hush MCP server

hush

Envelope-encrypted team secrets your AI agent can use but never read.

You keep your API keys in a .env file. It is plaintext, every process you launch can read it, and the day you pointed an AI coding agent at the repo it went into the agent's context window — and from there, wherever transcripts go.

hush fixes that without a server, an account, or a shared password. Your secrets live encrypted inside the repo itself. hush npm run dev puts them in that one process and nowhere else. Your coding agent gets tools that can use a key but never read one. A teammate gets access with one command, and removing them re-encrypts everything. Zero dependencies; one npm install.

hush init acme                  # a vault in .hush/vault.json — commit it
hush add .env --as "Dev"        # your existing secrets, now encrypted, as a set called dev
hush npm run dev                # injected into the process, never onto disk
hush team add sam hush_pk_1xM…  # commit; sam can decrypt. no invite email.
hush team rm sam                # re-keys the vault, re-seals every value

[!IMPORTANT]

Status: early. This works and is heavily tested, but it is pre-1.0, it has

one author, and it has not had an external security review. The crypto is

a standard construction (age's, rebuilt on

node:crypto) rather than anything invented here, and there is a

differential test suite against an

independent reimplementation — but that is not the same as someone qualified

having looked at it. docs/REVIEW-SCOPE.md is the brief

for the review it needs.

Development happens on macOS; Linux is covered by CI. Windows is in beta:

your key is kept with DPAPI, approvals are a native Windows dialog, hush run

npm … works through npm.cmd, secret files get owner-only ACLs, and there is

a PowerShell hook — a Windows CI job checks those paths, but it has not had

much real use yet. Fingerprint approval (Windows Hello) is not there yet.

Tell me what broke if you try

it somewhere unusual.

Found a way to read a vault you should not? Please [report it

privately](https://github.com/omarei-omoto/hush/security/advisories/new)

rather than opening an issue.

Install

One file, no Node needed — macOS, Linux (glibc and musl), and Windows (beta):

curl -fsSL https://raw.githubusercontent.com/omarei-omoto/hush/main/scripts/install.sh | sh
brew install omarei-omoto/tap/hush

irm https://raw.githubusercontent.com/omarei-omoto/hush/main/scripts/install.ps1 | iex
scoop install https://github.com/omarei-omoto/hush/releases/latest/download/hush.json

Shortened. The full README is on GitHub.