MCP-NixOS — Watchlist

MCP100 Assessment

Watchlist / Tracking

Why we’re tracking it

Track NixOS channel and package-index changes as system metadata evolves

Reviewed Oct 5, 2026 · Documentation review; complete setup workflow not independently tested

Best fit

NixOS package, option and documentation lookup

What we know

MCP server for real-time NixOS package, option, documentation and cache queries.

Maintenance / activity evidence

Observed Sep 5, 2026 (UTC)release: v3.1.0 ( 216)

Tracking evidence observed Oct 5, 2026. These dated signals do not establish current maintenance. Reviewed enrichment confidence: high.

Activity source · commits ↗Activity source · releases ↗

Verification gaps / watch-outs

Installation and comprehensive security have not been independently audited.
Read/query NixOS/package metadata.
Local stdio none; remote unresolved.
Search/query data only; no persistent sensitive store established.

Primarily read-oriented package/documentation lookup; remote-mode auth should still be verified before exposure.

Security source · repository notice ↗

Full authority, access and evidence limits are available in Review context and Access & risk.

Popularity

851 repository stars

Stars observed Oct 6, 2026.

30-day package downloads intentionally left null because the package-stats provider ran out of credits during Batch 3 QA.

All limitations / Review context

Which NixOS queries and system actions remain available through MCP?

The bounded assessment reviewed the official README, repository notices, security policy path, and security page for known material public-tracking blockers. No such blocker was identified. This is a public-tracking assessment, not an installation safety certification.

Primarily read-oriented package/documentation lookup; remote-mode auth should still be verified before exposure.
Read/query NixOS/package metadata.
Local stdio none; remote unresolved.
Search/query data only; no persistent sensitive store established.
Installation, client compatibility and comprehensive security have not been independently audited. Authentication and access depend on the configured services.
A project-specific SECURITY.md policy was not available at the fetched official path; the review remains limited to published repository notices.
No installation, runtime, client matrix, or complete tool-contract audit was performed in this review.
The fetched official SECURITY.md path returned HTTP 404; it was not treated as positive evidence.
Remote auth model
Exact auth behavior for remote HTTP mode was not fully established.

Original activity observations

2026-09-05T02:30:06Z: release: v3.1.0 ( 216)

Technical identity

github.com/utensils/mcp-nixos

Exact implementation source: https://github.com/utensils/mcp-nixos ↗
Reviewed resource type: MCP Server
Repository identity: utensils/mcp-nixos
Package identity: pypi:mcp-nixos

Evidence & Sources

Evidence basis: Recorded source evidence
Setup runtime verification: Not independently runtime-tested by MCP100 for this setup workflow.

Reviewed Oct 5, 2026 · Latest source observation Oct 6, 2026

GitHub repository ↗
utensils/mcp-nixos
Recorded repository material and project history.

Setup · Watchlist

Install & Agents

Publisher instructions.

Source evidence observed Oct 14, 2026.

Additional setup details required — see the specific gaps below.

Install / connect
Publisher instructions
MCP-NixOS provides read-only NixOS package/config documentation over MCP.
stdio server launch · Publisher instructions
uvx mcp-nixos
Configure / authenticate
MCP100 setup guide
Run via uvx then register that command under the client's MCP settings; local Nix install is unnecessary.
Previously reviewed prerequisites / client guidance: Official Claude Desktop or compatible JSON client: {"mcpServers":{"nixos":{"command":"uvx","args":["mcp-nixos"]}}}. No Nix installation required. For Codex translate through Codex CLI/TOML, do not paste mcpServers JSON.
Check connection
Suggested check
Confirm NixOS package tools are visible in MCP client.
Remove / uninstall / revoke
MCP100 setup guide
Remove the NixOS MCP registration under its configured host name, e.g. `claude mcp remove nixos` if registered as nixos. If explicitly installed in a Python environment, `python -m pip uninstall mcp-nixos` is package cleanup; uvx needs no global uninstall.
Client unregistration, program uninstall, persistent-data deletion, and credential revocation must be treated separately.
Remove client registration · Claude Code only · MCP100 composed guide
claude mcp remove nixos

Official Documentation & Sources

What it does

MCP server for real-time NixOS package, option, documentation and cache queries.

Capability: Search & Web
Resource type: MCP Server
Industry: Software & Technology
Best fit: NixOS package, option and documentation lookup

Representative uses

Search packages/options
Inspect package details
Check binary cache

Limitations

Exact auth behavior for remote HTTP mode was not fully established.

Reviewed access

Access & risk

Review the exact access boundary before connecting this MCP to accounts, credentials, or sensitive data.

Authentication: Local stdio none; remote unresolved.
Permissions: Read/query NixOS/package metadata.
Data handling: Search/query data only; no persistent sensitive store established.
Cost: free
Risk and cautions: Primarily read-oriented package/documentation lookup; remote-mode auth should still be verified before exposure.

Access scope and cautions

Write actions: None in the reviewed inventory
Risk level: low

FAQ

Based on reviewed evidence as of 2026-10-06. Watchlist tracking is not a recommendation or a security certification.

Which tasks are documented for this implementation?

The reviewed tasks include: Search packages/options; Inspect package details; Check binary cache.

What setup and authentication are documented?

Recorded installation/entrypoint step: uvx mcp-nixos. Recorded transport: stdio, streamable_http. Recorded environment-variable notes: MCP_NIXOS_TRANSPORT; MCP_NIXOS_HOST; MCP_NIXOS_PORT. No configuration values are supplied here. Prerequisites: Python/uv. These are the documented setup details, not a claim that installation or client compatibility was independently tested. Authentication: Not established for remote mode.

Can it modify data or perform write operations?

The reviewed inventory lists no write actions. An empty inventory alone does not establish read-only authority. Recorded permission boundary: Read/query NixOS/package metadata.

What data-handling boundary should I consider?

Search/query data only; no persistent sensitive store established.

What limitations and risks should I check before use?

Primarily read-oriented package/documentation lookup; remote-mode auth should still be verified before exposure. Exact auth behavior for remote HTTP mode was not fully established. A project-specific SECURITY.md policy was not available at the fetched official path; the review remains limited to published repository notices.

Is this an official MCP?

utensils is listed as Community implementation in MCP100’s current evidence.