Semantic code index for .NET projects. Gives AI coding agents instant access to symbols, references, call graphs, type hierarchies, and dependency analysis — powered by Roslyn and exposed via MCP.
Requires .NET 10 SDK.
git clone <repo-url>
cd sextant
./scripts/install-cli.shcd /path/to/your/dotnet/repo
sextant index path/to/Solution.slnsextant install claude-code # or: cursor, copilot, vscode, codex, opencodeYour AI agent now has access to 13+ semantic tools. It can find symbols, trace references, walk call hierarchies, analyze dependencies, and assess change impact — all from the pre-built index, without reading files.
The research_codebase tool lets your agent ask freeform questions about the codebase. It requires an LLM:
sextant config llm| Tool | What it does |
|---|---|
find_symbol |
Look up any symbol by name (exact or fuzzy) |
find_references |
Every usage of a symbol across the solution |
get_call_hierarchy |
Who calls this method? What does it call? |
get_type_hierarchy |
Inheritance chains up and down |
get_implementors |
All implementations of an interface |
get_type_members |
Methods, properties, fields of a type |
get_file_symbols |
Everything defined in a file |
get_project_dependencies |
Project dependency graph |
get_api_surface |
Public API with breaking change detection |
get_impact |
Blast radius analysis before refactoring |
semantic_search |
Full-text search over symbol names and docs |
get_index_status |
What's indexed and how fresh |
research_codebase |
Ask questions in plain English (requires LLM) |
Sextant uses Roslyn to extract a complete semantic graph from your .NET solution and stores it in SQLite. The MCP server queries the database directly — responses are instant (< 5ms for exact lookups).
A background daemon watches for file changes and incrementally re-indexes, so the data stays fresh as you code.
Source Files → [Daemon] → [Indexer] → [SQLite] → [MCP Server] → AI Agent
| Doc | Contents |
|---|---|
| Configuration | sextant.json, env vars, LLM setup, CLI reference, AI tool install details |
| MCP Tools | Full tool parameters, response formats, query examples |
| Daemon | File watching, incremental indexing, status endpoints, auto-start setup |
| Architecture | System design, data flow, technology stack |
| Indexing | Roslyn extraction pipeline, incremental indexing, project identity |
| Schema | SQLite tables, migrations, FTS5 |
dotnet build Sextant.slnx
dotnet test Sextant.slnxFunctional Source License 1.1 (FSL-1.1-Apache-2.0). Free to use, modify, and distribute for any non-competing purpose. Converts to Apache 2.0 on 2028-03-05. See LICENSE for full terms.