PredictorLab

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Upload your data. Say what you want to predict. Get an honest model with a confidence interval, a profit-optimized threshold, and a REST API — in 5 minutes.

PredictorLab is self-hosted tabular ML for analysts who need ML but don't have a DS team. You know your data, you know your business costs — PredictorLab handles the ML: catches leakage, splits correctly, calibrates probabilities, and converts them into decisions in rubles.

Spoiler: the model that shows 99% accuracy on your first upload is almost certainly broken. This tool will tell you exactly why — and fix it for you.

Who this is for

What you need: a dataset with a labeled outcome column, and rough numbers for what a correct prediction earns vs what a wrong one costs. That's it.

What you don't need: Python, scikit-learn, or a DS degree. But if you have them — the REST API and MCP server give you full programmatic control.

Related MCP server: RiskProbe Agent

The Problem

I've watched this scenario play out dozens of times:

1. A business team uploads a customer churn dataset to a mass-market "no-code ML" tool

2. They get ROC-AUC 0.98 — everybody celebrates

3. The model goes to production, predicts nothing useful, and dies quietly

The 0.98 was never real. The dataset had a cancel_date column — filled in only after a customer had already churned. The model learned to read the future, not to predict it. Mass-market no-code tools don't block on this — at best they show a yellow warning that nobody clicks. Enterprise tools like DataRobot do detect leakage, but they cost $$$ and require an implementation team.

The second problem is even more insidious: even with a "good" model, business people get probabilities — not decisions. "This customer has a 73% churn probability." Great. What do I do with that? Call them? Offer a discount? The tool never says, because the tool doesn't know what a phone call costs or what a saved customer is worth.

PredictorLab solves both — in the gap between "too simple to trust" and "too expensive to buy":

How it looks

Leakage Guard in action — the killer feature. Upload the leaky demo dataset, and the system doesn't just warn — it refuses to show results and tells you what to do:

The "What does this mean?" block explains AUC, lift, and conformal coverage in business terms — not jargon.

Training panel — real-time SSE progress, 7 stages with descriptions, live leaderboard, elapsed/remaining time:

Profit optimization — the threshold is set where your money is maximized, not where F1 looks pretty:

Sharing predictions — three ways, each one click. Web form for non-technical users, API key for developers, batch for processing your entire customer base:

Single prediction — probability, conformal interval, reasons in plain language, OOD flag:

Model Card — auto-generated with leakage report, assumptions, limitations. Exportable to Markdown and PDF:

How it works

  ┌────────────────── Web Interface ──────────────────┐
  │  React UI ←SSE→ FastAPI + asyncio jobs + ProcessPool │
  │         │                                          │
  │         │   ┌─────── REST API :8000 ────────┐      │
  │         │   │  /api/v1/models/{id}/predict  │      │
  │         │   │  /api/v1/models/{id}/whatif   │      │
  │         │   │  /api/v1/jobs/{id}            │      │
  │         │   └───────────────────────────────┘      │
  │         │                                          │
  │         │   ┌─────── MCP Server :8100 ──────┐      │
  │         │   │  predict, explain, what_if,   │      │
  │         │   │  counterfactual, model_card   │      │
  │         │   └───────────────────────────────┘      │
  │         │                                          │
  │         ▼                                          │
  │  ┌─── Core Pipeline ──────────────────────────┐    │
  │  │                                            │    │
  │  │  CSV/XLSX/Parquet ← PII scanner            │    │
  │  │       ↓                                    │    │
  │  │  Feature Builder (point-in-time SQL)       │    │
  │  │       ↓                                    │    │
  │  │  Leakage Guard (9 deterministic checks)    │    │
  │  │       ↓                                    │    │
  │  │  Splits (OOT / group / stratified)         │    │
  │  │       ↓                                    │    │
  │  │  Training (CatBoost + LightGBM + Optuna)    │    │
  │  │       ↓                                    │    │
  │  │  Calibration + Conformal + OOD + SHAP       │    │
  │  │       ↓                                    │    │
  │  │  Profit → Threshold → Counterfactuals       │    │
  │  │       ↓                                    │    │
  │  │  Monitoring (PSI drift + live metrics)      │    │
  │  │                                            │    │
  │  └────────────────────────────────────────────┘    │
  │                                                    │
  │  DuckDB (data) · SQLite (metadata) · joblib       │
  │  PostgreSQL / MySQL / ClickHouse / SQLite (RO)     │
  └────────────────────────────────────────────────────┘

1. Upload CSV, XLSX or Parquet — encoding and delimiter detected automatically (including cp1251). PII columns (email, phone, INN, SNILS, passport, card) are detected and excluded from training by default.

2. Pick a target — from a dropdown or describe it in words (LLM suggests the column and SQL).

3. Leakage Guard runs 9 deterministic checks. If BLOCK — you see exactly which columns leak and why. One click: "Exclude and retrain". Advanced users can override (recorded in Model Card).

4. Train — Quick (CatBoost + linear, ~2 min) or Full (Optuna searches CatBoost + LightGBM within a time budget). Watch live progress: stages, candidate leaderboard, elapsed time.

5. Result — AUC/MAE vs baseline, conformal coverage, calibration curve, SHAP drivers. Set the cost matrix → profit curve → optimal threshold. Try What-If sliders.

6. Share — create a web form link, an API key, or batch-predict an entire file.

7. Monitor — PSI drift alerts, live metrics on real outcomes, webhooks, one-click retrain.

Leakage Guard: the demo that sells the product

The demo-data/b2b_leaky.csv dataset contains a deliberate trap: cancel_date is filled only for customers who already churned. Here's what happens:

Leakage Guard — Verdict: BLOCK

[x] cancel_date almost perfectly predicts the target (AUC 0.998).
    Value appears to be known only after the event has occurred.
[x] final_status: column name resembles a post-event feature.
[x] cancel_date contains dates after the event time (100% of rows) — feature from the future.

Results will not be shown.
[ Exclude (cancel_date, final_status) and retrain ]

After "Exclude and retrain", AUC drops to 0.85. That's the real model. It's still good — but it's honest. The 0.998 was never yours.

Quick Start

git clone https://github.com/MarkIvor/predictorlab.git
cd predictorlab
cp .env.example .env    # change ADMIN_EMAIL / ADMIN_PASSWORD / secrets
docker compose up -d

Default admin is created from .env on first boot. Password change is required on first login.

Dev without Docker:

python -m venv .venv && .venv/bin/pip install -r backend/requirements.txt
cd backend && uvicorn app.main:app --port 8000
# second terminal:
cd frontend && npm install && npm run dev

Works fully offline and without LLM. When LLM_BASE_URL is empty, all LLM features are hidden. Training, predictions, intervals, thresholds — everything is deterministic code. LLM is only for: natural-language target suggestion, semantic column checking, and Model Card text. Raw data rows never leave the system (enforced by code + tested by a spy test).

Predict in 60 seconds

# Create a key in the UI (API tab) — shown once, stored as SHA-256 hash
export KEY=pl_live_...

# Get the model's input schema
curl http://localhost:8000/api/v1/models/1/schema -H "Authorization: Bearer $KEY"

# Predict with reasons
curl -X POST http://localhost:8000/api/v1/models/1/predict \
  -H "Authorization: Bearer $KEY" -H "Content-Type: application/json" \
  -d '{"data": [{"days_since_last_order": 75, "satisfaction": 2.1}], "include": ["reasons"]}'

Response:

{
  "predictions": [{
    "prediction_id": "prd_01J...",
    "label": "churn",
    "probability": 0.81,
    "decision": true,
    "threshold": 0.27,
    "conformal": {"coverage": 0.9, "prediction_set": ["churn"]},
    "out_of_distribution": false,
    "top_reasons": [
      {"feature": "days_since_last_order", "value": 75,
       "text": "No orders in 75 days: +18pp to risk"}
    ]
  }],
  "latency_ms": 62
}

Snippets for curl, Python, JavaScript, and 1C are auto-generated per model schema — they work without edits.

Share predictions

What-If and Counterfactuals

What-If sliders let you change any feature and watch the prediction and interval recalculate in real time (150ms debounce). A permanent disclaimer: "This is the model's response to a feature change, not a proven causal effect."

Counterfactuals go further: they find the minimum-cost change to actionable features that flips the prediction across the threshold. You define: allowed range, direction (only up / only down), and cost per unit of change. The system searches (greedy + random restarts, with a timeout) and returns:

Action: reduce discount_pct from 12% to 5%
Cost: 3,000 ₽
Probability before: 0.81 → after: 0.31
Expected ROI: 21,400 ₽

If the model says "change the customer's age" — it won't, because you marked it as immutable.

Monitoring

After the model is in production:

• Every prediction is logged (PII masked, TTL configurable)

• PSI drift computed per feature and per prediction distribution (7/30-day windows)

• Live metrics: real AUC/MAE from feedback vs validation numbers

• Webhooks fire on DRIFT or live-metric drop

• One-click retrain on fresh data; version comparison and rollback

Benchmarks

Full results: BENCHMARKS.md · Run: make bench

Tests & CI

make check     # lint + typecheck + unit + property + integration + llm + security + frontend (~2 min)
make test-e2e  # Playwright end-to-end
make test-ml   # ML quality: golden datasets, determinism, invariants
make bench     # performance benchmarks → BENCHMARKS.md

Honesty & Limitations

• Counterfactuals ≠ causality. "Reduce discount → probability drops" is the model's response to a feature change, not proof that the discount caused the churn.

• Conformal guarantee is marginal. 90% coverage holds on average across predictions, not for every individual object. For heavily imbalanced classes, set coverage may exceed α — that's a mathematical property of the method (see DECISIONS.md D-12).

• Small datasets give wide intervals. 200 rows → the interval is nearly useless. We show this honestly instead of hiding it behind a single number.

• Profit in rubles is only as good as your assumptions. All formulas and coefficients are expandable in the UI. The "+1.84M ₽" is true exactly to the extent your cost/benefit estimates are true.

• LLM never affects the numbers. Training, probabilities, intervals, thresholds, profit — all deterministic code. LLM writes texts only, and those pass a number validator that rejects any number not present in the computed fields.

• Time-series forecasting (v0.3) is pragmatic: lags + rolling stats + calendar features, one series at a time. Strong exotic seasonality is not modeled (DECISIONS.md D-10).

Tech Stack

License

MIT — like all Ivor's Lab repositories.

Telco Customer Churn © IBM (Apache 2.0 mirror), California Housing from A. Géron's course — both included in demo-data/ for offline demos.