Seedream 4.5 Free: Precise Text-to-Image AI for Realistic Visuals on playground and API | RunComfy
Generate high-resolution, cinema-quality visuals entirely from text. Features advanced prompt understanding for detailed scenes and native support for 2K/4K outputs.
Table of contents
1. Get started
Use RunComfy's API to run bytedance/seedream-4-5/text-to-image. For accepted inputs and outputs, see the model's schema.
curl --request POST \
--url https://model-api.runcomfy.net/v1/models/bytedance/seedream-4-5/text-to-image \
--header "Content-Type: application/json" \
--header "Authorization: Bearer <token>" \
--data '{
"prompt": "A hyper-realistic street photograph of an old man walking alone on a quiet city street, captured with a Sony Alpha a9 II and Sony FE 200�?00mm f/5.6�?.3 G OSS lens. Shot in natural light, with ultra-detailed cinematic composition and muted, desaturated tones. The atmosphere is melancholic and introspective, evoking solitude and the passage of time. Styled like cinematic 35mm film photography, with soft depth of field, realistic textures, and emotional lighting that feels raw and human."
}'2. Authentication
Set the YOUR_API_TOKEN environment variable with your API key (manage keys in your Profile) and include it on every request as a Bearer token via the Authorization header: Authorization: Bearer $YOUR_API_TOKEN.
3. API reference
Submit a request
Submit an asynchronous generation job and immediately receive a request_id plus URLs to check status, fetch results, and cancel.
curl --request POST \
--url https://model-api.runcomfy.net/v1/models/bytedance/seedream-4-5/text-to-image \
--header "Content-Type: application/json" \
--header "Authorization: Bearer <token>" \
--data '{
"prompt": "A hyper-realistic street photograph of an old man walking alone on a quiet city street, captured with a Sony Alpha a9 II and Sony FE 200�?00mm f/5.6�?.3 G OSS lens. Shot in natural light, with ultra-detailed cinematic composition and muted, desaturated tones. The atmosphere is melancholic and introspective, evoking solitude and the passage of time. Styled like cinematic 35mm film photography, with soft depth of field, realistic textures, and emotional lighting that feels raw and human."
}'Monitor request status
Fetch the current state for a request_id ("in_queue", "in_progress", "completed", or "cancelled").
curl --request GET \
--url https://model-api.runcomfy.net/v1/requests/{request_id}/status \
--header "Authorization: Bearer <token>"Retrieve request results
Retrieve the final outputs and metadata for the given request_id; if the job is not complete, the response returns the current state so you can continue polling.
curl --request GET \
--url https://model-api.runcomfy.net/v1/requests/{request_id}/result \
--header "Authorization: Bearer <token>"Cancel a request
Cancel a queued job by request_id, in-progress jobs cannot be cancelled.
curl --request POST \
--url https://model-api.runcomfy.net/v1/requests/{request_id}/cancel \
--header "Authorization: Bearer <token>"4. File inputs
Hosted file (URL)
Provide a publicly reachable HTTPS URL. Ensure the host allows server‑side fetches (no login/cookies required) and isn't rate‑limited or blocking bots. Recommended limits: images ≤ 50 MB (~4K), videos ≤ 100 MB (~2–5 min @ 720p). Prefer stable or pre‑signed URLs for private assets.
5. Schema
Input schema
{
"type": "object",
"title": "Input",
"required": [
"prompt"
],
"properties": {
"prompt": {
"title": "Prompt",
"description": "The recommended length is no more than 600 English words. if the prompt is too long, the information may become scattered. The model might ignore details and only concentrate on the main points, resulting in a image with missing elements.",
"type": "string",
"default": "A hyper-realistic street photograph of an old man walking alone on a quiet city street, captured with a Sony Alpha a9 II and Sony FE 200�?00mm f/5.6�?.3 G OSS lens. Shot in natural light, with ultra-detailed cinematic composition and muted, desaturated tones. The atmosphere is melancholic and introspective, evoking solitude and the passage of time. Styled like cinematic 35mm film photography, with soft depth of field, realistic textures, and emotional lighting that feels raw and human."
},
"resolution": {
"title": "Resolution",
"description": "For 2K and 4K options, it will let the model determine the width and height. you should describe its aspect ratio, shape, or purpose in the prompt using natural language. For other options, you can choose the width and height you want.",
"type": "string",
"enum": [
"2K",
"4K",
"2048x2048 (1:1)",
"2304x1728 (4:3)",
"1728x2304 (3:4)",
"2560x1440 (16:9)",
"1440x2560 (9:16)",
"2496x1664 (3:2)",
"1664x2496 (2:3)",
"3024x1296 (21:9)",
"4096x4096 (1:1)"
],
"default": "2048x2048 (1:1)"
}
}
}Output schema
{
"output": {
"type": "object",
"properties": {
"image": {
"type": "string",
"format": "uri",
"description": "single image URL"
},
"video": {
"type": "string",
"format": "uri",
"description": "single video URL"
},
"images": {
"type": "array",
"description": "multiple image URLs",
"items": { "type": "string", "format": "uri" }
},
"videos": {
"type": "array",
"description": "multiple video URLs",
"items": { "type": "string", "format": "uri" }
}
}
}
}RunComfy is the premier ComfyUI platform, offering ComfyUI online environment and services, along with ComfyUI workflows featuring stunning visuals. RunComfy also provides AI Models, enabling artists to harness the latest AI tools to create incredible art.