Y Combinator Summer 2026 (S26) Companies

Robocurve develops open-source tools and benchmarks for evaluating the real-world capabilities of AI systems and robots. The company serves robotics labs and the broader public by providing independent, rigorous evaluation frameworks to assess progress in physical AI and general-purpose robotics.

1 investor

RonanRx offers personalized GLP-1 weight-management care delivered via text, where a licensed physician reviews a patient's history to set an individualized dose, titration schedule, and patient-specific adjunct, and a licensed pharmacist at the patient's selected pharmacy verifies and releases compounded, patient-specific prescriptions. It serves individual patients in the US (availability varies by state) and plans to add hormone therapy (HRT).

1 investor

Salem Robotics develops autonomy software for robotic radiological surveys and inspections in nuclear and hazardous environments. The platform automates route planning, radiation measurement collection, and compliance reporting on existing robot hardware to reduce worker exposure and improve data consistency.

1 investor

Screenpipe is a local-first context layer that captures screen activity for enterprise AI agents, enabling them to act on real user behavior. The platform serves enterprise organizations building or deploying AI agents.

1 investor

Shepherd is an AI assistant that integrates with a team's existing tools (messaging, code editors, CRM platforms) to create a unified memory system. It automatically captures messages, calls, and commits, allowing teams and AI agents to query and act on company information without manual tagging.

1 investor

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.

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.

1 investor

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.

1 investor

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.

1 investor

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.

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.

1 investor

Stratum is an AI platform that reads government application filings, checks them against agencies' existing review rubrics, and routes each step to the model that reviews it most accurately, clearing adjudication backlogs while a human officer still makes the final decision. It targets US government agencies handling filings such as patents, FDA registrations, SEC filings, building permits, passports, and veterans' benefits.

1 investor

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

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.

1 investor

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

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

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.

1 investor

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

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.

1 investor

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.

1 investor

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.

1 investor

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.

1 investor

TrustAI provides workflow automation software that captures and distributes organizational knowledge and instincts through AI-driven suggestions, with transparency and human oversight. The platform enables teams to automate repetitive tasks while preserving judgment and expertise across the organization.

1 investor