Jmunch MCP server

jmunch-mcp

<!-- mcp-name: io.github.jgravelle/jmunch-mcp -->

Transparent MCP proxy that reduces the token cost of large upstream tool responses for nearly every other MCP server imaginable. Wraps a single upstream MCP, forwards every call, and handle-ifies fat payloads into content-aware backends the agent can query with a small set of universal verbs (peek, slice, search, aggregate, describe, list_handles).

Benchmarks

Measured end-to-end against two popular real-world MCP servers. Each run fires a fixed script of tool calls twice — once direct, once through jmunch-mcp — with three follow-up jmunch.* verb calls on the proxied side to model an agent drilling into a large result rather than slurping it whole.

Wall-clock time was also faster with the proxy on both suites, despite the extra verb calls — the agent never has to page through the fat payload:

Tabular content (GitHub) routes to the SQLite backend and answers peek/slice/aggregate; JSON content (Firecrawl scrape/map) routes to the JSON-tree backend and answers peek/slice (JSONPath)/search. See bench/README.md to reproduce.

Install

pip install jmunch-mcp

From source:

git clone https://github.com/jgravelle/jmunch-mcp
cd jmunch-mcp
pip install -e .

Quickstart

jmunch-mcp init

init scans three sources — your MCP client configs (Claude Desktop, Claude Code, Cursor, Windsurf, Continue), running processes, and a small catalog of popular upstreams (GitHub, Firecrawl, filesystem, fetch, Brave Search, Slack) — and renders a checklist. Tick the upstreams you want wrapped, and it writes one .toml per selection into ./configs/. Non-interactive flags: --yes (pick everything already registered in a client), --dry-run, --overwrite, --out , --no-running, --no-catalog.

Manual

jmunch-mcp --config examples/config.toml

Configure your MCP client to launch jmunch-mcp --config instead of the upstream server directly. Add --report to print a session summary on shutdown.

Gateway mode (v2 — universal proxy)

The MCP proxy above saves tokens for MCP clients. The gateway saves tokens for any AI application that speaks the OpenAI or Anthropic HTTP API — LangChain, LlamaIndex, CrewAI, AutoGen, Continue, Cline, Aider, or a raw SDK. No code changes in the app; just point base_url at jmunch.

pip install 'jmunch-mcp[gateway]'
jmunch-mcp gateway --config configs/gateway.example.toml
# listening on http://127.0.0.1:7879

Point your app:

# OpenAI SDK, LangChain, Aider, Continue, Cline, Ollama-compat apps:
export OPENAI_API_BASE=http://127.0.0.1:7879/v1

# Native Anthropic SDK / Claude Code:
export ANTHROPIC_BASE_URL=http://127.0.0.1:7879

What it does, transparently:

Shortened. The full README is on GitHub.