warden-mcp

Programmatic Vaultwarden/Bitwarden vault management over MCP (Model Context Protocol), backed by the official Bitwarden CLI (bw).

This project exists to let agents and automation create/search/read/update/move vault items without re-implementing Bitwarden’s client-side crypto.

Published package: @icoretech/warden-mcp

Highlights

• MCP Streamable HTTP (SSE) endpoint at POST /sse + health check at GET /healthz
• Runtime guardrail metrics at GET /metricsz
• Item types: login, secure note, card, identity, plus an SSH key convention (secure note + standard fields)
• Attachments: create/delete/download
• Organization + collection helpers (list + org-collection CRUD)
• Safe-by-default: item reads are redacted unless explicitly revealed; secret helper tools return null unless reveal: true
• Strong fit for LLM automation: pair it with a browser-capable MCP host so an agent can fetch credentials, complete sign-in flows, read TOTP codes, and keep automating after login

LLM Automation Use Case

warden-mcp is not only useful for vault administration. A very practical use case is pairing it with an LLM that can also drive a browser.

That lets the agent do end-to-end authenticated workflows such as:

• open a site or backoffice in the browser
• read the right login from Vaultwarden or Bitwarden
• fill username and password without hardcoding secrets in prompts or config
• retrieve a current TOTP code with keychain.get_totp for TOTP-based MFA
• continue the real task after login, such as navigation, data entry, exports, or routine admin work

In practice, this is what makes the server useful for full automation, not just secret lookup. The same MCP session that gives the model browser control can also give it scoped access to the credentials and MFA material needed to finish the workflow.

Runtime Requirement

This package shells out to the official Bitwarden CLI, bw.

Runtime resolution order:

• BW_BIN if you set it explicitly
• bundled @bitwarden/cli optional dependency if it is present
• system bw from PATH

That means package installation can succeed even when the optional dependency is skipped by the environment. In that case you must install bw separately or point BW_BIN to it.

Explicit fallback install:

npm install -g @bitwarden/cli

Or run with an explicit binary path:

BW_BIN=/absolute/path/to/bw npx -y @icoretech/warden-mcp

Install And Run

Choose a transport

• Use --stdio when you want a local MCP host to spawn warden-mcp directly with one fixed Bitwarden profile
• Use default HTTP mode when you want one running warden-mcp service to serve multiple clients or multiple Bitwarden profiles via per-request X-BW-* headers

Local stdio mode

npx -y @icoretech/warden-mcp --stdio

For stdio mode, you must provide Bitwarden credentials up front via env vars:

BW_HOST=https://vaultwarden.example.com \
BW_USER=user@example.com \
BW_PASSWORD='your-master-password' \
npx -y @icoretech/warden-mcp --stdio

API key login works too:

BW_HOST=https://vaultwarden.example.com \
BW_CLIENTID=user.xxxxx \
BW_CLIENTSECRET=xxxxx \
BW_PASSWORD='your-master-password' \
npx -y @icoretech/warden-mcp --stdio

Shared HTTP mode

Start one long-lived MCP server:

npx -y @icoretech/warden-mcp

Verify it is up:

curl -fsS http://localhost:3005/healthz

This mode is what makes warden-mcp different from a simple local wrapper:

• the server stays stateless at the HTTP boundary
• Bitwarden/Vaultwarden credentials are sent per request via X-BW-* headers
• one running server can front different vault hosts or different identities without restarting
• it fits shared-agent and gateway setups much better than per-client local processes

Docker

docker run --rm -p 3005:3005 ghcr.io/icoretech/warden-mcp

Global install

npm install -g @icoretech/warden-mcp
warden-mcp

Connect From MCP Hosts

For local MCP hosts, stdio is the most portable option.

npx -y @icoretech/warden-mcp --stdio

The examples below use Bitwarden API-key auth. If you prefer username/password login, replace BW_CLIENTID + BW_CLIENTSECRET with BW_USER.

CLI-based hosts

These hosts let you register warden-mcp directly from the command line:

# Codex
codex mcp add warden \
  --env BW_HOST=https://vaultwarden.example.com \
  --env BW_CLIENTID=user.xxxxx \
  --env BW_CLIENTSECRET=xxxxx \
  --env BW_PASSWORD='your-master-password' \
  -- npx -y @icoretech/warden-mcp --stdio

# Claude Code
claude mcp add-json warden '{"command":"npx","args":["-y","@icoretech/warden-mcp","--stdio"],"env":{"BW_HOST":"https://vaultwarden.example.com","BW_CLIENTID":"user.xxxxx","BW_CLIENTSECRET":"xxxxx","BW_PASSWORD":"your-master-password"}}'

# Qwen Code
qwen mcp add warden \
  -e BW_HOST=https://vaultwarden.example.com \
  -e BW_CLIENTID=user.xxxxx \
  -e BW_CLIENTSECRET=xxxxx \
  -e BW_PASSWORD=your-master-password \
  npx -y @icoretech/warden-mcp --stdio

JSON config hosts

These hosts all use the same stdio payload shape. Only the config file location changes:

• Codex: ~/.codex/config.toml
• Cursor: ~/.cursor/mcp.json or .cursor/mcp.json
• Claude Desktop: ~/Library/Application Support/Claude/claude_desktop_config.json
• Qwen Code: ~/.qwen/settings.json or .qwen/settings.json

Shared JSON shape:

{
  "mcpServers": {
    "warden": {
      "command": "npx",
      "args": ["-y", "@icoretech/warden-mcp", "--stdio"],
      "env": {
        "BW_HOST": "https://vaultwarden.example.com",
        "BW_CLIENTID": "user.xxxxx",
        "BW_CLIENTSECRET": "xxxxx",
        "BW_PASSWORD": "your-master-password"
      }
    }
  }
}

Codex uses TOML instead of JSON:

[mcp_servers.warden]
command = "npx"
args = ["-y", "@icoretech/warden-mcp", "--stdio"]

[mcp_servers.warden.env]
BW_HOST = "https://vaultwarden.example.com"
BW_CLIENTID = "user.xxxxx"
BW_CLIENTSECRET = "xxxxx"
BW_PASSWORD = "your-master-password"

Windsurf

Windsurf uses the same stdio idea but stores it in ~/.codeium/windsurf/mcp_config.json:

{
  "mcpServers": {
    "warden": {
      "command": "npx",
      "args": ["-y", "@icoretech/warden-mcp", "--stdio"],
      "env": {
        "BW_HOST": "https://vaultwarden.example.com",
        "BW_CLIENTID": "user.xxxxx",
        "BW_CLIENTSECRET": "xxxxx",
        "BW_PASSWORD": "your-master-password"
      }
    }
  }
}

Shared HTTP connections

If your MCP host supports Streamable HTTP with custom headers, you can connect to one long-lived warden-mcp service instead of spawning a local stdio process.

Start the shared server:

npx -y @icoretech/warden-mcp

Every MCP request must include:

• X-BW-Host
• X-BW-Password
• either X-BW-ClientId + X-BW-ClientSecret, or X-BW-User

Example health check:

curl -fsS \
  -H 'X-BW-Host: https://vaultwarden.example.com' \
  -H 'X-BW-ClientId: user.xxxxx' \
  -H 'X-BW-ClientSecret: xxxxx' \
  -H 'X-BW-Password: your-master-password' \
  http://localhost:3005/healthz

Example MCP endpoint:

http://localhost:3005/sse?v=2

This shared-server mode is useful when:

• one MCP gateway needs to front multiple Bitwarden profiles
• you want to rotate vault credentials per request instead of per process
• you are integrating from a custom client or agent host that can attach HTTP headers
• you want one always-on service instead of each editor spawning its own bw-backed subprocess

Client examples for shared HTTP mode:

# Claude Code
claude mcp add-json warden '{"type":"http","url":"http://localhost:3005/sse?v=2","headers":{"X-BW-Host":"https://vaultwarden.example.com","X-BW-ClientId":"user.xxxxx","X-BW-ClientSecret":"xxxxx","X-BW-Password":"your-master-password"}}'

// Cursor (~/.cursor/mcp.json)
{
  "mcpServers": {
    "warden": {
      "url": "http://localhost:3005/sse?v=2",
      "headers": {
        "X-BW-Host": "https://vaultwarden.example.com",
        "X-BW-ClientId": "user.xxxxx",
        "X-BW-ClientSecret": "xxxxx",
        "X-BW-Password": "your-master-password"
      }
    }
  }
}

// Qwen Code (~/.qwen/settings.json)
{
  "mcpServers": {
    "warden": {
      "httpUrl": "http://localhost:3005/sse?v=2",
      "headers": {
        "X-BW-Host": "https://vaultwarden.example.com",
        "X-BW-ClientId": "user.xxxxx",
        "X-BW-ClientSecret": "xxxxx",
        "X-BW-Password": "your-master-password"
      }
    }
  }
}

// Windsurf (~/.codeium/windsurf/mcp_config.json)
{
  "mcpServers": {
    "warden": {
      "serverUrl": "http://localhost:3005/sse?v=2",
      "headers": {
        "X-BW-Host": "https://vaultwarden.example.com",
        "X-BW-ClientId": "user.xxxxx",
        "X-BW-ClientSecret": "xxxxx",
        "X-BW-Password": "your-master-password"
      }
    }
  }
}

Codex currently fits better with stdio here, because its MCP config supports a bearer token env var for remote servers but not arbitrary custom X-BW-* header injection.

Verify bw is available

bw --version

If that fails after install, your environment likely skipped the optional @bitwarden/cli dependency. Install it explicitly:

npm install -g @bitwarden/cli

How It Works

The server executes bw commands on your behalf:

• In HTTP mode, Bitwarden/Vaultwarden connection + credentials are provided via HTTP headers per request. Env-var fallback is disabled by default; set KEYCHAIN_ALLOW_ENV_FALLBACK=true to enable it for single-tenant HTTP deployments.
• In stdio mode, Bitwarden/Vaultwarden credentials are loaded once from BW_* env vars at startup.
• The server maintains per-profile bw state under KEYCHAIN_BW_HOME_ROOT to avoid session/config clashes.
• Writes can optionally call bw sync (internal; not exposed as an MCP tool).

Required Headers

• X-BW-Host (must be an HTTPS origin, for example https://vaultwarden.example.com)
• X-BW-Password (master password; required to unlock)
• Either:
  • X-BW-ClientId + X-BW-ClientSecret (API key login), or
  • X-BW-User (email for user/pass login; still uses X-BW-Password)
• Optional:
  • X-BW-Unlock-Interval (seconds)

Security Model

There is no built-in auth layer in v1. Run it only on a trusted network boundary (localhost, private subnet, VPN, etc.).

Credential resolution:

• HTTP mode requires X-BW-* headers on every request by default. Without them, tools return an error.
• Stdio mode reads BW_* env vars at startup (single-tenant).
• To allow HTTP mode to fall back to server env vars when headers are absent (single-tenant HTTP), set KEYCHAIN_ALLOW_ENV_FALLBACK=true. Security warning: this means any client that can reach the HTTP endpoint gets full vault access without providing credentials. Only use this behind network-level access control.

Mutation control:

• Set READONLY=true to block all write operations (create/edit/delete/move/restore/attachments).
• Set NOREVEAL=true to force all reveal parameters to false server-side. Clients can still request reveal: true, but the server will silently downgrade to redacted output. This prevents prompt injection from tricking an LLM agent into exfiltrating secrets.
• Session guardrails:
  • KEYCHAIN_SESSION_MAX_COUNT (default 32)
  • KEYCHAIN_SESSION_TTL_MS (default 900000)
  • KEYCHAIN_SESSION_SWEEP_INTERVAL_MS (default 60000)
  • KEYCHAIN_MAX_HEAP_USED_MB (default 1536, set 0 to disable memory fuse)
  • KEYCHAIN_METRICS_LOG_INTERVAL_MS (default 0, disabled)
  • NOREVEAL / KEYCHAIN_NOREVEAL (default false; force all reveals to false)
  • KEYCHAIN_ALLOW_ENV_FALLBACK (default false; HTTP env-var credential fallback)

Redaction defaults (item reads):

• Login: password, totp
• Card: number, code
• Identity: ssn, passportNumber, licenseNumber
• Custom fields: hidden fields (Bitwarden type: 1)
• Attachments: attachments[].url (signed download URL token)
• Password history: passwordHistory[].password

Reveal rules:

• Tools accept reveal: true where applicable (default is false).
• Secret helper tools (get_password, get_totp, get_notes, generate, get_password_history) return structuredContent.result = { kind, value, revealed }.
  • When reveal is omitted/false, value is null (or historic passwords are null) and revealed: false.

Production Deployment Checklist

If you run warden-mcp beyond local development, review these items:

1. TLS everywhere. Always terminate TLS in front of the HTTP endpoint. X-BW-* headers carry master passwords in cleartext — without TLS they are visible to anyone on the network.

2. Network isolation. Bind the server to 127.0.0.1 or place it behind an authenticated reverse proxy. The service has no built-in authentication; anyone who can reach /sse can issue vault operations.

3. Do not enable KEYCHAIN_ALLOW_ENV_FALLBACK on shared networks. This flag makes the server's own vault credentials available to any HTTP client that omits headers. Only use it in single-tenant setups where the network is fully trusted.

4. Enable READONLY=true when writes are not needed. This blocks all mutating tools at the MCP layer, limiting blast radius if an agent or client is compromised.

5. Restrict filesystem access to /data/bw-profiles. The bw CLI stores decrypted state under its HOME directory. Ensure the profile directory is not world-readable and is mounted with appropriate permissions (the Docker image runs as non-root by default).

6. Disable debug logging in production. KEYCHAIN_DEBUG_BW and KEYCHAIN_DEBUG_HTTP emit request details and CLI invocations to stdout. Debug logs may include session metadata and request structure. Keep them off unless actively troubleshooting.

7. Set NOREVEAL=true when secrets should never leave the server. This forces all reveal parameters to false server-side, regardless of what the client requests. Use this when the MCP host is an LLM agent that could be influenced by prompt injection — it prevents tricked agents from exfiltrating passwords or TOTP codes.

8. Monitor /metricsz. The endpoint is intentionally unauthenticated (for scraper compatibility) but exposes session counts, heap usage, and rejection counters. If this data is sensitive in your environment, restrict access at the network level.

Quick Start

Minimal local run

Run the published package in HTTP mode and verify the server is up:

npx -y @icoretech/warden-mcp
curl -fsS http://localhost:3005/healthz

Local Development

Docker Compose

Starts a local Vaultwarden + HTTPS proxy (for bw), bootstraps a test user, and runs the MCP server.

cp .env.example .env
make up
curl -fsS http://localhost:3005/healthz

Run integration tests:

make test

Run session flood regression locally (guardrail sanity):

npm run test:session-regression

Local dev (host)

npm install
cp .env.example .env
npm run dev

Tool Reference (v1)

Vault/session:

• keychain.status
• keychain.encode (base64-encode a string via bw encode)
• keychain.generate (returns a generated secret only when reveal: true)

Items:

• keychain.search_items, keychain.get_item, keychain.update_item
• keychain.create_login, keychain.create_note, keychain.create_card, keychain.create_identity, keychain.create_ssh_key
• keychain.delete_item, keychain.restore_item

Folders:

• keychain.list_folders, keychain.create_folder, keychain.edit_folder, keychain.delete_folder

Orgs/collections:

• keychain.list_organizations, keychain.list_collections
• keychain.list_org_collections, keychain.create_org_collection, keychain.edit_org_collection, keychain.delete_org_collection
• keychain.move_item_to_organization

Attachments:

• keychain.create_attachment, keychain.delete_attachment, keychain.get_attachment

Sends:

• keychain.send_list, keychain.send_template, keychain.send_get
• keychain.send_create (quick create via bw send)
• keychain.send_create_encoded, keychain.send_edit (advanced create/edit via bw send create|edit)
• keychain.send_remove_password, keychain.send_delete
• keychain.receive

Direct “bw get …” helpers:

• keychain.get_username (returns { kind:"username", value, revealed:true })
• keychain.get_password / keychain.get_totp / keychain.get_notes (only return real values when reveal: true)
• keychain.get_uri, keychain.get_exposed
• keychain.get_folder, keychain.get_collection, keychain.get_organization, keychain.get_org_collection
• keychain.get_password_history (only returns historic passwords when reveal: true)

Known Limitations

• bw list items --search (and thus keychain.search_items) does not reliably search inside custom field values.
• SSH keys are stored as secure notes in v1 (until bw supports native SSH key item creation).
• High-risk CLI features are intentionally not exposed yet (export/import).

Contributing

See AGENTS.md for repo guidelines, dev commands, and testing conventions.