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name: generate-header-image description: Generate a blog post header image via Replicate, import it into Bhart R2 media storage, and set the post hero_image_url + hero_image_alt via the Bhart Codex API.

Generate Header Image

Use this skill when the user wants to create or replace an existing post's header/hero image.

This workflow:

1. generates an image with Replicate
2. imports the generated image URL into the bhart.org R2 media bucket (so it is served from /media/...)
3. updates the target post's hero_image_url + hero_image_alt

Requirements

• CODEX_BHART_API_TOKEN (for Bhart Blog Automation API)
• REPLICATE_API_TOKEN (for Replicate)

Bhart API note

This skill uses a Codex API media helper endpoint:

• POST /api/codex/v1/media/import
  • Downloads source_url (must be an image) into the MEDIA_BUCKET R2 bucket
  • Creates a media_assets row in D1
  • Returns { media: { id, key, url, ... } } where url is a site-local /media/<key> URL

Recommended workflow

1. Identify the post:
   • GET /posts/by-slug/:slug (preferred) or GET /posts/:id
2. Generate alt text:
   • Keep it short, descriptive, and literal (what the image shows), not marketing copy.
3. Generate the image on Replicate:
   • Prefer passing the logo as an input image if the model supports it (e.g. OpenAI image models support input_images).
4. Import into R2:
   • Call POST /media/import with source_url, alt_text, and the post author fields.
5. Update the post hero fields:
   • PATCH /posts/:id with hero_image_url, hero_image_alt, and expected_updated_at.

Script (preferred)

Run:

bash .codex/skills/generate-header-image/scripts/generate_header_image.sh --slug <post-slug> --prompt-file <prompt.txt> --logo-url <https://.../logo.png>

Notes:

• Set --model and --replicate-input if you are using a model that needs custom input fields.
• Default model is google/nano-banana-pro.
• Default aspect ratio is 16:9 (header-friendly); override via --aspect-ratio.
• If you omit --replicate-input, the script uses a default input compatible with google/nano-banana-pro (prompt, image_input, aspect_ratio, resolution, output_format).