{"version":"2.1.246","anchor":"assistant-messages-tell-you-which-prompt-they-answer","canonical_anchor":"assistant-messages-tell-you-which-prompt-they-answer","heading":"Assistant messages tell you which prompt they answer","tier":"use","area":"SDK","scope":null,"heads_up":null,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.246\/e\/assistant-messages-tell-you-which-prompt-they-answer","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.246","markdown":"### Assistant messages tell you which prompt they answer\n\nSDK replies now carry the uuid of the prompt they answer, on the first frame.\n\n**What**\n\nSDK assistant messages can now carry `user_message_uuid`, the id you passed as `options.uuid` when you sent the prompt. It is stamped on the turn's first reply frame only, so a consumer can bind a reply to the send it answers without waiting for the result message.\n\n**Details**\n\n- Sits at the wrapper level next to `type` and `session_id`, never inside `message.content`.\n- With `--include-partial-messages`, it lands on the first non-ping stream event of the turn instead.\n- Also attached to error results (`error_max_turns`, `error_during_execution`, `error_max_budget_usd`, `error_max_structured_output_retries`) and to success results even when `is_error` is set.\n- Absent on subagent frames, on synthetic or scheduled turns, and on turns where you sent no client uuid.\n\n**Evidence**\n\n`Client uuid of the user message that triggered this turn (submitMessage options.uuid), stamped on the turn's FIRST reply frame only`, `user_message_uuid`\n\n- Area: SDK\n- Names: `user_message_uuid`, `options.uuid`\n- Tier: Use it now\n- Useful: 3\/5\n- Signal: 3\/5"}