Talmai — Addition A 15: Both the king and Mordecai record the incident.
Licence: English and apparatus CC BY 4.0 (Talmai, Wroot Press); Greek from Swete, CC BY-SA. https://talmai.wrootpress.com/rights/
Canonical: https://talmai.wrootpress.com/unit/esth-plus-01.01-15/
Source edition: H. B. Swete, The Old Testament in Greek, 19.prologue

GREEK: καὶ ἔγραψεν ὁ βασιλεὺς τοὺς λόγους τούτους εἰς μνημόσυνον, καὶ Μαρδοχαῖος ἔγραψεν περὶ τῶν λόγων τούτων·
ENGLISH (draft-awaiting-approval): and the king wrote these things down for a record, and Mordecai wrote concerning these matters;

PARALLELS:
- [Verbatim] Tosefet le-Esther, בגתן ותרש (Tosefet le-Esther (he.wikisource editorial page: Additions to Esther in Hebrew)) — conduit: medieval retranslation. 'ונכתב בספר הזכרונות... ויתן לו מתן רב' renders Addition A's doubled record and royal reward, content absent from MT's bare notice.
- [Motif] Yalkut Shimoni on Nach 1057:3 (Yalkut Shimoni on Esther (Remez 1046-1061)) — conduit: lost intermediary. 'ויש אומרים אליהו ז"ל בא וכתבן' supplies a second, non-royal writer of the memorial alongside the king's scribe — the same doubling the plus makes with 'the king wrote... and Mordecai wrote,' a detail MT lacks.
- [Flagged] Pirkei DeRabbi Eliezer 50:4 (Pirkei DeRabbi Eliezer 49-50) — conduit: oral. PDRE doubles the record exactly as the plus does: the incident is written in the royal archive AND Mordecai's report is separately 'written on a book,' matching Addition A's distinctive double authorship (king writes, Mordecai writes) against MT's single notice.