Image Generation via Replicate
Generate images programmatically using Replicate's hosted ML models.
Purpose
Enable Alex to create images for documentation, UI assets, banners, and visual content without manual design tools.
When to Use
| Trigger |
Action |
| "Create an image of..." |
Generate via Replicate |
| "Make a banner/icon/logo" |
Generate with appropriate model |
| "Visualize this concept" |
Generate illustration |
| Documentation needs visual |
Generate diagram or illustration |
Model Selection
| Model |
Best For |
Speed |
Quality |
black-forest-labs/flux-schnell |
Fast drafts, iteration |
⚡ Fast |
Good |
black-forest-labs/flux-dev |
High quality finals |
🐢 Slow |
Excellent |
stability-ai/sdxl |
General purpose |
Medium |
Very Good |
stability-ai/stable-diffusion-3 |
Latest SD |
Medium |
Excellent |
Default: flux-schnell for speed. Upgrade to flux-dev for final assets.
Prompt Engineering
Structure
[Subject] [Style] [Details] [Technical specs]
Style Modifiers
| Style |
Prompt Addition |
| Photorealistic |
"photorealistic, 8k, detailed" |
| Illustration |
"digital illustration, clean lines" |
| Icon/Logo |
"minimal, vector style, simple shapes, no text" |
| Technical diagram |
"technical diagram, clean, labeled, white background" |
| Abstract |
"abstract, geometric, modern" |
Negative Prompts
Always include to avoid common issues:
blurry, low quality, distorted, text, watermark, signature
For icons/logos add:
complex background, photorealistic, detailed textures
API Reference
Authentication
REPLICATE_API_TOKEN=r8_xxxxx
Create Prediction
curl -X POST https://api.replicate.com/v1/predictions \
-H "Authorization: Bearer $REPLICATE_API_TOKEN" \
-H "Content-Type: application/json" \
-d '{
"version": "<model-version-id>",
"input": {
"prompt": "...",
"negative_prompt": "...",
"width": 1024,
"height": 1024,
"num_outputs": 1
}
}'
Poll for Result
curl https://api.replicate.com/v1/predictions/<id> \
-H "Authorization: Bearer $REPLICATE_API_TOKEN"
Response States
| Status |
Meaning |
starting |
Model is loading |
processing |
Generating image |
succeeded |
Done — output contains URLs |
failed |
Error — check error field |
Common Sizes
| Use Case |
Dimensions |
| Square (social, avatar) |
1024×1024 |
| Banner (GitHub, docs) |
1280×640 |
| Thumbnail |
512×512 |
| Wide (header) |
1920×1080 |
Output Handling
- Download the generated URL immediately (expires)
- Save to workspace with descriptive name
- Optimize if needed (large files)
Decision Framework
User wants image
↓
Is it a quick draft? → flux-schnell
↓
Is it final quality? → flux-dev
↓
Is it an icon/logo? → Add "minimal, vector style"
↓
Is it a photo? → Add "photorealistic, 8k"
↓
Generate → Download → Save
Common Mistakes
| Mistake |
Fix |
| Prompt too vague |
Add style + technical specs |
| Expecting text in image |
AI models can't do text reliably |
| Not downloading output |
URLs expire — save immediately |
| Wrong aspect ratio |
Match intended use case |
| Forgetting negative prompt |
Always include quality negatives |
Troubleshooting
| Issue |
Cause |
Fix |
| 401 Unauthorized |
Bad/missing token |
Check REPLICATE_API_TOKEN |
| Model loading slow |
Cold start |
Wait or use popular model |
| Output is blurry |
Low quality prompt |
Add "high quality, detailed, 8k" |
| Wrong style |
Prompt mismatch |
Be explicit about style |
fabioc-aloha