Y Combinator Summer 2026 (S26) Companies

Shielded combines a company's internal datasets with external information sources to map how external prices and events affect margins and cash flow, continuously tracking supply chain and financial risks. The platform automatically quantifies risks and opportunities, flags pricing discrepancies, contract deviations, and billing errors, and sends proactive alerts about market events, supplier issues, tariffs, and regulations.

2 investors

Shiraz builds a robot foundation model that learns a new manufacturing task from a single human video demonstration, without programming or retraining, and delivers the full stack of hardware, model, and on-site deployment. It targets high-mix manufacturers whose production lines change frequently.

1 investor

Sidekick is a mobile-first work order and knowledge management platform that helps workers report maintenance issues via SMS text, automatically routes them to the right technician, and captures repair knowledge into a searchable digital archive. The system serves manufacturing and facility operations teams by eliminating app dependencies, automating triage, and preserving institutional know-how when experienced workers retire.

2 investors

Skymerse provides an automated flight operations decision platform for airlines that checks every flight against live NOTAMs, weather, runway constraints, and aircraft limits to generate flight-ready operational decisions. The company also operates Notamify, a product that transforms NOTAM data into briefings and operational signals for airline crews and dispatchers.

1 investor

Spaceflow deploys and operates an on-premise enterprise AI stack—open frontier models, a governance gateway, and AI agents—that learns a company's existing systems and automates procurement and supply chain work such as reading supplier emails, comparing quotes, matching invoices to purchase orders, and routing approvals. It targets enterprises with air-gapped or regulated environments, including manufacturers, banks, and defence organizations.

2 investors

Spectre Intelligence is building an AI-driven quantitative trading firm structured as a multi-strategy ("pod shop") hedge fund, where AI agents run and evolve trading strategies while the company deploys its own capital and learns from each trade. It currently operates pods focused on semiconductors and biotech.

2 investors

Speko provides a unified API gateway for voice AI that benchmarks and routes speech-to-text, language models, and text-to-speech providers to the optimal stack for each call across 10+ languages. Developers can describe voice agents in plain English, test them in a browser, and deploy to phone numbers, web widgets, or APIs without managing multiple provider credentials.

2 investors

Standard Machines is building reinforcement learning environments for long-horizon chip design tasks. Its first product targets the semiconductor design workflow using RL-based methods.

3 investors

Standard Medical is a primary care clinic that uses AI under physician supervision, with a licensed physician making every clinical decision while AI gradually takes on clinical tasks. It aims to lower costs and expand access to care, and plans to see its first patients in Utah in 2026.

1 investor

Stoa operates a marketplace for buying and selling GPUs, offering price discovery, RFQ-to-settlement workflows, and verified counterparties. It serves GPU brokers, data center operators, AI labs, cloud providers, OEMs, resellers, and lenders trading AI hardware.

3 investors

Studio builds simulated "societies" that model consumer cohorts of a market and runs a company's proposed decisions—such as price changes, product placements, or promotions—through them to forecast outcomes before launch. It serves insight and marketing teams at enterprises in sectors like retail, streaming, banking, and consumer goods, drawing on public data and a client's own sales, loyalty, and app data.

3 investors

SubVysion creates high-precision 3D mapping technology that reveals the locations of subsurface utilities, enabling construction teams to identify and navigate around buried infrastructure during excavation work.

1 investor

Sunflower Sober operates a digital community and support group for people pursuing sobriety, enabling peer connection and shared recovery journeys.

5 investors

Synapse Semiconductor is a semiconductor research lab building image sensors that run neural-network computation directly on the sensor, integrating light capture and AI processing in each pixel to replace GPU-based edge vision. Its chips target computer vision applications in self-driving cars, drones, humanoid robotics, and space systems.

3 investors

TareBio operates a platform for developing personalized and population-level vaccines against cancer and infectious diseases by analyzing immune cells already responding to a disease and reverse-engineering the antigens that activate them. The company works in the biotechnology and vaccine development space.

1 investor

TariffLo uses AI to audit importers' customs entries — reviewing entry packets, HTS codes, and ACE reports to find classification, rate, and origin errors — and works with a third-party broker to file Post Summary Corrections and recover overpaid U.S. tariffs. It serves importers on a contingency basis, charging only after refunds are recovered from Customs and Border Protection.

2 investors

tash is an investment platform that lets users buy and sell shares in professionally selected indexes of graded trading cards held inside registered investment vehicles with vaulted custody. It functions as a brokerage-style exchange for the trading card asset class, allowing investors to trade positions without shipping physical cards.

1 investor

Tenor builds managed AI "workers" that own defined jobs across a company — each with a role, manager, permissions, tools, and configurable workflows — so users describe an outcome in plain language and the worker builds and executes the workflow. It also ties AI spend, completed work, and human interventions to business outcomes so leaders can measure ROI on AI worker use.

3 investors

Tensor operates fully autonomous factories that manufacture custom designs on-demand, 24/7, targeting unit-level production economics. The company serves manufacturers and businesses requiring rapid prototyping or short-run production.

1 investor

Torus is an AI system that analyzes engineering documents such as P&IDs, datasheets, and specifications to identify cross-document inconsistencies and automate engineering workflows. The platform serves engineering firms and project teams managing capital-intensive infrastructure projects like substations, pipelines, and treatment plants.

3 investors

Touchmark operates a live order book for reserved AI inference capacity, letting buyers commit forward to blocks of tokens on named models at posted discounted prices while providers sell capacity ahead to lock in revenue against GPU buildouts. It also publishes a price index for model capacity and plans additional AI-contract markets such as quality-priced and benchmark-settled contracts.

3 investors

Touchy is developing a consumer AI personal assistant designed to perceive a user's physical and digital context and act through their apps, returning minimal information while filtering large amounts of data. The company focuses on agent harnesses, AI alignment, on-device models, and continual learning to build a non-addictive alternative to current AI assistants.

1 investor

Toven provides AI agents that automate compliance work for institutional brokerages, performing a first-pass review of communications, surveillance alerts, and research reports and auto-clearing false positives while escalating cases that need human judgment. Its tools integrate with a firm's existing chat, voice, surveillance, and archiving systems and produce documented, cited audit trails for regulators.

1 investor

Traceforce is an on-device security platform that monitors and controls AI applications, desktop apps, CLI agents, and MCP (Model Context Protocol) connectors across an organization's device fleet, tracking tool calls and blocking dangerous actions in real time. It offers device inventory, incident intelligence, automated remediation, and integrates with MDM tools like Jamf, JumpCloud, and NinjaOne for enterprise IT teams.

3 investors