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.

VerifiedSTDIODesktop onlyDeveloper ToolsAI & ML

Overview

AI-generated 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.
Before you install
Every invocation is counted on the tokensavermcp.com dashboard; anonymous usage telemetry is on unless TOKENSAVER_NO_TELEMETRY is set to 1. The tool reads project files on disk, and TOKENSAVER_API_URL points reporting at an external service.

Installation

In SourceWeft

  1. Open TokenSaver in the dashboard and add it to a workspace.
  2. 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

ToolWhat it doesReduction
OutlineCSharpFileSignatures of every type and member — no bodies. Best for "what's in this file?"70–95%
MinifyFileLossless minify of an entire file — strips comments and whitespace, logic unchanged. Auto-dispatches by extension (C#, Razor, JS/TS, Python, HTML, CSS, JSON, YAML, XML, C, C++, X++, VB.NET).20–50%

* 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.

ToolWhat it does
TraceDiRegistrationsFinds every Dependency-Injection registration referencing a type (interface or concrete) and returns a compact table of file:line, method, ServiceType -> ImplType, and key. Answers "where is IFoo wired, and to what?"

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):

Question typeToolTokens sentReduction
"What's in this file?"OutlineCSharpFile1,03989%
"Read one method body"OutlineCSharpFile + narrow Read of the // L.. range~300~95%
"Audit the whole file"MinifyFile5,52540%

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:

Model running the agentReal-task token saving vs no tool
Top-tier (reads tightly already)~1% — negligible
Mid-tier (Sonnet-class)~5–7%
Smaller / cheaper (Haiku-class)~8%

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

TierLanguages
Primary (Roslyn, full support)C# .cs, Razor .razor, VB.NET .vb, .NET project files .csproj .props .config .xml
Basic (comment-strip + whitespace collapse)JavaScript, TypeScript, Python, HTML, CSS/SCSS/LESS, JSON/JSONC, YAML, C, C++, X++

OutlineCSharpFile and TraceDiRegistrations are C# only; MinifyFile works across every supported language.

Source: README.md at commit d5dd52e

Tools

0
SourceWeft has not started this package in its sandbox yet, so its tools are not known.

Version history

1
  1. v1.15.5LatestSep 16, 2026

Score

50% of the applicable checks met

How complete this listing is, computed from the registry entry, the endpoint and public sources. Not a rating of the server and not a statement that it is safe or working today: reachability is a dated check, and no installs or reviews go into the score.

  • Reached in the last 30 days25 pts

    Keep the endpoint answering the MCP handshake; SourceWeft probes it every 30 days.

  • Auth declared10 pts

    Declare the credential headers in the registry entry, or keep the endpoint answering the probe so its auth can be classified.

  • Tools listed15 pts

    Answer tools/list without a credential, or ship a package that starts in a sandbox without one.

  • DescriptionRequired15 pts
  • Logo10 pts
  • Documentation15 pts
  • License10 pts