Picked up a build guide this week: 9 pages, walks through wiring up a "/generate" media skill, images and video through cheap model routing. Handed it to my chief of staff and told it to build the valuable half into BubbleBeam, my actual SaaS with paying users, same day. It didn't follow the doc literally. First move was splitting the ask, writing its own design spec, then a 9-task implementation plan. Then it dispatched itself: Opus agents doing the implementation, a separate reviewer agent grading each task before the next one started, and a final adversarial review of the whole branch. All of it ran in an isolated git worktree while I did other things. Two catches made the whole process worth it. Catch one: the guide's request format for the image model was wrong. The live API wanted a different field shape than what was in the doc. An agent caught it by pulling the provider's actual OpenAPI spec before spending a dollar on it. First paid call worked first try. Catch two: the guide's video cost estimate was low. It quoted roughly $1.60-2.80 per 8-second clip. Real list price is about $3.20. Doesn't sound huge until you're running it at volume with no ceiling. So video generation shipped behind an admin-only flag with cost controls until the pricing settles, instead of going straight to every user. What actually shipped: admin-only text-to-video on Veo 3.1 (async jobs, stored clips, a live progress readout), and a user-facing "Text-heavy image" toggle that routes to GPT Image 2 when you need readable text in an image, a nickel a shot, with automatic fallback to Gemini if it fails. Total spend to prove both paths worked live: about $3.30. First video: 8 seconds, 720p, audio, generated in under a minute. First image: a neon diner sign with text you could actually read, which is the exact problem GPT Image 2 solves and Gemini usually botches. The generation itself isn't the hard part anymore. Every model provider ships that. What made this shippable same day was the stuff around it: cost gates, routing to the cheapest model that still does the job, a review agent grading every task before the next one starts, one flat storage path instead of three. Guides teach you the API call. They don't teach you the rails that keep the API call from becoming an expensive mistake.