Plugin System

Grove's plugin system lets you extend the ORM with custom behavior at lifecycle boundaries. Plugins are simpler than hooks — they respond to high-level events rather than intercepting individual queries.

Base Interface01

Every plugin must implement the Plugin interface:

import "github.com/xraph/grove/plugin"

type Plugin interface {
    Name() string
}

Lifecycle Hooks02

Plugins opt into events by implementing additional interfaces:

Model Events

type AfterRegisterModel interface {
    OnModelRegistered(ctx context.Context, table *schema.Table)
}

Connection Events

type AfterConnect interface {
    OnConnected(ctx context.Context, db *grove.DB)
}

type BeforeClose interface {
    OnClosing(ctx context.Context, db *grove.DB) error
}

Migration Events

type AfterMigrate interface {
    OnMigrated(ctx context.Context, migrations []migrate.AppliedMigration)
}

Registering Plugins03

// Step 1: Create and connect the driver
pgdb := pgdriver.New()
pgdb.Open(ctx, "postgres://localhost:5432/mydb", driver.WithPoolSize(20))

// Step 2: Open grove.DB with plugins
db, _ := grove.Open(pgdb,
    grove.WithPlugin(&MyAuditPlugin{}),
    grove.WithPlugin(&MyMetricsPlugin{}),
)

Type-Assertion Discovery04

The plugin registry uses type assertions to discover which events each plugin handles. Implement only the interfaces you need:

type MyPlugin struct{}

func (p *MyPlugin) Name() string { return "my-plugin" }

// Only implement OnConnected — other events are ignored
func (p *MyPlugin) OnConnected(ctx context.Context, db *grove.DB) {
    log.Printf("connected to database")
}

Built-in Plugins05

Chronicle Audit Plugin

Emits database events to Chronicle for audit trails:

import "github.com/xraph/grove/audit"

auditPlugin := audit.New(chronicleClient)
db, _ := grove.Open(pgdb,
    grove.WithPlugin(auditPlugin),
)

Events emitted:

grove.query.select / grove.query.insert / grove.query.update / grove.query.delete
grove.migration.applied / grove.migration.rolled_back
grove.connection.opened / grove.connection.closed

Prometheus Metrics Plugin

Exports query performance metrics:

import "github.com/xraph/grove/observability"

metricsPlugin := observability.New()
db, _ := grove.Open(pgdb,
    grove.WithPlugin(metricsPlugin),
)

Metrics:

grove_queries_total — Total queries by operation and table
grove_query_duration_seconds — Query latency histogram
grove_connections_active — Active connection count
grove_migrations_total — Migration execution count

KV Store Plugin Compatibility06

The KV module (grove/kv) uses the same grove/plugin package for plugin registration. The grove/hook package is shared between the ORM and KV store, so middleware written as hooks works seamlessly across both. See the KV Middleware Overview for KV-specific middleware patterns.

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