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# Code System Graph
**System-level code intelligence across repositories**
Understand what connects your repositories and what a change could break before you ship it.
[](LICENSE)
[](https://crates.io/crates/code-system-graph)
[**Get started**](#get-started) |
[**Supported technologies**](docs/SUPPORTED_TECHNOLOGIES.md) |
[**Connect an agent**](docs/AGENT_SETUP.md) |
[**Documentation**](#documentation)
</div>
Code System Graph builds a local, evidence-backed map of the boundaries between repositories:
APIs, events, schemas, packages, databases, deployments, tests, owners, and documentation. Your
coding agent can then answer system-level questions that are difficult to solve by searching one
repository at a time.
## What problem does it solve?
Your repositories already describe how the system works, but the evidence is scattered:
- a frontend calls an endpoint declared in another repository;
- an API publishes an event consumed by a worker;
- several services read the same table or depend on the same package;
- a deployment, test, owner, or ADR explains a boundary somewhere else.
Code System Graph connects those facts into one federated graph and keeps the evidence, confidence,
freshness, and coverage behind every answer. It helps answer:
- **Impact:** "If I change this API, event, schema, or package, what else may be affected?"
- **Architecture:** "How does checkout travel from the web app to the API and worker?"
- **Ownership:** "Which repositories and owners are involved in this capability?"
- **Change review:** "Which tests matter, and do these pull requests overlap?"
- **Unknowns:** "Where is the evidence stale, ambiguous, or incomplete?"
It is deliberately conservative: missing evidence is reported as unknown, not safe.
### Code System Graph and CodeGraph
[CodeGraph](https://github.com/colbymchenry/codegraph) is an independent open-source project by
Colby Mchenry, distributed under the MIT License. It is not part of, maintained by, or distributed
with Code System Graph. The two projects solve different levels of the same problem:
| Symbols, callers, callees, and implementation flow inside one repository | [CodeGraph](https://github.com/colbymchenry/codegraph), optional |
| Contracts, dependencies, ownership, and impact across repositories | Code System Graph |
| One end-to-end answer with both levels | Code System Graph with optional CodeGraph enrichment |
CodeGraph does not add its private nodes or relationships to the persisted Code System Graph.
When enabled, it can add evidence to existing implementation links and provides bounded,
request-time `explore` context and local impact. Without it, the federated graph remains available,
but repository-local implementation detail does not.
Code System Graph is useful on its own. It does not install, initialize, or read CodeGraph's private
database. See the [CodeGraph integration notes](docs/CODEGRAPH_INTEGRATION.md) for the supported
public interface and attribution details.
## What does `scan` connect?
`scan` examines every repository declared in the workspace and joins matching evidence into one
graph:
| HTTP client call, OpenAPI operation, and server route | Client **calls** contract; server **implements** contract |
| Event publisher, AsyncAPI channel, and subscriber | Producer **publishes**; consumer **subscribes**; channel **delivers to** consumer |
| GraphQL operation, schema field, and resolver | Client **consumes** field; schema **provides** field; resolver **implements** it |
| Generated gRPC marker, protobuf service, and server marker | Client **calls** RPC; service **provides** it; server **implements** it |
| Literal SQL statement and one declared table | Code **reads from** or **writes to** the table |
| Package, deployment, documentation, ownership, and config declarations | Dependency, deploys/provides, documents, owns, and config-key links |
It does not guess through dynamic routes, interpolated table names, duplicate providers, or prose.
Those cases remain incomplete or ambiguous so an agent cannot mistake missing evidence for safety.
## Supported languages and frameworks
Source scanning currently recognizes these focused framework and language patterns:
| TypeScript / JavaScript | Fetch, Axios | Express, Fastify, NestJS, Next.js App Router | Literal SQL | Not recognized |
| Python | requests, HTTPX, aiohttp, static method registries | FastAPI, Flask | psycopg/psycopg2, PyMySQL, SQLAlchemy, Alembic, literal SQL | pytest, unittest, Factory Boy model links |
| Go | `net/http` | `net/http`, Gin, Chi | Literal SQL | Not recognized |
| Java | WebClient, Feign | Spring MVC | Literal SQL | Not recognized |
| Rust | Reqwest | Axum, Actix Web; advisory Utoipa/OpenAPI operations | SQLx, `mysql_async`, Diesel, literal SQL | Built-in tests, Tokio tests, rstest |
Other boundary support is shared across these languages rather than tied to one web framework:
- **gRPC:** protobuf services and exact generated client/server markers;
- **events:** AsyncAPI plus Kafka, RabbitMQ, SNS/SQS, NATS/JetStream, Google Pub/Sub, and generic
publish/subscribe calls;
- **GraphQL:** SDL, operations, persisted operations, federation, and resolver patterns;
- **data:** language-specific access above plus Prisma schemas, standalone query files, and SQL
migrations. Exact table identities are shared across languages and repositories, so readers and
writers implemented with different clients converge on the same table node.
Executable Rust routes and Utoipa/OpenAPI annotations coexist as separate evidence. Exact
Actix/Axum declarations have greater authority; documentation-oriented annotations remain
searchable and linkable at lower confidence because they can lag behind runtime registration.
Supporting files also add Docker Compose, Kubernetes, Helm, Terraform/OpenTofu, common package
ecosystems, Markdown, CODEOWNERS, service catalogs, and configuration key names.
See [Supported technologies](docs/SUPPORTED_TECHNOLOGIES.md) for what is extracted, concrete
cross-repository examples, automatic linking rules, and known limits. The implementation-level
validation matrix remains in [Extractor coverage](docs/EXTRACTOR_COVERAGE.md).
## Get started
### 1. Install
Prebuilt binaries are available for Linux x86_64/ARM64, macOS x86_64/ARM64, and Windows x86_64.
See [Installation](docs/INSTALLATION.md) for platform status, verification, upgrades, and
uninstall.
**Recommended: prebuilt binaries with cargo-binstall** (no Rust compiler required):
```bash
cargo binstall code-system-graph code-system-graph-hooks
```
Requires Cargo and [cargo-binstall](https://github.com/cargo-bins/cargo-binstall). Both binaries are
installed to Cargo's binary directory, normally `$HOME/.cargo/bin`.
The crates.io package is `code-system-graph`; the user-facing CLI command is `csgraph` (not
`code-system-graph`). The hooks runtime installs as `code-system-graph-hooks`.
**From crates.io** (builds locally; requires Rust 1.97.1 or newer):
```bash
cargo install code-system-graph code-system-graph-hooks
```
**From a trusted checkout** (for development or unreleased changes):
```bash
cargo +stable install --locked --path crates/code-system-graph-cli && cargo +stable install --locked --path crates/code-system-graph-hooks
```
Verify either path:
```bash
csgraph --version
command -v code-system-graph-hooks
```
`code-system-graph-hooks` is an internal runtime for optional agent routing hooks, not a
user-facing CLI. Installing both avoids a later partial setup.
### 2. Describe the repositories in your system
For multiple sibling repositories, use their parent directory as the Code System Graph workspace:
```text
my-project/
|-- code-system-graph.yaml
|-- .code-system-graph/
| `-- code-system-graph.db
|-- repo_1/
`-- repo_2/
```
Run `csgraph` commands from `my-project/`. Keep both the manifest and database in that parent, not
inside `repo_1` or `repo_2`. Declare each repository explicitly:
```yaml
version: 1
name: my-project
repos:
repo_1:
path: ./repo_1
repo_2:
path: ./repo_2
```
Only `version`, `name`, `repos`, and each repository's `path` are required. Code System Graph
discovers supported contracts and boundaries under those paths; you do not list every file,
framework, or dependency.
`csgraph init` does not discover sibling repositories. If you use it in `my-project/`, it creates
one `root` entry with `path: .`; replace that entry with `repo_1` and `repo_2` before the first
scan. You can also create the short YAML above directly.
For a workspace containing only one repository, run `init` inside that repository:
```bash
cd /path/to/my-repository
csgraph init . --name my-repository
```
`init` creates the manifest without overwriting an existing one. If the workspace directory belongs
to a Git worktree, it also preserves the existing `.gitignore` and adds `.code-system-graph/` if
needed. It does not create `.gitignore` when an unversioned parent only contains child repositories.
Commit `code-system-graph.yaml` and any generated `.gitignore` update when the workspace definition
is ready to share.
`init` does **not** scan, create the database, detect sibling repositories, or configure an agent.
### 3. Build the system graph
Run this from the directory containing `code-system-graph.yaml`:
```bash
mkdir -p .code-system-graph && csgraph scan --config code-system-graph.yaml --database .code-system-graph/code-system-graph.db
```
The first scan discovers supported boundaries and publishes an atomic SQLite snapshot. Later scans
reuse unchanged extraction results.
### 4. Add repository-level CodeGraph context (optional)
Install the independent CodeGraph CLI from its official repository:
```bash
```
Initialize it once in every repository declared in `code-system-graph.yaml`:
```bash
codegraph init ./repo_1
codegraph init ./repo_2
```
Each command creates a local `.codegraph/` index inside that repository. Then one Code System Graph
command keeps the initialized CodeGraph indexes and the federated graph current:
```bash
csgraph sync --config code-system-graph.yaml --database .code-system-graph/code-system-graph.db
```
Run `sync` after relevant changes or use `sync --watch` during a development session. Repositories
without `.codegraph/` are skipped; `--no-codegraph` updates only Code System Graph.
Verify both layers:
```bash
csgraph status --config code-system-graph.yaml --database .code-system-graph/code-system-graph.db
codegraph status ./repo_1
codegraph status ./repo_2
```
Code System Graph never reads CodeGraph's private database. It uses CodeGraph's public CLI and MCP
interfaces. See [Use CodeGraph with a workspace](docs/CODEGRAPH_INTEGRATION.md) for Windows, npm,
custom binary, watch mode, and troubleshooting instructions.
### 5. Connect your coding agent
Code System Graph exposes a local MCP server. For Codex:
```bash
codex mcp add code-system-graph -- \
csgraph mcp \
--codegraph \
--workspace my-project \
--database /absolute/path/to/my-project/.code-system-graph/code-system-graph.db
```
`--codegraph` exposes bounded repository-local `explore` context through Code System Graph. Omit it
when CodeGraph is not installed; `explore` then remains unavailable while the federated tools keep
working.
Claude Code, Codex, Gemini CLI, Antigravity, and Cursor are supported. Each agent uses its own MCP
configuration format; optional routing hooks are a separate step. Follow
[Connect an agent](docs/AGENT_SETUP.md) for exact commands, configuration files, verification, and
limitations.
You can now ask the agent:
```text
Which repositories depend on the orders API, and what evidence connects them?
Trace checkout from the web client to the event consumer.
What could be affected if POST /orders changes?
Which tests and owners should be involved in this change?
Where is coverage incomplete or stale?
```
## What is automatic?
| Discover supported contracts, package manifests, source boundaries, tests, infrastructure, ownership, and docs inside declared repositories | Automatic during `scan` |
| Link exact, evidence-backed relationships across declared repositories | Automatic during `scan` |
| Reuse unchanged extractor results on later scans | Automatic |
| Ignore generated database and hook state when the workspace belongs to a Git worktree | Automatic during `init` |
| Keep source bodies and secret values out of the persisted graph | Automatic |
| Start network services or access GitHub/Bitbucket | Never automatic |
| Detect sibling repositories or choose workspace aliases | Manual manifest configuration |
| Publish updates after files or the manifest change | Manual with one-shot `scan` or `sync`; automatic while `sync --watch` is running |
| Register the MCP server with an agent | One explicit agent-specific command or config |
| Install routing hooks | Optional, one explicit command per agent and repository |
| Enable CodeGraph enrichment | Optional |
## Configuration at a glance
### Required
- one or more local repository directories;
- a `code-system-graph.yaml` manifest with a workspace name and repository paths;
- a writable path for the embedded SQLite database;
- Linux x86_64/ARM64, macOS x86_64/ARM64, or Windows x86_64 for a prebuilt installation.
### Optional
- explicit OpenAPI paths or manual links when automatic evidence is insufficient;
- repository-specific `excludes` and `includeDefaults` discovery globs;
- Git for local change, revision, and strict pre-commit analysis;
- [CodeGraph](docs/CODEGRAPH_INTEGRATION.md) for repository-local source and symbol context;
- GitHub or Bitbucket Cloud access for pull-request analysis;
- agent routing hooks and a strict pre-commit gate;
- the HTTP server or administrative MCP tools.
No external database, API key, cloud account, or network connection is required for local scan,
query, trace, impact, status, CLI, or MCP workflows.
See [Configuration](docs/CONFIGURATION.md) for all manifest fields and safe defaults.
Use `csgraph config show --config code-system-graph.yaml` to inspect configured and implicit
discovery rules without opening a database.
## Common use cases
### Before changing a contract
Search for the contract, select its stable node ID, and inspect upstream impact:
```bash
csgraph query "POST /orders" --workspace my-project --database .code-system-graph/code-system-graph.db
csgraph impact --target <node-id> --workspace my-project --database .code-system-graph/code-system-graph.db
```
### Trace a flow across repositories
```bash
csgraph trace --from <source-node-id> --to <target-node-id> --workspace my-project --database .code-system-graph/code-system-graph.db
```
### Review local work before committing
```bash
csgraph changes --repo repo_1 --scope staged --workspace my-project --database .code-system-graph/code-system-graph.db
```
Code System Graph reports evidence and recommended tests; it never stages files, runs tests,
commits, pushes, or merges.
For a complete first workspace, including multi-repository layout and expected outputs, follow the
[Getting started guide](docs/GETTING_STARTED.md).
## Privacy and safety
- Local workflows run without telemetry or required network access.
- Source bodies and secret values are not persisted.
- SQLite snapshots are local and atomically replaced.
- Remote pull-request access is disabled by default and requires explicit enablement and consent.
- MCP is read-only by default; administrative tools require an explicit server flag.
- HTTP never starts implicitly and binds to loopback by default.
Read [Security](SECURITY.md) before enabling remote providers, admin tools, strict hooks, or
non-loopback HTTP access.
## Documentation
### Start here
- [Installation, upgrade, and uninstall](docs/INSTALLATION.md)
- [First workspace](docs/GETTING_STARTED.md)
- [Supported languages, frameworks, contracts, and relationships](docs/SUPPORTED_TECHNOLOGIES.md)
- [Configuration](docs/CONFIGURATION.md)
- [Use CodeGraph with every repository in a workspace](docs/CODEGRAPH_INTEGRATION.md)
- [Connect Claude Code, Codex, Gemini, Antigravity, or Cursor](docs/AGENT_SETUP.md)
- [CLI reference](docs/CLI.md)
- [Troubleshooting with `doctor`](docs/GETTING_STARTED.md#troubleshooting)
### Analysis guides
- [Impact and risk](docs/IMPACT.md)
- [Local changes and pull requests](docs/CHANGES.md)
- [Communities](docs/COMMUNITIES.md)
Implementation details, data contracts, extractor coverage, delivery internals, ADRs, performance,
and release engineering live in the separate [Technical documentation index](docs/TECHNICAL.md).
Contributors should start with [CONTRIBUTING.md](CONTRIBUTING.md).
## License
Licensed under Apache-2.0. See [LICENSE](LICENSE), [NOTICE](NOTICE), and
[THIRD_PARTY_NOTICES.md](THIRD_PARTY_NOTICES.md).