A Copy-Paste Spec Template for AI Coding Agents
One-line prompts produce generic apps. Steal this short spec template — goal, scope, constraints, done criteria — and get dramatically better agent output.
Ask an agent to "build me a booking app" and you'll get a booking app — technically competent, instantly forgettable, and probably not the one you imagined. The gap between disappointing and useful results is rarely model quality; it's input quality. Agents are literal, fast, and confident, and when your instructions leave gaps they fill them with defaults averaged from everything they've ever seen. That's why under-specified projects come out looking like everyone else's. The fix isn't a formal product requirements document. It's about fifteen minutes with a template.
The template
Copy this, fill in the brackets, and paste it as your first message — or drop it in the project as a file the agent can always read:
Project: <one sentence — what this is and who it's for>
Goal: <the single outcome that defines success>
Users: <who uses it, and what they're trying to get done>
Must have:
- <a feature or behavior, phrased so you could test it>
Out of scope for now:
- <anything you do NOT want built yet>
Constraints:
- Stack: <tools or services the project must use, if fixed>
- Look and feel: <references, tone, anything visual that matters>
Done means: <the exact actions you'll run to decide it's finished>
Every line exists to remove a decision the agent would otherwise make for you.
Connect the Claude or Codex you already pay for — the rest runs on workers that cost a fraction.
Download meshcode →Why each section earns its place
Goal is singular on purpose. Hand an agent three competing objectives and it optimizes for none of them; one outcome keeps every later decision pointed the same direction.
Must-have items phrased testably do double duty: "a user can reset their password from the login screen" is simultaneously a requirement, a build order, and a test case. "Auth stuff" is none of those things.
Out of scope is the highest-leverage section and the one beginners skip. Left unstated, agents pad projects with uninvited admin dashboards, analytics pages, multi-language scaffolding, and settings screens nobody asked for. Saying "don't build these yet" cuts the work substantially and keeps the result shaped like your idea instead of the average idea.
Constraints matter only where you actually have them. If the technology choices are genuinely yours to delegate, say so explicitly and let the agent pick sensible defaults rather than asking you questions you can't answer.
Done means converts an open-ended session into a finishable one. Without it, "are we finished?" has no answer; with it, you have a concrete checklist the two of you can walk together.
Fill it fast, not perfectly
The template rewards ten honest minutes, not ten hours. Bullet fragments are fine, and "like a well-known checkout page, but friendlier" is a perfectly legitimate constraint. Where you don't know something — the right stack, the ideal flow — write the uncertainty into the spec and ask the agent to recommend an approach, then lock the answer into the document. Treat the spec as a steering wheel rather than a contract: revising it as real feedback arrives is progress, not failure. Vague prompting is one of the most common vibe coding mistakes, and a filled-in template retires most of it in one move.
When the agent drifts from the spec
Drift is normal and correctable, not a reason to start over. Point the agent back to the specific must-have line and ask where the project currently stands against it. One useful ritual: ask the agent to audit the build against every must-have and report status item by item — done, partial, missing — before fixing anything, so the gaps get prioritized instead of guessed at. When the build finally satisfies the list, walk it once more yourself — a structured pass of reviewing AI-generated code against the written criteria catches the gaps that enthusiasm overlooks.
The meshcode angle
Keep the finished spec as a file at the root of the repository, where every tool and session can read it. In meshcode — a native desktop app for macOS and Windows — each pane is its own agent session working over the same folder, so the spec stays authoritative no matter which pane you're typing into: one pane builds against the must-haves while another audits the result against them. Bring the Claude Code or Codex CLI subscription you already pay for, or use meshcode's own metered models, billed pay-as-you-go with no monthly fee.
👉 Download meshcode — Mac, Windows