diff --git a/schema.sql b/schema.sql
index 1e20195..c171964 100644
--- a/schema.sql
+++ b/schema.sql
@@ -83,3 +83,50 @@ CREATE INDEX IF NOT EXISTS idx_timeline_ticket ON ticket_timeline (ticket_id);
 CREATE INDEX IF NOT EXISTS idx_audit_tenant_zeit ON audit_log (tenant_id, zeit DESC);
 CREATE INDEX IF NOT EXISTS idx_services_tenant ON services (tenant_id);
 CREATE INDEX IF NOT EXISTS idx_users_tenant ON users (tenant_id);
+
+-- Vorbereitung fuer spaetere AD/LDAP-Anbindung (Nutzer-Vorgabe 2026-07-13):
+-- 'local' = im ITSM selbst verwaltetes Konto (heutiger Stand), 'ldap' reserviert
+-- fuer die kommende Ausbaustufe. Kein Verhaltensunterschied heute, nur Vorbereitung.
+ALTER TABLE users ADD COLUMN IF NOT EXISTS auth_source TEXT NOT NULL DEFAULT 'local';
+
+-- ── Wissensdatenbank ──────────────────────────────────────────────────────────
+CREATE TABLE IF NOT EXISTS kb_articles (
+    id             SERIAL PRIMARY KEY,
+    tenant_id      INTEGER NOT NULL REFERENCES tenants(id) ON DELETE CASCADE,
+    titel          TEXT NOT NULL,
+    kategorie      TEXT NOT NULL DEFAULT 'Allgemein',
+    inhalt         TEXT NOT NULL,
+    tags           TEXT,
+    autor_user_id  INTEGER REFERENCES users(id) ON DELETE SET NULL,
+    created_at     TIMESTAMPTZ NOT NULL DEFAULT now(),
+    updated_at     TIMESTAMPTZ NOT NULL DEFAULT now()
+);
+CREATE INDEX IF NOT EXISTS idx_kb_tenant_kategorie ON kb_articles (tenant_id, kategorie);
+
+-- ── CMDB (Configuration Management Database) ──────────────────────────────────
+CREATE TABLE IF NOT EXISTS configuration_items (
+    id            SERIAL PRIMARY KEY,
+    tenant_id     INTEGER NOT NULL REFERENCES tenants(id) ON DELETE CASCADE,
+    name          TEXT NOT NULL,
+    ci_typ        TEXT NOT NULL DEFAULT 'Sonstiges',
+    status        TEXT NOT NULL DEFAULT 'Aktiv',
+    beschreibung  TEXT,
+    attribute     JSONB NOT NULL DEFAULT '{}'::jsonb,
+    created_at    TIMESTAMPTZ NOT NULL DEFAULT now(),
+    updated_at    TIMESTAMPTZ NOT NULL DEFAULT now()
+);
+CREATE INDEX IF NOT EXISTS idx_ci_tenant_typ ON configuration_items (tenant_id, ci_typ);
+CREATE INDEX IF NOT EXISTS idx_ci_tenant_status ON configuration_items (tenant_id, status);
+
+CREATE TABLE IF NOT EXISTS ci_relationships (
+    id              SERIAL PRIMARY KEY,
+    tenant_id       INTEGER NOT NULL REFERENCES tenants(id) ON DELETE CASCADE,
+    from_ci_id      INTEGER NOT NULL REFERENCES configuration_items(id) ON DELETE CASCADE,
+    to_ci_id        INTEGER NOT NULL REFERENCES configuration_items(id) ON DELETE CASCADE,
+    beziehungs_typ  TEXT NOT NULL DEFAULT 'haengt ab von',
+    created_at      TIMESTAMPTZ NOT NULL DEFAULT now()
+);
+CREATE INDEX IF NOT EXISTS idx_cirel_tenant ON ci_relationships (tenant_id);
+CREATE INDEX IF NOT EXISTS idx_cirel_from ON ci_relationships (from_ci_id);
+CREATE INDEX IF NOT EXISTS idx_cirel_to ON ci_relationships (to_ci_id);
+