What causes "Extensions are only supported by Postgres." in laravel/framework?

Gate the call on the connection driver: if (Schema::getConnection() instanceof \Illuminate\Database\PostgresConnection).

laravel/framework · error · RuntimeException

Extensions are only supported by Postgres.

Error message

Extensions are only supported by Postgres.

What it means

Builder::ensureExtensionExists() hard-checks that the connection is a PostgresConnection and throws RuntimeException otherwise, because CREATE EXTENSION is a Postgres-only DDL. ensureVectorExtensionExists() delegates here, so it inherits the same restriction. The guard is an explicit instanceof - no fallback, no no-op.

Solutions

Gate the call on the connection driver: if (Schema::getConnection() instanceof \Illuminate\Database\PostgresConnection).
Move ensureExtensionExists / ensureVectorExtensionExists calls into a Postgres-only migration or a service provider branch keyed on config('database.default').
In tests, skip these migrations on SQLite or stub them out via a testing-specific migration path.

Example fix

// before
Schema::ensureVectorExtensionExists();

// after
use Illuminate\Database\PostgresConnection;

if (Schema::getConnection() instanceof PostgresConnection) {
    Schema::ensureVectorExtensionExists();
}

Defensive patterns

Strategy: type-guard

Validate before calling

use Illuminate\Database\PostgresConnection;

$connection = Schema::getConnection();
if ($connection instanceof PostgresConnection) {
    Schema::ensureVectorExtensionExists();
} else {
    throw new \DomainException('Vector extensions require a Postgres connection.');
}

Type guard

use Illuminate\Database\PostgresConnection;

function isPostgres(\Illuminate\Database\Connection $connection): bool
{
    return $connection instanceof PostgresConnection;
}

Try / catch

try {
    Schema::ensureExtensionExists('vector');
} catch (\RuntimeException $e) {
    if (str_contains($e->getMessage(), 'only supported by Postgres')) {
        return; // skip on non-Postgres connections
    }
    throw $e;
}

Prevention

Centralise extension setup in a Postgres-only service provider or migration.
Make the testing connection Postgres-compatible or skip extension migrations in test env.
Guard any code path inherited from a Postgres codebase when porting to a new engine.

When it happens

Trigger: Calling Schema::ensureExtensionExists($name, $schema) or Schema::ensureVectorExtensionExists($schema) on any non-Postgres connection (mysql, sqlite, sqlsrv, or a custom driver whose Connection class is not Illuminate\Database\PostgresConnection).

Common situations: A migration that unconditionally calls ensureVectorExtensionExists() but is run against the testing suite's SQLite connection; an app migrated from Postgres to MySQL where the extension bootstrap was left in place; a multi-database app that runs the same migration set on every connection.

Related errors

AI-assisted analysis of laravel/framework@e0f6eb3518 (2026-08-11). Data as JSON: /api/errors/f711cb714cf9bf3a. Report an issue: GitHub.

Appendix: source

Thrown at src/Illuminate/Database/Schema/Builder.php:683

     */
    public function ensureVectorExtensionExists($schema = null)
    {
        $this->ensureExtensionExists('vector', $schema);
    }

    /**
     * Create a new extension on the schema if it does not exist.
     *
     * @param  string  $name
     * @param  string|null  $schema
     * @return void
     *
     * @throws \RuntimeException
     */
    public function ensureExtensionExists($name, $schema = null)
    {
        if (! $this->getConnection() instanceof PostgresConnection) {
            throw new RuntimeException('Extensions are only supported by Postgres.');
        }

        $name = $this->getConnection()->getSchemaGrammar()->wrap($name);

        $this->getConnection()->statement(match (filled($schema)) {
            true => "create extension if not exists {$name} schema {$this->getConnection()->getSchemaGrammar()->wrap($schema)}",
            false => "create extension if not exists {$name}",
        });
    }

    /**
     * Execute the blueprint to build / modify the table.
     *
     * @param  \Illuminate\Database\Schema\Blueprint  $blueprint
     * @return void
     */
    protected function build(Blueprint $blueprint)
    {

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