Mastra (YC W25) — The javascript framework for building AI agents, from the gatsby devs
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 a Y Combinator company in the Winter 2025 batch. Its directory entry describes it as: The Javascript framework for building AI agents, from the Gatsby devs. The founders listed are Sam Bhagwat (Founder/CEO), Abhi Aiyer (Founder/CTO), Shane Thomas (Founder) (Y Combinator directory entry, January 17, 2025).
Get an email when Mastra changes status, grows its team or files a funding notice. One email first to confirm; nothing else until you click it. At most one a day, one click to stop. Free for up to 3 companies.
Example from a real report (our sample on Target): “Target eliminated approximately 1,800 corporate positions, with around 1,000 employees receiving layoff notices and the remainder accounted for by eliminating open roles.” Source: NBC News
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.
Sam Bhagwat
Founder/CEO
Abhi Aiyer
Founder/CTO
Shane Thomas
Founder
Founders, titles and bios as the company published them. Photographs are our own copies of the ones on that record, so they do not break when the original link expires.
One of 634 companies held here in B2B › Engineering, Product and Design.
No investor is drawn from a Form D — the form states how many invested and never who. The one investor on this graph is named because a batch has exactly one.
Want the whole picture on Mastra?
Example from a real report (our sample on Target): “Target eliminated approximately 1,800 corporate positions, with around 1,000 employees receiving layoff notices and the remainder accounted for by eliminating open roles.” Source: NBC News
A Full Report on Mastra: verified, sourced, every claim cited, ready in a few minutes. See pricing.
What the Full Report on Mastra covers
The Short Answer
Which Company This Is
What They Do, And How The Money Works
Who Runs It, And How To Reach Them
The Money: Funding, Valuation, Runway
Who Pays Them, And Who They Are Up Against
Warning Bells
Sources
1 cited source found
Plus the sections for what you are deciding, which you pick after ordering.
You get an alert in MentionFox the next time this company shows up.
Is this you?
If you're behind Mastra: acceptance into a YC batch is one of the few weeks a young company gets looked up by people who matter — investors, other founders, press. FoxPlug turns the commits, deploys, and releases you're already making into that story automatically, so anyone who looks finds something current. GetFoxChat puts a guide on your own site so the people YC's own page just sent you don't read one line and leave.
Mastra (YC W25) — The javascript framework for building AI agents, from the gatsby devs. MentionFox, 2026-10-20. https://mentionfox.com/funding/yc-mastra
