code-review-graph Export Formats: GraphML, Neo4j, Obsidian, and More

code-review-graph supports five distinct export formats including GraphML for desktop visualization tools, Neo4j Cypher for graph databases, and Obsidian vaults for knowledge bases, alongside JSON and SVG outputs.

The code-review-graph project by tirth8205 analyzes code review data to generate relationship graphs. Once your graph is constructed, the exports module in code_review_graph/exports.py provides multiple serialization strategies, allowing you to move data into specialized tools for further analysis or visualization.

Supported Export Formats

The tool can serialize graphs into five interchangeable formats, each implemented as a dedicated function in the exports module.

JSON

The JSON export produces a UTF-8 encoded file containing the complete graph payload—nodes, edges, and community metadata. This format is ideal for programmatic consumption or archival storage. The implementation resides in export_json at code_review_graph/exports.py lines 23-52.

GraphML

GraphML is an XML-based format supported by desktop visualization tools such as Gephi, yEd, and Cytoscape. Exporting to this format allows you to apply force-directed layouts and advanced filtering outside the CLI environment. Use the export_graphml function found in exports.py.

Neo4j Cypher

The Neo4j Cypher export generates a text file containing CREATE statements compatible with Neo4j Browser or cypher-shell. You can paste these statements directly into a Neo4j instance to populate a native graph database.

Obsidian Vault

The Obsidian vault export creates a directory of Markdown files with YAML front-matter and wikilinks, ready for import into Obsidian. This format includes community overview pages, making it suitable for personal knowledge management and documentation workflows. The export_obsidian_vault function handles this conversion in exports.py.

SVG

SVG exports produce static vector images of the graph layout. This requires the optional matplotlib dependency and is handled by export_svg in exports.py.

How the Export Pipeline Works

All exports follow a three-stage pipeline defined across visualization.py and exports.py.

1. Data Gathering: The export_graph_data function in code_review_graph/visualization.py (lines 172-19) queries the GraphStore and builds a canonical dictionary containing nodes, edges, and community metadata.

2. Serialization: Each format-specific function—such as export_graphml or export_neo4j_cypher—transforms the dictionary into its target representation (XML strings, Cypher commands, Markdown pages, etc.).

3. Atomic Write: Exporters write to a temporary file before atomically replacing the target path. This pattern, visible in export_json at lines 30-47 of exports.py, ensures file integrity even if the process terminates unexpectedly.

Exporting via the Python API

You can invoke exports programmatically after constructing a GraphStore instance.

from pathlib import Path
from code_review_graph.graph import GraphStore
from code_review_graph.exports import (
    export_json,
    export_graphml,
    export_neo4j_cypher,
    export_obsidian_vault,
    export_svg,
)

store = GraphStore(Path("/tmp/mygraph.db"))

# JSON

export_json(store, Path("out/graph.json"))

# GraphML

export_graphml(store, Path("out/graph.graphml"))

# Neo4j Cypher

export_neo4j_cypher(store, Path("out/graph.cypher"))

# Obsidian vault (directory)

export_obsidian_vault(store, Path("out/obsidian_vault"))

# SVG (requires matplotlib)

export_svg(store, Path("out/graph.svg"))

Exporting via the Command Line

The visualize command in code_review_graph/cli.py exposes all formats via the --format flag. Outputs are written to <repo_root>/.code-review-graph/data/.

# Export as GraphML for Gephi

code-review-graph visualize --format graphml

# Export as Neo4j Cypher statements

code-review-graph visualize --format cypher

# Export as an Obsidian vault

code-review-graph visualize --format obsidian

# Export as SVG image

code-review-graph visualize --format svg

The CLI dispatcher maps each format string to its corresponding export function: export_json, export_graphml, export_neo4j_cypher, export_obsidian_vault, or export_svg.

Key Implementation Files

File	Role
code_review_graph/exports.py	Implements all export functions and atomic write logic.
code_review_graph/visualization.py	Contains export_graph_data, the shared data preparation routine.
code_review_graph/cli.py	Parses --format arguments and dispatches to the appropriate exporter.

Summary

• code-review-graph offers five export formats: JSON, GraphML, Neo4j Cypher, Obsidian vault, and SVG.
• All exports use a three-step pipeline: data gathering via export_graph_data, format-specific serialization, and atomic file writing.
• Use the Python API for custom workflows or the CLI visualize --format command for quick exports.
• GraphML targets desktop visualization tools, while Cypher enables Neo4j database imports and Obsidian vaults support knowledge management.

Frequently Asked Questions

Which export format should I use for Gephi or Cytoscape?

Use the GraphML format. The export_graphml function in code_review_graph/exports.py generates XML compatible with these desktop applications, preserving node and edge attributes for interactive exploration.

Can I import graph data directly into a Neo4j database?

Yes. Select the Cypher export format using --format cypher or the export_neo4j_cypher Python function. The resulting .cypher file contains CREATE statements that you can execute in Neo4j Browser or pipe directly into cypher-shell to populate your graph database.

What does the Obsidian vault export include?

The Obsidian vault export generates a directory of Markdown files with YAML front-matter describing each node, plus wikilinks representing edges. Community detection results are summarized in overview pages, allowing you to navigate code review relationships as a linked knowledge base inside Obsidian.

Is matplotlib required for all exports?

No. The SVG format is the only export that requires the optional matplotlib dependency. JSON, GraphML, Cypher, and Obsidian exports function with only the base package installed.

{
  "mcpServers": {
    "instagit": {
      "command": "npx",
      "args": ["-y", "instagit@latest"]
    }
  }
}