Bestony AI Provider for StepFun

StepFun (阶跃星辰) as a provider for the WordPress AI Client: text, vision and image generation with Step models.

What it does

• Fetches the model list live from GET /v1/models, so newly released models show up on their own.
• Text generation and chat history, including tool calling, structured output (JSON schema) and stop sequences.
• Vision input with step-3.7-flash and the step-1v-* / *-vision families, so Alt Text Generation works.
• Text-to-image generation with the step-image-* / step-2x-* models, returned inline or as a URL.
• Reasoning output surfaces as thought parts instead of being mixed into the answer.
• A Settings → Bestony AI Provider for StepFun page that picks which StepFun host to talk to, including the Step Plan endpoints.

Requirements

• WordPress 7.0 or newer, with the PHP AI Client SDK (bundled in WordPress 7.0, or provided by the AI plugin)
• PHP 7.4 or newer
• A StepFun account with API access

Install

Download the zip from Releases and upload it through Plugins → Add New → Upload Plugin, or copy the plugin folder to wp-content/plugins/bestony-ai-provider-for-stepfun/. Activate it, then open Settings → Connectors, open the StepFun card and paste your API key. If your key is for Step Plan, also pick the matching host on Settings → Bestony AI Provider for StepFun.

Settings

Settings → Bestony AI Provider for StepFun chooses the API host:

The choice is stored per site and is used for the model list and every generation request. A value outside this list falls back to the default. The plugin's row on the Plugins screen also has a Setup Step Plan shortcut to the page.

The admin screens are available in English, Simplified Chinese (zh_CN) and Traditional Chinese (zh_TW).

Configuration

The API key is read in order of precedence from:

1. the STEPFUN_API_KEY environment variable
2. the STEPFUN_API_KEY PHP constant
3. the connectors_ai_stepfun_api_key option (Settings → Connectors)

Optional settings are environment variables or PHP constants:

Changing an environment variable does not invalidate the AI Client's cached model list; run wp cache flush if a new value does not take effect.

To change which model the AI plugin picks for its features, use the standard filter — this plugin already puts its preferred models first:

add_filter( 'wpai_preferred_text_models', function ( $models ) {
    array_unshift( $models, array( 'stepfun', 'step-3.5-flash' ) );
    return $models;
} );

Not implemented

• Video generation. StepFun's video models are asynchronous jobs, but the SDK's only video entry point is synchronous. step-video-* models appear in the list with no capability rather than shipping code the SDK never calls.
• Image editing. Only POST /v1/images/generations is implemented.

Data and privacy

Prompts you send to the AI, plus whatever the calling plugin or theme adds to them (system instructions, conversation history, tool definitions, a JSON schema, attached files), are sent to StepFun. Your API key is stored on your own site and is only ever sent to the StepFun host configured above. Nothing is sent until your site actually asks the AI Client for a generation.

• Platform and docs: https://platform.stepfun.com/
• Terms of Service: https://platform.stepfun.com/docs/zh/agreement/userservice
• Privacy Policy: https://platform.stepfun.com/docs/zh/agreement/userprivacy
• International platform: https://platform.stepfun.ai/

Development

php scripts/selfcheck.php                                              # logic checks, no WordPress needed
php scripts/selfcheck.php --sdk=/path/to/php-ai-client/src             # plus live-SDK checks

The self-check asserts model classification, sort order, the declared capabilities and options, the request shapes for chat and images, and that the declared metadata satisfies the requirements the AI plugin's features actually send. It needs neither WordPress nor an API key.

Release: push a tag matching the plugin version (git tag v<version> && git push origin v<version>). The release workflow verifies the tag against Version:/Stable tag:, verifies a matching changelog entry exists, builds the plugin zip and publishes it.

License

GPL-2.0-or-later. See LICENSE.

The assets/images/stepfun.svg mark comes from Lobe Icons (MIT) and is a trademark of StepFun, used only to identify the service this plugin connects to.

The full WordPress plugin readme, including the changelog, lives in readme.txt.