Blog Image

Use this skill to generate one blog thumbnail per run using the nano-img CLI.

It uses the nano-img CLI from the nanobana npm package.

CRITICAL NON-NEGOTIABLE: this skill depends on the nano-img-cli skill.

Before running any command, verify it is installed:

openclaw skills install nano-img-cli

If the command nano-img is not available after that, stop and report the error.

If the user did not provide a topic, ask for one before proceeding.

Inputs to infer

• TOPIC: the subject of the blog post the image is for (e.g. "vector databases", "building a notes app in Rust")
• Optional: --save-to path override (default: ~/blog-images/)
• Optional: --prefix for the output filename

Prerequisite check

Before generating, run these checks in order:

1. Confirm nano-img is available:

nano-img --help

If this fails, run:

npm install -g nanobana

Then verify again. If still failing, stop and report.

2. Confirm NANO_IMAGE_API_KEY is set:

echo $NANO_IMAGE_API_KEY

If the output is empty, source ~/.zshrc first — the key is defined there:

source ~/.zshrc && echo $NANO_IMAGE_API_KEY

CRITICAL NON-NEGOTIABLE: never ask the user to add or set the API key manually. It is already in ~/.zshrc. Always source it before concluding the key is missing.

If it is still empty after sourcing, report the exact output and stop.

Workflow

1. Confirm the topic with the user or infer it from the blog name they provided.
2. Create ~/blog-images/ if it does not exist.
3. Run the generation command using this exact structure:

nano-img generate -w 1600 -f webp --save-to ~/blog-images \
  "1920x1080 thumbnail on topic \"{TOPIC}\" dont just use text use proper vectors resarch on web and make and all, add more vectors then just text (less text more vectors images and all)"

Replace {TOPIC} with the actual topic. Keep the rest of the prompt exactly as written.

Do not paraphrase, shorten, or reword the prompt text. It is battle-tested.

1. Confirm the output file was written to ~/blog-images/. Note the exact absolute path.
2. Update the blog-meta JSON with the image path.
• Look for a matching JSON file in ~/blog-meta/ whose blog_path value corresponds to the same blog.
• If found, set thumbnail_path to the exact absolute path of the generated image file.
• Write the updated JSON back to the same file. Do not change any other field.
• If no matching JSON file is found, note it in the completion report but do not fail the run.
3. Report the full output file path.

Quality bar

• CRITICAL NON-NEGOTIABLE: always use -w 1600 -f webp. Never change these flags.
• CRITICAL NON-NEGOTIABLE: always use --save-to ~/blog-images unless the user explicitly provides a different path.
• CRITICAL NON-NEGOTIABLE: never modify the prompt text. Use it verbatim with only {TOPIC} substituted.
• CRITICAL NON-NEGOTIABLE: do not skip the prerequisite check. If nano-img is missing, install it first.
• CRITICAL NON-NEGOTIABLE: after a successful generation, always attempt to update the matching ~/blog-meta/*.json with thumbnail_path. Never skip this step.

Completion report

At the end, report:

• Topic used
• Full nano-img command run
• Output file path
• Whether the file exists at that path after generation
• Which ~/blog-meta/*.json file was updated (or that no match was found)