LogosKG

A neural symbolic knowledge graph retrieval framework for efficient graph reasoning

LogosKG enables large language models to query massive knowledge graphs with sub-second latency, uncovering deep, multi-hop connections. Designed as a model-agnostic framework, it integrates into diverse downstream applications. By replacing traditional graph traversal with optimized sparse matrix operations, LogosKG makes deep graph exploration practical on standard hardware while preserving complete, interpretable reasoning paths.

LogosKG is an open-source academic research project from the University of Colorado Anschutz.

LogosKG is the framework that combines matrix-based efficiency with billion-scale scalability and complete path reconstruction—all on standard hardware.

Method (year) Matrix-based Scalability Path Tracking Device
Neo4j (Neo4j, Inc., 2025) CPU
TigerGraph (Deutsch et al., 2019) CPU
GraphBLAS (Kepner et al., 2016) CPU
igraph (Csardi and Nepusz, 2006) CPU
NetworkX (Hagberg et al., 2008) CPU
graph-tool (Peixoto, 2014) CPU
SNAP (Leskovec and Sosič, 2016) CPU
cuGraph (RAPIDS AI, 2025) GPU
DGL (Wang et al., 2019) GPU
PyG (Fey and Lenssen, 2019) GPU
LogosKG (ours, 2025) CPU/GPU

Table 1: Comparison of retrieval systems and libraries. Matrix-based indicates the use of linear-algebra primitives for retrieval. Note: Entries reflect default design; unavailable features can be achieved with additional code or preprocessing, at the cost of extra time and memory.

The Challenge: Traditional graph retrieval methods struggle with deep multi-hop queries over large knowledge graphs. As query depth increases, memory usage explodes and response times become impractical, forcing researchers to limit exploration to just 1-3 hops, missing valuable distant connections.

01

Efficient

Matrix-based operations replace pointer-chasing, achieving sub-second multi-hop queries even on deep knowledge graph traversals.

02

Scalable

Integrates graph partitioning, cross-partition routing, and on-demand caching to enable querying of massive knowledge graphs on a single machine, even with limited hardware resources.

03

Interpretable

Preserves complete reasoning paths, allowing clinicians and researchers to trace exact multi-hop connections for transparent diagnosis.

04

Model Agnostic

Easily integrated as a plug-and-play retrieval module to enhance downstream LLMs and various clinical decision support applications.

LogosKG uses a matrix-based workflow to process patient input, extract entities, and generate an initial diagnosis with an LLM. For very large graphs, it splits the graph into smaller subgraphs to achieve fast retrieval locally and merge the results globally. The retrieved evidence is then used to filter and enhance the diagnosis in a two-round pass, which improves prediction quality.

LogosKG System Architecture

Comprehensive evaluation of retrieval fidelity, computational efficiency, scalability, and downstream clinical impact.

Results Block 1

Retrieval Fidelity

We evaluate how accurately LogosKG retrieves relevant biomedical entities compared to established baselines using Jaccard similarity across hop distances.

Table A.1: Jaccard Similarity (LogosKG vs. Baselines)

LogosKG family Hop 1 Hop 2 Hop 3 Hop 4 Hop 5
Neo4j 1.00 1.00 1.00 1.00 1.00
GraphBLAS 1.00 1.00 1.00 1.00 1.00
igraph 1.00 1.00 1.00 1.00 1.00
NetworkX 1.00 1.00 1.00 1.00 1.00
graph-tool 1.00 1.00 1.00 1.00 1.00
SNAP 1.00 1.00 1.00 1.00 1.00
cuGraph 1.00 1.00 1.00 1.00 1.00
DGL 1.00 1.00 1.00 1.00 1.00
PyG 1.00 1.00 1.00 1.00 1.00

Higher values indicate stronger agreement (1.00 = identical results). LogosKG maintains perfect fidelity with established CPU/GPU baselines.

Results Block 2

Computational Efficiency

Comparison of Query Time (QT) in milliseconds and Timeout Rate (TR) across increasing hop distances on a standard CPU workload.

Method Hop 1 (2000 ms) Hop 2 (4000 ms) Hop 3 (6000 ms) Hop 4 (8000 ms) Hop 5 (10000 ms)
QT (ms) TR (%) QT (ms) TR (%) QT (ms) TR (%) QT (ms) TR (%) QT (ms) TR (%)
Baselines
NetworkX 0.21 0.00 5.47 0.00 93.92 0.00 621.95 0.00 1511.28 0.00
igraph 1.15 0.00 26.13 0.00 309.90 0.00 837.12 0.00 580.91 0.00
graph-tool > 1458.79 45.33 > 1900.01 10.00 > 2141.41 2.00 > 2396.95 0.67 > 2306.34 0.67
SNAP 1.80 0.00 10.02 0.00 115.00 0.00 378.81 0.00 446.15 0.00
GraphBLAS 3.03 0.00 43.64 0.00 291.89 0.00 528.07 0.00 415.43 0.00
Neo4j > 923.86 11.33 > 1946.43 20.00 > 5739.02 95.33 > 8000.00 100 > 10000.00 100
cuGraph > 722.66 3.33 > 919.30 0.67 1204.00 0.00 1504.82 0.00 1616.55 0.00
DGL > 966.65 10.00 > 989.91 0.67 1042.25 0.00 1121.70 0.00 1099.26 0.00
PyG 249.66 0.00 271.46 0.00 365.90 0.00 646.96 0.00 735.34 0.00
LogosKG family
LogosKG (Numba) 12.28 0.00 28.72 0.00 77.65 0.00 140.07 0.00 204.25 0.00
LogosKG (SciPy) 13.81 0.00 34.97 0.00 104.21 0.00 289.61 0.00 677.23 0.00
LogosKG (Torch-CPU) 526.55 0.00 884.89 0.00 1321.05 0.00 1803.18 0.00 2207.25 0.00
LogosKG (Torch-GPU) 6.00 0.00 14.40 0.00 43.07 0.00 77.73 0.00 101.05 0.00
LogosKG (Large-Numba) 4.76 0.00 25.52 0.00 226.83 0.00 1411.72 0.00 > 4085.72 4.00
LogosKG (Large-SciPy) 7.64 0.00 63.93 0.00 324.95 0.00 > 1660.91 0.67 > 4532.75 5.33
LogosKG (Large-Torch-CPU) 126.61 0.00 > 1205.50 0.67 > 2551.68 5.33 > 4836.16 22.00 > 7467.56 48.67
LogosKG (Large-Torch-GPU) 13.75 0.00 103.50 0.00 412.38 0.00 1634.93 0.00 > 4482.14 6.00
Table 2 Note: Retrieval efficiency comparison across hops. Timeout limits are fixed at 2000, 4000, 6000, 8000, and 10000 ms for 1–5 hops, respectively. All methods are run under the same CPU workload for fair comparison. For each hop, the best method is shown in bold and the second-best is underlined.
Results Block 3

Scalability Analysis

Performance analysis of LogosKG-Large on the PKG dataset across varying hops, batch sizes, cache sizes, and backends.

Exp. 1: hops (Numba, cache size n = 16, batch size=50)
Factor Value QT (ms) Loads Evicts
hops 1 3410.90 16 0
hops 2 1610.78 16 0
hops 3 6114.69 16 0
hops 4 19592.08 16 0
hops 5 62726.25 16 0
Exp. 2: batch size (Numba, cache size n = 16, hops k = 2)
Factor Value QT (ms) Loads Evicts
batch size 1 100912.09 12 0
batch size 10 5489.45 16 0
batch size 25 1365.09 16 0
batch size 50 1499.39 16 0
batch size 100 1444.68 16 0
batch size 150 1483.49 16 0
Exp. 3: cache size (Numba, hops k = 2, batch size=50)
Factor Value QT (ms) Loads Evicts
cache size 1 441870.19 3010 3009
cache size 2 419436.59 2918 2916
cache size 4 384086.42 2659 2655
cache size 8 304066.00 1967 1959
cache size 16 4037.69 16 0
Exp. 4: backend (cache size n = 16, hops k = 2, batch size=50)
Factor Value QT (ms) Loads Evicts
backend Numba 4143.16 16 0
backend SciPy 3889.86 16 0
backend Torch-CPU 245311.21 16 0
backend Torch-GPU 6409.32 16 0

Featured Projects

Clinical Application

Clinical Diagnosis Prediction

Leveraging LogosKG to enhance LLM diagnostic accuracy on complex patient narratives through 2-round multi-hop retrieval.

Facilitate LLM Finetuning

KG-Based LLM Finetuning

Fine-tuning large language models with structured reasoning paths retrieved by LogosKG to improve downstream applications, such as biomedical reasoning.

Ongoing Project · Under Construction

Biomedical Discovery

Scaling retrieval across billion-scale biomedical knowledge graphs for robust hypothesis generation and validation.

Interactive Sandbox

Query the KG in real-time. Graph visualization dynamically truncates large retrievals for browser stability.

Heart Disease Diabetes Hypertension
Traversal Depth k=2
Compute Latency 0ms
Total Retrieved 0
Depth k=0
⚠️ Graph truncated: Displaying limited paths to prevent browser instability.
Computing Sparse Matrices...
Citation
@article{cheng2026scaling, title={Scaling Biomedical Knowledge Graph Retrieval for Interpretable Reasoning: Applications to Clinical Diagnosis Prediction}, author={Cheng, He and Wu, Yifu and Khatwani, Saksham and Kruse, Maya and Dligach, Dmitriy and Miller, Timothy and Afshar, Majid and Gao, Yanjun}, journal={medRxiv}, pages={2026--01}, year={2026} }
Cheng, H., Wu, Y., Khatwani, S., Kruse, M., Dligach, D., Miller, T., Afshar, M., & Gao, Y. (2026). Scaling Biomedical Knowledge Graph Retrieval for Interpretable Reasoning: Applications to Clinical Diagnosis Prediction. medRxiv, 2026-01.
Cheng H, Wu Y, Khatwani S, et al. Scaling Biomedical Knowledge Graph Retrieval for Interpretable Reasoning: Applications to Clinical Diagnosis Prediction. medRxiv. 2026:2026-01.
Acknowledgment

This research is supported by the National Institutes of Health (NIH). We gratefully acknowledge the support from the National Library of Medicine (NLM).

NIH Logo

Supported by NIH Grants: R00LM014308

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