigger links, effect links, description template, and Exotic weapon scope together with the weapon. Server validation rejects an exotic talent ID not already owned by the edited weapon and rejects any talent shared by another weapon. Converting a weapon back to standard clears the relationship and archives its now-unowned exotic talent. Exotic talent creation and editing are rejected by the shared Talent Registry so ownership cannot be bypassed.

OS Protocol progression

OS Protocols use dedicated normalized tables because their talent progression has six calculated states (base plus five upgrades) rather than the shared two-tier talent model. Each protocol owns one os_protocol_primary_effects record and one os_protocol_talents record. Talent effects and reusable triggers live in their respective join tables.

The three secondary attributes are normalized separately. One os_protocol_secondary_profiles record exists for each configured quality + attribute-type combination, with its three fixed stat/value pairs in os_protocol_secondary_effects. Every matching protocol inherits that profile; secondary values are not copied onto individual protocol records.

The unique primary value uses base × (1 + (level − 1) / 49) for levels 1–50, while talent effects use base × (1 + upgrades / 5) for zero to five upgrades. Server actions validate all relationships and append the full owned graph to the existing game_data audit history.