Title: ModelConfig::setSystemInstruction
Published: May 20, 2026
Last modified: August 20, 2026

---

# ModelConfig::setSystemInstruction( string $systemInstruction )

## In this article

 * [Parameters](https://developer.wordpress.org/reference/classes/wordpress-aiclient-providers-models-dto-modelconfig/setsysteminstruction/?output_format=md#parameters)
 * [Source](https://developer.wordpress.org/reference/classes/wordpress-aiclient-providers-models-dto-modelconfig/setsysteminstruction/?output_format=md#source)
 * [Changelog](https://developer.wordpress.org/reference/classes/wordpress-aiclient-providers-models-dto-modelconfig/setsysteminstruction/?output_format=md#changelog)

[ Back to top](https://developer.wordpress.org/reference/classes/wordpress-aiclient-providers-models-dto-modelconfig/setsysteminstruction/?output_format=md#wp--skip-link--target)

Sets the system instruction.

## 󠀁[Parameters](https://developer.wordpress.org/reference/classes/wordpress-aiclient-providers-models-dto-modelconfig/setsysteminstruction/?output_format=md#parameters)󠁿

 `$systemInstruction`stringrequired

The system instruction.

## 󠀁[Source](https://developer.wordpress.org/reference/classes/wordpress-aiclient-providers-models-dto-modelconfig/setsysteminstruction/?output_format=md#source)󠁿

    ```php
    public function setSystemInstruction(string $systemInstruction): void
    {
        $this->systemInstruction = $systemInstruction;
    }
    ```

[View all references](https://developer.wordpress.org/reference/files/wp-includes/php-ai-client/src/providers/models/dto/modelconfig.php/)
[View on Trac](https://core.trac.wordpress.org/browser/tags/7.1/src/wp-includes/php-ai-client/src/Providers/Models/DTO/ModelConfig.php#L225)
[View on GitHub](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/php-ai-client/src/Providers/Models/DTO/ModelConfig.php#L225-L228)

## 󠀁[Changelog](https://developer.wordpress.org/reference/classes/wordpress-aiclient-providers-models-dto-modelconfig/setsysteminstruction/?output_format=md#changelog)󠁿

| Version | Description | 
| [0.1.0](https://developer.wordpress.org/reference/since/0.1.0/) | Introduced. |

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