Slack image bot: vector logos and marketing art on demand

When someone @-mentions me in one of my allow-listed Slack channels, I want you to read their creative brief, generate the right kind of image with Recraft, and post the result back into the same Slack thread. Build this as an agent workflow.

The trigger is a Slack Events API webhook on the app_mention event using the Slack Bot integration. Configure the workflow with an allow-list of channel IDs. As the very first step, compare the event's channel id against the allow-list; if it is not on the list, exit silently without replying and without calling Recraft.

Once the channel check passes, strip the leading <@BOT_USER_ID> mention off the message text so you are left with just the brief. Then run two guardrails before any generation: (1) refuse if the brief names a real, identifiable person, whether public figure, celebrity, or a named employee/customer; (2) refuse if it references a trademarked brand, franchise, or logo (examples: Nike, Marvel, Coca-Cola, Star Wars). On either refusal, reply in-thread with a friendly one-line explanation and stop.

Choose the Recraft operation based on the brief. Use Recraft Generate Vector Image (SVG) when the user says logo, icon, mark, SVG, vector, flat, line art, or asks for anything they'll want as a scalable file. Use Recraft Generate Image for photorealistic, hero, banner, product shot, ad creative, marketing art, cinematic, or 3D render. When the brief is ambiguous, default to raster (Generate Image).

Before calling Recraft, expand the user's one-liner into a fuller, style-aware prompt. Keep the subject faithful, but add clean style descriptors. For the vector branch favor language like "flat vector illustration, clean shapes, no gradients, high contrast, centered composition, transparent background". For the raster branch favor language like "photorealistic, natural lighting, editorial composition, shallow depth of field" or whatever style adjective the user provided. Keep the expanded prompt under 300 characters.

Call the chosen Recraft operation with the expanded prompt and read the image URL from the response (data[0].url for both Generate Image and Generate Vector Image (SVG)).

Post the reply with Slack Bot's Send a Message operation. Set channel to the original event's channel id and thread_ts to the ts of the incoming mention so the reply lands inside the thread (not as a new top-level channel post). The message body should have three lines: (1) a short human line naming what you made, e.g. "Here's a flat vector logo for a coffee subscription:"; (2) the image URL on its own line so Slack unfurls it inline; (3) a single regenerate hint of the form "Reply in this thread with a tweak to regenerate, e.g. `warmer palette` or `swap to a coffee bean icon`."

Failure handling: if the Recraft call errors or returns no image, reply in-thread with a short apology and the error summary; do not silently retry. If the initial channel allow-list check fails, do nothing at all (no reply, no error). Never repost the original brief back to the user, and never send a reply outside the thread.