{"version":"2.1.205","anchor":"append-subagent-system-prompt-flag","canonical_anchor":"append-subagent-system-prompt-flag","heading":"--append-subagent-system-prompt flag","tier":null,"area":null,"scope":null,"heads_up":null,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.205\/e\/append-subagent-system-prompt-flag","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.205","markdown":"### `--append-subagent-system-prompt` flag\n\n**What**\n\nAppends a custom system prompt to every Task-tool subagent launched by Claude Code, propagated recursively to nested subagents.\n\n**Usage**\n\n`claude --print --append-subagent-system-prompt \"Always respond in JSON\" ...` **Details** - Only works with `--print` (non-interactive mode) - Sets `CLAUDE_CODE_ENABLE_APPEND_SUBAGENT_PROMPT=1` automatically - Propagates the appended prompt through nested subagent chains - Useful for enforcing output format, language, or tool constraints across all agents in a pipeline **Evidence** CLI flag description (search for `\"Append a system prompt to every Task-tool subagent\"`) \u2014 `UCp()` at line ~763864"}