What
TaskCreate, TaskUpdate and TaskList used to be available unless your organization sat on a denylist. They now require both that tasks are not disabled by CLAUDE_CODE_ENABLE_TASKS=false and that todo tools are on, which happens for certain session kinds, when CLAUDE_CODE_ENABLE_TODO_TOOLS is true, or when the tengu_rosy_wren flag is on. That flag is off by default in this build.
Evidence
Strings lifted out of the shipped bundle, so the claim above can be checked against them.
Names in the bundleCLAUDE_CODE_ENABLE_TASKSCLAUDE_CODE_ENABLE_TODO_TOOLS
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 Environment variables touched a line naming CLAUDE_CODE_ENABLE_TODO_TOOLS after this was published.
| `CLAUDE_CODE_ENABLE_TODO_TOOLS` | Set to `1` to get the task-tracking tools on every model. Without it, Claude Code provides them by default only on the models listed under [Task tool availability](/docs/en/tools-reference#task-tool-avai…env-vars see the edit
Added since
A small documentation edit on Environment variables touched a line naming CLAUDE_CODE_ENABLE_TASKS after this was published.
| `CLAUDE_CODE_ENABLE_TODO_TOOLS` | Set to `1` to get the task-tracking tools on every model. Without it, Claude Code provides them by default only on the models listed under [Task tool availability](/docs/en/tools-reference#task-tool-avai…env-vars see the edit
Confirmed since
Anthropic's documentation has since written up CLAUDE_CODE_ENABLE_TASKS, on Agent SDK reference - Python.
Wherever the tools are available, Claude Code provides the four Task tools, or `TodoWrite` instead when you set `CLAUDE_CODE_ENABLE_TASKS=0`.agent-sdk/python see the edit
Confirmed since
Anthropic's documentation has since written up CLAUDE_CODE_ENABLE_TODO_TOOLS, on Claude Code changelog.
* Changed the task-tracking tools (TaskCreate/Get/Update/List, TodoWrite) to be offered only on Claude 3.x, Opus 4.0–4.7, Sonnet 4.0–4.6, Haiku 4.5; set `CLAUDE_CODE_ENABLE_TODO_TOOLS=1` elsewherechangelog 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 CLAUDE_CODE_ENABLE_TODO_TOOLS, on Claude Code changelog.
Anthropic's release notes agree
Todo/task-tracking tools (TaskCreate/Get/Update/List, TodoWrite) are no longer available on Opus 4.8, Sonnet 5, Fable 5, Mythos 5, and newer…
The name it cites is new in this build
New in this build: CLAUDE_CODE_ENABLE_TODO_TOOLS