Y Combinator Fall 2026 (F26) Companies

Acyclic Labs runs agent swarms that break a task into parallel work across many sandboxed agents and merge their outputs into a single result, cutting the wall-clock time of long agentic workflows. Accessible via CLI, dashboard, or coding agents over MCP, it supports user-supplied model keys and self-hosted sandboxes atop an open-source harness, serving coding, research, and data workloads.

1 investor

Agent 37 provides persistent, pre-configured sandboxes for running AI agents such as Claude Code and Hermes, retaining files, code, and settings between sessions. It offers usage-based compute billing, single-command backend setup, and connections to tools like Slack, Gmail, and GitHub for developers deploying autonomous agents.

1 investor

Agent Relay provides infrastructure for software teams to coordinate coding agents such as Claude Code, Codex, OpenCode, and custom agents, offering shared messaging, session history, and integrations with tools like GitHub, Linear, and Slack. It lets teams monitor agent activity, run resumable workflows, and intervene manually, with deployment options in the cloud, locally, or on their own hardware.

2 investors

Ageospatial provides an AI service that analyzes satellite and street-level imagery, maps, public records, and insurers' own data to assess property risk remotely without physical inspections. It serves insurance carriers and MGAs, supporting their underwriting, claims, and pricing teams.

1 investor

Antimattr is building voice-first interfaces focused on memory and voice productivity, positioned as an ecosystem of products for natural human-machine interaction. Its first product, Project Mnemosyne, is scheduled to begin shipping in Q4 2026.

1 investor

Antropi Robotics develops autonomous CNC factories that automate machining processes to accelerate hardware production. The company operates in the industrial robotics and manufacturing automation sector.

1 investor

Applied Kinetics develops AI agents that manage supplier coordination for energy and data center construction projects, tracking equipment approvals, delivery dates, and delays. It serves project teams building out energy and data center infrastructure.

1 investor

Archangel Health provides infrastructure to post-train and evaluate medical AI, including reinforcement learning environments built inside de-identified electronic health records, physician-verified training data, and benchmarks for clinical reasoning. It serves frontier AI labs, medical AI companies, and health systems looking to post-train open-source models on their own data.

1 investor

Asakana uses AI to convert restaurant orders sent by email, text, and photo into entries in a food distributor's ERP system, flagging unclear items for human review. It serves food distributors, currently seafood distributors in the US, as an order-entry automation tool.

1 investor

Ascenix provides software for long-term care and nursing facilities that captures, classifies and tracks resident incidents such as falls, pressure injuries, hydration shortfalls and behavioral events across units. The system consolidates documented triggers, repositioning and wound assessments to support care teams in monitoring resident safety.

1 investor

Asim develops technology that helps robots operate safely in real-world environments, serving companies building and deploying robotic systems.

1 investor

Aviern develops fixed-wing unmanned aircraft that launch, fly, and land autonomously from unattended docks to inspect infrastructure corridors, using onboard perception to detect leaks, encroachments, and vegetation risk. Sold as a per-mile service starting with regulated pipeline patrol, it serves operators of pipelines, power grids, rail, borders, and military bases in the geospatial intelligence and infrastructure monitoring sector.

1 investor

Ascii offers preconfigured Ubuntu cloud virtual machines, called boxes, that come with a desktop, browser, common programming languages, Docker, snapshots, and management tools via CLI, SDK, and API. The service is aimed at running AI agents at scale for tasks such as coding and knowledge work including legal, research, reporting, and auditing.

1 investor

boxes.dev provides each AI coding agent its own cloud Linux machine ("devbox") preloaded with the developer's dev environment, letting agents run native Claude Code or Codex and be controlled from desktop, mobile, terminal, Slack, or Linear. It targets individual developers and engineering teams who want to run multiple cloud coding agents in parallel.

1 investor

Bryel builds an AI agent that automates AI research engineering tasks for researchers and engineers.

1 investor

Buildbox is a platform that detects failed user journeys in AI agents that pass their evals but still fail to help users complete tasks, ranking these failures by business impact. It ties agent failures to outcomes and tests alternative agent behaviors against the same customer task before release.

3 investors

ByteAsk provides an AI coding agent for C and C++ that builds, debugs, and tests each code change with the actual toolchain to verify it works. It runs from the terminal or within editors like VS Code, Neovim, and Emacs, offers an on-premises option, and targets developers working on systems such as trading platforms, automotive software, chips, and operating systems.

1 investor

Capveon is an AI platform that reads public-record sources — federal, state, and local budgets, board minutes, capital plans, and portals like SAM.gov, USAspending, and Grants.gov — to surface public-infrastructure work before an RFP posts. It serves government contractors and manufacturers, carrying pursuits from early demand signals through bid/no-bid qualification, competitor analysis, price-to-win, compliance review, and proposal drafting.

1 investor

Clean is a sales intelligence tool that identifies prospective buyers by analyzing dated records of company activity—such as loans, permits, customs shipments, and contract awards—and reasoning across them to explain why a company is worth reaching. It ranks companies against a user's ICP, names who to contact, and integrates read-only with tools like LinkedIn, Gmail, HubSpot, Granola, and Attio for sales teams.

1 investor

Collar is an AI agent for investment deal teams that automates the deal funnel — sourcing deals against a firm's thesis, ingesting datarooms, running due diligence, sending chaser emails, and drafting financial models, IC reports, and memos while leaving the final investment decision to the user. It serves individual investors, private market firms, and asset managers, running inside the firm's own cloud on SOC 2 Type II and ISO 27001 certified infrastructure.

1 investor

Composal runs swarms of AI agents that interact with a product the way real users would, testing actual flows and edge cases to surface bugs and gaps before a release. It is a software testing tool for product and engineering teams evaluating whether features are ready to ship.

1 investor

CONUS is an AI knowledge layer for medical devices that connects manufacturers with hospitals, bringing together product information, hospital protocols, and medical research so doctors and sales reps can quickly find answers on surgical systems and implants. It serves hospitals and medical device manufacturers, with deployments across European hospitals.

1 investor

Covera builds ready-to-use AI agents for insurance brokers and captive agents that automate policy servicing tasks such as document intake, quoting across carrier portals, coverage comparison, claims handling, and collections. The agents integrate with agency management systems, CRMs, email, and storage, while keeping binding, pricing, and advice under human review.

1 investor

Cyclon is developing a smartphone that uses AI as its primary interface, letting users speak requests instead of navigating apps and screens, and launch AI agents to control the device or run tasks in the background.

2 investors