Mastra YC Application

Winter 2025Active

Mastra went through Y Combinator in the Winter 2025 batch as a B2B company. Below: what the company does, who founded it, and its application to YC, reconstructed question by question in the real YC form.

YC batch: Winter 2025
Industry: B2BEngineering, Product and Design
Team size: 8
Status: Active
Launched: 2025

Founders

Sam BhagwatFounder
Abhi AiyerFounder
Shane ThomasFounder

What Mastra does

Mastra is the easiest way to build a production AI application, built by the team that brought you Gatsby. We provide a complete set of AI primitives: workflows for complex operations, agents for autonomous decisions, RAG for knowledge integration, and evals for quality & accuracy. Mastra is open-source, modular, and built in Typescript for product developers. You can deploy Mastra on any cloud, and it gives you a straightforward syntax to solve the hardest problems building with AI: human-in-the-loop workflows, agent memory and tool selection, and output quality.

Mastra's YC application, reconstructed

Y Combinator application

Mastra, Winter 2025 batch. The real form questions, answered from public data.

Founders2
Company7
Progress7
Idea4
Equity3
Curious2
Batch Preference1

Company

Company name

Mastra

Describe what your company does in 50 characters or less.

The Javascript framework for building AI agents

What is your company going to make? Please describe your product and what it does or will do.

We are building Mastra, a Javascript framework that simplifies building production AI applications. It offers AI primitives like workflows to manage complex operations, autonomous agents for decisions, retrieval-augmented generation for knowledge integration, and evaluation tools for accuracy. Our framework is modular, open-source, written in Typescript, and targets product developers who want to deploy AI-driven functionality with human-in-the-loop workflows and agent memory, all deployable on any cloud.

Where do you live now, and where would the company be based after YC?

We live and work in San Francisco, CA, and have a remote team. After YC, the company will remain based in San Francisco with a distributed team.

Explain your decision regarding location.

We are in San Francisco because it is a hub for product developers and AI startups. Our team is remote-friendly to attract talent beyond the Bay Area, but the HQ remains in SF to maintain proximity to the core engineering and founding team.

21 more answers in the full application

Founders, Progress, Idea, Equity, Curious, Batch Preference are in the full version. Create a free account to open it in YC Insights, next to every other YC batch.

See full application

Frequently Asked Questions

Is this the real Mastra YC application?

No. Y Combinator keeps submitted applications private. This is a reconstruction: the real YC form questions, answered from Mastra's public data (launch notes, founder backgrounds, product description). It shows how a company like Mastra would present itself to YC, not the text they submitted.