Rendeverance/toolfunnel

> A zero-dependency MCP and Local tool gateway: host your own tools in any language, forward and curate tools from other MCP servers, expose them leanly to cut agent token cost, gate every call through your own policy hooks before it runs, create your own MCP servers easily with zero code - and **wrap any MCP server so it speaks both protocol eras, invisibly**.
**Zero code, zero dependencies: your own MCP server in 60 seconds** - from three ordinary scripts to a named, packaged, policy-gated MCP server (everything on screen is real output; see demo/):
**📖 Full documentation: the ToolFunnel User Manual** - installation, the web UI, writing tools, attaching MCP servers, the policy gate, packaging, and troubleshooting, all illustrated with screenshots and worked examples. This README is the overview; the manual is the reference.
The problem
Toolfunnel is designed to solve multiple issues in one package :)
The Model Context Protocol (MCP) lets an AI agent call tools from many servers. But every connected server dumps **all** of its tool schemas into the model's context on every turn. Connect a handful of rich MCP servers and you've spent thousands of tokens describing tools the agent won't use this turn - slower, costlier, noisier.
Similarly, working with AI I found myself generating many many tools, some of which I wanted to use with different AI workflows, some I didn't, and I didn't want to keep setting them up, I also didn't wish to keep many different setups for different workflows. Therefore ToolFunnel was born so that all of my multi-use tools and common MCP servers can be in one place, with any workflow, and I can easily select which I want to use with whatever workflow and even change or add tools during a session with simple toggles in the UI. I also wanted to wire up and test MCPs *live*, in the running session, without resetting the CLI or restarting anything - and have their tools show up in the tools list straight away; ToolFunnel does exactly that.
Often also, there's also no consistent way to **govern** what an agent may run: hooks and policies live in the *host* (a specific CLI or otherwise), so they don't travel when you switch clients - with ToolFunnel, this is easy because your hooks travel with the tools - it can become your one swiss-army knife for many different workflows.
Additionally, I wanted an easy and consistent way to package my own tools and create new MCP servers from other tools, whatever language they were written in. FastMCP could do that, but not everything is written in python. I also didn't want to audit huge numbers of dependencies - a personal choice, yes - so I wanted something that could be audited quickly and easily.
Finally, when the MCP changes were announced as breaking changes, it became apparent this would eventually break a lot of MCP servers and/or clients out there, many of which might not be actively maintained. Not only that but changing MCP protocol generations takes time and might take considerable effort depending on the complexity of the server - therefore I added a quick, simple single command tool that allows ToolFunnel to wrap an MCP and easily translate between new and legacy protocols - quick, low effort, maximum gain.
At the time of writing, I have 14 MCP tools and 98 local tools all accessed through toolfunnel, gated as required.
What ToolFunnel does
ToolFunnel is one small MCP server that sits between your agent and everything else:
1. **Hosts your own tools** - define first-party tools in a JSON register and serve them directly. Seven demo tools ship in the box.
2. **Forwards other MCP servers - leanly.** Attach an upstream MCP and its tools appear in the same lean register as your own, runnable through the gate. Curate which appear, promote a chosen few to top-level "every-turn" tools, or leave them lean by default.
3. **Lean register** - the agent sees short tool *briefs*; the full instructions for a tool are fetched on demand, so context stays small. *(This is the token saver.)*
4. **Server-side policy gate** - every server-side execution path fires your PreToolUse / PostToolUse hooks inside the gateway, so your policy works on any client, not just hosts that support hooks. The gate travels with the gateway, and fails closed.
5. **Configure by file, UI, or in-band** - plain JSON files, an optional loopback web UI, or ten in-band management functions (tf_*) all add / curate / toggle tools, upstreams, and hooks - live, no restart - and package the whole setup for deployment.