{"version":"2.1.296","anchor":"tool-call-dispatch-passes-session-version-and-subagent-flag","canonical_anchor":"tool-call-dispatch-passes-session-version-and-subagent-flag","heading":"Tools can now tell whether a subagent called them","tier":"internal","area":"Subagents","scope":"individual","heads_up":false,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.296\/e\/tool-call-dispatch-passes-session-version-and-subagent-flag","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.296","markdown":"### Tools can now tell whether a subagent called them\n\nWhen Claude Code runs some tool calls, it now tells the tool the session's version and whether a subagent made the call\n\n**Unclear.** Whether any tool actually behaves differently for subagents or by session version yet is not shown.\n\n**What**\n\nA tool call is a request from Claude to use one of its tools, such as reading a file or running a command. On one of the paths Claude Code uses to run tool calls, it now gives the tool two more pieces of information:\n\n- `sessionVersion`: the version of the session the call is running in\n\n- `isSubagent`: whether the call came from a subagent, which is a helper agent Claude starts to handle part of a task\n\nBefore, the tool got neither of these.\n\n**Why**\n\nTools on this path now have what they need to act differently for subagents, or for different session versions.\n\n- Area: Subagents\n- Tier: Under the hood\n- Useful: 1\/5\n- Signal: 2\/5\n- Scope: individual\n- Heads-up: no"}