LawRuler MCP server

Connect Claude and other MCP clients to LawRuler to create leads, track intake status, assign owners, add notes and tags, and update custom fields.

LawRuler MCP server is a Model Context Protocol server for LawRuler, the legal CRM and intake platform. It registers 15 tools that read and write LawRuler leads. It runs over stdio by default, for desktop clients such as Claude Desktop, and offers an opt-in stateless Streamable HTTP mode that implements MCP specification 2026-07-28. LawRuler credentials stay on the machine that runs the server: they come from the setup command and your operating system's keyring, never from the client.

Features

• Create leads: create a lead with core fields, with the full field set (address, date of birth, contact preferences), or on behalf of another party without the duplicate check.

• Retrieve leads: look up a lead by LeadID.

• Status and assignment: update a lead's status, assignee, owner and case type.

• Notes and tags: update the case summary, add conversation notes and tags, and set the preferred language.

• Contact details: update phone, email and address.

• Custom fields: set one custom field, or update several standard and custom fields at once.

Related MCP server: LACRM MCP Server

Tools

The server registers 15 tools.

Prompts and resources

The server also registers three prompts and three resources.

Requirements

• Python 3.12+.

• A LawRuler portal and API key (in LawRuler: Setup → 3rd Party Integrations).

• An MCP client such as Claude Desktop.

Installation

Install uv, then clone the repository and install its locked dependencies:

git clone https://github.com/RosenAdvertising/lawruler-mcp.git
cd lawruler-mcp
uv sync --locked

Releases are also published to PyPI: pip install lawruler-mcp installs version 0.1.2, which predates the HTTP mode described below. Install from source to use HTTP mode.

Configuration

Run the setup command once. It prompts for your portal URL and API key, tests the connection, and saves both values (see Credential storage). Find your API key in LawRuler under Setup → 3rd Party Integrations.

uv run lawruler-mcp-setup

Check the connection at any time:

uv run lawruler-mcp-verify

Server messages that say to run lawruler-mcp-setup mean uv run lawruler-mcp-setup from your clone. The server reads its credentials once at startup, so restart the MCP server after changing them.

The server reads these variables, which you can also set in its environment:

Credential storage

By default both values are stored in your operating system's native secret store via the cross-platform keyring library:

Secrets are saved under the service name lawruler-mcp when a keyring backend is available. The file fallback described below stores values on disk.

File fallback. On a host with no keyring backend (for example a headless Linux box without Secret Service), or if you set LAWRULER_MCP_USE_KEYRING=0, the values fall back to a ~/.lawruler-mcp/.env file with 0600 permissions:

LAWRULER_BASE_URL=https://yourfirm.lawruler.com
LAWRULER_API_KEY=your_api_key

On Windows, the file is stored in the user's profile and protected by Windows' default per-user access rules. On POSIX, files are created with 0600 permissions and writes fail closed if private permissions cannot be established.

Read order. A value set in the process environment is used as is. When a variable is not set, the server reads the OS keyring, then the ~/.lawruler-mcp/.env file. A key exported in your shell therefore overrides the keyring and the file, and the keyring entry written by setup is used only while the variable is unset.

Pluggable backend. keyring lets you point at any secret store. For example, install keyrings.cryptfile for an encrypted file backend, or a cloud backend, then select it with the standard PYTHON_KEYRING_BACKEND environment variable or a keyringrc.cfg. See the keyring configuration docs.

Usage with Claude Desktop

Add the server to Claude Desktop's configuration file (~/Library/Application Support/Claude/claude_desktop_config.json on macOS, %APPDATA%\Claude\claude_desktop_config.json on Windows):

{
  "mcpServers": {
    "lawruler": {
      "command": "uv",
      "args": ["run", "--locked", "--directory", "/absolute/path/to/lawruler-mcp", "lawruler-mcp"]
    }
  }
}

Replace /absolute/path/to/lawruler-mcp with the path of your clone, then restart Claude Desktop. Any other stdio MCP client uses the same command and arguments.

HTTP mode

Stdio is the default. Set LAWRULER_MCP_TRANSPORT=streamable-http to serve the stateless Streamable HTTP transport from MCP specification 2026-07-28 at /mcp. Each request stands alone: no initialization handshake and no Mcp-Session-Id. Clients on earlier protocol versions are served on the same endpoint.

Security: this endpoint has no authentication and no TLS. Anyone who can reach the port can run every tool, including write tools, with this server's vendor credentials. Keep the default loopback bind (127.0.0.1), or put the server behind an authenticating TLS proxy on a private network. LAWRULER_MCP_ALLOWED_HOSTS and LAWRULER_MCP_ALLOWED_ORIGINS protect against browser DNS rebinding, not against direct callers. A proxy in front of it needs connection and idle timeouts: a legacy-style GET /mcp with Accept: text/event-stream holds a stream open until the client disconnects.

LawRuler credentials come from the same configuration as stdio (see Configuration), never from the request.

LAWRULER_MCP_TRANSPORT=streamable-http PORT=8080 uv run --locked lawruler-mcp

Point the MCP client at http://127.0.0.1:8080/mcp.

Error handling

A failed tool call returns an MCP error result (isError) with a fixed message. The server never passes a LawRuler response body, a request URL or a credential back to the client.

Each request has a connect timeout of 3.05 seconds and a read timeout of 30 seconds, and redirects are never followed. On HTTP 429 the server waits for the Retry-After interval (10 seconds when the header is missing or unreadable) and retries, for up to three attempts in all and 60 seconds of total waiting; if the next wait would exceed what is left, the tool returns the rate-limit message at once. The server does not retry timeouts, connection failures or 5xx responses. A failed resource read returns "Requested LawRuler resource was not found." or "Unable to read the requested LawRuler resource."

At startup the server exits with a message on stderr and a non-zero status when LAWRULER_BASE_URL is set but is not a valid LawRuler portal origin, when LAWRULER_MCP_TRANSPORT is neither stdio nor streamable-http, when PORT is not an integer, or when a non-loopback LAWRULER_MCP_HOST is set without LAWRULER_MCP_ALLOWED_HOSTS.

Portal URL and write validation

LAWRULER_BASE_URL must be an HTTPS origin on lawruler.com or a subdomain, for example https://yourfirm.lawruler.com. Startup, setup and verify share the same validator. IP addresses, unrelated domains, userinfo, query strings, fragments, paths other than /, and ports other than 443 are rejected before requests or setup credential storage. Redirects are disabled on every request. LawRuler's public API guide uses https://sample.lawruler.com/api-legalcrmapp.aspx.

All three create tools require a nonblank full_name, or both first_name and last_name. They also require cell_phone and primary email, which the API guide's Available Fields table marks required. The existing tool schemas are unchanged; missing data is rejected locally. All update paths require at least one meaningful changed value; explicit custom values 0 and false remain valid. For presence checks, text is normalized with Unicode NFKC and whitespace and Unicode categories Cc/Cf/Zs/Zl/Zp are removed. NUL anywhere and unpaired surrogate characters are rejected outright. Meaningful original values (including non-ASCII names such as José García) are preserved in the request.

Custom API field names must match [A-Za-z_][A-Za-z0-9_]* after NFKC normalization. Empty names, whitespace anywhere (including wrapped names), control/format characters, surrogates and other punctuation are rejected. Normalized, case-folded key, operation, leadid, overridelead, returnjson and returnxml are reserved. Names are validated before empty values are omitted; any invalid name rejects the call. Accepted names are sent in normalized form. This applies to single custom-field writes and multi-field updates. Verify prints a fixed success message without displaying the returned lead record.

Testing

The test suite runs offline and needs no LawRuler account: every LawRuler API call is answered by a test double for the requests session. It covers tool requests and responses, input and custom-field-name validation (including Unicode edge cases), portal URL checks, error handling and rate-limit retries, credential file handling, the setup and verify commands, the stdio server, and the Streamable HTTP transport including the 2026-07-28 wire format, Host and Origin checks and stateless requests.

uv sync --locked
uv run --locked pytest -q

CI runs the suite on every push and pull request to main.

License

MIT. See LICENSE.