# Stable Diffusion 3.5 Medium

Stable Diffusion 3.5 Medium is 2.5 billion parameter image model with improved MMDiT-X architecture

## API Information

- **Model Slug:** stable-diffusion-3-5-medium
- **Branded URL:** https://www.eachlabs.ai/stability/stable-diffusion/stable-diffusion-3-5-medium
- **Provider:** Stability
- **Category:** Text to Image
- **Output Type:** image
- **Status:** active
- **Version:** 0.0.1
- **Base Cost:** Fixed price per execution: $0.035
- **Estimated Processing Time:** 8 seconds
- **Last Updated:** 2026-04-06
- **Interactive Demo:** https://www.eachlabs.ai/ai-models/stable-diffusion-3-5-medium

## Pricing

- **Charge Type:** dynamic
- **Estimated Price (default example):** $0.0350
- **Pricing Details:** Fixed price per execution: $0.035

### Pricing Rules

| Condition | Pricing |
| --- | --- |
| Rule 1 | Fixed price per execution: $0.035 |

## Input Schema

| Parameter | Type | Required | Default | Constraints | Description |
|-----------|------|----------|---------|-------------|-------------|
| prompt | string | No | - | - | Text prompt for image generation |
| aspect_ratio | string | No | 1:1 | 1:1,16:9,21:9,3:2,2:3,4:5,5:4,3:4,4:3,9:16,9:21 | An enumeration. |
| cfg | number | No | 5 | 0–20 | The guidance scale tells the model how similar the output should be to the prompt. |
| image | string | No | - | image/jpeg, image/png, image/jpg, image/webp | Input image for image to image mode. The aspect ratio of your output will match this image. |
| prompt_strength | number | No | 0.85 | - | Prompt strength (or denoising strength) when using image to image. 1.0 corresponds to full destruction of information in image. |
| steps | integer | No | 40 | 1–50 | Number of steps to run the sampler for. |
| seed | integer | No | - | 1–0 | Set a seed for reproducibility. Random by default. |
| output_format | string | No | webp | webp,jpg,png | An enumeration. |
| output_quality | integer | No | 90 | 0–100 | Quality of the output images, from 0 to 100. 100 is best quality, 0 is lowest quality. |

## Example Request

```bash
curl -X POST https://api.eachlabs.ai/v1/prediction/ \
  -H "X-API-Key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "model": "stable-diffusion-3-5-medium",
  "input": {}
}'
```

## Output Schema

Response returned by `GET /v1/prediction/{id}` when the job completes:

```json
{
  "status": "success",
  "predictionID": "string",
  "output": "string (URL of generated image)",
  "metrics": {
    "predict_time": "number (seconds)"
  }
}
```

## Polling

```bash
curl https://api.eachlabs.ai/v1/prediction/{PREDICTION_ID} \
  -H "X-API-Key: YOUR_API_KEY"
```

| Status | Meaning |
|--------|---------|
| `processing` | Still running — poll again |
| `success` | Done — read `output` |
| `error` | Failed — read `message` / `details` |

## Webhook (alternative to polling)

Pass `"webhook_url": "https://your.host/path"` in the create request. Eachlabs POSTs this payload when the job ends:

```json
{
  "exec_id": "prediction-uuid",
  "status": "succeeded",
  "output": "https://...",
  "error": ""
}
```

`status` is `"succeeded"` or `"failed"`. `exec_id` equals the `predictionID` from create. Return 2xx within 30 seconds.

## Errors

Error body: `{ "status": "error", "message": "...", "details": "..." }`

| Code | Meaning |
|------|---------|
| `400` | Invalid input |
| `401` | Missing / invalid `X-API-Key` |
| `404` | Unknown model or prediction id |
| `429` | Rate limit — 100 creates / min, 10 concurrent per key |
| `5xx` | Retry with backoff |

## Overview

**stable-diffusion-3.5-medium — Text-to-Image AI Model**

Developed by Stability as part of the **stable-diffusion** family, **stable-diffusion-3.5-medium** is a text-to-image AI model that generates high-quality images from text prompts with exceptional speed and efficiency on consumer hardware. This 2.5-4 billion parameter model delivers photorealistic results and accurate text rendering, solving common issues like garbled typography in previous versions while matching the quality of larger models. Ideal for developers seeking a **Stability text-to-image** solution or creators needing fast **text-to-image AI model** generation, **stable-diffusion-3.5-medium** supports resolutions from quarter to two megapixels, making it accessible without high-end GPUs.

## Usage Notes

- API Base URL: `https://api.eachlabs.ai/v1`
- Authentication: send `X-API-Key: YOUR_API_KEY`. Generate a key from the Eachlabs dashboard at https://www.eachlabs.ai/dashboard/api-keys.
- File-typed parameters (`*_url`, `image_url`, `video_url`, `audio_url`, etc.) accept publicly-reachable HTTPS URLs only. Upload your asset first (GCS / S3 / your CDN) and pass the resulting URL. Data-URIs and localhost URLs are rejected.
- For structured parameters (arrays / objects) send real JSON values, not stringified payloads.
- Monetary values are reported in USD; per-token / per-megapixel rates may be billed in micro-cents internally.
- Prefer `webhook_url` over polling for long-running predictions — see the Webhook Callback section.