Higgsfield Image Generation

Auth System (CRITICAL — two separate auth mechanisms)

Higgsfield has TWO auth systems. generate_image requires OAuth tokens, NOT the API key.

The API key pair does NOT work for `generate_image`. That tool requires a valid Clerk OAuth access token.

Quick Reference

Tool: mcporter call higgsfield.generate_image Model: nano_banana_2 (Nano Banana Pro, 4K quality) Auth: OAuth Bearer token from mcporter credentials

Generate an Image

mcporter call higgsfield.generate_image params='{"model":"nano_banana_2","prompt":"YOUR PROMPT","aspect_ratio":"4:5"}'

With Reference Image (Character Consistency)

mcporter call higgsfield.generate_image params='{"model":"nano_banana_2","prompt":"YOUR PROMPT...same woman as reference...","aspect_ratio":"4:5","medias":[{"value":"https://URL-TO-REFERENCE-IMAGE.PNG","role":"image"}]}'

IMPORTANT: Use value (not url) for the media reference.

OAuth Token Refresh

If generate_image returns "Invalid or expired token", the OAuth session has expired:

mcporter auth higgsfield --reset

This opens a browser for Clerk OAuth login and stores new tokens in ~/.mcporter/credentials.json.

Token status check:

cat ~/.mcporter/credentials.json | python3 -c "
import json,sys
d=json.load(sys.stdin)
e=d['entries'].get('higgsfield|fb7b405dd99c24b1',{})
print('Has tokens:', 'tokens' in e and bool(e.get('tokens')))
print('Updated:', e.get('updatedAt'))
"

Check Generation Status

mcporter call higgsfield.show_generations type="image" size=5

Poll every ~30 seconds. 4K images take 30-50 seconds to generate.

Models Available

Aspect Ratios

• 1:1 — Square (Instagram post, thumbnail)
• 4:5 — Portrait (Instagram post, fashion)
• 2:3 — Portrait tall (fashion editorial)
• 3:4 — Portrait (standard)
• 9:16 — Story/Reel vertical
• 16:9 — Landscape (YouTube, banner)
• 21:9 — Ultrawide (banner)

Resolution Options

• 1k — 1024px (fast draft)
• 2k — 2048px (standard)
• 4k — 4096px (premium, default for nano_banana_2)

Character Photo System Prompt

Always include for realistic fashion photography:

The image must look like it was captured with a high-end DSLR fashion camera using an 85mm lens, with natural depth of field, realistic light diffusion, and authentic photographic detail. The result must be extremely photorealistic, studio-quality fashion photography in ultra 4K resolution, indistinguishable from a real camera photograph, with no AI artifacts or synthetic appearance. Maintain true-to-life skin texture, natural wrinkles, pores, and realistic lighting reflections. No beauty filters, no artificial smoothing.

Complete Workflow Example

1. Generate product photo with character

# Start generation
RESULT=$(mcporter call higgsfield.generate_image params='{"model":"nano_banana_2","prompt":"Full-length studio fashion photograph of a mature woman (47 years old, Franco-Canadian, elegant professional style, same face as reference) wearing a cozy plaid fleece jacket in rich autumn colors. She stands confidently in a clean white studio setting, full body visible, natural depth of field, 85mm lens photography, ultra realistic fashion editorial, authentic photographic detail, no AI artifacts.","aspect_ratio":"2:3","medias":[{"value":"https://d8j0ntlcm91z4.cloudfront.net/user_3AFZ6u2cNdsIdJPF7lWsctX8zrH/hf_20260418_172507_97ef24b2-a658-4cd9-acb8-00429c66948d.png","role":"image"}]}')
JOB_ID=$(echo $RESULT | python3 -c "import json,sys; print(json.load(sys.stdin)['results'][0]['id'])")
echo "Job ID: $JOB_ID"

# Wait and check
sleep 40
mcporter call higgsfield.show_generations type="image" size=5 | python3 -c "
import json, sys
data = json.load(sys.stdin)
for g in data.get('items', []):
    if g.get('id') == '$JOB_ID':
        print('STATUS:', g.get('status'))
        if g.get('status') == 'completed':
            print('URL:', g.get('results', {}).get('rawUrl'))
"

2. Download generated image

curl -s "IMAGE_URL" -o ./generated_image.png

Quality Notes

• nano_banana_2 produces 8/10 fashion photography — excellent skin textures, realistic lighting
• 4K generation takes 30-50 seconds
• Reference images must be accessible HTTPS URLs (no local files in MCP context)
• For Margot character: use margot_APPROVED.jpg as reference

Troubleshooting

"Invalid or expired token": OAuth session expired. Run mcporter auth higgsfield --reset on the Mac Mini.

"Model not found": Check model ID is correct — use nano_banana_2 not nano-banana-pro

"Invalid arguments: expected string, received undefined": The medias field requires {value: string, role: string}, not {url: ..., roles: [...]}

Generation pending forever: Poll show_generations with size=5 to find your job ID

Credentials Locations

The API key pair and OAuth tokens are TWO DIFFERENT things. mcporter.json's API key only works for read-only tools like tools/list.