MCP, native to the BEAM.

Temporary sandbox · GitHub + Google login · OAuth required

One session. Your assistant, files and Postgres.

Hosted sign-in requires a configured GitHub or Google provider. If sign-in is unavailable, provider setup is still pending; the setup instructions below remain available.

mcp.elixirmcp.dev gives each authorization its own in-memory playground. Sign in with GitHub or Google, approve access, then browse the demo documents and the virtual device controls — the hosted sandbox is read-only for security. Your real files and databases are never connected.

Sandbox data is temporary and isolated by authorization, not shared with other visitors. Refresh keeps the same session; a new authorization creates a fresh one. Data expires after one hour or a server restart. The /dev endpoints are virtual control files over WebSocket, not operating-system devices or local Unix sockets.

Connect Postgres through the engine

pg_mcp (v0.3.0) is the pgrx-based PostgreSQL extension behind this demo: it surfaces MCP servers as foreign data wrapper tables you can read and write with plain SQL. Every upstream call is brokered by the Noizu.MCP.Engine HTTP plug — Postgres never talks to MCP servers directly, and credentials stay in the engine. Supports PostgreSQL 16, 17 and 18. Source: pg/pg_mcp · extension guide.

1. Install the extension

Docker — layer the compiled extension onto a Postgres image (the fastest path):

# From the repository root (no registry needed for a stock postgres:17 base):
git clone https://github.com/noizu-labs-ml/elixir-mcp-lib.git
cd elixir-mcp-lib
docker build -f pg/docker/Dockerfile \
  --build-arg BASE_IMAGE=postgres:17 --build-arg FINAL_USER=root \
  -t pg_mcp:pg17 .
docker run --name pg17-mcp -e POSTGRES_HOST_AUTH_METHOD=trust -p 5432:5432 pg_mcp:pg17
# The image layer ships the extension (.so + control + SQL), so:
psql -h localhost -U postgres -c "CREATE EXTENSION pg_mcp;"
psql -h localhost -U postgres -X -f pg/docker/smoke-production.sql

From source — pgrx 0.19.2 (pinned by ADR-002), PostgreSQL 18 by default, 16/17 via --features flags:

# Requires Rust + a local Postgres 18 dev install with matching pg_config
# and headers. (PG 16/17: build with --features pg16 / --features pg17.)
git clone https://github.com/noizu-labs-ml/elixir-mcp-lib.git
cd elixir-mcp-lib
cd pg/pg_mcp
cargo install --locked [email protected]
cargo pgrx init --pg18 "$(command -v pg_config)"
cargo pgrx install -c "$(command -v pg_config)"

2. Start the engine with your existing session

The engine source includes HTTP bearer authentication. Use the demo launcher. The launcher reads the same token file as your VFS daemon and binds only to 127.0.0.1:4040.

# From the root of the elixir-mcp-lib checkout (cloned in step 1):
mix deps.get
curl -fSLo oauth-token.py https://elixirmcp.dev/downloads/oauth-token.py
curl -fSLo demo-engine.exs https://elixirmcp.dev/downloads/demo-engine.exs
# Reuse the SAME token file created for the VFS to share one sandbox.
DEMO_TOKEN_FILE="$HOME/.config/elixirmcp/demo-token.json" mix run --no-halt demo-engine.exs

The local bridge trusts processes on your own machine; keep it on loopback. The hosted upstream always requires OAuth. A separate Claude connector authorization gets a separate sandbox; it does not automatically share this helper’s token.

3. Read your session notes with SQL

Run this once in a local development database. The required URI filter selects the resource to read. Change the notes through the VFS or MCP, then run the SELECT again.

CREATE EXTENSION pg_mcp;
CREATE SERVER elixirmcp_demo FOREIGN DATA WRAPPER mcp_fdw
  OPTIONS (url 'http://127.0.0.1:4040', auth 'none', timeout_ms '15000');
CREATE SCHEMA demo;
IMPORT FOREIGN SCHEMA mcp FROM SERVER elixirmcp_demo INTO demo;
SELECT uri, text FROM demo.resource_contents
  WHERE uri = 'mcp+engine://demo/demo://workspace';

This demo uses a read-through foreign table. For durable local tables, see opt-in PostgreSQL cache synchronization: local indexed reads, SQL write-back and explicit conflict handling for sources that support conditional writes and durable operation replay. The hosted session sandbox does not provide durable synchronization. See the extension guide for supported versions and build details.

Features

Everything a production MCP deployment needs, in one package.