Actual results may differ materially, and we disclaim any obligation to update any forward-looking statements or outlook. A historical reconciliation to comparable GAAP metrics can be found in today's earnings release. Q4 ended above the high end of our guidance with a record $107 million in free cash flow, our first ever nine-digit free cash flow quarter. For the full fiscal year ended March 31st, revenue was $645 million, up 13% year-on-year.
On the bottom line, our adjusted EBITDA margin was 45% in Q4 and 55% for the full year. Our benchmark workflow engagement reached over 800,000 unique quarterly active prescribers in Q4, up roughly 30% year-on-year, a significant acceleration from the high single-digit growth we saw a year ago. We saw record high engagement across our entire platform last quarter as doctors increasingly turned to us to be their AI assistant. In the nine months since we acquired Pathway, our AI Search and Scribe active users have tripled.
We've already closed our first few AI Search deals with top 20 pharma manufacturers, but these are early innings in a nascent and regulated market, and our financial guidance reflects that. We've forecasted minimal AI revenue contribution this fiscal year while allowing for a wider range of AI investments and related expenses, meaning higher R&D, compute, and marketing spend that will weigh on near-term margins. He began on the buy side at Capital Research, giving him a long-term perspective across tech. fourth quarter revenue grew to $145 million, up 5% year-over-year, exceeding the high end of our guidance range.