Stillvault MCP server

Give an AI agent access to real secrets — API keys, database passwords — with a named human approving each release on their device, and without the secret ever entering the model's context.

This is a thin shim over the stillvault CLI. It contains no cryptography and holds no secret material: every release, approval, and unsealing happens in the CLI and on the approver's device, exactly as it does from a shell. The agent calls a tool; a human approves on their phone or the web console; the secret is used and never shown to the model.

Why the secret never reaches the model

The headline tool, stillvault_run, doesn't return secret values. It runs a command you choose, substitutes stillvault://<path> references into that process after approval, and returns only the command's output. The plaintext lives only in the child process, on the local machine, for that command's lifetime — never in the conversation, and never in your LLM provider's logs.

There is a second tool, stillvault_reveal, for the rare case where the value itself must be read. It says plainly what it costs (the secret enters the model context) and should be the exception.

Onboarding

1. Install the stillvault CLI

curl -fsSL https://stillvault.ai/install.sh | sh      # macOS / Linux
# Windows (PowerShell):
irm https://stillvault.ai/install.ps1 | iex

2. Enrol this machine as an agent

The agent gets its own signing key — the org key never lives here. Create an enrolment token in the web console (Agents), then:

stillvault agent-enroll --agent claude-prod --org <your-org-id> --token <one-time-token>

An admin admits it in the console after checking the fingerprint. Scope the paths it may request with an access policy. See https://stillvault.ai/docs/agents/.

3. Add the MCP server to your client

It runs over stdio via npx — no separate install.

Claude Desktop / Claude Code (claude_desktop_config.json or .mcp.json):

{
  "mcpServers": {
    "stillvault": {
      "command": "npx",
      "args": ["-y", "@wolstapp/stillvault-mcp"],
      "env": {
        "STILLVAULT_AGENT": "claude-prod",
        "STILLVAULT_TENANT": "<your-org-id>"
      }
    }
  }
}

Claude Code, one-liner:

claude mcp add stillvault -e STILLVAULT_AGENT=claude-prod -e STILLVAULT_TENANT=<org-id> \
  -- npx -y @wolstapp/stillvault-mcp

That's it. The agent can now request secrets, and you approve each release on your device.

The tools

stillvault_run (preferred)

Runs a local command with secrets injected, never revealing them.

• command — the executable, e.g. psql, curl, ./deploy.sh.
• args — arguments; any stillvault://<path> is replaced with the secret after approval. Embed inside a longer string with {{stillvault://<path>}}.
• secret_env — optional map of environment variables whose values contain references (e.g. {"DATABASE_URL": "stillvault://db/prod/dsn"}). Switches to the safer mode where secrets go in the child's environment, not its command line.

Returns the command's stdout/stderr and exit code. Blocks until a human approves (or the wait times out, default 130s).

stillvault_reveal (exposes the value)

Returns a secret's plaintext into the conversation after approval. This puts the secret in the model's context and your provider's logs. Prefer stillvault_run.

• path — the secret path, e.g. db/prod/password.

Configuration

Env var	Default	Purpose
STILLVAULT_AGENT	(none)	Enrolled agent id; releases are signed with its key. Set this for managed use.
STILLVAULT_TENANT	(none)	Your org id (managed broker per-tenant lookup).
STILLVAULT_BROKER	https://stillvault.ai	Broker URL (set for self-hosted).
STILLVAULT_BIN	stillvault	Path to the CLI if not on PATH.
STILLVAULT_APPROVAL_WAIT	130	Seconds to wait for each approval.

What this server is and isn't

• It is a launcher for the stillvault release loop, surfaced as MCP tools.
• It does not decrypt anything, hold keys, or talk to the broker directly — the CLI does that, and the key that opens a secret only ever exists on the approver's device.
• Approval is per release. A short, policy-bounded lease in the CLI means a tight loop reading the same secret doesn't prompt a human on every call — see https://stillvault.ai/docs/how-it-works/.

Develop locally

npm install
npm run build
npm start        # serves over stdio