Roslyn CodeLensSAFE
Roslyn-based MCP server giving AI agents deep semantic understanding of .NET/C# codebases — 67 tools for navigation, call graphs, diagnostics & code fixes, safe refactoring, code-quality auditing, test intelligence, DI graphs, and IL/external-assembly inspection.
Overview
From the repository's own README, as read at the audited commit. Badges and raw HTML are left out.
[](https://mcptoplist.com/server/io.github.MarcelRoozekrans%2Froslyn-codelens)
[](https://www.nuget.org/packages/RoslynCodeLens.Mcp) [](https://www.nuget.org/packages/RoslynCodeLens.Mcp) [](https://www.npmjs.com/package/roslyn-codelens-mcp) [](https://github.com/MarcelRoozekrans/roslyn-codelens-mcp/actions) [](https://github.com/MarcelRoozekrans/roslyn-codelens-mcp/blob/main/LICENSE) [](https://marcelroozekrans.github.io/roslyn-codelens-mcp/) [](https://github.com/sponsors/MarcelRoozekrans)
A Roslyn-based MCP server that gives AI agents deep semantic understanding of .NET codebases — type hierarchies, call graphs, DI registrations, diagnostics, refactoring, and more.
Hosted deployment
A hosted deployment is available on [Fronteir AI](https://fronteir.ai/mcp/marcelroozekrans-roslyn-codelens-
4d7d06811ca5OBSERVED · 2026-10-08Connect
Built from this server's own package name, version and transport as found in its source — not copied from anyone's documentation, so it cannot drift against a page we do not control.
claude mcp add roslyn-codelens-mcp -- npx -y [email protected]
Trust audit
SAFEgrade B · trust 89/100 Nothing in the source contradicts what it says it does. Grade A is reserved for packages that have also passed the behavioural sandbox.
| Layer | What it checks | Result |
|---|---|---|
| L0 | Provenance & inventory | PASS |
| L1 | Static analysis of the code | PASS |
| L2 | Instruction surface (what it tells the agent) | PASS |
| L3 | Class-specific surface | PASS |
| L4 | Behavioural (sandbox) | SKIPPED |
What the source does
- Filesystem
- none-observed
- Network
- none-observed
- Shell
- none-observed
- Dependencies
- not all pinned
- Secrets in source
- none-found
Findings (6)
.release-please-manifest.json
.nojekyll
roslyn-codelens-mcp /path/to/MySolution.sln --http # http://127.0.0.1:3001
"url": "http://127.0.0.1:3001"
@mdx-js/react, clsx, prism-react-renderer, react, react-dom, @types/react, typescript
Gates applied: no_behavioural_pass.
4d7d06811ca5full audit observations/trust-audit/mcp-server/marcelroozekrans__roslyn-codelens.json · Report an issue / request a re-scanAudit history
Every audit this server has had. A grade with a past is a grade somebody is still checking.
| Date | Source | Verdict | Grade | Score | Change |
|---|---|---|---|---|---|
| 2026-10-08 | 4d7d06811ca5 | SAFE | B | 89 | first audit |
Questions
What is the Roslyn CodeLens MCP server?
Roslyn-based MCP server giving AI agents deep semantic understanding of .NET/C# codebases — 67 tools for navigation, call graphs, diagnostics & code fixes, safe refactoring, code-quality auditing, test intelligence, DI graphs, and IL/external-assembly inspection.
Is Roslyn CodeLens safe to connect to an agent?
The audit found nothing in the source that contradicts what it says it does, and graded it B (89/100). Grade A is held back for packages that have also passed a sandboxed behavioural run, which is why a clean server reads B.
What credentials does Roslyn CodeLens need?
No credential environment variables were found in its source, so it appears to need none.
How does Roslyn CodeLens run?
It speaks stdio, so it runs as a local process your client starts. It is published on npm as roslyn-codelens-mcp at 2.18.1.
How current is this page?
The grade is for one exact copy of the source (4d7d06811ca5), read on 2026-10-08. The repository is watched and re-audited when it changes.