Welt Python SDK

From a DataFrame to a prediction. Use familiar Classifier and Regressor estimators backed by durable predictors in your private Welt workspace. Install welt-client, import welt. Python 3.11–3.13.

Start here · Guides · Reference · Models and limits

Install

python -m pip install "welt-client[parquet]==0.7.1"

Create a workspace API key at Welt with Allow writes, fits and predictions enabled. Configure WELT_API_KEY through local secret configuration or a hidden getpass prompt. Keep the secret out of source, notebooks, logs and shell history. SDK 0.7 defaults to https://welt.ergodic.dev; an explicit base_url overrides WELT_BASE_URL, which overrides that default. Local development must explicitly select localhost.

Learn with real data

Download Iris from our research inventory, look at the table, split train/test, fit a classifier, predict unseen rows, and measure the result:

from pathlib import Path
from tempfile import mkdtemp
import pandas as pd
from sklearn.model_selection import train_test_split
from sklearn.metrics import accuracy_score, classification_report
from welt import Client, Classifier

# 1. Get a real table from Welt's research inventory.
dataset_id = "asset-d839644b6de36fc5cafdda18c5daeca3"
version = "d839644b6de36fc5cafdda18c5daeca3284a5ce8bb6169aff2fcb3fbb4a12021"
path = Path(mkdtemp(prefix="welt-iris-")) / "iris.parquet"
with Client() as client:
    info = client.research_dataset(dataset_id)
    print("Dataset:", info["name"], "— License:", info["license"])
    for notice in info["license_notices"]:
        print(notice)
    client.download_research_dataset(dataset_id, path, version=version)
data = pd.read_parquet(path)
target = "__target__#0"  # The target recorded in this research snapshot.

# 2. Look at the rows before modelling.
print(data.head())
print("Rows and columns:", data.shape)
data.info()
print(data[target].value_counts())

# 3. Set aside test rows before fitting; never train on their answers.
train, test = train_test_split(
    data, test_size=0.2, random_state=9, stratify=data[target])
query = test.drop(columns=target)
y_test = test[target]
print("Training rows:", len(train), "— Test rows:", len(test))

# 4. Create a model and train it on the training table.
model = Classifier(model="tabicl-v2", random_state=9)
model.fit(train, target=target)

# 5. Predict the held-out rows, without passing their target column.
predictions = model.predict(query)
print(pd.DataFrame({"actual": y_test.to_numpy(), "predicted": predictions}).head())

# 6. Compare predictions with the answers we kept aside.
print("Test accuracy:", accuracy_score(y_test, predictions))
print(classification_report(y_test, predictions, zero_division=0))
print("Keep this predictor ID:", model.predictor_id_)

Accuracy and per-class precision/recall/F1 describe your held-out run, not a promised benchmark score. Start explains each step and teaches numeric predictions with real Yacht data. fit uploads only your training rows; your workspace retains the resulting dataset and predictor for reuse.

SDK 0.7 adds explicit DataFrame target convenience and hosted credential guidance while preserving fit(X, y), sync/async resources, durable jobs, research downloads and native causal objects. Available hosted tasks and workers follow the service catalogue. Bounded TabICLv2, Kumo Medium, TabDPT1.3 and Mitra-v2 classification and regression previews are separately qualified: 500 training rows, 20 features, 100 query rows, and 10 classes for classification. Other tasks need separate qualification. File reads load into memory. Held resumable CSV and large batch APIs are excluded.

A local wait timeout leaves server work running. Reconnect by its job ID rather than fitting again; recovery describes typed failures, authentication, cancellation and retry behavior. Probabilities are not calibrated coverage. ArrowFM, CDFM and AVICI discovery preserve native graph and score semantics; causal conversion is restricted to declared native DAGs and the separately approved Ergodic co-release artifact. Public Ergodic distribution and the complete all-model catalogue remain gated.

Examples and development

Runnable script · Jupyter notebooks · Research datasets · Contributing

uv sync --frozen
uv run --frozen pytest -q
uv build

Offline tests patch HTTP transport outside user examples; they neither contact the hosted service nor measure foundation-model quality. Notebook sources have cleared outputs; clean-wheel execution and bounded authorized live acceptance are separate evidence. CI requires no private backend, credentials or checkpoints.

Apache 2.0: see LICENSE. Model weights and hosted service are separate from this SDK licence.