You'll noticeTier: how much it should matter to you
1Useful: my rating, 1 to 5
1Signal: worth watching, 1 to 5
MCPArea: what it touches
ImprovementsKind: in v2.1.282,
ImprovementsSection of the release
Unclear How a user starts Claude Code in diskless mode is not known.
What
MCP servers are outside programs that give Claude Code extra tools. Claude Code can keep a cache on disk of what it has discovered about them. When Claude Code is launched in diskless mode (with no disk storage available to it), that cache is now switched off for the rest of the session, whatever MCP_DISCOVERY_CACHE or the remote off switch says.
Previously the cache could only be forced off by MCP_DISCOVERY_CACHE, the remote off switch, or not being enabled.
Why
A machine with no disk should not try to read or write a cache that lives on disk.
The entry above is what we published on the day. These lines were added later, as Anthropic's own pages caught up, and they sit beside the original rather than replacing it.
Confirmed sinceAnthropic's documentation has since written up MCP_DISCOVERY_CACHE, on Claude Code changelog.* \[Cloud sessions] Changed `MCP_DISCOVERY_CACHE=1`, when set in your cloud environment's variables rather than a settings file, to reuse your connectors' tool lists after a session restart; other MCP servers are no longer cached and conne…changelogsee the edit
How sure we are
Something disagreesSomething we can check disagrees with this entry, or the writer said they could not settle it.
The writer flagged doubtHow a user starts Claude Code in diskless mode is not known.
Anthropic's documentation agreesAnthropic's documentation has since written up MCP_DISCOVERY_CACHE, on Claude Code changelog.
