Yujohn Nattrass

Current: Software Engineer @mastra_ai
Previous: Software Engineer @netlify

[Yujohn Nattrass @sirwhyjay]

Excited to share experiments in @mastra. Create test cases, score the results, and compare runs side by side to see if the changes actually helped. Swap a model, tweak a prompt, run again, and compare.

Do it all in Studio or via the API. 1/5

[Sam Bhagwat @calcsam]

Today we're excited to launch our Vitest integration!

Catch agent regressions with your favorite testing library:

[Yujohn Nattrass @sirwhyjay]

Something that's often overlooked when running experiments is the side effects caused by tools.

Glad to see support for tool mocks!

[Sam Bhagwat @calcsam]

Excited to ship experiment mocks!

Mock results for actions like refunding a payment or sending an email, so experiments never touch live APIs:

[Sam Bhagwat @calcsam]

Excited to ship experiment mocks!

Mock results for actions like refunding a payment or sending an email, so experiments never touch live APIs:

[Sam Bhagwat @calcsam]

Today we're excited to launch the feedback API endpoint!

Pull your feedback data into whatever service you want:

[Sam Bhagwat @calcsam]

Today we're excited to launch server health on the Mastra platform!

Monitor requests to catch failing endpoints or spot latency spikes:

[Sam Bhagwat @calcsam]

Today we're excited to launch filesystem skills!

Auto-discover SKILL.MD files in subdirectories, then make them available to all your agents:

[Alex Booker @bookercodes]

Today we're announcing Mastra Factory!

Most teams just want to build their product - not take on building and maintaining a factory too.

So we're open-sourcing ours.

Now you can own your factory without having to build it yourself.

Demo:

[Sam Bhagwat @calcsam]

Today we're launching Mastra Factory.

When we started building a factory, we weren't sure what to expect.

But over the last few weeks it's has been writing 30% of our PRs, closing 60% of issues.

Factory is free + open-source, now you can try it too:

https://t.co/9RuKyCaVm7

[Sam Bhagwat @calcsam]

Today, we're excited to launch filesystem mounts!

Mount multiple filesystems into a single Mastra workspace:

[Sam Bhagwat @calcsam]

Today we're excited to launch sandbox lifecycle controls in Mastra!

Create your sandbox, then pause it, mount it, stop it, kill it, snapshot it:

[Abhi Aiyer @abhiaiyer]

look ma, mastra

[Abhi Aiyer @abhiaiyer]

das nice

[Yujohn Nattrass @sirwhyjay]

Nonetheless, looking forward to presenting

https://t.co/kHzA6ToXWT

[Yujohn Nattrass @sirwhyjay]

I’ve been preparing for the Evals 101 workshop and there’s so many new features to squeeze in that I might be able to get through everything in an hour 😅

[Shane Thomas @smthomas3]

amazing to see mastra make the IA40

[Yujohn Nattrass @sirwhyjay]

@smthomas3 Ohhhhh this makes more sense…. I saw my neighbor just standing on the roof with a leaf blower. I thought he was just just getting debris off. But using it to clean the actual gutters 🤯

[Yujohn Nattrass @sirwhyjay]

Cleaning the gutters is kind of satisfying. It’s moving the ladder a couple of feet at a time is the pain in the ass.

[Yujohn Nattrass @sirwhyjay]

@oscargaske indeed it is sparkling water.... and one milkis :)

[Yujohn Nattrass @sirwhyjay]

Wife is in Korea for 6 months and she’s worried about my eating habits… I think I got the essential but am I missing anything?

[Yujohn Nattrass @sirwhyjay]

@jsumnersmith thank you!

[Yujohn Nattrass @sirwhyjay]

@mfrachet I agree

[Yujohn Nattrass @sirwhyjay]

@lekt8_ yum indeed