Toolathlon

flagged-transactions

Pull each high-net-worth client's 2025 transactions from BigQuery, flag those above the client's mean plus three standard deviations, and write them, sorted by ID, into an Excel audit report.

Task Prompt

Perform anomaly detection on high-net-worth clients’ transactions: Extract the 2025 transactions of clients in `high_value_clients.csv` from BigQuery  `all_transactions.recordings` and mark the abnormal transactions with `amount > mean + 3*std` for each client, and fill them into  `anomaly_audit_report.xlsx`, the result should be sorted by the "transaction_id" (remove the sample data  
before adding results).