#Configuration

config/nestedset.php:

return [
    'columns' => [
        'lft'       => 'lft',
        'rgt'       => 'rgt',
        'parent_id' => 'parent_id',
        'depth'     => 'depth',
    ],

    'auto_transaction' => true,

    'aggregate_locking' => 'auto',   // 'auto' | 'always' | 'never'

    'queue' => [
        'connection' => env('NESTEDSET_QUEUE_CONNECTION'),
        'queue'      => env('NESTEDSET_QUEUE'),
    ],

    'events_enabled' => true,
];

#columns

Column names are read globally — change them once in config and every model using NodeTrait picks up the new names via the getLftName() / getRgtName() / getParentIdName() / getDepthName() accessors.

To use different column names per model, override those accessors on the model:

class Category extends Model implements HasNestedSet
{
    use NodeTrait;

    public function getLftName(): string  { return 'tree_lft'; }
    public function getRgtName(): string  { return 'tree_rgt'; }
}

#auto_transaction

When true (default), every tree mutation (save() after a appendToNode / prependToNode / insertBeforeNode / insertAfterNode / makeRoot / up / down) is wrapped in a DB::transaction() so the gap-shift UPDATE, the row INSERT/UPDATE, and any aggregate maintenance hooks all commit together. Set to false if you wrap calls in your own transaction at the call site.

#aggregate_locking

Controls whether the aggregate maintenance path issues SELECT ... FOR UPDATE on the ancestor chain before recomputing MIN/MAX (or raw-filter) columns. The right setting for almost every application is 'auto'.

• 'auto' (default) — lock the ancestor chain only on the recompute path (MIN, MAX, raw-filter, fixAggregates). Delta-only updates (SUM, COUNT, AVG) rely on the engine's single-statement row locks, which are sufficient under default isolation on all supported backends.
• 'always' — lock the ancestor chain before every aggregate maintenance UPDATE, including deltas. Choose this if you run with non-default isolation levels (e.g. PostgreSQL REPEATABLE READ) or have seen drift under concurrent load.
• 'never' — issue no explicit locks. Marginally faster on the recompute path; can produce drift on PostgreSQL READ COMMITTED with concurrent recomputes against overlapping subtrees.

#queue

Routing used by Model::queueFixAggregates() when the caller doesn't pass an explicit onConnection: / onQueue: override. Either key may be null — that falls back to Laravel's default queue connection / queue name. The defaults pull from environment so you can override per-deployment without code changes:

NESTEDSET_QUEUE_CONNECTION=redis
NESTEDSET_QUEUE=aggregates-low

#events_enabled

When true (default), the package fires typed events on Laravel's event bus around its meaningful operations — fixTree, fixAggregates (including per-chunk progress), bulkInsertTree, structural moves of existing nodes, the boundary marker for withDeferredAggregateMaintenance, and aggregate-maintenance failures. Listen via Event::listen() to wire metrics, Sentry, or audit logs — see Production Notes → Telemetry.

Set to false to short-circuit every firing site. Useful only on genuinely hot paths where you've measured the cost of constructing event objects you'll never observe.