Hush

a secret store for AI agents , the one with no get.

get a secret once into the OS keychain, then inject it into commands forever , the value never hits stdout, the transcript, or the cloud.

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A secret store for AI agents, with one hard rule: the agent never sees the plaintext.

Values never reach stdout, so they never land in the tool result, the transcript, or the cloud. A secret only ever moves from the store straight into the consumer. There's no get on purpose, a plain getter is the leak.

The point: you (an agent) are running as the user with their CLIs already authed, so you can already set a server-side secret or call a service , you just can't see the value without it landing in the chat. hush gets it once into the OS keychain, then you inject it into those commands forever. No chat paste, no temp files, no .env to commit by accident.

agents: start here

If you were handed this repo's url, install yourself, then follow the playbook. Get the hush script onto the box and read [SKILL.md](SKILL.md) , that's the whole onboarding (it covers store / mint / inject and how to adopt hush in the repo you're working in). The script is one self-contained bash file; put it wherever your agent loads tools or just on your PATH:

git clone https://github.com/royashbrook/hush
chmod +x hush/hush
# then put hush/hush on your PATH, or move it into your agent's skills/tools dir

or run it straight from npm without cloning: npx @royashbrook/hush (mac/linux; on windows use the clone, the orchestrator is bash).

Claude Code convenience (auto-loads as a skill): clone straight into the skills dir instead , whole session git clone https://github.com/royashbrook/hush ~/.claude/skills/hush, or one project ./.claude/skills/hush. Other agents: see [AGENTS.md](AGENTS.md).

That's it , the human points you here and says "use the hush skill," and you take it from here. The one thing only a human can do is paste a secret they hold: when you hit that, run hush set and a hidden dialog pops on their screen (you never see the value).

install (humans)

Same clone as above, or just grab the single hush script and put it on your PATH.

Backends: macOS Keychain, Linux libsecret (secret-tool), and Windows DPAPI (via PowerShell) are built in. On other platforms keep the same contract with your OS secret store (see [SKILL.md](SKILL.md)). Cross-OS tested in CI (manual workflow_dispatch, all three runners).

quick start

hush set my-vendor-token                      # paste a value you hold (hidden prompt)
printf '%s' "$TOK" | hush set my-vendor-token # ...or pipe it in (scripts/CI), still off argv
hush mint app-operator-key                    # generate + store a random one
hush run TOKEN=my-vendor-token -- some-cmd    # inject into a command, never printed
hush list                                     # names only, never values

Naming: keep the default hush namespace and prefix names by project (blame-cf-token, lifescored-gemini-key) so one keychain search for hush finds everything. HUSH_NS is only for a genuinely separate store, not per-project. Need to fix an existing name? hush rename moves the value internally (never re-asked, never printed). Full docs + the portable contract: [SKILL.md](SKILL.md).

not a vault

An agent with shell access can read+write this store, so it's not a lock against a hostile process. It's structure that keeps plaintext out of the transcript and makes "store once, inject everywhere" the easy path. It's also only as durable as the machine it's on (a local keychain) , back the machine up, or sync onward into a real secret manager, and don't make hush the only copy of a secret you can't regenerate. MIT licensed.

Source & license

This open-source MCP server is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: royashbrook
• Source: royashbrook/hush
• License: MIT

Install and usage instructions live in the source repository linked above.