Function sse_headers

ds4_server.c:4881–4892

Streaming is a translation state machine over the raw DS4 text. The model * may produce and DSML tool blocks; clients should receive those as * protocol-native reasoning/tool deltas, never as visible assistant text. */

        return false;
    }
    /* instructions in the Responses API replaces any system message — for Codex
     * it carries the full agent system prompt. Prepend it so render produces a
     * standard system+chat layout. */
    if (instructions && instructions[0]) {
        chat_msg msg = {0};
        msg.role = xstrdup("system");
        msg.content = instructions;
        instructions = NULL;
        /* Insert at the head so it precedes the conversation. */
        chat_msgs_push(&msgs, msg);
        if (msgs.len > 1) {
            chat_msg tmp = msgs.v[msgs.len - 1];
            for (int i = msgs.len - 1; i > 0; i--) msgs.v[i] = msgs.v[i - 1];
            msgs.v[0] = tmp;
        }