# Binary-level call-graph extraction and symbol graph construction

## Module
Signals

## Status
IMPLEMENTED

## Description
Call-graph ingestion, normalization, and parsing services exist for processing binary call targets into normalized graph structures.

## Implementation Details
- **Modules**: `src/Signals/StellaOps.Signals/Services/`, `src/Signals/StellaOps.Signals/Parsing/`, `src/Signals/StellaOps.Signals/Models/`
- **Key Classes**:
  - `CallgraphIngestionService` (`src/Signals/StellaOps.Signals/Services/CallgraphIngestionService.cs`) - ingests call-graph documents and builds symbol graphs
  - `CallgraphParserResolver` (`src/Signals/StellaOps.Signals/Parsing/ICallgraphParserResolver.cs`) - resolves language-specific call-graph parsers
  - `CallgraphDocument` (`src/Signals/StellaOps.Signals/Models/CallgraphDocument.cs`) - root document model for call-graph data
  - `CallgraphNode` (`src/Signals/StellaOps.Signals/Models/CallgraphNode.cs`) - represents a function/method node in the call graph
  - `CallgraphEdge` (`src/Signals/StellaOps.Signals/Models/CallgraphEdge.cs`) - represents a call edge between nodes
  - `CallgraphEntrypoint` (`src/Signals/StellaOps.Signals/Models/CallgraphEntrypoint.cs`) - entry point into the call graph (API endpoint, main method)
- **Interfaces**: `ICallgraphIngestionService`, `ICallgraphParserResolver`
- **Source**: Feature matrix scan

## E2E Test Plan
- [ ] Ingest a call-graph document via `CallgraphIngestionService` and verify nodes and edges are stored
- [ ] Verify parser resolution: submit call graphs for different languages and confirm the correct parser is selected
- [ ] Verify symbol normalization: ingest a binary call graph and confirm symbols are normalized to canonical form
- [ ] Verify entry point detection: ingest a call graph with API endpoints and confirm they are identified as entrypoints
- [ ] Query the constructed symbol graph and verify call paths from entry to vulnerable function