GraphWizard

A complete graph algorithm library for Go

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GraphWizard provides 40+ graph algorithms through a clean, consistent API built on gonum/graph interfaces. Cleanroom implementations from academic papers, plus unified wrappers around gonum's built-in algorithms — one import per domain, no iterator gymnastics required.

New: The diskgraph package provides a bbolt-backed graph that is faster than in-memory gonum graphs for most algorithms while also supporting persistence and out-of-core processing. See Recommended: diskgraph below.

Origin Story

GraphWizard was born out of the ACT-IAC 2026 AI Hackathon, where our team at Intelligrit built Integrity — an AI-powered system that detects anomalous Medicare provider billing patterns using only public data. We won the hackathon.

Integrity's graph analysis pipeline relied on Memgraph and its MAGE algorithm library for fraud network detection: community clustering, centrality scoring, bridge detection, and co-prescribing anomaly analysis across 5.8 million provider nodes and 82.6 million edges. When we evaluated our long-term architecture, we realized we needed a pure Go solution — no external graph database, no Docker dependency, no Bolt protocol. Just algorithms that run in-process on gonum graph structures loaded from DuckDB.

We looked at the Go ecosystem and found gonum covers the basics well, but there's no comprehensive library that fills the gaps: no Leiden, no Katz, no bipartite matching, no bridge detection, no MST, no embeddings. So we built one — including diskgraph, a bbolt-backed graph store that turned out to be faster than gonum's in-memory graphs for most algorithms, while also handling our 82.6M edge dataset without requiring everything in RAM.

Every algorithm is implemented cleanroom from the original academic papers. Every exported function has godoc, examples, and tests. The result is a library we needed — and that we think the Go graph community needs too.

Install

go get github.com/intelligrit/graphwizard

Packages

Package	Algorithms	Source
diskgraph	Disk-backed Undirected/Directed graphs with auto-preloading, bbolt storage	Custom
centrality	PageRank, Betweenness, Closeness, Harmonic, HITS, Katz, Degree, Personalized PageRank, Eccentricity, Diameter, Radius, Influence Maximization	Custom + gonum
community	Leiden, Louvain, Label Propagation, Spectral Clustering	Custom + gonum
connectivity	Bridges, Biconnected Components, Articulation Points, WCC, SCC, Cycles, Union-Find, DAG Condensation, K-Core, Degeneracy, Topological Sort	Custom + gonum
embedding	Node2Vec Walks, DeepWalk Walks, SVD Embedding	Custom
flow	Max Flow (Dinic), Min Cut	Custom + gonum
matching	Hopcroft-Karp Bipartite Matching	Custom
paths	Dijkstra, Bellman-Ford, Floyd-Warshall, A*, Yen's K Shortest	Custom + gonum
similarity	Jaccard, Overlap, Cosine, SimRank, Common Neighbors, Adamic-Adar, Preferential Attachment, Link Prediction	Custom
structure	Clustering Coefficient, Triangle Count, Cliques, Coloring, Set Cover, Kruskal MST, Prim MST, TSP, Bipartite Projection	Custom + gonum
traverse	BFS, DFS, BFS Path	gonum

Quick Start

package main

import (
    "fmt"

    "github.com/intelligrit/graphwizard/centrality"
    "github.com/intelligrit/graphwizard/community"
    "github.com/intelligrit/graphwizard/connectivity"
    "github.com/intelligrit/graphwizard/diskgraph"
)

func main() {
    // Build a graph on disk (persisted to a file).
    b, _ := diskgraph.NewUndirectedBuilder("example.db")
    b.Batch(func(tx *diskgraph.UndirectedTx) error {
        tx.AddEdge(0, 1)
        tx.AddEdge(1, 2)
        tx.AddEdge(2, 0)
        tx.AddEdge(2, 3)
        return nil
    })
    b.Close()

    // Open the graph — adjacency is auto-preloaded for speed.
    g, _ := diskgraph.OpenUndirected("example.db")
    defer g.Close()

    // Find bridge edges.
    bridges := connectivity.Bridges(g)
    fmt.Printf("Bridges: %d\n", len(bridges)) // 1 (edge 2-3)

    // Degree centrality.
    deg := centrality.Degree(g)
    fmt.Printf("Node 2 centrality: %.2f\n", deg[2]) // 1.00

    // Community detection.
    comms := community.Louvain(g, 1.0, nil)
    fmt.Printf("Communities: %v\n", comms)
}

Recommended: diskgraph

We recommend diskgraph as the default graph storage for all GraphWizard workloads. It replaces gonum/graph/simple with a bbolt-backed implementation that is:

• Faster — benchmarks show diskgraph matches or beats in-memory simple.UndirectedGraph on 40+ algorithms. Algorithms like PreferentialAttachment run 4x faster; most run 10-30% faster.

• Persistent — build the graph once, reopen it instantly across program runs. No serialization, no import step. The bolt file is the database.

• Scalable — graphs too large for RAM work automatically. Pass NoPreload and the graph reads directly from disk via memory-mapped I/O.

• Tunable — pass Preload to cache adjacency data in Go memory for O(1) HasEdgeBetween on algorithms like ClusteringCoefficient. Without it, reads go through bolt's memory-mapped file with zero heap allocation.

// Build once (use Batch for best write performance).
b, _ := diskgraph.NewUndirectedBuilder("providers.db")
b.Batch(func(tx *diskgraph.UndirectedTx) error {
    for _, edge := range edges {
        tx.AddWeightedEdge(edge.From, edge.To, edge.Weight)
    }
    return nil
})
b.Close()

// Open anywhere, any time — file IS the graph.
g, _ := diskgraph.OpenUndirected("providers.db")
defer g.Close()

// All GraphWizard algorithms work unchanged.
comms := community.Leiden(g, 1.0, rng)
scores := centrality.Degree(g)
bridges := connectivity.Bridges(g)

When to use simple.UndirectedGraph instead: Only when you need a mutable graph (adding/removing edges after construction) or when building ephemeral throwaway graphs in tests. For all analytical workloads, use diskgraph.

Best Practices

See BEST_PRACTICES.md for detailed guidance on: choosing algorithm variants for your graph size, loading from SQL, anomaly detection pipelines, streaming updates, performance tips, and a complexity reference table for every algorithm.

Design Principles

• One import per domain. No need to learn gonum's iterator patterns or juggle multiple package imports. centrality.PageRank(g, 0.85, 1e-6) just works.

• Consistent return types. Centrality measures return map[int64]float64. Components return [][]int64. No custom iterator types to unpack.

• Standard interfaces. Every function accepts graph.Graph, graph.Undirected, or graph.Directed from gonum. Build your graph with diskgraph (recommended) or simple.NewUndirectedGraph() and pass it to any algorithm.

• Cleanroom implementations. Custom algorithms are implemented from academic papers, not ported from existing libraries. Each function documents its reference paper.

• Tested and documented. 97.3% test coverage. 36 runnable examples. Every exported function has godoc comments.

Academic References

Algorithm	Paper
Leiden	Traag, Waltman, van Eck. "From Louvain to Leiden." Scientific Reports, 2019
Label Propagation	Raghavan, Albert, Kumara. "Near linear time algorithm to detect community structures." Physical Review E, 2007
Katz Centrality	Katz. "A New Status Index Derived from Sociometric Analysis." Psychometrika, 1953
Personalized PageRank	Haveliwala. "Topic-Sensitive PageRank." WWW, 2002
Hopcroft-Karp	Hopcroft, Karp. "An n^(5/2) Algorithm for Maximum Matchings in Bipartite Graphs." SIAM J. Computing, 1973
Yen's K Shortest	Yen. "Finding the K Shortest Loopless Paths in a Network." Management Science, 1971
Bridges	Tarjan. "A Note on Finding the Bridges of a Graph." Information Processing Letters, 1974
Biconnected Components	Hopcroft, Tarjan. "Algorithm 447." Communications of the ACM, 1973
Kruskal MST	Kruskal. "On the Shortest Spanning Subtree." Proceedings of the AMS, 1956
Prim MST	Prim. "Shortest Connection Networks." Bell System Technical Journal, 1957
Node2Vec	Grover, Leskovec. "node2vec: Scalable Feature Learning for Networks." KDD, 2016
DeepWalk	Perozzi, Al-Rfou, Skiena. "DeepWalk: Online Learning of Social Representations." KDD, 2014
SVD Embedding	Levy, Goldberg. "Neural Word Embedding as Implicit Matrix Factorization." NIPS, 2014
Clustering Coefficient	Watts, Strogatz. "Collective dynamics of 'small-world' networks." Nature, 1998
Set Cover	Chvatal. "A Greedy Heuristic for the Set-Covering Problem." Mathematics of Operations Research, 1979
TSP 2-opt	Croes. "A Method for Solving Traveling-Salesman Problems." Operations Research, 1958
Adamic-Adar	Adamic, Adar. "Friends and neighbors on the Web." Social Networks, 2003
SimRank	Jeh, Widom. "SimRank: A Measure of Structural-Context Similarity." KDD, 2002
Influence Maximization	Kempe, Kleinberg, Tardos. "Maximizing the Spread of Influence." KDD, 2003
CELF Optimization	Leskovec et al. "Cost-effective Outbreak Detection in Networks." KDD, 2007
Spectral Clustering	Ng, Jordan, Weiss. "On Spectral Clustering." NIPS, 2001
Min Cut	Ford, Fulkerson. "Maximal Flow Through a Network." Canadian J. Math, 1956

Stats

• 50+ source files, 50+ test files
• 7,500+ lines of Go
• 220+ test and example functions
• 97%+ statement coverage (5 packages at 100%)
• Dependencies: gonum (algorithms), bbolt (disk storage)

License

MIT. See LICENSE.

About Intelligrit

Intelligrit LLC is a technology company focused on AI-powered solutions for government program integrity. GraphWizard is one piece of the analytical toolkit we built to detect fraud, waste, and abuse in federal healthcare programs.