Unclear It is not clear when Claude Code runs in REPL mode, so whether these changes reach you is unknown.
REPL mode is a way of working where Claude writes small scripts that call tools, instead of calling each tool one at a time. This release adds a large set of rules for it:
- Certain hook events, including
PreToolUse(the hook that runs before a tool call and can block it), now mark a plugin as one that may check tool calls - If such a plugin is installed, or Claude Code cannot tell whether one is, a tool call made from inside a script is refused with a message saying the call was not made
- Queued scripts are checked by auto mode, the setting where Claude Code decides on its own which actions are safe to run
- Output from a script that finishes later is cut once it passes a byte limit, with a note saying so
- Shell commands run from a script get their results formatted, including text about saved output and background tasks
A separate server-controlled switch makes MCP tools (tools supplied by outside servers you connect) raise an error inside a script when they fail. Its built-in fallback, used only when the server sends nothing, is on.
Tool calls made from inside a script can no longer slip past a plugin that is meant to inspect every tool call, and auto mode now applies to scripts too. Very long output from a script no longer floods the conversation.
tengu_repl_mcp_error_throw Not enough to sayNothing here resolved what this flag was doing on this version, so nothing here should be read as on or off.
This account: no value returned · anonymous baseline: no value returned · compiled default in v2.1.318: on
These values were read against a different version of Claude Code, so treat them as the nearest reading available instead of one taken on this release.
Read once, for one account on one subscription tier, against v2.1.318. It isn't a statement about your account. What a flag value here can and cannot tell you
It is not clear when Claude Code runs in REPL mode, so whether these changes reach you is unknown.
New in this build: tengu_repl_mcp_error_throw