OwnCord/docs/architecture/data-model.md

Data Model

Verified against: commit ddc49f0, 2026-07-19

The canonical schema is the ordered migration set Server/migrations/001–015 (embedded via go:embed, applied by the custom runner in Server/db/migrate.go, tracked in the schema_versions table). SQLite is the only supported engine — Server/main.go rejects any other database.type at startup.

D5 — Entity-relationship overview

All 23 application tables, grouped by domain. Junction/leaf detail columns are elided; the goal is the relationship graph, not full DDL (see docs/schema.md for DDL — note it is currently 6 migrations behind, see audit-2026-07-19.md §2).

erDiagram
    %% ── Identity & access ──
    roles ||--o{ users : "role_id"
    users ||--o{ sessions : "user_id"
    roles ||--o{ channel_overrides : "role_id"
    channels ||--o{ channel_overrides : "channel_id"
    users ||--o{ user_blocks : "blocker_id / blocked_id"
    users ||--o{ invites : "created_by / redeemed_by"

    %% ── Messaging ──
    channels ||--o{ messages : "channel_id"
    users ||--o{ messages : "user_id"
    messages ||--o{ messages : "reply_to"
    messages ||--o{ attachments : "message_id"
    messages ||--o{ reactions : "message_id"
    users ||--o{ reactions : "user_id"
    users ||--o{ read_states : "user_id"
    channels ||--o{ read_states : "channel_id"

    %% ── Direct messages (channels with type='dm') ──
    channels ||--o{ dm_participants : "channel_id"
    users ||--o{ dm_participants : "user_id"
    channels ||--o{ dm_open_state : "channel_id"
    users ||--o{ dm_open_state : "user_id"

    %% ── Voice ──
    users ||--o| voice_states : "user_id (PK)"
    channels ||--o{ voice_states : "channel_id"

    %% ── Plugins ──
    plugins ||--o{ plugin_kv : "plugin_id"

    %% ── Standalone (no FK edges) ──
    events
    settings
    audit_log
    login_attempts
    rate_lockouts
    emoji
    sounds

    users {
        int id PK
        int role_id FK
        string username
        string password_hash
        bool banned
    }
    roles {
        int id PK
        string name
        int permissions "31-bit bitfield"
        int position
    }
    channels {
        int id PK
        string name
        string type "text | voice | dm (trigger-enforced)"
    }
    messages {
        int id PK
        int channel_id FK
        int user_id FK
        int reply_to FK
        string content
    }
    attachments {
        string id PK "UUID"
        int message_id FK
        int uploader_id "added by 010"
    }
    events {
        int seq PK "AUTOINCREMENT, hub seq seeded from MAX(seq)"
        string type
        string payload
    }

Domain notes

Domain	Tables	Notes
Identity & access	roles, users, sessions, channel_overrides, user_blocks, invites, login_attempts, rate_lockouts	Sessions store only SHA-256 token hashes. Permissions are a bitfield on roles.permissions; channel overrides use Discord semantics (role &^ deny) | allow. rate_lockouts (011) persists rate-limiter lockouts across restarts.
Messaging	channels, messages, attachments, reactions, read_states, emoji	channels.type is constrained to text | voice | announcement | dm by INSERT/UPDATE triggers (migration 013, extended by 016 to allow announcement). Announcement channels read like text but require MANAGE_MESSAGES to post. attachments.uploader_id (010) backs upload-ownership checks.
Direct messages	dm_participants, dm_open_state	DMs are channels rows with type='dm'; these tables track membership and per-user open/closed UI state (009).
Voice	voice_states	One row per user (user_id is the PK) — a user occupies at most one voice channel.
Real-time replay	events	Cold tier of the 3-tier reconnect replay (websocket.md); written by the async EventPersister, pruned by retention. Hub seq counter is seeded from MAX(events.seq) at startup so seqs stay monotonic across restarts.
Plugins	plugins, plugin_kv	015. plugin_kv is per-plugin namespaced KV via composite PK (plugin_id, key).
Ops	settings, audit_log, sounds	settings is a generic KV read by admin and the WS hub (via db.GetSetting). Migration 003 rebuilds audit_log through a transient audit_log_v6 rename — only audit_log exists at runtime. sounds is dead schema — the soundboard feature was removed but the table remains.

How the schema is accessed (three coexisting styles)

1. Raw SQL in Server/db — hand-written queries (*_queries.go, ~178 call sites). This is what actually runs, used directly by Server/api handlers, Server/admin, and the ws.Hub.
2. store.Store interface (Server/store) — a 14-domain composed interface with SQLiteStore (delegates to db.DB) and MemStore (test double). Consumed by the Server/service layer only.
3. sqlc-generated Server/db/dbgen (~3.5k LOC, from Server/db/queries/sqlite/ per sqlc.yaml) — imported by nothing; dead code kept verified by the sqlc-verify CI job.

The coexistence of all three is the largest structural finding of the audit — see audit-2026-07-19.md §3.

Source of truth: Server/migrations/*.sql (schema), Server/db/migrate.go (runner), Server/db/*_queries.go (live queries), Server/store/store.go (interface), sqlc.yaml + Server/db/dbgen/ (dormant generated layer).