Developer Tools Startups funded by Y Combinator (YC) in New York 2026

Make AI phone calls from a single API call.

Alter is a zero-trust identity and access control platform purpose-built for AI agents. It wraps every tool call in strong authentication, fine-grained authorization, and real-time guardrails, so agents can move fast without breaking things. Each request is verified at the parameter level, authorized against granular policies, executed with least-privilege access, and fully audited in real time. Unsafe actions, whether it’s a rogue DROP TABLE or a payment above policy limits, are blocked before they touch production. Behind the scenes, Alter manages credentials, issuing ephemeral, scope-narrowed access for every interaction, then rotating or expiring it in seconds. The result: no long-lived secrets, no blind spots, and no surprises in audit. With Alter, teams can move fast on AI agent initiatives while staying fully compliant with SOC 2, HIPAA, GDPR, and internal security standards. A CISO-ready dashboard delivers real-time visibility, detailed audit logs, and compliance-ready controls, removing silos, eliminating excessive permissions, and providing complete oversight of every agent workflow.

Interfere is the experience layer for modern product teams. Detect, triage, and fix bugs automatically – no human required. Interfere finds issues in your app, understands what's happening, and owns resolution from first signal to production.

ParaQuery is a fully-managed GPU-accelerated Spark solution providing double the performance at half the cost compared to solutions like Databricks and BigQuery. It is fully Spark-compatible, cloud agnostic, and has seamless integrations everywhere, all without vendor lock-in. ParaQuery makes it trivial to run large SQL and Spark workloads efficiently and serverlessly, without any data migrations.

What Corsair is: Corsair gives you (or your agent) safe access to hundreds of integrations. It natively handles all integration plumbing. The only code you write is the code that's specific to your use case. Your data stays yours. Why we wrote it: Integrations make products capable. Integrations are also frustrating to write. If you look at any codebase with integrations, 95% of the code is identical. It's all just basic plumbing. The part of the integration that is unique to a codebase and actually adds value is probably just a few lines. We shouldn't waste time writing and maintaining the 95% for a few lines. The developer community has just accepted that we do. Corsair handles the 95% so you don't have to. It's really hard to get wrong.

BrowserBook makes it easy to reliably automate the web. It's a Jupyter-style IDE for browser automation that combines a live browser, executable code cells, and an AI coding assistant to generate Playwright scripts that are deterministic by default. Developers use BrowserBook to build, debug, and deploy robust web automations, powering AI agents, QA workflows, and data operations.

Ryvn provides the devtools and infrastructure to easily deploy any workload, on any cloud, and on-prem. Run apps in your own cloud and offer Bring Your Own Cloud (BYOC) to your customers in minutes, with built-in observability designed for sensitive industries.

Haystack helps teams review and merge more code without lowering quality. As AI-generated pull requests become more common, code review shifts from reading every line to deciding what actually deserves human attention. Haystack uses full codebase context and agent traces to recover author intent, verify changes, and route only the risky or ambiguous work to reviewers. Teams use it to keep standards high while moving faster through a growing volume of changes.

Hatchet abstracts away the infrastructure for managing task queues and message brokers, so you can focus on writing your background task and workflow logic. With Hatchet, you can run slow OpenAI requests in the background with async tasks, chain complex tasks together into workflows, and set retries and timeouts to recover from failure.

renderlet is a framework that makes it easy to develop interactive applications. Building applications with high-performance graphics is very hard – existing tools are cumbersome and aren’t truly platform agnostic, leading to frequent rework. With renderlet, developers can write high-level code to describe 2D and 3D graphics without having to use low-level, platform-specific APIs. renderlet automatically compiles graphics code to WebAssembly and embeds a portable rendering engine inside any app, enabling graphics to safely and automatically render on any platform’s GPU. Our runtime is open-source: https://github.com/renderlet/wander

Agentic Labs is making software design and architecture less painful by building AI into the process. Today, developers have no shortage of tools for instantly creating chunks of code, but designing the systems that integrate this code is the hardest and most manual part of software engineering. Our first product is Glide, an AI-first editor purpose-built for writing technical design docs. It connects to your codebase and saves your engineering team time on triage, planning, and implementation of complex code changes.

Identifying performance bottlenecks and strategizing ways to solve them takes 4-8x longer than actually writing the code to fix them. We're building an agent that is an expert at analyzing the performance GPU systems like inference engines at all levels of the stack - from CPU-GPU interactions down to GPU kernels. Pairing our agent with Cursor / Claude Code allows you to automate both the reasoning and code implementation steps of performance optimization. What used to take weeks can now be done in days. Along with our AI agent, we have features such as running diffs on system traces as well as sharing and collaboration features that make our VSCode extension the most powerful way to work on performance optimization.

Dragoneye helps devs build their custom video detection models in less than 5 minutes. These models can then be used to power apps and features that use images and videos. No more arduous process of annotating any training data or doing any machine learning work themselves. Try out our demo today at https://playground.dragoneye.ai/ !

Silogy is building an AI-powered platform for chip developers to simulate and debug their designs.

The first version of RecipeUI was a viral project at Robinhood that reached 100% adoption from all engineering and QA teams. When an API broke, anyone from Frontend to QA to PMs could debug without relying on backend engineers

Glide lets apps accept crypto deposits from any chain, wallet, or exchange using pre-built wallet funding flows. Users can fund wallets directly — no bridges, no swaps, no repeated KYC.

Cedana (YC S23) brings hyperscaler and frontier-lab orchestration capabilities for AI workflows. Our core capability is live migration for CPUs and GPUs workloads. This increases cost savings up to 80%, accelerates time to first token 2-10x, and enables stateful reliability of training jobs even through catastrophic GPU failures. We've integrated our solution into K8s, and support Kueue and Slurm for training distributed jobs, and Kserve for serving inference.   OpenAI, Meta and Microsoft have flavors of these capabilities internally and we’re bringing them to everyone.  Our vision is to transform cloud compute into a real-time, arbitraged commodity.  https://www.cedana.ai

Parea AI is the essential developer platform for debugging and monitoring every stage of LLM application development. We provide testing, evaluation, and monitoring in one unified platform. These capabilities help developers get visibility into LLM responses, quickly test and optimize prompts, and ensure customers get the best user experience.

Parse, extract, and split your hardest documents with unmatched accuracy. Read any layout with specialized vision models, and ship reliable pipelines in minutes, not months.

Fastgen is a low-code API and workflow builder with an integrated Postgres DB. Our drag-and-drop platform allows you to rapidly develop custom APIs and workflows with ease. Our integrated Postgres DB makes it even easier to create, read, update, and delete data in your applications.

Wild Moose automatically kicks off any root-cause investigation to improve MTTR. Our AI triages issues, analyzes impact, and suggests next steps - all before human intervention is needed.

Replace legacy scanners and manual offensive security processes with AI agents that discover, test, and remediate directly in your engineering workflows.

Prompting: Systematically iterate on prompts - Unified prompt management dashboard - Side-by-side model comparisons - Native support for tools, structured outputs, OpenAPI specs Workflows: The IDE for building steerable, agent-like systems. - Visual graph builder for orchestrating complex AI systems - Support for any model, custom code, and map/reduce functions - Built-in features like loops, parallelism, error handling Workflows SDK: A full-stack SDK + GUI for building AI apps with precision and flexibility. - Bi-directional sync between code and UI - Fine-grained control flow and global state management - Customizable with Docker and streaming support Evaluations: Test-driven development for AI. - Build scalable test suites via UI/API/CSV - Use pre-built or custom metrics for evaluation - Track quality, cost, latency, and regressions over time Retrieval: Powerful RAG infrastructure without the complexity. - Simple APIs for uploading and querying unstructured data - Tweak chunking, embeddings, and search for advanced use-cases - Supports various file types including tables and images Deployments: Update AI systems without redeploying your app. - One-click deploy across any model or provider - Staging environments for safe iteration - Scalable inference endpoints for production use Observability: Full visibility into AI system performance. - Audit logs, debugging tools, and feedback capture - Evaluation loops on live traffic - Dashboards to track cost, latency, errors, and trends

DataSuite provides a way to manage and collect multi-terabyte multi-media datasets, and train generative models (diffusion, gan, interactive video) models based on them. We make it trivial for non-technical builders to create their own networks by providing an instant way to collect with AI without worrying about data formats, unzipping power, caching, or data locality.

Mito is Cursor for data science. We’re building an AI enabled IDE to 10x the productivity of data people. Data analysts use Mito to automate reports without relying on internal engineering resources. Mito is used by thousands of business analysts, data scientists, and automation engineers at some of the world's largest banks, private equity shops, and consulting firms. Open source is key to our enterprise sales strategy. Mito is open source and built on top of Jupyter. That means getting started with Mito is as simple as running `pip install` and doesn't require enterprises to manager new infrastructure. Check us out at: https://www.trymito.io/

Axle is the AI-native clearinghouse for property and casualty insurance. Our infrastructure and AI agents automate complex insurance workflows for third parties including verification, monitoring, and policy updates. We've helped Fortune 500 businesses like Rocket Mortgage, Avis, and Experian speed up workflows by 95% while recovering over $220M in potential losses. Axle is backed by Gradient, Y Combinator, and the founding team of Plaid.

Brainboard is a collaborative and end-to-end solution for engineers to visually design & manage their Cloud infrastructures. We allow companies to lower the learning curve while moving to IaC, build a self serve model, have a service catalog to not reinvent the wheel. Both technical profiles with 25+ years of combined expertise and after working together at a major French Cloud provider, Chafik and Jeremy launched Brainboard in 2020.

We are building a cloud platform to help companies deploy and scale AI applications.

Beam is cloud platform for AI inference, sandboxes, and agents.

We build the tools companies need to provide performant and scalable authorization for their applications. We’re founded by 3 successful entrepreneurs with expertise in enterprise software, most recently as leaders at Red Hat. Jake and Joey met on the APIs team at Google in 2010. They went on to found Quay, where Jimmy joined as their first hire. Over the past decade, they’ve changed the landscape for building and deploying software.

Porter is the easiest way to deploy and scale your applications on AWS, Azure, and GCP. Connect your own cloud account, and Porter will provision and manage the underlying infrastructure for you - simply point at your repository and Porter will handle the rest, from building your application to autoscaling it. Under the hood, Porter manages the same kind of infrastructure that growth-stage companies use and allows you to scale without DevOps overhead.

Flowglad is payment infrastructure for agents, with built-in human controls and hard spend limits. Bring your own agent or use ours. Flowglad gives agents the virtual cards, banking, approval flows, and programmable controls they need to spend real money safely. Embed spend policy directly into agent workflows while keeping clear boundaries around who can spend, how much, and under what conditions.

Infield helps software teams keep their open source dependencies up to date. We’re automating away the toilsome work of reading changelogs, assessing risk, and upgrading packages so that software teams can focus on shipping features. We’re a small team of repeat founders passionate about making open source easier to use.

Rutter is the unified API infrastructure powering the next generation of B2B fintech. We help tech-forward companies build seamlessly integrated financial products by connecting to their customers' systems of record, from accounting platforms to e-commerce systems. The financial operations landscape is fragmented across hundreds of platforms (QuickBooks, NetSuite, Shopify, Stripe, etc.). Without Rutter, companies must spend thousands of engineering hours building and maintaining these critical integrations. Our Universal API provides the same level of granularity as direct integrations while using a single, consistent schema. This enables our customers to build end-to-end workflows for financial planning, lending, expense management, AP/AR automation, and more, in days, not months. Leading fintechs like Mercury, Airwallex, and Orb trust Rutter to power their integrated financial solutions. Learn more: https://www.rutter.com/

Mobot (YC W19) is a QA-as-a-service platform using actual mechanical robots to automate testing of repetitive functions on real mobile devices. Mobot's human-supervised robots make it possible to automate mobile app tests that emulators, virtual devices, and existing frameworks can't. This approach eliminates thousands of hours of manual testing, increases testing efficiency and physical device coverage, and captures more bugs in-app before app store launches than software can do alone.

In the space of AI coding agents, Anima bridges the LLM design gap. With over 1.5 million installs, Anima is the first option for professional design, product, and R&D teams going from design to code. Thanks to On-brand Vibe-coding, anyone in the team can build fast without breaking your look and feel. No Figma skills required. Anima generates clean and developer-friendly code. So your prototypes could also be used for handoff. Three ways to start - Figma to Code → Instantly generate clean React, HTML, or Vue code from Figma designs. - Website to Code (Cloning / Remixing) → Import any live website and turn it into editable code. - Prompt to Design (coming soon) → Generate high-end UI directly from natural language prompts, automatically styled to your brand. Key features - Start at AnimaApp.com to bring your design or your website to Anima - Chat in Anima playground to iterate on your project's code while staying on-brand - Handoff playground link to engineering - Or, download code to continue with Clause code ot Cursor - Or, publish a public link to share with clients or stakeholders

Eligible is the nation's first insurance billing platform built for builders. Founded in Mountain View California in 2011, Eligible's platform gives bootstrapping healthcare startups the scale of enterprise, and the Fortune 500s the agility of the hungry entrepreneur. Eligible has been listed as one of Business Insider’s 19 Hottest Startups to Watch and Katelyn has been featured in Forbes 30 Under 30 in Healthcare, Fast Company's Most Creative People in Business, and was named a Rising Star of Healthcare by Becker’s IT & CIO Review.

Chatter is Postman for LLMs. Our platform helps companies and developers test their LLM models. Iterate on prompts, run them across model families and evaluate them against test cases – all in one place. With collaboration features, engineers can design LLM chains while QA can write test cases.

APIs underpin the internet but are still painful to work with. They are often untyped, unstandardized, and out-of-sync across multiple sources of truth. Fern helps companies deliver SDKs and API documentation that they’re are proud to share with their customers. Since launching in 2023, we’ve been trusted by over 200 customers, including industry leaders like Square, Webflow, ElevenLabs, Auth0, and Intercom, to power their developer and agent experiences. We’re fewer than 40 people, based in Brooklyn, NY, and are building open source.

Decent's core product,[The Box](https://decent.xyz/), enables 1-click transactions using any token across chains. For example, a user can purchase an Optimism NFT off primary or secondary sales using USDC on Arbitrum. As applications splinter across an increasing number of rollups and app chains, wallets and dapps will have to meet users at their point of liquidity vs. expecting users to jump through hoops to arrive with tokens on the correct network.

Avenue is a simple way for business teams to set up alerts from their database or data warehouse. Think Datadog / PagerDuty for operations teams. Operations teams create set-and-forget alerts on all their data, so they can be more proactive with their time (and monitor on more nuanced triggers than just what fits on their dashboard page). Avenue can improve response times to critical problems from several days to real-time by alerting directly on the data sources that customers already use.

Reflect is a no-code tool for automated website testing. Instead of building and maintaining complex Selenium tests, companies use Reflect to run automated end-to-end tests without writing code.

We help developers collaborate at scale and build better APIs. Optic’s open source tools makes it easy for developers to document API changes, review each other’s API changes during code review, and catch breaking changes before they reach production. **tl;dr** It’s version control but for behavior not code. We are taking the really successful ideas from Git / Code Review / CI and applying them to API descriptions and (future) other non-code artifacts. Engineers at [Snyk](https://snyk.io/) use Optic daily to make the new Snyk API great. Read their engineering blog: [Snyk's shift left approach to API development | Snyk](https://snyk.io/blog/snyk-api-development-shift-left/)

CodeStream's IDE plugins take the pain out of code reviews. With one command, request feedback on a snapshot of your repo, including uncommitted & unpushed code, allowing you to verify that your work-in-progress is on the right track. (You can also do it the old-fashioned way by committing & pushing at the end of your dev sprint, of course)