# NexQL Postgres MCP

**Category:** 🗄️ Databases  
**Repository:** https://github.com/NexQL-OSS/mcp  
**Views:** 0  
**Installs:** 0  
**Upvotes:** 0  
**Directory Page:** https://allmcps.com/mcp/nexql-postgres-mcp

## Description
Standalone Postgres MCP server — schema-aware, read-only by default, installable everywhere.

## Claude Desktop Quick Installation
Heuristic fallback — verify the package name and runner against the repository README before running it. Uses `npx` (confidence: low):

```json
"mcpServers": {
  "nexql-postgres-mcp": {
    "command": "npx",
    "args": ["-y","nexql-postgres-mcp"]
  }
}
```

## Documentation & README

# nexql-mcp

Standalone Postgres MCP server — schema-aware, read-only by default, installable everywhere.

NexQL Pro ships an in-process MCP server locked to VS Code (`pro/src/mcp/`). This repo extracts that capability into an independent Rust binary any MCP client can spawn: Claude Desktop, Cursor, VS Code Copilot, Zed, etc.

**Status:** Phases 0–6 + **Phase 7 extension cutover (stdio spawn)** + **Phase 8 HTTP (bearer, sessions, rate limit)** + **Phase 9 write/admin tools** landed. 53 tools across Schema, Query, Context, Perf, Write, and Admin. Full OAuth gateway stays pro-only; session-store LRU eviction cap not yet implemented. See [docs/CUTOVER.md](docs/CUTOVER.md).

## Why this exists

Competing Postgres MCP servers expose `connect → run query → return rows`. Models hallucinate table names against schemas that do not exist. NexQL's moat is the offline schema index (TF-IDF, join graph with inferred FKs, value profiles, optional embeddings, RRF fusion) built in `pro/src/features/dbindex/`. This repo ports that index plus 53 query/schema/DBA/meta tools from Pro into a fast, trivially installable binary.

## Architecture

```
crates/
├── nexql-mcp/      CLI, subcommands, wiring (binary)
├── nexql-proto/    MCP JSON-RPC types, transports
├── nexql-tools/    tool registry, schemas, executors
├── nexql-index/    dbindex port (builder, store, lexical, joins, embed)
├── nexql-conn/     connection resolution, pool, credentials
└── nexql-policy/   access modes, allow/deny, PII, caps, audit
npm/                npx shim (per-platform optionalDependencies)
mcpb/               one-click Claude Desktop bundle
docs/               per-client setup, tool reference
```

Layering is one-directional: `policy` + `conn` are leaves → `index` → `tools` → binary. `nexql-tools` never depends on `nexql-proto`.

## Install

Pick whichever fits your workflow — all methods ship the same binary.

**Linux system requirements:** prebuilt GNU/Linux binaries target **glibc 2.35+** (Ubuntu 22.04, Debian 12, RHEL 9, and newer). Releases from v0.2.1 and earlier were built on Ubuntu 24.04 and require glibc 2.39 — if `npm install nexql-mcp` fails with `GLIBC_2.39 not found`, upgrade to the next release, use [`cargo install`](#cargo-cratesio) (builds from source), or run the [Docker image](#docker). Musl/static Linux builds are not published yet.

### Quick install (Linux / macOS / Windows)

**Linux & macOS** — downloads the latest release, installs to `/usr/local/bin` (or `~/.local/bin` if sudo is unavailable), then prints setup steps:

```bash
curl -fsSL https://raw.githubusercontent.com/NexQL-OSS/mcp/main/scripts/install.sh | bash
```

Pin a version:

```bash
NEXQL_MCP_VERSION=v0.2.2 curl -fsSL https://raw.githubusercontent.com/NexQL-OSS/mcp/main/scripts/install.sh | bash
```

**Windows** (PowerShell) — installs to `%LOCALAPPDATA%\Programs\nexql-mcp` and adds it to your user `PATH`:

```powershell
irm https://raw.githubusercontent.com/NexQL-OSS/mcp/main/scripts/install.ps1 | iex
```

Pin a version:

```powershell
$env:NEXQL_MCP_VERSION = "v0.2.2"; irm https://raw.githubusercontent.com/NexQL-OSS/mcp/main/scripts/install.ps1 | iex
```

Or download and run the scripts locally: [`scripts/install.sh`](scripts/install.sh) · [`scripts/install.ps1`](scripts/install.ps1).

#### After install

```bash
# 1. Verify
nexql-mcp --version

# 2. Test a Postgres connection
nexql-mcp postgres://dev@localhost:5432/appdb doctor

# 3. Wire your MCP client (or run the guided wizard)
nexql-mcp init cursor          # Cursor
nexql-mcp init claude-desktop  # Claude Desktop
nexql-mcp init vscode-copilot  # VS Code Copilot
nexql-mcp tui                  # interactive profile + client wiring
```

Per-client config paths and paste blocks: [docs/clients/README.md](docs/clients/README.md).

### npm / npx

```bash
npx -y nexql-mcp postgres://dev@localhost:5432/appdb   # one-off, no install
npm install -g nexql-mcp                                # or install it once
```

[`nexql-mcp`](https://www.npmjs.com/package/nexql-mcp) is a shim ([`npm/bin/nexql-mcp.js`](npm/bin/nexql-mcp.js)) that resolves the right prebuilt binary from a per-platform `optionalDependency` (`@nexql/mcp-<os>-<arch>`) — no Rust toolchain needed.

### uv (PyPI)

[uv](https://docs.astral.sh/uv/) installs CLI tools from PyPI into isolated environments — same prebuilt binary, no Rust toolchain.

Install uv itself (if needed):

```bash
curl -LsSf https://astral.sh/uv/install.sh | sh   # macOS / Linux
```

```powershell
irm https://astral.sh/uv/install.ps1 | iex        # Windows
```

Install nexql-mcp:

```bash
uv tool install nexql-mcp
uv tool update-shell    # once, if uv warns the tool bin dir is not on PATH
```

One-off without installing:

```bash
uvx nexql-mcp postgres://dev@localhost:5432/appdb doctor
```

Pin a version:

```bash
uv tool install 'nexql-mcp==0.2.2'
```

Upgrade later:

```bash
uv tool upgrade nexql-mcp
```

Then follow [After install](#after-install) above.

> **PyPI status:** wheels are not published yet. Until the first PyPI release lands, use [quick install](#quick-install-linux--macos--windows) or npm. Maintainer steps: [docs/publish-pypi-uv.md](docs/publish-pypi-uv.md).

### cargo (crates.io)

```bash
cargo install nexql-mcp
```

Builds from source, so you need clang/libclang first (`pg_query`'s bindgen requires it):

```bash
sudo apt install clang libclang-dev   # Debian/Ubuntu
sudo pacman -S clang                  # Arch
```

### Manual download

Prefer the [quick install](#quick-install-linux--macos--windows) scripts above. To install by hand, grab the archive for your platform from the [Releases page](https://github.com/NexQL-OSS/mcp/releases/latest):

| Platform | Archive |
|----------|---------|
| Linux x64 | `nexql-mcp-<tag>-x86_64-unknown-linux-gnu.tar.gz` |
| Linux arm64 | `nexql-mcp-<tag>-aarch64-unknown-linux-gnu.tar.gz` |
| macOS Intel | `nexql-mcp-<tag>-x86_64-apple-darwin.tar.gz` |
| macOS Apple Silicon | `nexql-mcp-<tag>-aarch64-apple-darwin.tar.gz` |
| Windows x64 | `nexql-mcp-<tag>-x86_64-pc-windows-msvc.tar.gz` |

Extract and put `nexql-mcp` (or `nexql-mcp.exe`) on your `PATH`, then follow [After install](#after-install) above.

### Docker

Prebuilt, published on every release to [GHCR](https://github.com/NexQL-OSS/mcp/pkgs/container/mcp):

```bash
docker run --rm -i ghcr.io/nexql-oss/mcp:0.2.2 postgres://dev@host.docker.internal:5432/appdb
# or: ghcr.io/nexql-oss/mcp:latest
```

Or build locally from the distroless `Dockerfile`:

```bash
docker build -t nexql-mcp:0.2.2 .
docker run --rm -i nexql-mcp:0.2.2 postgres://dev@host.docker.internal:5432/appdb
```

### Claude Desktop (MCPB one-click bundle)

Each release attaches a platform `.mcpb` bundle (`nexql-mcp-<vendor>.mcpb`) — download the one matching
your OS/arch from the [Releases page](https://github.com/NexQL-OSS/mcp/releases/latest) and double-click
to install into Claude Desktop. Built from [`mcpb/manifest.json`](mcpb/manifest.json) via
[`scripts/package-mcpb.sh`](scripts/package-mcpb.sh).

### Homebrew

No published tap yet — each release renders a formula (`Formula/nexql-mcp.rb`, via
[`scripts/render-homebrew-formula.sh`](scripts/render-homebrew-formula.sh)) and attaches it as a release
asset for a future `homebrew-tap` repo to pick up. Until that tap exists, use the [quick install](#quick-install-linux--macos--windows) or cargo methods
above.

### MCP Registry

Listed in the [official MCP Registry](https://registry.modelcontextprotocol.io) as
`io.github.NexQL-OSS/nexql-mcp` ([`server.json`](server.json)), published automatically after each
release via GitHub OIDC (no stored credentials) — see
[`.github/workflows/publish-mcp-registry.yml`](.github/workflows/publish-mcp-registry.yml).

- mcp-name: io.github.NexQL-OSS/nexql-mcp

### From source

```bash
export LIBCLANG_PATH="${LIBCLANG_PATH:-/usr/lib}"   # or your llvm lib dir
cargo build --release -p nexql-mcp
./target/release/nexql-mcp postgres://dev@localhost:5432/appdb
```

## Set up a connection

**One-off**, no config — pass a connection string directly:

```bash
nexql-mcp postgres://dev@localhost:5432/appdb
```

**Saved profiles** — put connections in `~/.config/nexql-mcp/config.toml` (override the path with `NEXQL_MCP_CONFIG`):

```toml
default_profile = "local"

[profiles.local]
url = "postgres://dev@localhost:5432/appdb"
access_mode = "read"

[profiles.prod]
host = "prod.example.com"
dbname = "app"
user = "readonly_agent"
password_command = "op read op://vault/pg/password"   # never store plaintext secrets
sslmode = "verify-full"
access_mode = "read"
schemas = ["public", "billing"]
deny_tables = ["auth.*"]
pii_columns = ["public.users.ssn", "public.users.email"]
max_rows = 200
```

Full field reference: [docs/config.example.toml](docs/config.example.toml). Then run bare (`nexql-mcp`) to use `default_profile`, or `nexql-mcp --profile prod`.

**Test a connection** before wiring it into a client:

```bash
nexql-mcp postgres://dev@localhost:5432/appdb doctor
# or, for a saved profile (note: --profile goes before the subcommand):
nexql-mcp --profile prod doctor
```

**Guided setup** — an interactive profile editor plus one-keystroke wiring into whichever clients you use: `nexql-mcp tui` (see [Interactive TUI](#interactive-tui) below).

### Wire a client

```bash
nexql-mcp postgres://dev@localhost:5432/appdb init cursor
```

Supported `init` clients: `claude` | `claude-desktop` | `claude-code` | `cursor` | `vscode` | `vscode-copilot` | `zed` | `windsurf` | `continue` | `jetbrains` | `openai-agents`.

Per-client paste blocks: [docs/clients/README.md](docs/clients/README.md).

## Use with the NexQL VS Code extension

If you already use [`ric-v.postgres-explorer`](https://marketplace.visualstudio.com/items?itemName=ric-v.postgres-explorer) (+ NexQL Pro), you don't need any of the above — the extension can spawn this binary itself and reuse your existing saved connections instead of a separate `config.toml`.

1. Settings → search **NexQL: Mcp: Enabled** (`postgresExplorer.mcp.enabled`) → check it. Off by default.
2. That's it — it takes effect immediately (no reload needed) and picks up every connection already saved in `postgresExplorer.connections`. It shows up as an MCP server named **NexQL** in Copilot Chat / agent-mode tool pickers.

The extension resolves the binary in this order: `postgresExplorer.mcp.binaryPath` setting → `NEXQL_MCP_BIN` env var → a copy bundled with the extension → whatever `nexql-mcp` is on your `PATH` (i.e. anything installed via npm/cargo/curl above). Set `postgresExplorer.mcp.binaryPath` explicitly if you want the extension to use a specific install.

### Interactive TUI

```bash
nexql-mcp tui
```

Guided profile editor: add/edit/delete a connection profile, test-connect it live before saving, then pick any of 7 clients (Claude Desktop, Claude Code, Cursor, VS Code, Copilot Chat, Zed, Windsurf) to wire it into at once. Each selected client's real config file is read, merged (existing unrelated servers are preserved), shown as a diff, and only written after you confirm — a timestamped backup is kept alongside it. `continue` / `jetbrains` / `openai-agents` have no safe on-disk merge target, so those stay copy-paste snippets in the summary screen, same as `init`.

Keys: `n` new · `e`/Enter edit · `d` delete · `t` test · `w` wire into clients · `q` quit. Bare `nexql-mcp` (no URL, no flags) launches the TUI automatically when nothing else resolves a connection.

### Releases

Pushing a `v*` tag triggers [`.github/workflows/release.yml`](.github/workflows/release.yml): builds
darwin arm64/x64, linux gnu arm64/x64, and windows x64; attaches archives, per-platform `.mcpb` bundles,
a CycloneDX SBOM, and a rendered Homebrew formula to a GitHub release; publishes the npm packages and
GHCR image; and publishes the workspace crates to crates.io in dependency order. A follow-up workflow
([`publish-mcp-registry.yml`](.github/workflows/publish-mcp-registry.yml)) then lists the release on the
MCP Registry via GitHub OIDC. Linux GNU binaries are built on Ubuntu 22.04 (glibc 2.35). Musl targets remain deferred until a clang-enabled musl builder is validated.

## Development

```bash
cargo check          # workspace compile
cargo run -p nexql-mcp -- doctor
cargo test -p nexql-mcp -- init_clients
cargo fmt --all
cargo clippy --workspace --all-targets
```

Read [CLAUDE.md](CLAUDE.md) and [docs/REFERENCE.md](docs/REFERENCE.md) before implementing.

## License

GPL-3.0-only for all crates in this repo, from v0.2.0 onward. If you distribute this
program or a derivative — including bundled inside another application — you must
release your source under the GPL as well.

Releases up to and including **v0.1.6** were published under Apache-2.0. That grant
is irrevocable for those versions and is unaffected by this change.

Copyright is held solely by the NexQL-OSS Team, so commercial licenses that lift the
GPL obligation are available on request. Premium extensions (provider embeddings,
team sync, hosted gateway) live in a separate proprietary crate.

## Roadmap

| Phase | Deliverable |
|-------|-------------|
| 0 | Spike: tokio-postgres + candle MiniLM proof |
| 1 | `nexql-conn` + `nexql-policy` + pg_query validator |
| 2 | MCP stdio transport + ~8 catalog tools |
| 3 | `nexql-index` (byte-compatible with TS format) |
| 4 | Full tool surface, resources, prompts, completions |
| 5 | Local embeddings + RRF fusion |
| 6 | v1.0 ship: cargo-dist, npm, brew, Docker, MCPB |
| 7 | Extension cutover — VS Code spawns binary via stdio MCP definition |
| 8 | Streamable HTTP + bearer token (`--http` / `NEXQL_MCP_HTTP_TOKEN`) — OAuth gateway = pro |
| 9 | Write/admin tools + `validate_write_sql` (opt-in `--access-mode write\|admin`) |

Full plan: internal design doc (federated-greeting-badger). Cutover details: [docs/CUTOVER.md](docs/CUTOVER.md).

## Reference implementation

TypeScript sources in the sibling `nexql-pro` checkout (chat still uses these; MCP HTTP stack removed):

- `pro/src/mcp/McpDefinitionProvider.ts` — stdio spawn of this binary
- `pro/src/mcp/NexqlMcpStdioHost.ts` — ephemeral profile + binary resolve
- `pro/src/providers/chat/tools/ToolSpec.ts`
- `pro/src/providers/chat/tools/ToolExecutor.ts`
- `pro/src/features/dbindex/*`