
TokenSaver
io.github.ByggarepopPublished by GitHub account Byggarepopv1.15.5Updated Oct 24, 2026
Structural warm start for AI coding agents in .NET: cheap Roslyn signature maps of C#/.NET files.
Overview
TokenSaver gives AI coding agents a cheap Roslyn-based signature map of C#/.NET files so they read only the code slices they need.
- What you can do
- Outline a C# file as signatures of every type and member with line ranges, without bodies
- Minify a whole file losslessly by stripping comments and whitespace, auto-detecting C#, Razor, JS/TS, Python, HTML, CSS, JSON, YAML, XML, C, C++, X++, VB.NET
- Trace dependency-injection registrations across a project directory or .csproj and return a compact file:line table of service-to-implementation wiring
- When to use it
- Useful for agents working in .NET codebases, especially on large files or when running on smaller, cheaper models that tend to read whole files; a top-tier model gains little. It curbs wasteful reading rather than improving code quality.
- Requirements
- Runs locally over stdio, installed as the NuGet package TokenSaver.Mcp and launched with dnx; a .NET toolchain is needed. Optional environment variables TOKENSAVER_API_URL (reporting dashboard URL, defaults to tokensavermcp.com) and TOKENSAVER_NO_TELEMETRY.
Installation
In SourceWeft
- Open TokenSaver in the dashboard and add it to a workspace.
- Enable the server for the chats that should use its tools.
Desktop only via STDIO. STDIO servers start a local process, so they need the SourceWeft desktop host.
Other MCP clients
Follow the launch instructions in the repository.
README
TokenSaver
A structural warm start for AI coding agents in .NET. Instead of loading whole files into your assistant, TokenSaver hands it a cheap map of your code — every type and member as a signature, each tagged with its line range — so the model reads only the slice it needs instead of slurping the file. Built on the Roslyn compiler platform.
Where it pays off: outlining a file costs 70–95% fewer tokens than reading it — up to 90% on a large file. The end-to-end win is biggest on smaller / cheaper models (which over-read the most) and on large codebases: on real tasks it trims a Haiku-class model's token use by ~8%, and the savings climb with file size. A top-tier model already reads tightly, so it sees less benefit — the leaner the model, the more a warm start helps.
Works with Visual Studio 2026 (GitHub Copilot Chat), Claude Code, VS Code Copilot, Claude Desktop, and any other MCP client that speaks stdio.
→ Full docs and setup guide: mcp/README.md
→ Changelog: CHANGELOG.md
Install
See tokensavermcp.com/install for one-click install buttons, per-client config snippets, upgrade/uninstall instructions, and troubleshooting.
What the tools do
Single-file tools
* Reductions are measured against reading the whole file — the real alternative when you'd otherwise load it. The end-to-end saving on a task is smaller, because a capable model already reads somewhat selectively; it is largest on smaller/cheaper models and large files (see Token savings in practice below).
Cross-file traversal tools
These scan an entire project directory in one call — no need to know which file to look in first.
Both accept a directory path or .csproj file — obj/ and bin/ are excluded automatically.
Token savings in practice
Measured against this project's own FocusedEmitter.cs (9,261 tokens raw):
Those are per-read figures versus loading the whole file. The end-to-end saving on a real task is smaller, because a capable model already reads somewhat selectively — and that's the honest part of the story:
The leaner the model, the more it over-reads on its own — and the more a warm start saves. TokenSaver is most worth it for agents running on small/cheap models, large files, or any workflow that would otherwise read whole files. It won't make a top model meaningfully cheaper, and it won't make a model write better code — it curbs wasteful reading, which is where cheap-model token budgets actually leak.
Collective impact
Every invocation is counted at tokensavermcp.com — a live dashboard showing total tokens saved by the community. Fewer tokens processed means less GPU compute and a smaller carbon footprint for AI-assisted development.
Language support
OutlineCSharpFile and TraceDiRegistrations are C# only; MinifyFile works across every supported language.
Source: README.md at commit d5dd52e
Tools
0Version history
1- v1.15.5LatestSep 16, 2026
Score
50% of the applicable checks met
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