Y Combinator Summer 2026 (S26) Companies

Tracer is a research lab building Echo, an inference system that coordinates open-weight models behind a single OpenAI-compatible endpoint for chat, code, and agent workloads. It focuses on allocating computation and coordinating complementary models to improve performance per token for teams running AI in production.

2 investors

Trident is an AI-assisted security platform for continuous web and API penetration testing and cloud attack-path analysis, connecting cloud assets, identities, data stores, and application findings to prioritize risks. It serves security teams and integrates with cloud, identity, data, and developer platforms such as AWS, Azure, Google Cloud, Kubernetes, Snowflake, Okta, and GitHub.

2 investors

Trope is an AI-native platform that automates ERP implementation tasks including data migration, requirements documentation, configuration scanning, and change management for enterprise consulting partners. The platform helps ERP implementation teams reduce delivery risks and ensure successful project outcomes.

2 investors

TryNearby is a subscription platform that pairs local restaurants with nearby content creators who visit, film, and post reviews to social platforms like TikTok and Instagram, using AI agents to handle matching, booking, and creator communication. It serves local businesses in Southern California seeking to build a steady stream of social content and improve their discoverability.

2 investors

Tsenta automates job applications by monitoring 50,000+ career pages across major applicant tracking systems and submitting tailored, ATS-optimized applications within minutes of job postings. The platform serves active job seekers seeking to increase application volume and speed while maintaining quality application materials.

1 investor

Ultrasonium is a company focused on materials science and advanced manufacturing, developing engineering systems.

1 investor

Vendo offers an open-source customization layer that lets a software product's end users build their own features and micro-apps on top of it, describing what they need so the interface assembles live components, actions, and automations. It reads a product's repository to learn its components, API, and permission rules, running sandboxed within existing user permissions, and offers a paid cloud tier for multiplayer collaboration, publishing, and governance.

3 investors

Verdant is a software platform that manages the full planning and permitting workflow for local government agencies, from resident inquiries through final commission votes. It provides configurable modules for intake, plan review, and code research tailored to individual municipal ordinances and workflows.

1 investor

Verdict Machine builds an AI-based cybersecurity platform that maps a financial institution's on-chain environment, evaluates proposed transactions against its policies before execution, and provides cyber risk assessment, wallet screening, and security posture monitoring. It serves banks, asset managers, and digital-asset infrastructure providers.

3 investors

Vernius makes drop-in hardware modules that add autonomous or operator-assisted targeting to existing FPV interceptor drones. The module sits between the drone's receiver and flight controller to provide beyond-visual-range sensing, autonomous guidance, or target bearing data for manual pilots, aimed at low-cost, high-volume defense deployment.

1 investor

Vestris is an AI platform that automates mortgage title and closing operations, handling tasks such as contract parsing, title abstract generation, tax prorating, and title commitment issuance for title companies and lenders. It uses browser agents to access county records and coordinate with all parties involved in the closing process.

1 investor

Waddle Labs provides an API that connects to robots and, from a natural-language prompt, uses AI agents to generate a control policy for the robot to carry out the requested task. The product targets robotics developers and operators.

3 investors

Waybill provides an automated procurement service for hardware teams, handling sourcing, supplier negotiation, freight, customs clearance, delivery, and inventory tracking from a single approved payment. It consolidates orders, manages chain of custody, and integrates with tools like Slack for requests and approvals.

2 investors

Whitespace provides AI agents that analyze business data to forecast demand, recommend inventory order quantities, and automate inventory management processes for wholesale distributors and manufacturers.

3 investors

Wondering is a mobile learning app that breaks down topics such as machine learning, quantum mechanics, and product design into short lessons combining visuals, podcasts, and interactive exercises. Its learning paths are tailored to each user's background, learning style, and desired depth.

2 investors

WonderTx is an AI-native biotech that develops extrapolative AI models to discover oral drug molecules for targets with validated human biology that currently lack a viable pill-based treatment. The company aims to convert injectable therapies into pills and works on both its own and partner drug discovery programs.

3 investors

Zaplar is an autonomous operations platform for hotels that unifies rooms, events, spa, F&B, guest messaging, booking, and point-of-sale into one system. It automates routine work while letting staff review and approve suggested actions, aiming to reduce administration and capture more upsell for hoteliers.

2 investors

Zomma Labs builds AI agents that automate repetitive work and system operations, enabling teams to focus on higher-value tasks. The platform is designed for enterprise organizations seeking to augment their workforce capabilities rather than replace workers.

2 investors