Y Combinator Summer 2026 (S26) Companies

Osseus builds a permissioned research brain that connects tools and data across R&D teams to surface past experiments, expert knowledge, and next actions. The platform serves technical and research teams in biotech, manufacturing, and similar knowledge-intensive industries by maintaining continuous memory of how work evolved and preventing repeated efforts.

1 investor

Palette Technology provides AI-powered native image and video generation tools for creative teams, enabling them to produce audience-ready content across formats (video, visuals, structured content) from a single source material without rebuilding assets for each output.

1 investor

Pango is an AI-powered operating system for e-commerce logistics that unifies shipping, tracking, returns, and post-purchase operations in a single platform. It automates operational workflows so e-commerce teams can make logistics decisions faster and scale across markets without proportional increases in complexity.

3 investors

Parasma develops algorithms and infrastructure to train living neural systems for computation, aiming to make advanced AI far more energy-efficient and accessible by leveraging biological neurons as programmable compute. The company serves organizations seeking to reduce the energy footprint and hardware costs of AI systems.

1 investor

Notyfi is a monitoring and notification service that tracks user-specified topics across news, filings, databases, and websites, delivering alerts via email, dashboard, or direct API integration into workflows and AI agents.

1 investor

Petrarch operates a marketplace that connects buyers and sellers of specialized datasets and proprietary information.

1 investor

Pluto is an AI voice agent that captures professional information through a 10-minute conversation and makes users discoverable to recruiters and AI agents. It helps professionals build a career profile they control and provides warm introductions to relevant job opportunities.

1 investor

PokerClubHub is a licensed online poker platform that lets individuals open and run their own poker clubs, handling all player deposits, withdrawals, and payments on the club owner's behalf and paying owners affiliate fees on rake. It serves poker club operators and players seeking a regulated alternative to unlicensed private clubs, with deposits secured through Fireblocks.

1 investor

Poth Labs builds an AI-powered survey platform that uses adaptive questioning and knowledge graphs to convert employee feedback, customer surveys, and market research into statistically validated insights. The platform serves organizations seeking deeper understanding from survey data through automated analysis that replaces manual interpretation.

1 investor

Praxis AI collects egocentric video, 3D scans, and multimodal sensor data from industrial and residential work environments through partnerships with large corporations, then sells this real-world training data to AI companies developing physical robotics and other systems.

1 investor

Prescience is a financial technology platform providing health benefits administration, care navigation, and HSA management services for employers and their members.

1 investor

Prized is a low-code platform that enables non-engineers to build internal tools by describing them in plain language; the platform connects to existing enterprise systems with admin-approved connectors and maintains role-based access control and audit logging.

1 investor

Proprio Robotics develops robots that perform physical maintenance tasks inside data centers, such as fan insertion, cable switching, RAM extraction, GPU cabling, disk hot-swapping, and heatsink removal. The company aims to enable autonomous data center operations.

1 investor

ProvenMetal manufactures printed circuit boards with fast seven-day turnaround and 100% X-ray inspection coverage. The company serves hardware manufacturers requiring rapid prototyping and assembly with domestic US-based production.

1 investor

Rapidfolio automates manual processes for the financial industry using AI. The company was founded by the team behind Sable, a fintech that provided credit products to underbanked Americans.

1 investor

Rasyn.ai offers Marigold, an AI research assistant that lets scientists ask research questions, run tools, or delegate entire tasks, returning results such as structures, charts, code, and papers in panels. It provides 54 runnable tools, 40 executing on connected hardware and 14 on hosted endpoints.

1 investor

Rational provides AI agents that automate recurring accounts payable, close coordination, reconciliation, and document management tasks for finance teams, while keeping approvals and final decisions with human staff.

1 investor

RealPact provides voice-powered AI agents for real estate brokerages that automatically retrieve deed, property, and tax records, draft contracts, and move transactions from hours to minutes. The platform functions as an AI-native operating system handling operational work in real estate deals.

1 investor

Rekursiv.ai builds autonomous AI research teams that conduct experiments and generate scientific discoveries without human direction. The company's systems have demonstrated cost reductions in specific benchmarks while advancing solutions for combinatorial optimization problems.

1 investor

Rex is an agentic finance platform that connects to existing enterprise financial systems and automates manual operational finance work like collections, reconciliation, and portal uploads using AI agents. The product is designed for finance teams at scaled technology companies seeking to delegate repetitive tasks while maintaining governance and audit compliance.

1 investor

Riften provides a routing layer that sits between a company's applications and large language model APIs, directing each request to the least expensive capable model and using self-hosted open-weight models where possible to reduce inference costs. It also uses the resulting task data to train private, company-owned models on recurring work, serving businesses that run AI-powered applications.

1 investor

Rindler provides a platform that enables AI agents to reliably navigate and interact with any website, offering infrastructure for deterministic web access. The platform serves developers and organizations building AI agents that need to automate work across web-based systems.

1 investor

Rise Reforming converts stranded biogas from wastewater plants, farms, and landfills into valuable chemicals including dimethyl ether (DME), methanol, and dimethyl carbonate (DMC) using modular, containerized technology. The company serves the chemical industry, offering a low-carbon alternative to fossil fuel-dependent chemical production with domestic feedstock security.

2 investors

Risklytics simulates natural disaster risks (wildfire, flood, wind, earthquake, debris flow) on individual residential properties using digital twins built from building data and satellite imagery. The platform provides risk scores, modeled annual losses, and retrofit recommendations for homeowners.

1 investor