Milvus MCP: Milvus Lite URI must end in .db with an existing parent dir

TL;DR: Milvus Lite needs a URI ending in .db whose parent directory already exists. mkdir -p the parent, use an absolute path ending in .db, and the server starts.

Error: Milvus Lite URI must end with .db / parent directory does not exist

Fix it

1. Create the parent directory first:

mkdir -p [HOME]/...

1. Set the URI to an absolute path ending in .db:

{
  "env": {
    "MILVUS_URI": "[HOME]/..."
  }
}

1. Restart the MCP client.

Expected: the server starts with Milvus Lite. The first call creates the collection.

When to use this

• Using Milvus Lite (no server, no cloud) and the server fails at startup.
• The URI is relative or missing the .db suffix.

When NOT to use this

• MILVUS_URI points at http:// or https://. That is server/cloud mode; Lite rules do not apply.
• Permission denied on an existing Lite path. That is filesystem permissions.

Compatibility

• zilliztech/mcp-server-milvus with Milvus Lite (pymilvus + milvus-lite).
• macOS and Linux. Windows cannot run Milvus Lite; connect to a remote deployment instead.

Why it happens

Milvus Lite is an embedded library, not a server, so the URI is really a filesystem path with conventions: the .db suffix tells pymilvus it is a Lite path, and the parent must exist because Lite will not create it. The naming is misleading since the path becomes a directory tree (collections/, databases/, LOCK), not one file.

Edge cases

• Do not point two processes at the same Lite path concurrently. Lite locking is not multi-process safe.
• Back up the whole directory tree, not just a file. The data spans several subdirectories.
• Milvus Lite ignores the database name setting (no named databases in Lite). Leave MILVUS_DB at default.