YC Summer 2025 developer tools companies

• KERNELs25Active

  Crazy fast, open source infra for AI agents to use the Internet

  22 people · San Francisco, CA, USA · Developer Tools, Cloud Computing, Infrastructure, AI · YC page

• AgentMails25Active

  Email Inboxes for AI Agents

  10 people · San Francisco, CA, USA · Developer Tools, API, Email · YC page

• Cactus Computes25Active

  Automation Foundation Models For Tiny Devices

  8 people · San Francisco, CA, USA · Developer Tools, Hard Tech, Open Source, AI · YC page

• Dedalus Labss25Active

  Persistent computers for AI agents

  8 people · San Francisco, CA, USA · Developer Tools, DevOps, Cloud Computing, Infrastructure · YC page

• Interferes25Active

  Give engineering, product, and design teams insight into unseen issues

  8 people · New York City, NY, USA · Developer Tools, Design, AI · YC page

• Luminals25Active

  Making AI run fast on any hardware.

  7 people · San Francisco, CA, USA · AIOps, Developer Tools, Cloud Computing, AI · YC page

• Embedders25Active

  Hardware-Aware AI for Embedded Software

  6 people · San Francisco, CA, USA · Developer Tools, Hardware, AI · YC page

• Autosanas25ActiveOn DevHunt

  AI agents for E2E testing across mobile & web

  5 people · San Francisco, CA, USA · Developer Tools, Enterprise Software, AI · YC page

• Larks25Active

  The E2E testing layer for AI-driven development

  5 people · San Francisco, CA, USA · Developer Tools, DevOps, Automation, AI · YC page

• Manufacts25Active

  Cloud infrastructure for MCP servers and Claude / ChatGPT plugins.

  5 people · ZH, Switzerland · Developer Tools, Open Source, Infrastructure, AI · YC page

• Nottes25Active

  Browser infra for AI agents: sessions, auth, proxies, payments

  5 people · San Francisco, CA, USA · Developer Tools, API, Automation, AI · YC page

• Floots25Active

  The app platform inside Claude and ChatGPT.

  4 people · San Francisco, CA, USA · No-code, Web Development, AI · YC page

• Omnaras25ActiveOn DevHunt

  The Open-Source Alternative to Claude Managed Agents

  4 people · San Francisco, CA, USA · Developer Tools, AI, AI Assistant · YC page

• TraceRoot.AIs25Active

  Open Source AI Agent Improvement Platform

  4 people · San Francisco, CA, USA · Developer Tools, Open Source, Infrastructure, AI · YC page

• Modelences25ActiveOn DevHunt

  Production infrastructure on autopilot

  3 people · San Francisco, CA, USA · Developer Tools, Open Source, Infrastructure · YC page

• Montes25Active

  Continual Learning for Agents

  3 people · San Francisco, CA, USA · Reinforcement Learning, Infrastructure, AI · YC page

• Nozomios25Active

  product lab. focused on personal ai and context.

  3 people · San Francisco, CA, USA · Developer Tools, Consumer, AI · YC page

• Pangolins25Active

  Open networking and security for your workforce, AI agents, and infra

  3 people · New York City, NY, USA · Security, Open Source, Enterprise Software, Networks · YC page

• stagewises25Active

  The makers of Klex Bots, your own team of digital coworkers.

  3 people · Developer Tools, Open Source, AI · YC page

• VibeFlows25Active

  AI content manager that grows your company's online presence

  3 people · San Francisco, CA, USA · Developer Tools, Consumer, AI · YC page

• Alters25Active

  Privileged Access Management for AI Agents

  2 people · New York City, NY, USA · AIOps, Developer Tools, DevSecOps, Security · YC page

• argss25Active

  A better GItHub

  2 people · New York City, NY, USA · Developer Tools · YC page

• Cyberdesks25Active

  Self learning computer use agent for developers

  2 people · San Francisco, CA, USA · Developer Tools, Robotic Process Automation, Workflow Automation, Enterprise Software · YC page

• LLM Statss25Active

  Independent AI evaluations lab

  2 people · New York City, NY, USA · Infrastructure, AI · YC page

• Lotass25Active

  AI for quantitative trading

  2 people · San Francisco, CA, USA · Developer Tools, Data Science, Data Visualization, AI · YC page

• Magnitudes25Active

  Run open models as fast as your hardware allows

  2 people · San Francisco, CA, USA · Developer Tools, Open Source, Infrastructure, AI · YC page

• Okibis25Active

  Turns products into CLIs and agents into customers

  2 people · San Francisco, CA, USA · Developer Tools, AI · YC page

• Proliferates25Active

  Do your life's work with agents

  San Francisco, CA, USA · Developer Tools, AI · YC page

← Fall 2025Spring 2025 →All YC dev-tool companiesOpen-source YC companies

Source: Y Combinator's public company directory via the unofficial mirror yc-oss/api. DevHunt is not affiliated with Y Combinator.