Rails MCP Server — Watchlist

MCP100 Assessment

Watchlist / Tracking

Why we’re tracking it

Track Rails-version and project-tool compatibility as the implementation matures

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

Best fit

Structured local introspection of trusted Rails projects.

What we know

Rails MCP for files, routes, schema, models, controller/view relationships, environment configuration and framework guides; current 2.x is introspection-only.

Maintenance / activity evidence

Observed Aug 4, 2026 (UTC)Credit Pluto Security in SECURITY.md acknowledgments ( 62)

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.
Fixed read/introspection tools; project boot has host-process authority.
Authentication not yet verified.
Sensitive access: Source code, Rails config/environment

The direct arbitrary-code tool was removed, but booting a Rails app is not a security sandbox.

Security source · repository notice ↗Security source · policy file ↗Security source · policy file (attribution not established) ↗

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

Popularity

572 repository stars

Stars observed Sep 25, 2026.

Do not overwrite existing reviewed stars/download metrics with nulls from this enrichment batch.

All limitations / Review context

Which Rails project operations and server transports remain supported?

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.

The direct arbitrary-code tool was removed, but booting a Rails app is not a security sandbox.
Fixed read/introspection tools; project boot has host-process authority.
Local project data is exposed to the connected client.
Sensitive access: Source code, Rails config/environment
Installation, client compatibility and comprehensive security have not been independently audited. Authentication and access depend on the configured services.
No independent runtime, installation, or comprehensive security audit was performed.
No installation, runtime, client matrix, or complete tool-contract audit was performed in this review.
Current 2.0 removed arbitrary execute_ruby.
App-booting analyzers still execute trusted Rails initializers under server privileges.
Use only trusted projects.

Original activity observations

2026-08-04T17:06:09Z: Credit Pluto Security in SECURITY.md acknowledgments ( 62)

Technical identity

github.com/maquina-app/rails-mcp-server

Exact implementation source: https://github.com/maquina-app/rails-mcp-server ↗
Reviewed resource type: MCP Server
Repository identity: maquina-app/rails-mcp-server
Package identity: gem:rails-mcp-server
Service endpoint: http://localhost:6029

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 7, 2026

GitHub repository ↗
maquina-app/rails-mcp-server
Recorded repository material and project history.
Includes references whose attribution is not established.

Setup · Watchlist

Install & Agents

claude-desktop

Publisher instructions with a documented client setup path.

Source evidence observed Oct 14, 2026.

Additional setup details required — see the specific gaps below.

Install / connect
Publisher instructions
Install Ruby gem and use publisher interactive setup to configure Rails projects and Claude Desktop.
package install · Publisher instructions
gem install rails-mcp-server
client registration · Publisher instructions
rails-mcp-config
Configure / authenticate
Publisher instructions
Install gem install rails-mcp-server, then publisher rails-mcp-config interactive GUI/CLI to specify allowed Rails project paths and host integration.
Check connection
Suggested check
Validate project path via configuration tool before invoking any Rails write action.
Remove / uninstall / revoke
MCP100 setup guide
First remove `rails-mcp-server` entry from MCP host; this command removes Ruby gem, not Rails project configuration or app.
Distinguish client registration removal from software uninstall, persistent data deletion and provider OAuth/API-key revocation.
gem uninstall rails-mcp-server

Official Documentation & Sources

What it does

Rails MCP for files, routes, schema, models, controller/view relationships, environment configuration and framework guides; current 2.x is introspection-only.

Capability: Developer Tools
Resource type: MCP Server
Best fit: Structured local introspection of trusted Rails projects.

Representative uses

Inspect routes/schema/models
Read/list project files
Analyze controllers/views
Load Rails/Turbo/Stimulus/Kamal guides

Limitations

Current 2.0 removed arbitrary execute_ruby.
App-booting analyzers still execute trusted Rails initializers under server privileges.
Use only trusted projects.

Reviewed access

Access & risk

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

Authentication: Not documented in the reviewed sources
Permissions: Fixed read/introspection tools; project boot has host-process authority.
Data handling: Local project data is exposed to the connected client.
Cost: free
Risk and cautions: The direct arbitrary-code tool was removed, but booting a Rails app is not a security sandbox.

Access scope and cautions

Write actions: None in the reviewed inventory
Sensitive access: Source code Rails config/environment
Risk level: moderate

FAQ

Based on reviewed evidence as of 2026-10-07. Watchlist tracking is not a recommendation or a security certification.

Which tasks are documented for this implementation?

The reviewed tasks include: Inspect routes/schema/models; Read/list project files; Analyze controllers/views; Load Rails/Turbo/Stimulus/Kamal guides.

What setup and authentication are documented?

Recorded installation/entrypoint step: gem install rails-mcp-server. Recorded endpoint: http://localhost:6029. Recorded transport: stdio, http. Recorded environment-variable notes: RAILS_MCP_PROJECT_PATH optional. No configuration values are supplied here. Prerequisites: Ruby >=3.3. These are the documented setup details, not a claim that installation or client compatibility was independently tested. Authentication: No API key for local mode; HTTP uses local binding/origin/IP controls.

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: Fixed read/introspection tools; project boot has host-process authority.

What data-handling boundary should I consider?

Local project data is exposed to the connected client. Recorded sensitive-access context: Source code; Rails config/environment.

What limitations and risks should I check before use?

The direct arbitrary-code tool was removed, but booting a Rails app is not a security sandbox. Current 2.0 removed arbitrary execute_ruby. App-booting analyzers still execute trusted Rails initializers under server privileges. Use only trusted projects. No independent runtime, installation, or comprehensive security audit was performed.

Is this an official MCP?

maquina-app is listed as First-party MCP in MCP100’s current evidence.