Run a Coding Jam in your city.
Hosting a Coding Jam is one of the best ways to connect the builders in your community — a room of developers leaves with a working app, a new collaborator, and someone to text the next time they get stuck. Bring the room; the kit brings the rest. From planning to execution in 2 weeks.
A pre-flight checklist.
Drop this into your event description verbatim. Half the workshop time is currently lost to setup — this checklist gives it back. Drop-ins without the prereqs are still welcome; pair them with a TA.
Tip: pin the checklist in the RSVP email 48 hours before doors open. Re-share at T-2 hours.
- 1Install Antigravity
Download the desktop app from antigravity.google. The Jam runs on Antigravity — without it, participants can't follow the codelab.
- 2Install uv
macOS / Linux: `curl -LsSf https://astral.sh/uv/install.sh | sh`. Windows: see astral.sh/uv. uv replaces pip and venv — much faster, fewer surprises.
- 3GitHub account + Git installed
Each starter is a GitHub repo. Participants clone it during Setup (codelab phase 1).
- 4Google account (for Gemini API)
Used to create an API key at ai.google.dev. Free tier is enough for the workshop.
- 5Optional: GCP project + workshop credits
Recommended when running an official GDG event — workshop credits cover the API spend and tie to the chapter KPI. Skip for casual jams.
Everything in the box.
Each track ships with a starter, a Codelab, and a Spec Talk card. You facilitate; the kit handles the rest. Pick any track to host — they’re independent.
Scaffolded folder with context/, helper prompts, and pre-flight scripts. No solution code — participants build their own version.
A step-by-step guide that gets a participant from zero to a working app in 45 minutes. Drop-in friendly. Tested before doors open.
The 5 Spec Talk questions on one printable. Hang it in the room. Walk through it on the projector with the room.
Two hours. Five movements.
We keep the talking short and the building long. Organizers facilitate; the room creates. This shape repeats across every track — it’s the muscle memory.
The Build phase IS the codelab — Antigravity does the typing, participants direct it through six sub-phases (Setup, Plan, Review, Build, API, Verify).
Pre-warm the deploy target by pushing a hello-world before doors open. The first deploy of the night is usually the slowest.
Your demo is your most important deliverable. Practice it once on the morning of, with the actual production stack you’ll use on stage.
- 0:00 – 0:05Intro
Welcome, name tags, snacks within reach. The facilitator sets the tone: low pressure, high creativity, ship something messy.
- 0:05 – 0:15The Demo
Facilitator demos the polished version of tonight's project. Live or pre-recorded. The message: this is what's possible.
- 0:15 – 0:25Spec Talk
Walk the 5 questions on the projector. The output is a one-page PRD that Antigravity will turn into UI + engineering docs.
- 0:25 – 1:30Build (codelab)
Participants run the codelab. Antigravity writes the code; they direct it. Six phases inside this hour: Setup → Plan → Review → Build → API → Verify. Fix the doc, not the code.
- 1:30 – 2:00Sharing
Three volunteer screen-shares. Celebrate the messy, brilliant, half-finished prototypes. Quick wrap-up. Tease the next jam.
The skill participants take home.
The 45-minute apps are how the room practices. The Spec Talk is what participants take home. Eight reps over eight tracks — by Track 8, they’re running it solo on their own ideas.
Each track puts the spotlight on one of the five questions. You’ll find the per-track emphasis in the facilitator notes below.
- 1Magical momentWho's looking at this and what feeling are we going for?
- 2Input / outputWhat does the app take in, exactly? What does it give back?
- 3PersonalityWhat's the AI's tone? Witty? Quiet? Stern? Encouraging?
- 4Signature detailWhat's the one thing that makes ours different from the person next to us?
- 5Not building todayWhat are we explicitly NOT shipping? Name it out loud.
A four-phase rhythm, every track.
You ship the track's app live. Participants watch, no laptops. The 'this is what's possible' moment.
Walk the room through the 5 questions on the projector. Highlight the question this track emphasizes.
Participants run the codelab. Antigravity writes the code; they direct it. You and TAs circulate — unblock, don't code for them.
3 volunteer screen-shares. Celebrate the messy, the brilliant, the half-finished. Tease the polished version.
Six codelab sub-phases.
The codelab runs ~48 minutes of structured time + ~20 minutes of slack for help, iteration, and polish. Total ~75 minutes inside the 60–70 minute Build window with room to breathe.
Install Antigravity, clone the starter, init the environment.
Spec conversation generates three docs: PRD, UI/UX, engineering + tests.
Read the docs. Leave inline comments. Iterate until approved.
Antigravity generates the app and tests. Auto-fix loop on failures.
Create the GCP project, link credits, get the Gemini API key, fill .env.
Run the dev server. Click through. Fix the doc, not the code.
From decision to doors-open.
- •Lock workshop dates
- •Recruit TAs — 1 per 30 attendees
- •Set up the Wall of Vibes shared doc
- •Pre-provision the AI API account with billing
- •Verify image-gen + LLM API access
- •Run the Codelab end-to-end yourself, time it
- •Practice your demo with the real stack
- •Fix friction points found
- •Tease the track on social
- •Internal dry-run with TAs
- •30-min facilitator setup before doors open
- •Pre-warm the deploy target (push hello-world)
- •Codelab and starter repo URL on slide
- •Wall of Vibes link visible
- •Pizza, water, name tags
- ✓Participants quote the Spec Talk question they emphasized today
- ✓Someone says 'wait, that's a polished-version feature' mid-build
- ✓Drop-ins on later tracks are running the Spec Talk confidently
- ✓At Compare Notes, the variations between participants are wide
- !Participants copy the demo verbatim instead of making it theirs
- !Builds keep slipping past 45 minutes because everyone added more features
- !At Compare Notes, every project looks the same
- !Wall of Vibes stays empty halfway through
When you see the latter: pause, pull the Spec Talk card back up on the projector, and re-read the question this track emphasizes. The reset usually re-anchors the room.
What to demo, what to coach, what to fish for.
Participants see the high-level rhythm. You see the Spec Talk emphasis, the line to listen for, and the polished-version pull-ins to tease at Compare Notes. Expand any track below.
01Glow UpSelfie + a hairstyle → see the new you.Listen for: “OMG that's me with bangs.”+
Upload a selfie. Pick from preset hairstyles. AI does a virtual hair try-on via Vertex AI image generation — same person, new look — and shows before / after side by side.
This is the participants' first Spec Talk. The facilitator walks the room through it live — showing how 2 minutes of talking shapes the next 45 minutes of building. Question 4 (the signature detail) gets extra attention this week, because everyone's making a 'try-on' app — the signature is what makes theirs different from the person sitting next to them. Maybe one app writes a sassy stylist note. Another adds a 'vibe rating.' Same scaffolding, different soul. In Antigravity, the signature detail lives in the PRD — name it explicitly and the UI doc picks it up automatically.
- Outfit and accessory modes
- Custom typed-in prompts
- Share button
- Side-by-side compare
- Lookbook to save favorites
- 'Rate my friends' group photo
- Decade time machine
context/image-gen-tryon.md
02Avatar StudioPhoto (you OR your pet) + pick a style → one stylized avatar.Listen for: “My cat looks like a Pixar character.”+
Upload a photo — your face OR your pet's face. Pick from four preset styles (e.g. Pixar, anime). AI returns one stylized avatar.
Participants run more of the Spec Talk solo. The facilitator steps in for tricky questions. Question 2 (input/output) is where the real design work happens — does the app accept any photo, or only faces? Does it generate one avatar or 4 at once? Does it work on full-body photos or just close-ups? Get this tight in the Spec Talk and the UI doc Antigravity generates comes back almost finished.
- Generate multiple avatars at once
- Animated avatars (subtle motion)
- Full character lore generator (name + backstory)
- Social media format presets (Twitter PFP, Discord, LinkedIn)
- User-defined style prompts
context/image-gen-stylization.md
03Year in PoetryTell AI your meaningful dates → a year calendar you can read like a poem.Listen for: “My whole year, laid out like a poem.”+
During the Spec Talk, the participant tells AI the meaningful dates in their life — birthdays, anniversaries, the day they got their dog. AI generates a beautifully designed, scrollable year calendar with a short AI-written warm note for each date ('Grandma's birthday — call her' / 'One year since you and Sam').
Question 1 (the magical moment) is the star this week. Who's looking at this calendar? Just them, alone, on a quiet evening? Their family, printed and on the fridge? A version they can share online? The answer drives every visual decision. This is the week where participants discover that the magical moment isn't always 'wow factor' — sometimes it's 'feels like home.' Name that feeling in the PRD's opening paragraph; the UI doc inherits the whole mood from one sentence.
- Login + edit-your-own-dates flow
- Google Calendar sync
- Birthday reminder notifications
- Family-shared edition
- Monthly reflection poem
- Photo-per-date upload
- Audio bed (ambient soundscape)
context/calendar-layout.mdcontext/personal-data-from-spectalk.md
04FridgeChefType what's in your fridge → one recipe (with food photo).Listen for: “It actually used my random ingredients. And the photo looks like food.”+
One text box: 'what's in your fridge?' One button. AI returns one recipe — title, ingredients, steps — plus an AI-generated photo of the dish.
Halfway point. Participants now run the entire Spec Talk solo. The facilitator observes and helps individuals who get stuck rather than facilitating the whole room. Watch for Question 5 (not-building) — the temptation to add pantry / dietary / budget filters here is enormous. If a participant adds them to the PRD, they will appear in the build. The PRD is the gate.
- Mode picker (quick / grandma / budget / healthy / fancy)
- Local grocery store integration
- Shopping list generator
- Dietary preferences
- Family meal planner
- Photo input — show your fridge instead of typing
- Save & share recipe gallery
context/image-gen-food.md
05Mood JarType how you're feeling → a little token drops into your jar.Listen for: “My scattered thoughts just turned into a cute little token in my jar.”+
One text box: type what's on your mind. AI generates a mood sticker/item — kawaii emoji, glowing orb, tiny potion, pixel-art object — and drops it into a visual 'jar' on the page. The jar fills up as you keep writing.
Question 3 (Personality) becomes the heart of this week's Spec Talk — the AI's tone is the whole product. The facilitator highlights this so participants notice they're using the Spec Talk to make a real design decision, not just describe a feature. The personality goes verbatim into the PRD's voice section. Antigravity's engineering doc inherits it as the system prompt.
- Local storage so the jar persists
- Animated physics (tokens settle, jar tilts)
- Multi-day pattern detection
- Cross-device sync
- Mood history charts
- Share-your-jar mode
- Voice memo input
context/persona-prompt-pattern.md
06My CornerName + bio + 3 things → a live URL you can text your mom.Listen for: “I have a website I can text my mom.”+
Single page. Name, 2-line bio, 3 things you're proud of, one photo. Deploy to a real URL via Vercel/Netlify drag-and-drop. That's it.
This is the hardest Spec Talk because the topic is them. Most people freeze when asked 'what's your magical moment?' about themselves. The facilitator names this out loud and lets the room sit with it. The skill being practiced is using the Spec Talk for self-reflection — a transferable life skill. The PRD they write today is the first time many of them will have written a one-page spec about themselves.
- Custom domain
- Blog/log section
- Contact form
- Guestbook
- Seasonal/animated theme
- Links-tree mode
- AI-generated 'sounds like you' refinements
context/deploy-to-vercel.mdcontext/self-writing-prompts.md
07BulletProofPaste resume + paste job → tailored bullets.Listen for: “This is actually better than what I'd write.”+
Two text boxes — paste resume text, paste job posting text. One button. AI returns tailored resume bullets, ready to copy. No PDF parsing, no cover letter, no interview prep, no Word export.
Question 5 (What you're NOT building today) is the star this week — there are SO many tempting features (cover letter! PDF! interview prep!). The facilitator uses this week to drive home that 'not building' is what makes 45 minutes possible. The not-building list goes into the PRD as an explicit non-goals section. Antigravity respects it; without it, scope creep makes the build doc twice as long.
- Match score + missing keywords
- PDF parsing for resume input
- Cover letter generator
- Interview question generator
- Networking message writer
- Application tracker
- ATS scoring
context/long-context-handling.mdcontext/text-diff-pattern.md
08Character ChatDefine one character → chat with them.Listen for: “I made this person and I'm talking to them.”+
Define one character (name + 1-paragraph personality + 1 thing they'd never say). Chat with them — up to 5 messages back and forth. No persistent memory across sessions.
Open canvas. Participants run the Spec Talk on their own original idea — no menu, no demo to copy. This is the graduation moment. The Spec Talk works on anything. Now they prove it — write a PRD from scratch, run it through Antigravity, ship the build.
- Persistent memory across sessions
- Character avatars and voices
- Multi-character world
- Reverse mode (you play the character)
- In-character safety guardrails
- Themed visual packs (anime, sci-fi, noir)
context/character-system-prompts.mdcontext/character-guardrails.md
What trips people up — and the fix.
Four issues that come up in almost every room. If a participant is stuck for more than 5 minutes, check these first.
Symptom: Gemini API call returns 403 / quota error halfway through Verify.
Fix: During Setup, link workshop credits to the GCP project at console.cloud.google.com/billing. If you skipped GCP entirely, the free Gemini tier from ai.google.dev works for the codelab — just confirm the key is from there.
Symptom: App loads but every Gemini call returns 401.
Fix: Open the project root, confirm `.env` exists (NOT `.env.example`), and the key is `GEMINI_API_KEY=...` with no quotes around the value. Restart the dev server after editing.
Symptom: App opens but the agent panel hangs on first prompt.
Fix: Make sure you downloaded the arm64 build, not Intel. Quit the app fully (Cmd-Q, not just close window) and reopen. If still stuck, check Activity Monitor that the process is `Apple` architecture.
Symptom: Participant runs `pip install`, gets ModuleNotFoundError later.
Fix: The codelab uses uv. Direct them to `uv sync` (installs deps from pyproject.toml) and `uv run <command>` (replaces `python <command>`). pip will silently install into the wrong environment.
Got everything you need?
Open a track, grab the kit, and start preparing. Once you’ve hosted, share what your room shipped on the showcase — it helps other GDGs get started.