What I Built

NarraMeuGol turns a phone clip of an amateur "várzea" (Brazilian pickup) football
match into a hyped, radio-style commentary — written and voiced by AI, played over
your video, and exportable as a single ready-to-post .mp4.

Várzea is Brazilian street/park football: dirt fields, no cameras, no commentators —
just passion. My goal was to give every backyard goal the epic radio call it deserves.
It's not a match report; it's pure hype.

You upload a clip, pick a commentator style (classic or over-the-top), choose the
language, and seconds later you're hearing your goal narrated like it's a World Cup final —
Brazilian bordões (catchphrases), drawn-out "GOOOOL"s and all.

Code

rotirotirafa / narrameugol

NarraMeuGol ⚽

the AI that calls your street-football goal (PT-BR: "a IA que narra seu gol de várzea")

Upload a short clip of an amateur football match and an AI watches the video, writes a hyped Brazilian radio-style commentary, and turns it into audio — playing the narration over your (muted) clip, ready to download and post.

Built for the DEV Weekend Challenge (Passion Edition). Várzea is Brazilian pickup/park football — the whole point is passion and hype, not an accurate match report.

What it does

upload clip + style + language → Gemini (video → script) → ElevenLabs (script → mp3)
→ play muted video + synced narration → download mp3 / clip / one-click narrated mp4

Bilingual (PT-BR / EN): one toggle switches the entire UI and the narration language (the wordmark flips too: NARRA·MEU·GOL ↔ NARRATE·MY·GOAL). Non-Portuguese browsers start in English.
Two commentator styles: classic…

View on GitHub

How I Built It

A single Next.js 16 (App Router) app. One server route, /api/narrate, holds both API
keys and orchestrates the whole pipeline, so the browser never sees a secret:

upload → Gemini (video → script) → ElevenLabs (script → voice) → play over muted clip

🟦 Best Use of Google AI — Gemini actually watches the clip.
The uploaded video goes to Gemini 2.5 Flash via the Files API (upload → poll until
ACTIVE), which reads the play and writes a ~100-word broadcaster script in the chosen
language, with catchphrases and expressive markers — no invented names or scores, just hype.
Multimodal video understanding is what makes the narration about your goal.

🟪 Best Use of ElevenLabs — the voice is the soul of the product.
That script is sent to ElevenLabs (eleven_multilingual_v2), which turns it into an
expressive radio-broadcaster voice. The same multilingual voice serves both Portuguese and
English, so one toggle re-narrates the whole thing in another language.

Other decisions I'm happy with:

🛟 A demo that can't go silent. If Gemini can't read the clip, a template script keeps the narration flowing — a live demo never fully breaks.

🌎 Real bilingual (PT-BR / EN). A single typed message dictionary is the source of truth for the UI and the AI prompt, so the two never drift. The wordmark even flips: NARRA·MEU·GOL ↔ NARRATE·MY·GOAL.

🎬 One-click narrated mp4 — in the browser. ffmpeg.wasm muxes the muted clip + the narration into a single video client-side. Beyond skipping a server round-trip, it neatly sidesteps Vercel's function body limits — the browser already has both files.

🎨 A look with intent. A "night match" theme — pitch green, canarinho gold, chalk field-lines, an "ON AIR" pulse — built to feel like street-football radio, not a template.

Stack: Next.js 16 · React 19 · TypeScript · Tailwind v4 · Gemini (@google/genai) ·
ElevenLabs (@elevenlabs/elevenlabs-js) · ffmpeg.wasm · deployed on Vercel.

Prize Categories

Best Use of ElevenLabs — the entire narration voice is ElevenLabs (eleven_multilingual_v2), delivering the expressive PT/EN broadcaster audio that is the product.

Best Use of Google AI — Gemini's multimodal video understanding watches the clip and writes the commentary, so the narration actually reflects the play.

Made on the várzea, with coffee and passion. ⚽

DEV Community

NarraMeuGol: the AI that calls your street-football goal 🎙️⚽