How code-review-graph Handles Authentication: A Static Analysis Approach

code-review-graph does not implement authentication logic; it treats authentication code as ordinary user-code, parsing it into graph nodes and edges without executing or validating credentials.

The code-review-graph repository by tirth8205 is a static analysis and knowledge-graph engine designed to map code relationships, not to manage security. When you ask how code-review-graph handles authentication, the answer is straightforward: it doesn't handle authentication at all in the traditional sense. Instead, it analyzes authentication modules you provide and represents them as structural nodes and call-graph edges.

Authentication as Parsed Code, Not Runtime Logic

The core distinction is that code-review-graph operates entirely as a static analysis tool. It reads source files, builds an abstract representation of classes, functions, and their call relationships, and outputs a queryable graph. It never runs the code it analyzes.

In tests/fixtures/sample_python.py, the repository includes an example AuthService class that demonstrates this treatment:

# From tests/fixtures/sample_python.py

class AuthService(BaseService):
    def __init__(self, name: str, secret: str):
        self.name = name
        self.secret = secret

    def login(self, token: str) -> bool:
        return token == self.secret

    def logout(self) -> None:
        pass

When processing this code, the engine creates:

• Class node: auth.py::AuthService
• Function nodes: auth.py::AuthService.login, auth.py::AuthService.logout
• CALLS edges: connections from calling code into these authentication methods

The secret attribute and token validation logic are preserved as parsed syntax nodes, but the comparison token == self.secret is never executed.

How Authentication Code Appears in the Graph

The test suite in tests/test_visualization.py references src/auth.py::AuthService.login, showing how authentication methods become traceable graph elements. These references translate into CALLS edges that reveal which parts of your codebase depend on authentication functionality.

In tests/test_tools.py, queries validate that you can search for AuthService nodes and compute their impact radius—the set of functions that would be affected by changes to the authentication module. This analysis capability is the tool's actual purpose: understanding code structure, not enforcing security policies.

Architecture Documentation Confirms No Built-in Auth

The docs/architecture.md file describes the graph model in terms of files, classes, functions, and relationships. It contains no mention of authentication handling, token management, or access control because these concerns are explicitly outside the tool's scope. According to the code-review-graph source code, any security layer for the graph service itself must be added externally.

External Authentication Requirements

If you deploy code-review-graph as a service, you must implement authentication separately. Common approaches include:

• Web framework middleware (FastAPI/Flask auth dependencies) to protect graph endpoints
• CI pipeline guards to control which repositories the tool can access
• API keys or OAuth handled by a reverse proxy or gateway

The graph engine remains agnostic to these mechanisms, simply parsing whatever authentication code it encounters in analyzed repositories as ordinary user-code.

Key Files Related to Authentication Handling

File	Role
tests/fixtures/sample_python.py	Defines sample AuthService class used in tests
tests/test_visualization.py	References src/auth.py::AuthService.login to demonstrate graph edge creation
tests/test_tools.py	Validates graph queries for authentication-related nodes
docs/architecture.md	Outlines graph model without authentication features

Summary

• code-review-graph has no built-in authentication—it is a pure static analysis engine
• Authentication code in analyzed repositories is parsed into nodes and edges like any other code
• The tool never executes, validates, or stores credentials—it only maps code structure
• External layers must handle access control when deploying the tool as a service
• Authentication modules become traceable impact points in the graph for change analysis

Frequently Asked Questions

Does code-review-graph verify JWT tokens or API keys?

No. The engine parses token validation code as syntax nodes but never executes it. If your repository contains def verify_token(jwt: str) -> bool, the function appears in the graph as a node with incoming CALLS edges, but the actual signature verification does not run during analysis.

Can I use code-review-graph to find security vulnerabilities in authentication code?

Indirectly. The tool maps call relationships and data flow between authentication functions and other code, which can help you identify unusual patterns or overly broad access. However, it does not perform specialized security analysis—dedicated tools like Bandit or Semgrep serve that purpose better.

How should I protect a deployed code-review-graph instance?

Add authentication at the infrastructure layer. Deploy behind a reverse proxy with TLS termination, require API keys through your web framework's dependency injection, or restrict repository access via CI pipeline configuration. The graph engine itself remains stateless and unauthenticated by design.

Why does the repository include an AuthService example?

The AuthService class in tests/fixtures/sample_python.py provides a realistic test fixture that exercises the parser's ability to handle common Python patterns including class inheritance, method definitions, and conditional logic. It validates that the graph correctly represents authentication-related code structures without special-casing them.

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