nobs-canonicalize

Canonicalize verbose text strings into clean, deduplicated canonical groups using embeddings + LLM reasoning.

Given a list of noisy, verbose text strings (e.g. medical interventions, product names, user inputs), this library:

1. Clusters similar strings using BERTopic or FAISS+Leiden
2. Names each cluster with a clean canonical label via LLM (o3-mini)
3. Classifies outliers into the named groups, reducing ungrouped items

How it works

graph TD;
    A[Surface strings] --> B((1. Cluster<br>BERTopic or FAISS+Leiden));
    B -->|groups| C((2. Name groups<br>via LLM));
    B -->|outliers| D((3. Classify outliers<br>into groups));
    C -->|canonical labels| D;
    D --> E[Canonical Concepts];

1. Cluster — Groups surface strings using text-embedding-3-large embeddings
2. Name — o3-mini generates a clean canonical label for each group
3. Classify outliers — o3-mini assigns ungrouped strings into the named groups
4. Output — deduplicated canonical concepts ready for downstream use

Clustering backends

Two clustering backends are available, selectable via the backend parameter:

BERTopic (default)

Uses HDBSCAN + UMAP under the hood. Good for small-to-medium datasets.

FAISS+Leiden

Uses FAISS nearest-neighbor search to build a kNN similarity graph, then Leiden community detection to find clusters. Better for large datasets.

Why use FAISS+Leiden over BERTopic?

• Scale — BERTopic's UMAP+HDBSCAN pipeline slows down significantly past ~50K strings. FAISS is built for large-scale similarity search and Leiden scales to graphs with millions of nodes.
• Lighter dependencies — BERTopic pulls in hdbscan, umap-learn, and sentence-transformers. FAISS+Leiden only needs faiss-cpu and python-igraph.
• Tunable graph construction — You control the kNN graph directly via n_neighbors and min_sim (minimum cosine similarity threshold), which often matters more than clustering algorithm parameters.

Comparison on 1,022 diet intervention strings:

Both backends produce similar cluster quality. Outliers are handled downstream by the LLM classification step regardless of backend.

Install

pip install nobs-canonicalize

Requires python >= 3.11, < 3.15.

Example usage

OpenAI (BERTopic backend — default)

import os

from dotenv import load_dotenv
from rich import print

from nobs_canonicalize import nobs_canonicalize

load_dotenv()
openai_api_key = os.environ["OPENAI_API_KEY"]

texts = [
    "16/8 fasting",
    "16:8 fasting",
    "24-hour fasting",
    "24-hour one meal a day (OMAD) eating pattern",
    "2:1 ketogenic diet, low-glycemic-index diet",
    "30-day nutrition plan",
    "36-hour fast",
    "4-day fast",
    "40 hour fast, low carb meals",
    "4:3 fasting",
    "5-day fasting-mimicking diet (FMD) program",
    "7 day fast",
    "84-hour fast",
    "90/10 diet",
    "Adjusting macro and micro nutrient intake",
    "Adjusting target macros",
    "Macro and micro nutrient intake",
    "AllerPro formula",
    "Alternate Day Fasting (ADF), One Meal A Day (OMAD)",
    "American cheese",
    "Atkin's diet",
    "Atkins diet",
    "Avoid seed oils",
    "Avoiding seed oils",
    "Limiting seed oils",
    "Limited seed oils and processed foods",
    "Avoiding seed oils and processed foods",
]

clusters = nobs_canonicalize(
    texts=texts,
    openai_api_key=openai_api_key,
    reasoning_effort="low",  # low, medium, high
    subject="personal diet intervention outcomes",
)
print(clusters)

OpenAI (FAISS+Leiden backend)

clusters = nobs_canonicalize(
    texts=texts,
    openai_api_key=openai_api_key,
    reasoning_effort="low",
    subject="personal diet intervention outcomes",
    backend="faiss_leiden",  # use FAISS+Leiden instead of BERTopic
)

Azure OpenAI

import os

from dotenv import load_dotenv

from nobs_canonicalize import nobs_canonicalize_azure, AzureConfig

load_dotenv()

azure_config = AzureConfig(
    api_key=os.environ["AZURE_OPENAI_API_KEY"],
    api_version="2024-12-01-preview",
    azure_endpoint="https://your-resource.openai.azure.com/",
    embedding_deployment="text-embedding-3-large",  # default
    llm_deployment="o3-mini",                        # default
)

clusters = nobs_canonicalize_azure(
    texts=texts,
    reasoning_effort="low",
    subject="personal diet intervention outcomes",
    azure_config=azure_config,
    backend="faiss_leiden",  # optional, defaults to "bertopic"
)
print(clusters)

Example output

Contributing

git clone git@github.com:borisdev/nobs-canonicalize.git
cd nobs-canonicalize
pip install -e .
# set the OPENAI_API_KEY in the code or as an environment variable
poetry run pytest tests/test_models.py -v  # unit tests, no API key needed
poetry run pytest tests/test_main.py::test_nobs_canonicalize -v  # integration test