Summary

After upgrading to mempalace v3.1.0, my existing palace can no longer be opened.

The CLI/MCP reports:

No palace found at /Users/isapozhnik/.mempalace/palace
Run: mempalace init <dir> then mempalace mine <dir>

The palace is not missing. The Chroma DB exists and contains drawers.

What changed

v3.1.0 pins ChromaDB to:

chromadb>=0.5.0,<0.7

This appears to be incompatible with an existing palace DB created/opened with Chroma 1.x.

Evidence

With the published v3.1.0 tool environment:

mempalace 3.1.0
chromadb 0.6.3

Opening the existing palace fails internally with:

KeyError: '_type'

The CLI catches that and prints the misleading No palace found message.

The same existing palace opens successfully with Chroma 1.5.7:

chromadb 1.5.7
count 8429

I also tested mempalace v3.1.0 source locally with only the Chroma dependency changed to:

chromadb==1.5.7

That successfully opened the same palace and search worked.

Repro

uv tool upgrade mempalace
mempalace status

Result:

No palace found at ~/.mempalace/palace

But the DB exists:

ls ~/.mempalace/palace/chroma.sqlite3

And Chroma 1.5.7 can read it.

Expected

mempalace v3.1.0 should either:

1. Support existing Chroma 1.x palace databases, or
2. Detect incompatible Chroma schema and show a clear migration/rollback message, not No palace found.

Current workaround

Install v3.1.0 from source with the Chroma pin changed to chromadb==1.5.7.

Environment

• macOS
• Installed via uv tool upgrade mempalace
• Palace path: ~/.mempalace/palace
• Existing DB contains 8429 drawers