# How to Export the Code-Review Graph to Neo4j, GraphML, or Obsidian > Export code-review graphs to Neo4j, GraphML, or Obsidian. Learn how to use the visualize sub-command with the format flag for seamless data export and analysis. - Repository: [Tirth Kanani/code-review-graph](https://github.com/tirth8205/code-review-graph) - Tags: how-to-guide - Published: 2026-07-25 --- **The `code-review-graph` CLI exports internal dependency graphs to Neo4j Cypher scripts, GraphML XML files, or Obsidian vaults using the `visualize` sub-command with the `--format` flag.** The `code-review-graph` repository provides a Python-based tool for analyzing code dependencies and review patterns. Once the internal graph is built, you can export it to multiple portable formats to visualize in external tools like Neo4j Browser, Gephi, or Obsidian. All export logic resides in [`code_review_graph/exports.py`](https://github.com/tirth8205/code-review-graph/blob/main/code_review_graph/exports.py) and is exposed through the `visualize` command defined in [`code_review_graph/cli.py`](https://github.com/tirth8205/code-review-graph/blob/main/code_review_graph/cli.py). ## How the Export Pipeline Works The export process follows a structured pipeline that gathers graph data and dispatches it to format-specific serializers. 1. **Gather graph data** – The function `export_graph_data(store)` (defined in [`graph.py`](https://github.com/tirth8205/code-review-graph/blob/main/graph.py)) returns a dictionary containing `nodes`, `edges`, and optional `communities`. 2. **Parse format choice** – The CLI accepts a `--format` argument with specific choices. According to [`code_review_graph/cli.py`](https://github.com/tirth8205/code-review-graph/blob/main/code_review_graph/cli.py) around line 790, valid choices are: ```python choices=["html", "json", "graphml", "cypher", "obsidian", "svg"] ``` 3. **Dispatch to formatter** – Based on the format value, the CLI calls the matching export function (lines 1668‑1676 in [`cli.py`](https://github.com/tirth8205/code-review-graph/blob/main/cli.py)): ```python elif fmt == "graphml": out = export_graphml(store, out_path) elif fmt == "cypher": out = export_neo4j_cypher(store, out_path) elif fmt == "obsidian": out = export_obsidian_vault(store, out_dir) ``` 4. **Atomic write** – Each exporter writes output to a temporary file before renaming it to the final destination, ensuring data integrity. ## Exporting to GraphML The **GraphML** export generates a standards-compliant XML document suitable for import into Gephi, yEd, or Cytoscape. The `export_graphml()` function constructs the XML header and defines `` elements for node properties (`kind`, `file`, `language`, `community`) and edge properties (`edge_kind`). It iterates over the node and edge dictionaries to emit `` and `` elements, escaping XML-unsafe characters to prevent document corruption. Example XML structure generated: ```xml Class src/my/package/Class.java java 1 ``` Implementation details are located in [`code_review_graph/exports.py`](https://github.com/tirth8205/code-review-graph/blob/main/code_review_graph/exports.py) at lines 58‑67 and 85‑110. ## Exporting to Neo4j Cypher The **Neo4j Cypher** export produces a text file containing Cypher `CREATE` statements that can be executed directly in the Neo4j Browser or via `cypher-shell`. The `export_neo4j_cypher()` function generates: - A `CREATE (: {...})` statement for every node, using the node kind as the label and including properties like `qualified_name`, `file`, and `language`. - A `MATCH (a {qualified_name: "..."}), (b {qualified_name: "..."}) CREATE (a)-[:]->(b)` pattern for every edge. Property values are escaped using an internal `_cypher_escape()` helper to handle special characters in Cypher literals. The implementation spans lines 124‑166 in [`code_review_graph/exports.py`](https://github.com/tirth8205/code-review-graph/blob/main/code_review_graph/exports.py). ## Exporting to Obsidian Vault The **Obsidian** export creates a local folder structure compatible with the Obsidian knowledge base application, transforming graph nodes into linked markdown notes. The `export_obsidian_vault()` function performs the following: - Creates one `.md` file per node using a filesystem-safe slug generated by `_obsidian_slug()`. - Prepends **YAML front-matter** to each file containing `kind`, `file`, `language`, `community`, and `tags`. - Adds a "Connections" section with **wikilinks** (e.g., `[[slug|Name]]`) pointing to neighboring nodes. - Generates community overview pages named `_COMMUNITY_.md` and a global [`_INDEX.md`](https://github.com/tirth8205/code-review-graph/blob/main/_INDEX.md) for navigation. This implementation is found in [`code_review_graph/exports.py`](https://github.com/tirth8205/code-review-graph/blob/main/code_review_graph/exports.py) at lines 95‑143 (slug generation and file setup) and lines 191‑438 (vault structure and markdown generation). ## CLI Usage Examples Run these commands from your project root after installing `code-review-graph`. ### Export to GraphML ```bash code-review-graph visualize --format graphml \ --output /tmp/myproject.graphml ``` Open `/tmp/myproject.graphml` in Gephi or yEd to visualize the dependency structure. ### Export to Neo4j Cypher ```bash code-review-graph visualize --format cypher \ --output ./import.cypher ``` Execute the script against a running Neo4j instance: ```bash cat import.cypher | cypher-shell -u neo4j -p password ``` ### Export to Obsidian Vault ```bash code-review-graph visualize --format obsidian \ --output ./my-obsidian-vault ``` Open the `my-obsidian-vault` folder as a vault in Obsidian. Use the [`_INDEX.md`](https://github.com/tirth8205/code-review-graph/blob/main/_INDEX.md) file to browse the graph topology through linked notes. ## Summary - **GraphML export** (`export_graphml()`) creates portable XML for desktop graph visualization tools. - **Neo4j export** (`export_neo4j_cypher()`) generates executable Cypher scripts with proper literal escaping for property values. - **Obsidian export** (`export_obsidian_vault()`) builds a markdown-based knowledge graph with YAML front-matter and wikilinks. - All exporters reside in [`code_review_graph/exports.py`](https://github.com/tirth8205/code-review-graph/blob/main/code_review_graph/exports.py) and are invoked via the `visualize --format` CLI interface defined in [`code_review_graph/cli.py`](https://github.com/tirth8205/code-review-graph/blob/main/code_review_graph/cli.py). ## Frequently Asked Questions ### What tools are compatible with the GraphML export? The GraphML file generated by `export_graphml()` follows the GraphML XML standard and imports directly into **Gephi**, **yEd**, **Cytoscape**, and any other tool supporting the GraphML 1.0 specification. The export includes typed data keys for node properties like `kind`, `file`, and `community`. ### How do I import the Cypher export into a Neo4j database? You can pipe the generated `.cypher` file directly into `cypher-shell` using the command `cat filename.cypher | cypher-shell -u -p `, or copy-paste the contents into the Neo4j Browser query window. The script uses `CREATE` constraints and is idempotent if run against an empty database. ### What is the file structure of the Obsidian vault export? The Obsidian export creates a root folder containing individual markdown files for each code element (slugified via `_obsidian_slug()`), community overview pages (`_COMMUNITY_.md`), and a central [`_INDEX.md`](https://github.com/tirth8205/code-review-graph/blob/main/_INDEX.md). Each node file contains YAML front-matter with metadata and a "Connections" section populated with wikilinks to related nodes. ### Can I export the graph without installing Neo4j or Obsidian locally? Yes. The **GraphML** and **Cypher** formats produce standalone files that you can share or import into cloud-hosted instances. The **Obsidian** vault is a static folder of markdown files that requires no running server; you can zip the output folder and open it on any machine with Obsidian installed.