Challenge Hub
HF26 DEV Challenge Hub
Five challenges, one prompt, a new theme every week.
This year's Hacktoberfest is not about open source pull requests. There's no PR count to hit and no repos to hunt for. Instead, you build a brand-new project with open-source AI at its core, and write about it on DEV. Here's everything you need to know about Hacktoberfest 2026.
Hacktoberfest is here, and this year we're running five DEV Challenges back to back, all month long. Every challenge uses the same prompt. Every challenge gets its own theme, and each theme stays secret until the day it launches.
The Five Challenges
- Live Weekend Challenge Build for a Friend Oct 2 – 5 Winners: week of Oct 5 View challenge
- Upcoming Week 1 Revealed at launch Oct 5 – 11 Winners: week of Oct 12 View challenge
- Upcoming Week 2 Revealed at launch Oct 12 – 18 Winners: week of Oct 19 View challenge
- Upcoming Week 3 Revealed at launch Oct 19 – 25 Winners: week of Oct 26 View challenge
- Upcoming Week 4 Revealed at launch Oct 26 – 31 Winners: week of Nov 2 View challenge
How It Works
- Five challenges: a weekend challenge to start, then a new one every Monday in October.
- One prompt: the same prompt for all five, so you always know what we're looking for.
- A new theme each time: the theme gives each challenge its own flavor. We reveal it the day the challenge launches.
- One submission per challenge: that's up to five in October. Each submission is automatically in the running for the overall prize and every partner category it qualifies for. You can win once per challenge, and we'll aim to celebrate as many different builders as possible across the month.
- New projects, not pull requests: each submission is a new project built during that challenge's window. Pull requests to existing projects don't count this year.
Joining late? No problem. Every challenge is a fresh start, so someone who finds us in week four competes on the same footing as someone who's been here since day one.
Prizes
Every challenge has its own winners, and we'll share each challenge's prizes when it launches. Here's what's up for grabs in the Weekend Challenge:
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Overall winner: $250, a DEV++ membership, and an exclusive DEV badge.
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Featured partner categories: $200 for each winner.
-
Partner categories: $100 for each winner.
Every winner also gets an exclusive DEV badge, and everyone with a valid submission gets a completion badge.
Free partner credits
Several partners are giving participants credits and promo codes, including Tinker, Render, Backboard, and ElevenLabs. Claim yours at hacktoberfest.com/my/promos.
Challenge Prompt
Our Prompt (all five challenges)
Build something with open-source AI at its core.
That can mean running an open-weight model, building on an open-source agent harness or framework, running inference locally, or all three. Whatever you pick, the open pieces should be what makes your project work.
In your post, tell us why open innovation matters for what you built. Does it run on a laptop with no internet? Keep someone's data off a server they don't control? Let you fine-tune, swap models, or change how your agent behaves? Cost nothing to run? Tell us where your open-based approach worked better than a closed one.
Show your work. We'd love to see how you built it. Save your agent session with DevRelay and embed it in your post, or link to it. It's optional, but it helps the judges understand your process.
Judging Criteria
- Writing Quality (weighted most heavily)
- Relevance to the Prompt and Theme
- Creativity
- Technical Execution
- Use of Partner Technology (optional)
Prize Categories
Featured categories
$200 for each winner
Best Use of Render
Use Render as your project's AI runtime, to host an agent's front end, or to run Hermes or OpenClaw.
Prizes
Best Use of TabPFN
Use TabPFN, Prior Labs' tabular foundation model, to forecast, predict, classify, or spot anomalies from historical data like a CSV. Use it inside an agent tool (with or without the MCP server) or on its own.
Prizes
Best Use of Tinker
Use Thinking Machines' Tinker to fine-tune a model for a specific task, and show a clear improvement in performance, latency, or cost over a baseline.
Prizes
Best Use of Arduino
Build with an Arduino UNO Q: run a model on the board, build a physical agent that senses and acts, or optimize a model for it with Qualcomm AI Hub. Open to anyone building with an UNO Q, whether you got one at an in-person Fest or have your own.
Prizes
Best Use of DigitalOcean
Build or deploy your project on DigitalOcean: host your app or agent, run an open-weight model on a GPU Droplet (1-Click Models make this quick), or build an agent on the Gradient AI Platform.
Prizes
Best Use of Gemma
Use Gemma, Google's open-weight model, in building your project: run it locally, fine-tune it, or serve it through Google Cloud or another provider.
Prizes
Partner categories
$100 for each winner
Best Use of Backboard
Build with R-CLI, Backboard's open-source terminal coding agent, compare open-weight models through a single Backboard API key, or give an open-source project's assistant memory and RAG.
Prizes
Best Use of ElevenLabs
Give an open-source agent a voice, transcribe audio for a local model, or generate narration for your demo.
Prizes
Best Use of Entire
Share the agent sessions behind your project in the write-up, or search past agent work to explain why code exists.
Prizes
Best Use of GitHub Copilot
Build with Copilot's coding agent, the Copilot CLI, or the new Copilot app, automate your project with GitHub Actions, or review contributors' PRs with Copilot.
Prizes
Best Use of Mastra
Orchestrate an agent over open models, add memory and tools to a chat agent, or build a workflow that triages GitHub issues.
Prizes
Best Use of MongoDB Atlas
Use Atlas as your data layer: Atlas Vector Search for retrieval, long-term memory for an agent, or the database behind an app built on an open-weight model.
Prizes
Best Use of Sentry Agent Tracing
Show your agent's work: how it's set up, how it performs (latency, tokens, cost), what you found, and how you debugged it. Include traces or screenshots in your write-up.
Prizes
Best Use of SerpApi
Give an agent live web search, ground a RAG app in fresh results, or track news for an open-source project.
Prizes
Best Use of Temporal
Make your agent durable. Wrap it in a Temporal workflow so it survives failures, retries flaky tool calls, and picks up where it left off.
Prizes
Best Use of Tiger Data
Store embeddings with pgvector, run hybrid keyword and vector search for an agent, or let an agent manage a database through Tiger MCP.
Prizes
Partner categories may change from challenge to challenge as new partners join.
How To Participate
Pick the challenge that's live, then publish a post on DEV using the submission template on that challenge's page. Tell us what you built and who it's for, show us a demo, and explain why open innovation matters for what you built. Each challenge has its own template, tags, and official rules.
Helpful Links & Resources
Need help? Come hang out and ask questions in the MLH Discord, and read Everything You Need To Know About Hacktoberfest 2026.
Partner credits: Several partners are giving participants credits and promo codes, including Tinker, Render, Backboard, and ElevenLabs. Claim yours at hacktoberfest.com/my/promos.
Partner docs:
Frequently Asked Questions
The Five Challenges
Do pull requests count this year?
No. This year's Hacktoberfest is not about open source pull requests. There's no PR count to hit and no repos to hunt for. Instead, you build a brand-new project with open-source AI at its core, and write about it on DEV. Here's everything you need to know about Hacktoberfest 2026.
How do the Hacktoberfest challenges work?
We're running five DEV Challenges back to back through October: a Weekend Challenge to start (October 2 to 5), then a new challenge every Monday (October 5, 12, 19 and 26). Every challenge uses the same prompt, and each one gets its own theme. We reveal each theme the day its challenge launches. See all five on the HF26 DEV Challenge Hub.
What's the prompt?
The same for all five challenges: build something with open-source AI at its core (an open-weight model, an open-source agent harness or framework, local inference, or any mix), and tell us why open innovation matters for what you built.
Can I enter more than one challenge?
Yes, enter as many as you like. You can publish one submission per challenge, so that's up to five in October. Each submission has to be a new project built during that challenge's window.
Can one submission win more than once?
No. Each submission is automatically in the running for the overall prize and every partner category it qualifies for, but you can win once per challenge, and we'll aim to celebrate as many different builders as possible across the month.
I'm joining late. Is it worth it?
Absolutely. Every challenge is a fresh start, so someone who finds us in week four competes on the same footing as someone who's been here since day one.
Prizes and Partner Categories
What can I win?
Every challenge has its own winners, and we'll share each challenge's prizes when it launches. Here's what's up for grabs in the Weekend Challenge:
-
Overall winner: $250, a DEV++ membership, and an exclusive DEV badge.
-
Featured partner categories: $200 for each winner.
-
Partner categories: $100 for each winner.
Every winner also gets an exclusive DEV badge, and everyone with a valid submission gets a completion badge.
How do partner categories work?
You opt in by using the partner's technology in your project and listing each category you're entering in the Prize Categories section of your post. One project can enter as many categories as it genuinely uses. You don't need to use any partner technology to win the overall prize.
Which partner categories are open?
Featured categories ($200):
Partner categories ($100):
Partner categories may change from challenge to challenge as new partners join. Each challenge page lists the categories open for that challenge.
Who can enter Best Use of Arduino?
Anyone building with an Arduino UNO Q, whether you got one at an in-person Fest or have your own.
How do I claim partner credits?
Several partners are giving participants credits and promo codes, including Tinker, Render, Backboard, and ElevenLabs. Claim yours at hacktoberfest.com/my/promos.
Submission
Can I submit a pull request to an existing project?
No. New projects, not pull requests: each submission is a new project built during that challenge's window. Pull requests to existing projects don't count this year.
Can I work on an old project?
No, all submissions and their respective repositories must be started and completed within the challenge window. Commits made after the submission deadline must be noted in the project's readme. Failure to do so may result in disqualification.
Can I work on a team?
Yes, you can work on teams of up to four people.
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If you collaborate with anyone, you'll need to list their DEV handles in your submission post so we can award a badge to your entire team! Please only publish one submission per team.
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DEV does not handle prize-splitting, so in the event that your submission wins, you will need to split the prize amongst yourselves. Thank you for understanding!
Should I include my agent session?
Show your work. We'd love to see how you built it. Save your agent session with DevRelay and embed it in your post, or link to it. It's optional, but it helps the judges understand your process.
Can my submission include open source code?
Riffing on open source code and borrowing and improving on previous work/ideas is encouraged but it's important your changes are significant enough to ensure your submission is valid.
What happens if my submission is considered plagiarized or invalid?
Anything deemed to be plagiarism will not be eligible for prizes. Incidental plagiarism may simply result in your disqualification from the challenge (regardless of the number of other valid submissions you have published). Egregious plagiarism will result in your suspension from DEV entirely. Any non-generic, non-trivial usage of prior work, including open source code must be credited in your submission.
Do submissions have to be in English?
Non-english submissions are eligible for a completion badge but not eligible for prizes due to the current limitations of our judges. We will not be judging on mastery of the English language, so please don't let this deter you from submitting if you are not a native English speaker! We hope to evolve this in the future to be more accommodating.
Can I use AI?
Use of AI is allowed as long as all other rules are followed. We want to give you a chance to show off your skills in realistic scenarios. If you use AI tools to help you achieve your submission, all the power to you.
Eligibility
How old do I have to be to participate?
Participants need to be 18+ in order to participate.
If I live in X, am I eligible to participate?
For eligibility rules, see our official challenge rules.
Judging and Prizing
How are submissions judged?
This is DEV, so your write-up matters most. A great project with a thin write-up won't win. We judge on Writing Quality (weighted most heavily), Relevance to the Prompt and Theme, Creativity, Technical Execution, and, if you're entering a partner category, Use of Partner Technology.
When are winners announced?
Winners are announced the week after each challenge closes. Each challenge's page lists the week under Key Dates.
Can there be ties?
In the event of a tie in scoring between judges, the judges will select the entry that received the highest number of positive reactions on their DEV post to determine the winner.
When will I receive my DEV badge?
Both participation and winner badges will be awarded, in most cases, the same day as the winner announcement.
When will I receive my prizes?
The DEV Team will contact you via the email associated with your DEV profile within, at most, 10 business days of the announcement date to share the details of claiming your prizes.
What steps do I need to take to receive my cash prize?
The winner (including each member of a team) may be required to sign and return an affidavit of eligibility and publicity/liability release, and provide any additional tax filing information (such as a W-9, social security number or Federal tax ID number) within seven (7) business days following the date of your first email notification.
Questions
Where can I ask questions?
Drop them in the comments on the challenge's announcement post, and follow the #hf26challenge tag so you don't miss a theme reveal.
