GenAIScript

/* * Markdown image alt text updater */ script({ title: "Image Alt Textify", description: "Generate alt text for images in markdown files", accept: "none", unlisted: true, parameters: { docs: { type: "string", description: "path to search for markdown files", default: "docs", }, force: { type: "boolean", description: "regenerate all descriptions", default: false, }, assets: { type: "string", description: "image assets path", default: "./slides/public", }, dryRun: { type: "boolean", description: "show matches, do not compute alt text", default: false, }, }, }) /** ------------------------------------------------ * Configuration */ const { docs, force, assets, dryRun } = env.vars /** ------------------------------------------------ * Helper functions (update as needed) */ /** * Return the resolved url for the image */ const resolveUrl = (filename: string, url: string) => { // github assets ok if (/^https:\/\/github.com\/user-attachments\/assets\//i.test(url)) return url if (url?.startsWith("https://raw.githubusercontent.com/")) return url // ignore external urls if (/^http?s:\/\//i.test(url)) return undefined // map / to assets else if (/^\//.test(url)) return path.join(assets, url.slice(1)) // resolve local paths else return path.join(path.dirname(filename), url) } /** ------------------------------------------------ * Collect files */ // search for  in markdown files and generate alt text for images const rx = force // upgrade all urls ? // match  with any alt /!\[[^\]]*\]\(([^\)]+)\)/g : // match  where alt is empty /!\[\s*\]\(([^\)]+)\)/g console.log(`Searching for ${rx} in ${docs}`) const { files } = await workspace.grep(rx, { path: docs, glob: "**/*.md*", readText: true, }) /** ------------------------------------------------ * Generate alt text for images * and update markdown files */ // a cache of generated alt text for images const imgs: Record<string, string> = {} // process each file for (const file of files) { const { filename, content } = file console.log(filename) const matches = Array.from(content.matchAll(rx)) console.log(`.. found ${matches.length} matches`) // pre-compute matches for (const match of matches) { const url = match[1] if (imgs[url]) continue // already processed console.log(`.. processing ${url}`) const resolvedUrl = resolveUrl(filename, url) if (!resolvedUrl) { console.log(`... unknown image url`) continue // can't process url } console.log(`└─ ${resolvedUrl}`) if (dryRun) continue // execute a LLM query to generate alt text const { text, error } = await runPrompt( (_) => { _.defImages(resolvedUrl) _.$` You are an expert in assistive technology. You will analyze the image and generate a description alt text for the image. - Do not include alt text in the description. - Keep it short but descriptive. - Do not generate the [ character.` }, { // safety system message to prevent generating harmful text system: [ "system.assistant", "system.safety_jailbreak", "system.safety_harmful_content", "system.safety_validate_harmful_content", ], maxTokens: 4000, temperature: 0.5, cache: "alt-text", label: `alt-textify ${resolvedUrl}`, } ) if (error) throw error else if (!text) console.log(`.. no description generated`) else imgs[url] = text.replace(/\[/g, "") // remove [ from alt text } // apply replacements const newContent = content.replace( rx, (m, url) => `![${imgs[url] ?? ""}](${url})` ) // save updated content if (newContent !== content) { console.log(`.. updating ${filename}`) await workspace.writeText(filename, newContent) } }