Task Types

Task types define the input/output contract for jobs and workflow nodes. Each model supports one or more task types — see the Models reference for which models support which tasks.

Overview

Task Type	Category	Sync	Description
`openai/chat-completion`	Text	Yes	Chat completion (LLM)
`openai/chat-completion/vision`	Text	Yes	Chat completion with image input
`openai/chat-completion/ocr`	OCR	Yes	OCR via vision model
`openai/embeddings`	Text	Yes	Text embeddings
`openai/rerank`	Text	Yes	Document reranking
`openai/score`	Text	Yes	Text pair similarity scoring
`openai/audio-speech`	Audio	Yes	Text-to-speech
`openai/audio-transcription`	Audio	Yes	Speech-to-text
`openai/image-generation`	Image	Yes	Image generation (OpenAI format)
`fal/text-to-image`	Image	Yes	Image generation (Fal format)
`fal/image-edit`	Image	Yes	Image editing / inpainting
`fal/text-to-video`	Video	No	Text-to-video generation
`fal/image-to-video`	Video	No	Image-to-video animation
`fal/speech-to-video`	Video	No	Speech-driven video (talking head)
`fal/audio-transcription`	Audio	Yes	Speech-to-text (Fal format)
`fal/video-interpolate`	Video	No	Frame interpolation (slow motion)
`fal/video-upscale`	Video	No	Video super-resolution

Sync = can be dispatched synchronously (result returned inline). Async tasks return a request_id for polling.

Text Tasks

`openai/chat-completion`

Standard chat completion following the OpenAI API format.

Field	Type	Required	Description
`messages`	array	Yes	Array of `{role, content}` message objects
`model`	string	No	Model ID (set automatically when using a specific endpoint)
`temperature`	number	No	Sampling temperature (0-2)
`top_p`	number	No	Nucleus sampling
`max_tokens`	number	No	Maximum tokens to generate
`stream`	boolean	No	Enable streaming response
`stop`	string/array	No	Stop sequences
`tools`	array	No	Tool/function definitions

Output: choices[0].message.content (text)

Models: qwen3-0.6b, qwen3.5-4b, qwen3.5-9b, gpt-oss-20b, deepseek-ocr-v1, deepseek-ocr-v2

`openai/chat-completion/vision`

Chat completion with image input. Same parameters as openai/chat-completion, but messages can include image content:

{
  "messages": [{
    "role": "user",
    "content": [
      {"type": "text", "text": "What's in this image?"},
      {"type": "image_url", "image_url": {"url": "https://..."}}
    ]
  }]
}

Models: qwen3.5-4b, qwen3.5-9b

`openai/chat-completion/ocr`

OCR via a vision-capable model. Uses the same message format as vision, optimized for text extraction from images.

Models: deepseek-ocr-v1, deepseek-ocr-v2

`openai/embeddings`

Generate vector embeddings for text.

Field	Type	Required	Description
`input`	string/array	Yes	Text or array of texts to embed
`encoding_format`	string	No	`float` or `base64`
`dimensions`	number	No	Output dimensions

Output: data[0].embedding (float array)

Models: qwen3-0.6b-embed, gpt-oss-20b-embed

`openai/rerank`

Rerank documents by relevance to a query.

Field	Type	Required	Description
`model`	string	Yes	Model ID
`query`	string	Yes	Search query
`documents`	array	Yes	Array of strings or `{text}` objects
`top_n`	number	No	Number of top results to return
`return_documents`	boolean	No	Include document text in results

Output: Ranked documents with relevance scores

Models: qwen3-0.6b-score, gpt-oss-20b-score

`openai/score`

Compute similarity scores between text pairs.

Field	Type	Required	Description
`model`	string	Yes	Model ID
`text_1`	string/array	Yes	First text(s)
`text_2`	string/array	Yes	Second text(s)

Output: Similarity scores

Models: qwen3-0.6b-score, gpt-oss-20b-score

Audio Tasks

`openai/audio-speech`

Convert text to spoken audio.

Field	Type	Required	Description
`input`	string	Yes	Text to speak
`voice`	string	No	Voice ID (model-specific)
`response_format`	string	No	`mp3`, `opus`, `aac`, `flac`, `wav`, `pcm`
`speed`	number	No	Playback speed multiplier

Output: audio_url (audio file URL)

Models: qwen3-tts (9 voices), fox-tts (150+ voices)

`openai/audio-transcription`

Transcribe audio to text.

Field	Type	Required	Description
`audio_url`	string	Yes	URL to the audio file
`language`	string	No	Language code (ISO 639-1)
`task`	string	No	`transcribe` or `translate`

Also supports multipart file upload with a file field.

Output: text (transcribed text)

Models: whisper-large-v3

`fal/audio-transcription`

Same as openai/audio-transcription but using the Fal request format.

Field	Type	Required	Description
`audio_url`	string	Yes	URL to the audio file
`language`	string	No	Language code
`task`	string	No	`transcribe` or `translate`

Output: text

Models: whisper-large-v3

Image Tasks

`openai/image-generation`

Generate images using the OpenAI-compatible format.

Field	Type	Required	Description
`prompt`	string	Yes	Image description
`n`	number	No	Number of images
`size`	string	No	Image dimensions
`quality`	string	No	`standard` or `hd`
`response_format`	string	No	`url` or `b64_json`

Output: data[0].url (image URL)

Models: qwen-image-2512

`fal/text-to-image`

Generate images using the Fal format. More parameters than the OpenAI format.

Field	Type	Required	Description
`prompt`	string	Yes	Image description
`negative_prompt`	string	No	What to avoid
`image_size`	string	No	`square_hd`, `square`, `portrait_4_3`, `portrait_16_9`, `landscape_4_3`, `landscape_16_9`
`num_inference_steps`	number	No	Denoising steps
`guidance_scale`	number	No	Prompt adherence strength
`num_images`	number	No	Number of images (max 10)
`seed`	number	No	Reproducibility seed
`loras`	array	No	LoRA configs `[{path, scale}]` (scale 0-4)
`enable_safety_checker`	boolean	No	Content safety filter
`output_format`	string	No	Output image format

Output: images[0].url (image URL)

Models: nunchaku-flux1-schnell, sglang-diffusion-flux2-klein-4b, qwen-image-2512, qwen-image-2512-lightx2v-fp8, sglang-diffusion-qwen-image-2512-fp8

`fal/image-edit`

Edit or inpaint images.

Field	Type	Required	Description
`prompt`	string	Yes	Edit instruction
`image_url`	string	Yes	Source image URL
`mask_url`	string	No	Mask for inpainting
`strength`	number	No	Edit strength (0-1)
`num_inference_steps`	number	No	Denoising steps
`guidance_scale`	number	No	Prompt adherence
`num_images`	number	No	Number of results (max 10)
`seed`	number	No	Reproducibility seed
`loras`	array	No	LoRA configs

Output: images[0].url (image URL)

Models: nunchaku-flux1-schnell, sglang-diffusion-flux2-klein-4b, qwen-image-edit-2511, qwen-image-edit-2511-lightx2v-fp8, sglang-diffusion-qwen-image-edit-2511-fp8

Video Tasks

All video tasks are async only — they return a request_id for polling.