B-Roll Match Desk
Documentary editors paste narration beats and available clip notes, and Jev routes each beat to a b-roll coverage type while judging how well the footage supports it.
The kernel.
Videographers paste in what arrives for Documentary editing and Jev picks exactly one option from a fixed list, with the odds for every option shown — unclear cases get a "needs review" badge.
Why this primitiveTyped coverage categories and support scores help editors spot missing visuals faster than generated shot suggestions.
Required key.
Add this in your Lovable project under Settings → Secrets before pasting the prompt below.
The build prompt.
Paste into a fresh Lovable project. Make sure the key above is set first. read the build strategy →
Build "B-Roll Match Desk" as a ONE-SHOT Lovable build (~5 credits, no follow-ups).
Single-page TanStack Start app, one route, cut scope ruthlessly.
THIS PROMPT IS SELF-CONTAINED
Do not assume the participant knows Jev or has read any other page. TypeSafe Jev is a decision model,
not a text generator. It receives `state` plus a map of typed `questions` and returns JSON that code can
use directly. Use Choice to select exactly one defined option, Noul for a yes/no probability from 0 to 1,
and Score for a probability-weighted position across ordered levels. Keep rules, thresholds, arithmetic,
and actions in code. Use a generative model only if the product separately needs prose.
CONCEPT
Documentary editors paste narration beats and available clip notes, and Jev routes each beat to a b-roll coverage type while judging how well the footage supports it.
Discipline: Videography & Film (Documentary editing).
Jev pattern: Choice Router (pick one of a set) — a Jev `choice` question that routes each incoming item to one handler/category from a fixed option map, plus branch-specific questions asked in the same request.
Why typed decisions: Typed coverage categories and support scores help editors spot missing visuals faster than generated shot suggestions.
ENGINE: TypeSafe Jev (typed decisions, not text)
- Before writing code, ask the participant for `TYPESAFE_API_KEY` with Lovable's secure secret form. Never
ask them to paste it into chat, never prefix it with `VITE_`, and never expose it to browser code.
- Put the callable server function in `src/lib/jev.functions.ts`; do not import a server-only module from UI code.
- Validate the user's input before the handler and read `process.env['TYPESAFE_API_KEY']` inside the handler.
- From the server, call:
POST https://api.typesafe.ai/v1/systemone
Authorization: Bearer <TYPESAFE_API_KEY>, Content-Type: application/json
body: { "model": "jev-latest", "state": <Narration outline, footage inventory, and coverage labels>, "questions": QUESTIONS }
- Ask all questions in ONE request (they run in parallel and cannot see each other).
- Read Choice from `answers[id].choice`, `.probabilities`, and `.confidence`; Score from `.score`,
`.probabilities`, `.legend`, and `.confidence`; Noul from `.noul` only (it has no separate confidence).
SERVER IMPLEMENTATION (adapt the input name and result mapping to this concept)
```ts
import { createServerFn } from "@tanstack/react-start";
import { z } from "zod";
const Input = z.object({ text: z.string().trim().min(1).max(20000) });
export const decide = createServerFn({ method: "POST" })
.inputValidator((input: unknown) => Input.parse(input))
.handler(async ({ data }) => {
const apiKey = process.env['TYPESAFE_API_KEY'];
if (!apiKey) return { ok: false as const, status: 500, message: "TYPESAFE_API_KEY is not configured." };
const requestBody = {
model: "jev-latest",
state: { text: data.text },
questions: QUESTIONS,
};
let response: Response | undefined;
for (let attempt = 0; attempt < 3; attempt += 1) {
response = await fetch("https://api.typesafe.ai/v1/systemone", {
method: "POST",
headers: { Authorization: `Bearer ${apiKey}`, "Content-Type": "application/json" },
body: JSON.stringify(requestBody),
});
if (response.ok || (response.status !== 429 && response.status < 500)) break;
if (attempt < 2) await new Promise((resolve) => setTimeout(resolve, 750 * 2 ** attempt));
}
if (!response) return { ok: false as const, status: 503, message: "Jev did not respond." };
if (!response.ok) {
const message = (await response.text()).slice(0, 500) || `Jev request failed (${response.status}).`;
return { ok: false as const, status: response.status, message };
}
const result = await response.json();
return { ok: true as const, answers: result.answers };
});
```
In the page component, call `decide` with `useServerFn`, preserve the participant's input while loading or
on error, disable duplicate submissions, and render the returned typed values rather than parsing prose.
QUESTIONS (start here, refine wording if needed)
{
"coverage_route": {
"type": "choice",
"instructions": "What kind of visual coverage should be checked for this beat?",
"criteria": {
"literal": "Directly depicts the person, place, or action mentioned",
"contextual": "Provides relevant setting or background context",
"emotional": "Supports the beat's mood or human impact",
"evidence": "Shows an artifact, process, or verifiable detail"
}
},
"coverage_fit": {
"type": "score",
"instructions": "For the selected coverage type, how well does available footage support this beat?",
"criteria": [
"No usable match identified",
"Weak or indirect support",
"Good usable support",
"Strong, specific match"
]
},
"claim_support": {
"type": "noul",
"instructions": "For this beat, could the selected footage mislead viewers about what happened?",
"criteria": {
"true": "The footage risks implying an unsupported event or claim",
"false": "The footage does not appear to create that risk"
}
}
}
DECISION RULES (in code, not in the model)
- choice/score: if confidence < 0.6 show a "needs review" badge instead of acting.
- noul: >= 0.75 = yes, <= 0.25 = no, otherwise "review".
- score: normalise with score / (levels - 1) before combining with weights.
- Missing or malformed answers go to review. Show safe HTTP status and message in the UI. Retry only 429/5xx,
at most twice with increasing delay; never retry 400/401/402/403/404 and never invent results.
- If the product needs prose (a summary, a message), use Lovable AI for that text only; Jev makes the decisions.
UI
a paste box that shows the chosen option, the full probability bar chart, and a 'needs review' badge when confidence is low. Include 2 sample inputs as one-click chips so the demo works instantly.
Tailwind + shadcn, editorial look, footer: "Built during the Creative AI & Quantum Hackathon organised by StreetKode Fam during Indian Krump Festival 14".
NO database, NO auth, NO extra pages, NO tests.
BEFORE YOU FINISH
- Run the app and test both sample inputs through the real server function.
- Confirm the browser receives no API key and no fabricated fallback result.
- Confirm Choice/Score confidence and Noul probability drive the stated review rules.
- Confirm loading, success, review, empty-input, and service-error states are readable on mobile.
Reference only if needed: https://docs.typesafe.ai/api and https://docs.typesafe.ai/primitives
Market sizing.
Indicative figures for hackathon pitches — refine with your own research before raising.