Open-Source AI Prize Challenge

Every Hacktoberfest Hack Day runs this challenge. MLH adds it to your OrganizerHQ event automatically. Include it in your project prompts, submission instructions, opening slides, and winner-selection plan.

Best Open-Source AI Project

Build an original project that uses open-source or open-weight AI as an important part of how it works. Teams could create an agent skill, build with an open-weight large or small language model, or build or adapt an open-source model harness. These are examples within one challenge, and teams may combine them.

Requirements

• Open-source or open-weight AI must be an important part of the project.
• The project must be published in a public GitHub repository and use an open-source license.
• An agent skill must comply with the Agent Skill Open Standard.
• A model-harness entry must include an original implementation or meaningful changes to an existing open-source harness.

What These Terms Mean

• Open source: the project's source code is public and carries a license that allows others to use, modify, and share it. Common choices include MIT, Apache-2.0, and GPL-3.0. The OSI license list includes more options.
• Open-weight model: the trained model weights are available to download or run under the model provider's terms. Open-weight does not automatically mean that every part of a model is open source, so teams should name the model and link its license or terms in the README.
• Small and large language models: for this challenge, a small language model has 10 billion parameters or fewer, while a large language model has more than 10 billion parameters. Google's Gemma model overview includes examples on both sides of that boundary.
• Agent skill: a reusable set of instructions and supporting files that follows the Agent Skills open standard.
• Model harness: the software around a model that manages prompts, tools, memory, context, and actions. Teams may build one from scratch or make meaningful improvements to an existing open-source project such as OpenCode, Hermes Agent, OpenClaw, or Pi.

What a Strong Entry Looks Like

A strong project:

• Uses open-source or open-weight AI as an important part of how the project works
• Solves a clear problem or creates a useful experience
• Shows substantial technical work completed by the team
• Makes its source, license, model, and key dependencies easy to verify
• Has a working demonstration and a clear explanation of what the team built

Use this guidance alongside Project Submissions and Winner Selection. Ask teams to show the relevant code and explain the contribution of the AI technology in plain language.

Prize

The challenge has one winning team. Every member receives a DEV Badge on their DEV account. Depending on availability and your event's onboarding instructions, MLH may also provide MLH+DEV branded swag bags for the winning team. These may include a branded bag, notebook, and other items.

Hack Days Partner Prize Categories

Hack Days partner prize categories are separate from the Best Open-Source AI Project challenge. They may be assigned to selected Hacktoberfest Hack Day events by the MLH Hacktoberfest team. You may indicate a preference when applying, but an assigned category appears automatically in OrganizerHQ. See the partner challenge details.