Jem

for The DEV Team

Posted on Nov 13 AI-assisted

Congrats to the Hacktoberfest Open-Source AI Challenge Week 4: Ghost in the Machine Winners!

#devchallenge #hf26challenge #hacktoberfest #ai

The results are in for the final week of our Hacktoberfest DEV Challenges! For Ghost in the Machine, we asked you to build something spooky, or something that honors the past in the spirit of Día de los Muertos, with open-weight models or open-source AI.

You took the theme in every direction we hoped for, and plenty we didn't see coming. We saw digital ofrendas, ghosts of forgotten repos, and séances for dead code. Many of you showed exactly why open innovation matters here: family stories, inboxes, and photos that never leave your own machine.

Thank you for your patience while we reviewed every submission, and thank you to everyone who built with us this week and all month long. Now, let's celebrate our winners!

🎉 Congratulations To…

Overall Winner

Hacktoberfest Open-Source AI Challenge: Ghost in the Machine Submission 👻🌼

Toyyib Olamilekan

Oct 31

I gave a tiny AI a diary, then switched off its brain one night at a time

#devchallenge #hf26challenge #gemma #ai

8 min read

Featured Category Winners

Best Use of Render

Hacktoberfest Open-Source AI Challenge: Ghost in the Machine Submission 👻🌼

SRG-Cy

Oct 31

Halloween started in Ireland. I put a century of Irish ghost stories back on the map, and code wouldn't let the AI invent a single place

#devchallenge #hf26challenge #gemma #opensource

13 min read

Best Use of TabPFN

Hacktoberfest Open-Source AI Challenge: Ghost in the Machine Submission 👻🌼

Malbolged

Oct 29

The Empty Room: I held a séance over a 2015 sensor log

#devchallenge #hf26challenge #ai #python

8 min read

Best Use of Tinker

Hacktoberfest Open-Source AI Challenge: Ghost in the Machine Submission 👻🌼

Derby Prayogo

Oct 31

My grandpa took me to wayang every other Sunday. So I taught an open model to be the dalang.

#devchallenge #hf26challenge #gemma #opensource

11 min read

Best Use of Arduino

Hacktoberfest Open-Source AI Challenge: Ghost in the Machine Submission 👻🌼

Abhinav krishna N

Nov 1

Feed the Gargoyle: a stone imp that asks riddles, hears the answer and pays in candy, all offline on an Arduino UNO Q

#devchallenge #hf26challenge

18 min read

Best Use of DigitalOcean

Hacktoberfest Open-Source AI Challenge: Ghost in the Machine Submission 👻🌼

Tanmay Gajjar

Nov 1

I don't have a single photo of my great-grandparents. So I built an altar for the people nobody remembers.

#devchallenge #hf26challenge #opensource #ai

9 min read

Best Use of Gemma

Hacktoberfest Open-Source AI Challenge: Ghost in the Machine Submission 👻🌼

tushar shah

Oct 30

Nishi Daak: an Arduino UNO Q that calls your name twice when you come home late (local Gemma, no cloud)

#devchallenge #hf26challenge #arduino #gemma

8 min read

Partner Category Winners

Best Use of Auth0 for AI Agents

Hacktoberfest Open-Source AI Challenge: Ghost in the Machine Submission 👻🌼

Thilakasiri H.A.B.D

Oct 29

My forgotten subscriptions gave me nightmares, so I built Ghost Bills

#devchallenge #hf26challenge #ai #auth0

13 min read

Best Use of Backboard

Hacktoberfest Open-Source AI Challenge: Ghost in the Machine Submission 👻🌼

vrRanjith

Oct 31

GhostCommit: Every Abandoned Side Project Leaves a Ghost 👻

#devchallenge #hf26challenge #opensource #ai

7 min read

Best Use of Browserbase

Hacktoberfest Open-Source AI Challenge: Ghost in the Machine Submission 👻🌼

Ronak sarda

Oct 30

Your AI is hearing voices. I built the exorcist.

#devchallenge #hf26challenge #ai #opensource

14 min read

Best Use of ElevenLabs

Hacktoberfest Open-Source AI Challenge: Ghost in the Machine Submission 👻🌼

Jose Antonio Granero

Oct 31

Every rhyme rule I gave Gemma, it found a loophole. Catrina News turns today's tech headlines into Día de los Muertos calaveras

#devchallenge #hf26challenge #opensource #ai

7 min read

Best Use of Entire

Hacktoberfest Open-Source AI Challenge: Ghost in the Machine Submission 👻🌼

Mrituanjay Nath Jha

Oct 31

Localghost: a ghost story that knows where you live (and runs on your laptop)

#devchallenge #hf26challenge #llm #opensource

6 min read

Best Use of GitHub Copilot

Hacktoberfest Open-Source AI Challenge: Ghost in the Machine Submission 👻🌼

Aroso Emmanuel

Oct 28

Ghost Visitors: the people who left your website come back to haunt it

#devchallenge #hf26challenge #gemma #a11y

10 min read

Best Use of Mastra

Hacktoberfest Open-Source AI Challenge: Ghost in the Machine Submission 👻🌼

hongpengtan0-max

Oct 28

An AI invented half the memories on an ofrenda card. Ofrenda Keeper writes down only what you said, and asks about the rest

#devchallenge #hf26challenge #gemma #mastra

6 min read

Best Use of MongoDB Atlas

Hacktoberfest Open-Source AI Challenge: Ghost in the Machine Submission 👻🌼

Carlos José Castro Galante

Oct 30

Linkmortem, an Autopsy for Every Dead Link

#devchallenge #hf26challenge #ai #opensource

19 min read

Best Use of Sentry Agent Tracing

Hacktoberfest Open-Source AI Challenge: Ghost in the Machine Submission 👻🌼

Kamal

Oct 28

Revenant: I held a séance for a dead Python library, and it came back passing its tests

#devchallenge #hf26challenge #gemma #ai

12 min read

Best Use of SerpApi

Hacktoberfest Open-Source AI Challenge: Ghost in the Machine Submission 👻🌼

Kanak Waradkar

Oct 31

I held a séance for 31 dead websites. The most honest ghost said "that never made it into my HTML."

#devchallenge #hf26challenge #gemma #opensource

13 min read

Best Use of Temporal

Hacktoberfest Open-Source AI Challenge: Ghost in the Machine Submission 👻🌼

mohamedaminehamdi

Oct 29

Graveyard Shift: five AI ghosts work my night shift on local Gemma 4

#hf26challenge #devchallenge #ai #opensource

10 min read

Best Use of Tiger Data

Hacktoberfest Open-Source AI Challenge: Ghost in the Machine Submission 👻🌼

Ritesh Mahato

Oct 30

Lupita says 1959. Tío Chucho says 1961. The ofrenda keeps both.

#hf26challenge #opensource #devchallenge #ai

9 min read

Best Use of Ultramarine

Hacktoberfest Open-Source AI Challenge: Ghost in the Machine Submission 👻🌼

Kourtney Lee

Nov 1

Unhaunt: 215 ghost accounts in my inbox, and my local AI wanted to delete 23 I still use

#devchallenge #hf26challenge #ai #privacy

9 min read

Best Use of a .tech Domain

Hacktoberfest Open-Source AI Challenge: Ghost in the Machine Submission 👻🌼

Samarth Kumble

Oct 31

When someone dies, their money doesn't tell the family where it is. So a local Gemma reads their inbox.

#devchallenge #hf26challenge #ai #opensource

9 min read

Prizes

Overall winner: $250 USD, a DEV++ membership, and an exclusive DEV badge
Featured category winners: $200 USD and an exclusive DEV badge each
Partner category winners: $100 USD and an exclusive DEV badge each

All participants with a valid submission will receive a completion badge.

A huge thank you to our partners for making these prizes possible, this week and all month long!

That's a Wrap on Hacktoberfest 2026

Five challenges, five themes, and more open-source AI projects than we ever imagined. Thank you to every builder, partner and community member who showed up week after week. You made this the biggest Hacktoberfest on DEV yet.

Over 115k participants and 500+ global meetups