Mastra Playground broken with `@mastra/core` v0.20.1?

I'm getting a TypeError: agent.getInputProcessors is not a function error when running the Mastra Playground with the latest @mastra/core. Setup: - @mastra/core: v0.20.1 (installed) - mastra CLI: v0.15.1 (via npx mastra@latest dev) - Agents are properly defined and work fine in production (Next.js app) Error:
ERROR [2025-10-09 04:38:31.293 +0200] (Mastra CLI):
TypeError: agent.getInputProcessors is not a function
ERROR [2025-10-09 04:38:31.293 +0200] (Mastra CLI):
TypeError: agent.getInputProcessors is not a function
Issue: The playground can't display my agents. When I go to the Agents tab, it's empty. Tools show up but have no attached agents. From the @mastra/core CHANGELOG (v0.14.0-alpha), I can see the processor API was reworked, and getInputProcessors() seems to have been removed. The CLI (v0.15.1) is still calling this old method. Questions: 1. Is the Playground expected to work with @mastra/core v0.20.x? 2. Is there a newer CLI version I should be using? 3. Should I downgrade @mastra/core to use the playground, or is there a fix coming? My agents work perfectly in my app, so the code is fine - this is purely a playground issue.
4 Replies
_roamin_
_roamin_•2w ago
Hi @! .kinderjaje ! Yes, there's a bug in the playground, we have a open GH issue for this 😉
! .kinderjaje
! .kinderjajeOP•2w ago
oki, thanks for confirming
Jenil
Jenil•7d ago
Any timeline for fixing this one? Development is becoming an issue with new agents or local changes testing I think it is fixed for me in all the latest version of different packages of mastra. Currently on "@mastra/core@0.20.2"
! .kinderjaje
! .kinderjajeOP•6d ago
i didnt try yet, but will test all after new release

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