YC Fall 2026 x Moss: The Zero Latency Builder Sprint

Overview

The YC Fall 2026 x Moss: The Zero Latency Builder Sprint is a hackathon that challenges participants to create innovative AI applications. The core requirement is to leverage Moss, a technology capable of sub-10ms semantic search without a traditional vector database, to achieve low-latency performance in AI agents. Participants are encouraged to draw inspiration from Y Combinator's Fall 2026 Requests for Startups, focusing on problems where speed and responsiveness are critical. The sprint aims to foster the development of next-generation AI applications by emphasizing the competitive advantage that low latency can provide. Moss, developed by YC F25, allows AI agents to access necessary context rapidly, supporting various environments including browser, edge, on-device, and cloud. This enables the creation of highly responsive AI solutions for a range of use cases. The hackathon is open to individuals who are of legal age of majority in their country of residence, with standard country/territory exceptions. A total of ₹50,000 in cash prizes will be awarded across five placements.

What to build

Build a functional AI application inspired by one of YC's Fall 2026 Requests for Startups challenge themes. The project should demonstrate how fast retrieval with Moss improves the application's performance, responsiveness, or user experience, and must meaningfully use Moss in the retrieval layer. Specific themes include: 1. Real-Time Voice & Conversational AI: Build voice agents for various sectors. 2. Multiplayer AI & Collaborative Agents: Create AI-powered workspaces for human-agent collaboration. 3. Local-First AI & The Small Cloud: Develop privacy-first browser copilots, developer utilities, or edge AI applications. 4. Agent Reliability, Security & Evaluation: Build systems for trustworthy AI agents through guardrails, evaluation, and context validation.

Prizes

Key dates

• Hackathon StartSeptember 20, 2026 at 2:30pm EDT
• Submission DeadlineSeptember 20, 2026 at 11:59 PM IST
• DeadlineSeptember 21, 2026 @ 12:00am IST

How to enter

1. Read the complete hackathon details and understand the challenge.
2. Register on the HiDevs platform.
3. Join the official WhatsApp community for announcements and updates.
4. Explore the Moss documentation and starter resources.
5. Build, test, and submit your AI application before the deadline.

Submission requirements

• Build a functional AI application inspired by one of the challenge themes.
• The project should demonstrate how fast retrieval with Moss improves the application's performance, responsiveness, or user experience.
• The solution should be functional and demonstrate meaningful use of Moss in the retrieval layer.
• Every submission must include: Architecture Diagram, PRD (Product Requirements Document), GitHub Repository, Deployed Link of the Agent, Video Demo.
• The video demo should clearly demonstrate the working product and explain how Moss contributes to the solution.

Judging criteria

• Product and User Experience: Does the product solve a real problem and is the experience compelling?
• Technical Execution: How well does the architecture and AI pipeline work?
• Speed and Latency: Did you use Moss effectively to build a fast and responsive experience?
• Demo and Presentation: Can you clearly show what you built and why it matters?