Engines

Engines are no longer just “document parsing tools.” They now represent a broader set of specialized capability resources.

The main categories cover:

Website and file to Markdown conversion
Podcast generation
Image generation
Audio transcription

These engines usually work together with default models to form complete workflows.

1. Main engine categories

Engine category	Representative engines	Use case
Markdown parsing	Markitdown, Jina, MinerU API	Convert websites and files into Markdown
Podcast generation	Volc Podcast Engine, OpenAI Audio Engine	Document and section podcast output
Image generation	Banana Image	Section illustrations and PPT slides
Audio transcription	Volc STT Fast, Volc STT Standard	Audio-document transcription

2. Default engine slots are now split by responsibility

The product no longer uses one generic “default engine” slot.
Settings split default engines into:

Default website parse engine
Default file parse engine
Default podcast engine
Default image generation engine
Default audio transcription engine

Each of these defaults is validated for resource access before the setting is saved.

3. Differences between parsing engines

Jina

Still mainly used for website extraction and parsing
Not a good primary choice for file parsing
Requires a Jina API key

Markitdown

Can handle both websites and files
Better image-related parsing works when openai_api_key is configured
Also depends on the user’s default document-reading model in some flows

MinerU API

The official environment seeds an official hosted MinerU API engine
In the official initializer, it is the only seeded official engine with FREE plan access
It participates in website and file to Markdown workflows

4. Role of podcast, transcription, and image engines

Podcast engines

Podcast engines now power both document and section podcast flows.
If the default podcast engine is missing, both document-podcast and section-podcast entry points will warn that the required resource is not configured.

Representative engines include:

Volc Podcast Engine
OpenAI Audio Engine

In some modes, Volc Podcast Engine also depends on the default document-reading model to build dialogue-style podcast turns.

Transcription engines

Audio documents depend on the default transcription engine to become usable text content.
The official seed includes:

Official_Volc_Fast_STT
Official_Volc_Standard_STT

Image generation engines

Image generation is no longer only about section illustrations.

It also affects:

Automatic section illustrations
PPT slide image generation for sections

The official seed includes:

Official_Banana_Image

5. Official hosted engines

The codebase now treats engines as billable or plan-gated resources as well:

An engine can be marked is_official_hosted
It can define a billing_mode
It can define billing_unit_price
It can define a compute_point_multiplier

So an engine now communicates more than “this capability exists.” It can also express:

Whether the engine is officially hosted
How its usage converts into compute points
Which plan level is required to access it

6. Official seeded engine set

In official deployment initialization, the public seeded engines are:

Official_Banana_Image
Official_Volc_TTS
Official_MinerU_API
Official_Volc_Fast_STT
Official_Volc_Standard_STT

Among them:

Official_MinerU_API is seeded with FREE plan access
The others are seeded with PRO plan access

7. Engine community and forks

You can publish your own engines
Public engines can declare required plan levels
Other users can discover them in the community
To really use one as your own resource, you still need to fork it first

So seeing an engine and being able to assign it as a default engine are now different things. Discovery, default selection, runtime access, and plan restrictions are connected.