psamvault-mcp

MCP server for psamvault — lets AI agents use your stored credentials without ever seeing their plaintext values.

How it works

psamvault exposes two complementary flows depending on what the agent needs.

API request flow (use_credential)

When an AI agent needs to call an API on your behalf, psamvault decrypts the credential locally and forwards the authenticated request through its backend proxy.

The agent never sees the password. It only sees the HTTP response.

Agent: "Call the GitHub API using my stored credential"
         ↓
psamvault shows a consent dialog: "Allow agent to use github.com credential?"
         ↓ (you approve)
psamvault decrypts credential locally using your Vault Encryption Key
         ↓
psamvault makes: GET https://api.github.com/user
                 Authorization: Bearer <your token>
         ↓
Agent receives: {"login": "yourusername", "id": 12345, ...}

Browser login flow (browser_login)

When an AI agent needs to log you into a website, psamvault opens a real Chromium browser, navigates to the site, and fills in the credentials directly inside that browser process.

The agent never sees the credentials. It only sees whether the login succeeded.

Agent: "Log me into kaggle.com"
         ↓
psamvault opens Chromium → navigates to kaggle.com → finds the login page
         ↓
psamvault takes a screenshot of the confirmed login page
         ↓
psamvault shows a consent dialog with the confirmed login URL
         ↓ (you approve)
psamvault decrypts credential locally
         ↓
psamvault fills username + password fields directly in the browser
         ↓
If a CAPTCHA appears, psamvault takes a screenshot, pauses automation,
and tells you to solve the CAPTCHA and click Sign in manually
         ↓
Agent receives:
         {
           "success": true,
           "message": "Logged in to github.com successfully. The browser is open.",
           "steps_count": 8,
           "url": "https://github.com/dashboard",
           "captcha_detected": false,
           "captcha_screenshot": null,
           "failed_at": null,
           "hint": null
         }
         ↓
Browser stays open — you take over from there.
The browser session is saved and reused on subsequent calls to the same site.

Prerequisites

• Python ≥ 3.11

• psamvault installed and logged in

pipx install psamvault
psamvault configure
psamvault login

Installation

pipx install psamvault-mcp
playwright install chromium

Goose setup (recommended)

Goose is an open-source AI agent with native MCP support. There are three ways to add psamvault-mcp as a Goose extension:

Option A — One-click deeplink

Click or paste this URL into your browser while Goose Desktop is running:

goose://extension?cmd=psamvault-mcp&timeout=300&id=psamvault&name=psamVault&description=Use%20stored%20credentials%20without%20exposing%20them%20to%20the%20agent

Goose will prompt you to confirm, then the extension is added instantly.

Option B — Goose Desktop UI

1. Open Goose Desktop.

2. Click the sidebar button (top-left) → Extensions.

3. Click Add custom extension.

4. Fill in the form:

   Field	Value
   Type	Standard IO
   ID	psamvault
   Name	psamVault
   Description	Use stored credentials without exposing them to the agent
   Command	psamvault-mcp
   Timeout	300

5. Click Add.

The extension appears in your Extensions list — toggle it on to activate it.

Option C — Config file (advanced)

Edit ~/.config/goose/config.yaml and add the following under extensions::

extensions:
  psamvault:
    name: psamVault
    cmd: psamvault-mcp
    args: []
    enabled: true
    type: stdio
    timeout: 300

Save the file and restart Goose (or reload the session).

Verifying the extension works

Once added, start a Goose session and try:

What credentials do I have stored in my vault?

Goose will call list_vault_sites via psamvault-mcp. If you see your stored sites, everything is working.

Other MCP clients

Claude Desktop — config file location:

• macOS: ~/Library/Application Support/Claude/claude_desktop_config.json

• Windows: %APPDATA%\Claude\claude_desktop_config.json

{
  "mcpServers": {
    "psamvault": {
      "command": "psamvault-mcp"
    }
  }
}

Restart your MCP client after saving.

Configuration

psamvault-mcp reads its backend URL from ~/.psamvault/config.env, written automatically by psamvault configure.

To point at a self-hosted backend, set the variable in ~/.psamvault/config.env:

PSAMVAULT_API_URL=https://your-backend.example.com

Available tools

Injection modes

Example agent prompts

Once connected, you can ask your agent things like:

• "What credentials do I have stored in my vault?"

• "Check my GitHub notifications using my stored github.com credential"

• "List my AWS S3 buckets using my stored aws credential"

• "Log me into kaggle.com"

• "Open github.com and log me in"

Testing

# From the repo root
pytest

Tests live in tests/ and cover crypto primitives, session management, consent logic, the API client (with httpx mocking), and MCP tool behaviour. The test suite requires no real network access or OS keychain — all external dependencies are mocked.

Security

• Credentials are decrypted locally on your machine — never sent to the agent

• Every credential use requires explicit approval via a consent dialog

• The agent only receives HTTP responses, never credential values

• All communication with the psamvault backend uses HTTPS

License

MIT — see LICENSE.