# Blog Image Gen > Generate hero images for blog posts using the blog repo's OpenAI image-generation scripts after verifying current official API docs for model names, tool syntax, size/quality options, and pricing. Use when the user asks to create, generate, regenerate, or batch produce hero/header images for blog posts in priv/content/posts. Also use to ingest manually-downloaded images from the art/ folder into the served location and wire them to the blog. - Skill: `bogdanbaciu21/blog-image-gen` (Agent Skill, multi-file: 5 files) - Install (CLI): `npx skillmds@latest add bogdanbaciu21/blog-image-gen` - Raw SKILL.md: https://api.skillmd.com/api/skills/bogdanbaciu21/blog-image-gen/raw - Safety review: pending - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: AI & ML - Author: bogdanbaciu21 (https://skillmd.com/u/bogdanbaciu21) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/bogdanbaciu21/blog-image-gen --- # Blog Image Generation Generate editorial hero images for posts on bogdanbaciu.com via the blog repo's image-generation scripts. Images land at `priv/static/images/posts//hero.png` and are auto-rendered on the post page by `Bogdan.Content.Post.detect_hero/1` (no frontmatter changes needed). ## When to use - "Generate the image for ``." - "Generate images for every post that's missing one." - "I dumped some PNGs into `art/` — wire them up." - "Show me what's done and what's still pending." ## Required setup (verify once per session) 1. Work from the blog repo root. On this machine the expected repo is: `/Users/danb/Desktop/bogdanbaciu-dot-com`. 2. Confirm the project scripts exist before invoking anything: ```bash test -f scripts/gen_blog_image.py && test -f scripts/ingest_art.py ``` If either script is missing, stop and locate it with: ```bash rg --files /Users/danb/Desktop | rg '(^|/)gen_blog_image\.py$|(^|/)ingest_art\.py$' ``` 3. `OPENAI_API_KEY` is set in the shell that will run the script. 4. `pip show openai` returns a version (install with `pip install --upgrade openai` if not). 5. Verify current OpenAI image-generation model names, tool syntax, pricing, size limits, and quality options from official OpenAI docs before quoting or relying on them. Do not treat model names or per-image costs in this skill as evergreen. 6. Confirm estimated batch cost with the user before any `--all` run. ChatGPT subscriptions do not imply API credits. ## Workflow ### Step 1 — Check what's pending ```bash python3 scripts/gen_blog_image.py --list ``` This prints one line per post showing whether it's already done (and where) or PENDING. Posts are considered done if EITHER of these exists: - `priv/static/images/posts//hero.png` (script output, served) - `art/.png` (manual download — needs ingest) ### Step 2 — If the user has manual downloads in `art/`, ingest first ```bash python3 scripts/ingest_art.py --dry-run # preview python3 scripts/ingest_art.py # do it ``` This copies `art/.png` → `priv/static/images/posts//hero.png` by matching the compact (no-hyphen) filename to a real post slug. Orphans (filenames that don't map to a slug) are reported but left alone. ### Step 3 — Smoke-test on one post (dry run, then real) ```bash python3 scripts/gen_blog_image.py --dry-run # prints final prompt python3 scripts/gen_blog_image.py # one real call (~$0.30) ``` Open the generated `priv/static/images/posts//hero.png` and confirm quality before any batch run. ### Step 4 — Batch the rest ```bash python3 scripts/gen_blog_image.py --all ``` Sequential, with `SLEEP_BETWEEN_CALLS_SEC = 3` between calls. Already-done slugs are skipped automatically. Failures are logged but don't halt the loop — re-run to retry. ### Step 5 — Verify rendering Boot the server (`mix phx.server`) and visit `/thoughts/`. The hero should appear between the title and the lede. If it doesn't: - Check `Bogdan.Content.Post.detect_hero/1` — it reads via `:code.priv_dir(:bogdan)`, which requires a recompile after adding files (touch `lib/bogdan/content.ex` or restart the server). - Confirm the file is at the exact path `priv/static/images/posts//hero.png`. ### Step 6 — Prompt-quality and thumbnail review Before accepting a generated image: - The image matches the post's concrete subject, not just its mood. - It is editorial and specific, not generic stock imagery. - It has no fake screenshots, fake UI, fake charts, unreadable text, distorted hands/faces, or accidental brand/logo claims. - It works as a crop at article-card size and as a full hero. - It is visually distinct from nearby posts in the image inventory. - The prompt mentions the one or two actual concepts the article is about and avoids stuffing in every paragraph of the post. Output a compact review table: | Slug | Thumbnail path | Pass/Revise | Reason | Follow-up | |---|---|---|---|---| | `` | `priv/static/images/posts//hero.png` | Pass | Specific to the article; clean crop | None | If a thumbnail needs revision, keep the prior image until the replacement is generated and reviewed. For batch review, build a local contact sheet from the blog repo root: ```bash python3 /Users/danb/src/skills/blog-image-gen/scripts/thumbnail_contact_sheet.py --repo . ``` Open `priv/static/images/posts/contact-sheet.html` and scan for duplicate visual ideas, awkward crops, distorted text, and subject drift before accepting a batch. ### Step 7 — Commit ```bash git add priv/static/images/posts/ git commit -m "blog: add hero images for posts" ``` The PNGs are committed to the repo (Fly.io builds the release from this tree; `priv/static/` ships in the artifact). ## Skill maintenance evals When editing prompt parsing or review workflow text in this skill, run: ```bash PYTHONDONTWRITEBYTECODE=1 python3 /Users/danb/src/skills/blog-image-gen/evals/prompt_fixture_eval.py ``` The fixture locks the contract that `--dry-run` output must expose the final prompt as a fenced `FINAL PROMPT` block before any real API call is made. ## Prompt sourcing `scripts/gen_blog_image.py` resolves the prompt for each slug in this order: 1. **Pre-written:** if `blog-image-prompts.md` has a section `## N. — ...` with a fenced code block, that exact prompt is used. 2. **Auto-generated:** otherwise the script prepends the house-style preamble to a one-liner derived from the post title + description (or first ~300 words of body if no description). The auto path is fine for batch but pre-written prompts produce noticeably better results — encourage the user to draft one in `blog-image-prompts.md` for any post they care strongly about before running. ## Tunable knobs (top of `scripts/gen_blog_image.py`) Verify current allowed values in official OpenAI docs before changing these. | Constant | Default | Notes | |---|---|---| | `MODEL` | script-defined | Verify current image-generation model name | | `SIZE` | script-defined | Verify current allowed sizes and aspect limits | | `QUALITY` | script-defined | Verify current quality options | | `OUTPUT_FORMAT` | `"png"` | `png` / `jpeg` / `webp` (jpeg is faster) | | `MODERATION` | `"auto"` | `auto` / `low` | | `SLEEP_BETWEEN_CALLS_SEC` | `3` | Polite throttle for batch runs | ## On "thinking" / reasoning mode The script may use the Responses API with an image-generation tool and a separate planning model. Verify the current OpenAI API surface before editing this path; model names, tool payloads, and reasoning options are time-sensitive. ```python client.responses.create( model="", input=prompt, tools=[{"type": "image_generation", "model": "", "size": "", "quality": "", "output_format": "webp", "moderation": "auto"}], reasoning={"effort": ""}, ) ``` Image bytes come back as a base64 string on the image-generation output item. Do not downgrade to another API path without checking the project script and the current official docs. ## What this skill does NOT do - Does not edit blog post frontmatter — hero detection is automatic via filename. - Does not push images to a CDN — they ship in the Phoenix release artifact. - Does not retry failed API calls inline — re-run the command to retry skipped slugs. - Does not write prompts for you when a pre-written one is desired; draft those in `blog-image-prompts.md` first.