Use RunComfy's API to run blackforestlabs/flux-3-max/text-to-video. For accepted inputs and outputs, see the model's schema.
curl --request POST \
--url https://model-api.runcomfy.net/v1/models/blackforestlabs/flux-3-max/text-to-video \
--header "Content-Type: application/json" \
--header "Authorization: Bearer <token>" \
--data '{
"prompt": "A young man with tousled light brown hair and a charcoal overcoat speaks from the stone steps of a red-brick courthouse in a New England town in autumn. Only the crowd's hands show at the bottom of the frame. No signs, no captions, no readable flags. He lifts one hand as fallen leaves cross the steps. A clear speaking voice and distant traffic."
}'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.
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/blackforestlabs/flux-3-max/text-to-video \
--header "Content-Type: application/json" \
--header "Authorization: Bearer <token>" \
--data '{
"prompt": "A young man with tousled light brown hair and a charcoal overcoat speaks from the stone steps of a red-brick courthouse in a New England town in autumn. Only the crowd's hands show at the bottom of the frame. No signs, no captions, no readable flags. He lifts one hand as fallen leaves cross the steps. A clear speaking voice and distant traffic."
}'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 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 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>"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.
{
"type": "object",
"title": "Input schema",
"required": [
"prompt"
],
"properties": {
"prompt": {
"title": "Prompt",
"description": "Describe the subject, action, camera, light, and any sound you want.",
"type": "string",
"default": "A young man with tousled light brown hair and a charcoal overcoat speaks from the stone steps of a red-brick courthouse in a New England town in autumn. Only the crowd's hands show at the bottom of the frame. No signs, no captions, no readable flags. He lifts one hand as fallen leaves cross the steps. A clear speaking voice and distant traffic."
},
"aspect_ratio": {
"title": "Aspect Ratio",
"description": "Output frame shape. auto uses 16:9 when no image is attached.",
"type": "string",
"enum": [
"auto",
"21:9",
"2:1",
"16:9",
"4:3",
"1:1",
"3:4",
"9:16"
],
"default": "16:9"
},
"resolution": {
"title": "Resolution",
"description": "Output resolution. 720p is the default. 1080p is the sharper option.",
"type": "string",
"enum": [
"720p",
"1080p"
],
"default": "720p"
},
"duration": {
"title": "Duration",
"description": "Clip length in whole seconds.",
"type": "integer",
"enum": [
5,
6,
7,
8,
9,
10,
11,
12,
13,
14,
15,
16,
17,
18,
19,
20
],
"default": 5
},
"generate_audio": {
"title": "Generate Audio",
"description": "Create an audio track with the video. Turn this off for a silent clip.",
"type": "boolean",
"default": true
},
"reasoning_level": {
"title": "Reasoning Level",
"description": "low returns sooner. high spends more time on the prompt and is slower.",
"type": "string",
"enum": [
"low",
"high"
],
"default": "high"
},
"seed": {
"title": "Seed",
"description": "Optional. Leave empty and the model picks a random seed.",
"type": "integer"
}
}
}{
"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.