Liquid MCP Server

Connect your agent to any HTTP API on the fly — discover, map, and fetch typed data.

Remote serverstreamable-httpPython

What is the Liquid MCP server?

Most database access work still happens through a UI a human drives. Liquid MCP server moves it into the conversation instead. Connect your agent to any HTTP API on the fly — discover, map, and fetch typed data.

The short version

Point Liquid at a URL or a database and it works out the interface for you: discovers its shape, maps it to the fields you asked for, and handles auth, pagination and normalization — typed records, no client code. When the upstream drifts, it re-maps and keeps going. The same small API — fetch · query · write · sense — reaches web APIs, databases, other agents (MCP/A2A), email, and even IoT and industrial systems (MQTT, Modbus, OPC UA, BACnet). An LLM does the learning at setup (and on drift); the data path itself makes no model call.

The tools it exposes

The server publishes 9 tools. What each one is for:

  • Interface — Runtime
  • GraphQL — ✅ query + Relay pagination
  • gRPC — ✅ unary + server-streaming (reflection)
  • WebSocket — ✅ bounded batch reads + subscribe + live sense
  • SQLite — ✅ tables/views, filters, pagination
  • DuckDB — ✅ tables/views, filters, pagination
  • Discovery — Where it looks
  • Databases — catalog introspection (postgres://, mysql://, mongodb://, redis://, neo4j://, …)
  • Browser — Playwright capturing network

Getting it running

Because this one is hosted, setup is mostly authentication — you point your client at the endpoint and approve access. Nothing runs on your machine, so there is no runtime to keep patched.

What it needs from you

Configuration is passed through the environment: OPENAI_API_KEY, GEMINI_API_KEY, ANTHROPIC_API_KEY, OPENAI_BASE_URL. Treat anything key-shaped as a real credential — scope it to the minimum the server needs, and rotate it if it ever lands in a shared config.

How it compares

Among the database access options, the useful question is rarely "what can it do" but "what does it cost you to run" — permissions, credentials, and how much of your context its toolset consumes. Liquid's toolset — Interface, GraphQL, gRPC and 6 more — is a fair guide to whether it matches your workflow. It is maintained by ertad-family; worth a glance at recent repository activity before you build anything load-bearing on it.

This entry was verified against Liquid's own documentation before publication; SyncDev keeps the directory reviewed rather than auto-generated.

Things to watch

  • Your data travels to the provider's service, so the usual questions apply about what you send and what they retain.
  • With 9 tools registered it takes up a noticeable share of the context window; turn it off in projects that never touch Liquid.
  • Missing credentials fail quietly in some clients — if no tools show up, check the environment block first.
  • Keep per-call confirmation enabled while you learn its behaviour; it is the cheapest safeguard you have.

Available tools

ToolWhat it does
InterfaceRuntime
GraphQL✅ query + Relay pagination
gRPC✅ unary + server-streaming (reflection)
WebSocket✅ bounded batch reads + subscribe + live sense
SQLite✅ tables/views, filters, pagination
DuckDB✅ tables/views, filters, pagination
DiscoveryWhere it looks
Databasescatalog introspection (postgres://, mysql://, mongodb://, redis://, neo4j://, …)
BrowserPlaywright capturing network

How to install the Liquid MCP server

Claude Desktop / any MCP client:

```json
{ "mcpServers": { "liquid": {
  "command": "uvx",
  "args": ["liquid-mcp"],
  "env": { "OPENAI_API_KEY": "sk-..." }
} } }

Configuration as documented by the project. Restart the client after saving.

Configuration

VariableDescriptionRequired
OPENAI_API_KEYCredential the server authenticates with.Yes
GEMINI_API_KEYCredential the server authenticates with.Yes
ANTHROPIC_API_KEYCredential the server authenticates with.Yes
OPENAI_BASE_URLEndpoint or connection string the server talks to.Yes

Example prompts to try

  • Use Liquid to Interface.
  • Use Liquid to GraphQL.
  • Use Liquid to gRPC.

Frequently asked questions

It connects Liquid to MCP-compatible AI assistants such as Claude and Cursor, exposing 9 tools (Interface, GraphQL, gRPC, and more) that the assistant can call on your behalf. Instead of copying data back and forth by hand, the assistant works with Liquid directly.