HSX_E_DEV_SESSION_MULTI_APP

Dev session spans multiple HubSpot apps.

What this error means

One HubSpot dev session can serve UI extensions from only one app at a time.

When this error stops a command, hs-x exits with code 10. With --json, the failure is reported as a structured error whose code field is HSX_E_DEV_SESSION_MULTI_APP — stable to match on in scripts and agents.

Likely causes

  • The selected components belong to more than one app in the project IR

How to fix it

  • Pass --component and select components that belong to the same app

Still stuck? Re-run the command with --debug for the wire-level detail, or hs-x doctor to check accounts, link state, and connectivity in one pass.