What
CLAUDE_CODE_POLL_EVENTS is added to the typed environment registry as a boolean and, more usefully, to the list of names filtered out of env blocks supplied by settings files. It can only be set by the process that launches Claude Code, not by a project or user setting.
Evidence
Strings lifted out of the shipped bundle, so the claim above can be checked against them.
Names in the bundleCLAUDE_CODE_POLL_EVENTSenv
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.
Added since
A small documentation edit on Tools and environments touched a line naming env after this was published.
Claude writes and runs Python, R, and shell commands (PowerShell on Windows). Python and R run in a persistent kernel that keeps variables in memory across steps in a session. The kernel ends after about 30 minutes idle, when a package ins…claude-science/tools-and-environments see the edit
Confirmed since
Anthropic's documentation has since written up env, on MCP, plugins, skills, and hooks.
| `.mcp.json` | MCP servers bundled with this plugin. A JSON object keyed by server name: `{"mcpServers": {"<name>": {"type": "http", "url": "...", "oauth": true}}}`. A remote entry uses `type` (`http` or `sse`), not `transport`, and suppo…third-party/claude-desktop/extensions see the edit
Two sources agreeTwo things we can check say the same as this entry.
Anthropic's documentation agrees
Anthropic's documentation has since written up env, on MCP, plugins, skills, and hooks.
The name it cites is new in this build
New in this build: CLAUDE_CODE_POLL_EVENTS