mcpcat

A curl for the Model Context Protocol. One command that talks to any MCP server from a shell, and turns any shell command into an MCP server.

Install

curl -fsSL https://get.sliccy.ai/mcpcat | sh

The same installer from the GitHub release, if the short URL is unreachable:

curl -fsSL https://github.com/ai-ecoverse/mcpcat/releases/latest/download/install.sh | sh

Options pass through, for example curl -fsSL https://get.sliccy.ai/mcpcat | sh -s -- --help.

mcpcat upgrade (alias update) replaces an installer install with the latest release, after checking it against the release’s SHA256SUMS; mcpcat upgrade --check only reports.

Or via npm:

npm install -g @ai-ecoverse/mcpcat

mcpcat runs natively on macOS, Linux and Windows (Node ≥ 26), and inside Sliccy Seven as a kernel program, with the same flags, the same output and the same config file in both places. Orphan-free shutdown of stdio server trees in the kernel needs slicc-kernel ≥ 1.74.0; on older kernels only the direct child is signalled. A SIGKILLed mcpcat runs no handler. On slicc-kernel ≥ 1.88.0, mcpcat spawns stdio servers and served commands with a parent death signal (like Linux PR_SET_PDEATHSIG), so the kernel SIGKILLs each server’s process group when mcpcat dies. On older kernels, and on the host, where there is no portable equivalent, servers that exit on stdin EOF (most MCP servers) still stop, but servers that ignore it keep running.

CI and releases

.github/workflows/ci.yml is the only workflow. It calls slicc-shared-web’s pipeline: lint (Biome, tsc and the shared rules) on every event; on pull requests and in the merge queue the integration suite (npm test, every test/integration/*.test.mjs on Node 26, split over Linux shards); on pull requests a Claude and a Codex review. The checks to require are ci / integration and ci / review. Every merge to main is released to npm as latest by semantic-release, with provenance, through trusted publishing bound to ci.yml. When a merge releases (a new v* tag at the commit), the binaries job packs the published tarball, runs the installer tests on Ubuntu (with and without Node) and Alpine, and attaches the tarball, install.sh and SHA256SUMS to the GitHub release. kernel-floor.test.mjs runs the kernel tests on the engines.slicc-kernel floor; MCPCAT_KERNEL_DIR points the kernel tests at any installed @ai-ecoverse/slicc-kernel.

Quick start

mcpcat https://mcp.example.com/mcp
mcpcat weather get-forecast --lat 51.5 --lon -0.12
mcpcat serve --http 8808 ./scripts/jira.jsh

Agent skill