SERF: Agentic Semantic Entity Resolution Framework

SERF is an open-source framework for semantic entity resolution — identifying when two or more records refer to the same real-world entity using large language models, sentence embeddings, and agentic AI.

SERF runs multiple rounds of entity resolution until the dataset converges to a stable state, with DSPy agents controlling all phases dynamically.

Source: Entity Resolution: Identifying Real-World Entities in Noisy Data

Features

Phase 0 — Agentic Control

DSPy ReAct agents dynamically orchestrate the entire pipeline, adjusting blocking parameters, selecting matching strategies, and deciding when convergence is reached.

Phase 1 — Semantic Blocking

Clusters records using Qwen3 sentence embeddings and FAISS IVF to create efficient blocks for comparison. Auto-scales block size across iterations.

Phase 2 — Schema Alignment, Matching and Merging

All three operations in a single LLM prompt via DSPy signatures with the BAMLAdapter for structured output formatting. Block-level matching lets the LLM see all records simultaneously for holistic decisions.

Phase 3 — Edge Resolution

For knowledge graphs: deduplicate edges that result from merging nodes using LLM-guided intelligent merging.

Architecture

Component	Technology
Package Manager	uv
Data Processing	PySpark 4.x
LLM Framework	DSPy 3.x with BAMLAdapter
Embeddings	multilingual-e5-base via sentence-transformers
Vector Search	FAISS IndexIVFFlat
Linting/Formatting	Ruff
Type Checking	zuban (mypy-compatible)

Quick Start

Installation

git clone https://github.com/Graphlet-AI/serf.git
cd serf
uv sync --extra dev

Docker

# Build
docker compose build

# Run any serf command
docker compose run serf benchmark --dataset dblp-acm

# Run benchmarks
docker compose --profile benchmark up

# Run tests
docker compose --profile test up

# Analyze a dataset (put your file in data/)
docker compose run serf analyze --input data/input.csv --output data/er_config.yml

Set your API key in a .env file or export it:

echo "GEMINI_API_KEY=your-key" > .env

System Requirements

• Python 3.12+
• Java 11/17/21 (for PySpark)
• 4GB+ RAM recommended

CLI Usage

# Profile a dataset
serf analyze --input data/companies.parquet

# Run the full ER pipeline
serf resolve --input data/entities.csv --output data/resolved/ --iteration 1

# Run individual phases
serf block --input data/entities.csv --output data/blocks/ --method semantic
serf match --input data/blocks/ --output data/matches/ --iteration 1
serf eval --input data/matches/

# Benchmark against standard datasets
serf download --dataset dblp-acm
serf benchmark --dataset dblp-acm --output data/results/

Python API

from serf.block.pipeline import SemanticBlockingPipeline
from serf.match.matcher import EntityMatcher
from serf.eval.metrics import evaluate_resolution

# Block
pipeline = SemanticBlockingPipeline(target_block_size=50)
blocks, metrics = pipeline.run(entities)

# Match
matcher = EntityMatcher(model="gemini/gemini-2.0-flash")
resolutions = await matcher.resolve_blocks(blocks)

# Evaluate
metrics = evaluate_resolution(predicted_pairs, ground_truth_pairs)

DSPy Interface

import dspy
from serf.dspy.signatures import BlockMatch
from serf.dspy.baml_adapter import BAMLAdapter

lm = dspy.LM("gemini/gemini-2.0-flash", api_key=GEMINI_API_KEY)
dspy.configure(lm=lm, adapter=BAMLAdapter())

matcher = dspy.ChainOfThought(BlockMatch)
result = matcher(block_records=block_json, schema_info=schema, few_shot_examples=examples)

Benchmark Results

Performance on standard ER benchmarks from the Leipzig Database Group. Blocking uses multilingual-e5-base name-only embeddings + FAISS IVF. Matching uses Gemini 2.0 Flash via DSPy BlockMatch.

Dataset	Domain	Left	Right	Matches	Precision	Recall	F1
DBLP-ACM	Bibliographic	2,616	2,294	2,224	0.8849	0.5809	0.7014

Blocking uses name-only embeddings for tighter semantic clusters. All matching decisions are made by the LLM — no embedding similarity thresholds.

Project Structure

src/serf/
├── cli/             # Click CLI commands
├── dspy/            # DSPy types, signatures, agents, adapter
├── block/           # Semantic blocking (embeddings, FAISS, normalization)
├── match/           # UUID mapping, LLM matching, few-shot examples
├── merge/           # Field-level entity merging
├── edge/            # Edge resolution for knowledge graphs
├── eval/            # Metrics, benchmark datasets
├── analyze/         # Dataset profiling, field detection
├── spark/           # PySpark schemas, utils, Iceberg, graph components
├── config.py        # Configuration management
└── logs.py          # Logging

Configuration

All configuration is centralized in config.yml:

from serf.config import config
model = config.get("models.llm")  # "gemini/gemini-2.0-flash"
block_size = config.get("er.blocking.target_block_size")  # 50

Development

# Install dependencies
uv sync

# Run tests
uv run pytest tests/

# Lint and format
uv run ruff check --fix src tests
uv run ruff format src tests

# Type check
uv run zuban check src tests

# Pre-commit hooks
pre-commit install
pre-commit run --all-files

References

1. Jurney, R. (2024). "The Rise of Semantic Entity Resolution." Towards Data Science.
2. Khattab, O. et al. (2024). "DSPy: Compiling Declarative Language Model Calls into Self-Improving Pipelines." ICLR 2024.
3. Li, Y. et al. (2021). "Ditto: A Simple and Efficient Entity Matching Framework." VLDB 2021.
4. Mudgal, S. et al. (2018). "Deep Learning for Entity Matching: A Design Space Exploration." SIGMOD 2018.
5. Papadakis, G. et al. (2020). "Blocking and Filtering Techniques for Entity Resolution: A Survey." ACM Computing Surveys.

License

Apache License 2.0. See LICENSE for details.