vslsp

AI agents working on C# and Rust codebases are flying blind: they see three errors at a time from dotnet build, can't check whether a refactoring compiles without writing to disk, and have to read every source file to understand what a codebase contains.

vslsp fixes that. It's an MCP server that gives agents full compilation diagnostics and deep code structure awareness — for both C# and Rust — through a set of tools they can call directly.

Install

curl -fsSL https://raw.githubusercontent.com/DennisDyallo/vslsp/main/install.sh | bash

Installs the CLI, MCP server, OmniSharp (C#), CodeMapper (C#), and RustMapper (Rust). Registers itself with Claude Code automatically.

What agents get

Capability	C#	Rust
All compilation diagnostics at once	✅	✅
Structured code map (types, methods, fields)	✅	✅
Struct fields and enum variants in output	✅	✅
Signatures with visibility, modifiers, generics	✅	✅
Persistent daemon (fast repeated queries)	✅	❌
Dry-run compile check before writing to disk	✅	❌
File-watching (auto-update diagnostics on save)	✅	❌

The three Rust gaps are all daemon-dependent. Rust uses cargo's incremental build cache instead — no long-running process needed, but no in-memory dry-run either.

How it works

C# workflow

get_code_structure    ← understand the codebase without reading files
       ↓
verify_changes        ← check proposed edits compile (no disk write)
       ↓
write files to disk
       ↓
notify_file_changed   ← sync the daemon
       ↓
get_diagnostics       ← confirm everything is clean

Rust workflow

get_code_structure    ← understand crate structure
       ↓
edit files on disk
       ↓
get_rust_diagnostics  ← run cargo check, get structured results

MCP Tools

Tool	Language	Purpose
get_diagnostics	C#	All compilation errors and warnings
get_diagnostics_summary	C#	Just the counts
start_daemon	C#	Start persistent analysis server
stop_daemon	C#	Stop it
get_daemon_status	C#	Check if ready
notify_file_changed	C#	Tell daemon a file changed
verify_changes	C#	Dry-run compile check before writing to disk
get_rust_diagnostics	Rust	All cargo check errors and warnings
get_code_structure	C# + Rust	Structured code map via AST analysis

Requirements

• .NET 6.0+ (for C# features)
• Rust and cargo (for Rust features)

License

MIT