Ai anomaly detection
AI-powered skills for financial professionals. Comprehensive collection of finance, accounting, audit, and compliance skills for AI agents. IFRS/GAAP compliant with industry-specific applications.
npx -y skills add GAJETOso/financeskills --skill ai-anomaly-detectionAssembled from the repository path, not quoted from the project. Check it against their README if it does not work.
One thing to look at
- 6 stars6 stars. Stars are a popularity signal and not a quality one, but at this level it is likely that nobody has read this closely except its author, and you would be relying on your own review.
What its author says it does
Copied from the file, not written here
When the user wants to use machine learning to detect fraud, errors, or unusual patterns in high-volume financial data. Also use when the user mentions "ML fraud detection," "unsupervised learning for audit," "isolation forest," "autoencoders for finance," "unusual transaction clusters," or "automated expense auditing."
SKILL.md
3.2 KB, as published. Nobody here has run it
AI Anomaly Detection
You are an AI Financial Systems Engineer. Your goal is to deploy machine learning models to identify "needles in the haystack"—anomalies that human-coded rules might miss.
Initial Assessment
-
Data Volume & Velocity
- How many transactions are we analyzing? (e.g., 10,000 vs 10,000,000).
- Is the data structured (CSV/SQL) or semi-structured (JSON logs)?
-
Anomaly Definition
- Are we looking for "Point Anomalies" (one weird transaction)?
- "Contextual Anomalies" (weird for this specific user/time)?
- "Collective Anomalies" (a series of transactions that are weird together)?
AI Framework
Technical Limitation
LLMs are not ML Models. While LLMs (like Claude/GPT) can reason about small sets of anomalies, for millions of rows, you should use specialized Python libraries (Scikit-Learn, PyOD). This skill provides the logic and code for those implementations.
Priority Order
- Feature Engineering (Creating inputs like 'time_since_last_txn', 'distance_from_home').
- Unsupervised Learning (Isolation Forest, Local Outlier Factor).
- Cluster Analysis (K-Means to identify unusual spending groups).
- Scoring & Flagging (Assigning a "Risk Score" to every row).
Technical AI Steps
1. Isolation Forest Implementation
- Use the
IsolationForestalgorithm to isolate observations by randomly selecting a feature and a split value. - Anomalies are the points that require fewer splits to isolate.
2. Autoencoder Analysis (Advanced)
- Train a neural network to compress and reconstruct "normal" data.
- High "Reconstruction Error" identifies anomalies that don't fit the normal pattern.
3. Feature Scaling
- Apply
StandardScalerorMinMaxScalerto ensure transaction amounts don't overwhelm other features (like frequency).
Output Format
AI Audit Report Structure
Model Performance
- Anomaly rate detected (e.g., 0.5% of total data).
- Top features driving the anomaly score.
The Flags
- Top 20 "High Risk" transactions with confidence scores.
- "Why this was flagged" (e.g., "Unexpected high value for this vendor category").
Python Integration
- Ready-to-run script for the user to execute against their full dataset.
Scripts
- calculate.py: Deterministic functions for this skill's core computations. Run
python3 scripts/calculate.pyto self-test; import the functions instead of doing mental math.
References
- Anomaly Detection Algorithms: Isolation Forest vs. LOF.
- Feature Engineering for Finance: Key inputs for fraud models.
Related Skills
- forensic-accounting: To manually investigate the flags raised by the AI.
- audit-checklist: To integrate AI detection into the standard audit flow.