best-in-slot

The problem

Every small business gets the same two pieces of advice: run ads on Facebook and Instagram, and post on Instagram every day. Both are content treadmills. One decent Meta ad is a concept, an image cut to four different aspect ratios, and a stack of headlines and primary texts to test against each other; a living Instagram feed is that again, several times a week, indefinitely. An agency to do it costs more than the ads. The do-it-yourself tools open with a setup form that makes you explain your own business from scratch — then hand you a picture, not an ad, zipped up for you to upload into Ads Manager by hand. So the ad account sits idle, and the feed goes quiet the week things get busy.

best-in-slot does the homework once, and then does the work.

What it is

best-in-slot turns one description of a business into advertising. You give it your website; it reads your pages and writes up the business — what you sell, how you price it, what makes you different — alongside the audiences who buy and why, your brand colours and voice, your logo, and a handful of recurring themes worth posting about. You review all of it on a single screen, and from then on everything it makes is grounded in that one profile. You never re-explain your business.

Two products run on that one setup. Paid ads: concepts, image, copy, and a finished ad published into your Meta campaign. Organic Instagram: posts, carousels and stories, published now, scheduled ahead, or handed to an autopilot that keeps the feed going without you.

How it works

One setup, then a fork — and the two branches end differently on purpose.

1. Paste your website. It crawls your pages and drafts the brand: profile, audiences, colours, voice and content themes. Nothing is saved until you’ve read it and said yes.
2. Make an ad. Pick an audience and an angle and it pitches three concepts, each with a hook, a big idea and a visual direction. It draws the image in one of 66 ad styles, re-frames it — rather than stretching it — for all four Meta placements, then writes five primary texts, five headlines and a description while looking at the picture it just made. Or skip every step and run the whole chain in one click.
3. Make a post. A single image, a carousel or a story — picture, caption and hashtags drawn and written together, in the brand’s own voice. Publish it now, park it in the queue for a day and time, or let autopilot decide.
4. Ship it. An ad goes straight into your Meta ad set paused, for you to review and flip live. A post goes to your real Instagram profile on its own, at the time you picked.

What it does well

• No setup form. It reads what’s already on your site instead of asking you to describe yourself — and draws only on what’s actually there, so the profile sounds like your business rather than a template.
• An ad, not an image. Concept, creative and copy arrive as one piece, and the copy is written by a model that can see the picture it’s selling with.
• Straight into Ads Manager, not a zip file. Connect Meta once, pick a campaign and ad set, hit publish. One multi-asset ad carries all four sizes and every copy line, inherits the page, call-to-action and destination from the ads already in the set, and arrives paused — not a dollar moves until you say so.
• Pay for what you make. Credits instead of seats: 50 free to start, about five ads or posts, no card needed — and a generation that fails refunds itself.
• Ads that double as posts. A finished ad is already drawn in every shape Instagram takes, so turning it into a post only rewrites the words — for people who follow you, rather than strangers being interrupted — for a single credit.

Instagram on autopilot

This is the part that turns a tool into a habit. Set the cadence once — the days, up to three times a day, your timezone, the mix of single images, carousels and stories, and whether each post waits for your approval or just goes. From then on, a day ahead of every slot, best-in-slot decides what that slot should be, picks which theme and product get their turn, draws the picture and writes the caption. At the slot it publishes — or holds the post for your yes.

It never posts twice for one slot, never publishes a post you rejected, and skips a slot that has already passed rather than dumping four posts at once. If the balance runs out, the schedule pauses and emails you instead of failing quietly.

Under the hood

A FastAPI service, two Next.js apps — the product and the marketing site — and a Postgres schema all three agree on. Two facts shape almost every decision in the codebase.

Generation costs real money, so credits are the spine. Every paid action is charged before the work starts and refunded if it fails — idempotently, because four different recovery paths can race to refund the same charge — while a second ledger records what every model call actually cost in dollars, charged or not, so the margin is never a guess. Publishing is irreversible, because Instagram’s API has no delete: a double-published post is a permanent artefact on someone’s public profile. So the publish path is paranoid by design, and a single SQL claim with a lease is what stands between a double-clicked Publish button and a duplicate on a customer’s feed.

Some of the craft is invisible. Reasoning models ignore temperature, so variety is engineered rather than requested — each concept is assigned its own sub-angle, and each draft is a weighted draw over visual directions. Carousel slides after the cover are typeset by a compositor instead of generated, so a ten-slide carousel costs two image-model calls rather than ten, and text that won’t fit is re-planned, never clipped.

Why it matters

Most small businesses don’t lack ideas for their marketing; they lack the hours to turn them into a steady stream of finished work. best-in-slot collapses the whole pipeline — brief, concept, creative, copy, sizing, upload, scheduling — into one setup and a click, and stays honest about the line it won’t cross on its own: ads wait, paused, for a human to spend the money, and posts go out by themselves only where you’ve said they may. It’s the headline, delivered: ads in a click, Instagram on autopilot.