omnifabric-mcp

MCP server giving an LLM SQL access to a CloudSigma OmniFabric database (MatrixOne-compatible, MySQL wire protocol).

What It Does

Exposes one MCP tool, run_query, that runs any SQL statement against your OmniFabric/MatrixOne instance over the standard MySQL wire protocol (via mysql2) and returns the rows as JSON. No schema-specific tooling, no query rewriting — whatever SQL you (or the LLM) send is what runs.

Related MCP server: mariadb-mcp

Prerequisites

• Node.js 20.6+ (uses the native --env-file flag for local testing)

• A running OmniFabric instance and its connection details: host, port (default 6001), account UUID, username, role, password

• An MCP-compatible client (Claude Code, Claude Desktop, etc.)

Why a custom server instead of an existing one

• Memoria (matrixorigin/Memoria) is a semantic-memory product built on MatrixOne (store/retrieve/branch/merge memories), not a raw SQL passthrough tool — doesn't fit.

• mcp-server-mysql (generic community MySQL MCP server) looked like a fit but has two bugs for this use case: it hard-rejects any statement its SQL parser doesn't classify as SELECT (so SHOW DATABASES — the exact acceptance-test query — gets rejected), and it wraps every query in SET SESSION TRANSACTION READ ONLY, which isn't confirmed to work on MatrixOne/OmniFabric.

• So: this repo, built directly on mysql2 + @modelcontextprotocol/sdk (both do the heavy lifting — no custom wire protocol). One tool, run_query, passes SQL straight through.

Safety model

There is no app-level statement filtering (that's what broke the alternative above). Instead: connect with a read-only DB role. Ask CloudSigma/whoever provisioned the instance for a role scoped to SELECT only, or check whether OmniFabric supports creating one beyond accountadmin. Only point this server at a write-capable role if you actually need DDL/write access.

Quick install via AI agent

Give this prompt to Claude Code (or any AI coding agent with shell access):

Install the OmniFabric MCP server. Clone https://github.com/Momosasu/omnifabric-mcp.git, run npm install, copy .env.example to .env and ask me for my OmniFabric credentials (host, account UUID, username, role, password) to fill it in, add it to my MCP config at ~/.claude/.mcp.json with args set to ["--env-file=<absolute path to .env>", "<absolute path to index.js>"], and verify the connection by calling run_query with SHOW DATABASES.

Quick Start

1. Install

git clone https://github.com/Momosasu/omnifabric-mcp.git
cd omnifabric-mcp
npm install

2. Configure credentials

cp .env.example .env

Fill in .env with the credentials from your OmniFabric provisioning (CloudSigma console or mo_ctl deploy output):

OMNIFABRIC_HOST=your-instance.omni.example.cloudsigma.com
OMNIFABRIC_PORT=6001
OMNIFABRIC_ACCOUNT=your-account-uuid
OMNIFABRIC_USER=your-username
OMNIFABRIC_ROLE=your-role
OMNIFABRIC_PASSWORD=your-password

Optional: sanity-check the login works before touching MCP at all:

mysql -h <OMNIFABRIC_HOST> -P 6001 -u <ACCOUNT>:<USER>:<ROLE> -p

Then validate your .env assembles into a well-formed config (no live DB connection made):

npm test

3. Add to Claude Code

Add to your MCP config (~/.claude/.mcp.json or project .mcp.json), pointing at the .env you just filled in — no need to re-enter credentials here:

{
  "mcpServers": {
    "omnifabric": {
      "command": "node",
      "args": ["--env-file=/path/to/omnifabric-mcp/.env", "/path/to/omnifabric-mcp/index.js"]
    }
  }
}

Replace /path/to/omnifabric-mcp with your actual path.

4. Verify

Ask Claude: "Use run_query to run SHOW DATABASES"

Tools

• run_query(sql) — runs any SQL statement, returns rows as JSON.

That's it. No create_snapshot/restore_snapshot/UDF tools yet — the PRD explicitly says not to add those speculatively. Add a wrapper tool once there's a concrete use case for a specific OmniFabric SQL-Reference statement raw passthrough doesn't cover well.