r3bl-open-core

MCP server · GitHub · ★ 486 · graded 2026-10-19Source linked

Fully async Rust TUI engine 🦀. For powering AI/LLM coding agents, Cloud/SSH workflows & interactive CLIs: non-blocking readline, inline dialogs, React/Elm-style full-screen TUI, Markdown editor, PTY multiplexing & rust-analyzer MCP server.

No outside reports on file

r3bl-open-core runs shell or system commands and reads local files; restrict its folder reach, network access, and credentials before installing.

Based on public adoption and transparency signals as of Oct 19, 2026. Our opinion, not a code audit or security guarantee.

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What it can access

Local filesReads & writes local foldersREVIEW
Command executionRuns shell or system commandsREVIEW
Network reachConnects to outside service APINOTED
CredentialsNo API token requiredLOW
Package sourceGitHub (r3bl-org/r3bl-open-core)PUBLIC

Inferred from this listing’s public package details and description. Check the project’s source before installing.

Install

No npm or PyPI package is listed. Install from source: github.com/r3bl-org/r3bl-open-core ↗

All setup options ↓

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Everything known

We found nothing about this project in the sources we read (last checked 2026-10-30). That does not mean it has no problems.

0 incidents · 0 advisories · 0 news articles · 0 community threads · checked 2026-10-30

Popularity grade: C (from public signals such as stars and downloads, not a code review). Graded 2026-10-19.

Sources we read: OSV, GitHub Advisory Database, CISA Known Exploited Vulnerabilities, 44 security news feeds and our incident library. Last checked 2026-10-30.

Check a specific version →

About R3bl Open Core

R3bl Open Core is an MCP server focused on Developer tools and Files & documents: Fully async Rust TUI engine 🦀. For powering AI/LLM coding agents, Cloud/SSH workflows & interactive CLIs: non-blocking readline, inline dialogs, React/Elm-style full-screen TUI, Markdown editor, PTY multiplexing & rust-analyzer MCP server.

It is hosted on GitHub at r3bl-org/r3bl-open-core (486 GitHub stars). Based on its public metadata, its operational scope includes: reads local files, runs shell or system commands.

Setup

Check these steps against the project’s own instructions before running anything.

No standalone npm or PyPI package is listed for this MCP server. Clone and inspect the source repository directly:

bash

git clone https://github.com/r3bl-org/r3bl-open-core.git

Review the README and source files in https://github.com/r3bl-org/r3bl-open-core (opens external site) before running any setup commands.

Why this grade

CC — Moderate risk signals

Signal-based grade (2/7 points): public source code. This reflects adoption and transparency, not a code review.

Popularity and upkeep

30/100

GitHub stars: 486
Listing last refreshed: 2026-10-29

These are public popularity signals, not a maintenance check. Look at the repository’s commit history and open issues.

Risks to watch for

Command execution reach: Public metadata indicates shell, terminal, or container command execution. Run inside an isolated container or VM and require human approval before executing commands.
Local file read access: Reads local documents or database files. Point it only at the specific files needed for the task so sensitive workspace files remain out of reach.
Dependency & version pinning: Distributed via GitHub (r3bl-org/r3bl-open-core). Pin an exact release version or commit SHA rather than floating tags so upstream updates are reviewed first.

How to lower the risk

Least-privilege permissions

Give it access only to the specific folders, accounts or projects it needs, never your whole drive or admin account.
Use a separate, limited API key or login just for this tool so you can switch it off without affecting anything else.

Network isolation

Run it on a work computer or sandbox account, not one holding personal or company-sensitive data.
If your IT team can, limit which websites and services it is allowed to contact.

Monitoring

Check its activity history or logs weekly at first, and look at what it changed or sent.
Turn on alerts for new logins or unusual usage on any account it connects to.

Red flags to watch for

It asks for more access than its job requires, or prompts you to paste passwords.
It suddenly updates with new owners, or starts contacting unfamiliar websites.

Questions

How do I install R3bl Open Core?

R3bl Open Core does not publish a standalone npm or PyPI package. Clone or follow the setup instructions in its source repository at github.com/r3bl-org/r3bl-open-core.

Are there security reports about R3bl Open Core?

No reports found for this package in our research (last checked 2026-10-30). R3bl Open Core currently holds Grade C (Moderate risk signals) based on public adoption and transparency signals. Key risk areas to watch include command execution reach:, local file read access:, dependency & version pinning:.

Is R3bl Open Core actively maintained?

R3bl Open Core has 486 GitHub stars. Our directory data was last refreshed on 2026-10-29. Check recent commit activity, release tags, and open issues at github.com/r3bl-org/r3bl-open-core before pinning it in production.

What are alternatives to R3bl Open Core?

Compare R3bl Open Core side by side with similar MCP servers in the Related tools section on this page, or browse all MCP servers on AgentArmorHQ.

Maintain or use R3bl Open Core? Show its live grade in your GitHub README, docs site, or run a check from the terminal before you install.

AgentArmorHQ Risk Grade C for R3bl Open Core

GitHub README Markdown:

markdown

[![AgentArmorHQ Risk Grade for R3bl Open Core](https://agentarmorhq.com/api/badge/r3bl-org-r3bl-open-core)](https://agentarmorhq.com/skills/r3bl-org-r3bl-open-core)

HTML embed:

html

<a href="https://agentarmorhq.com/skills/r3bl-org-r3bl-open-core"><img src="https://agentarmorhq.com/api/badge/r3bl-org-r3bl-open-core" alt="AgentArmorHQ Risk Grade for R3bl Open Core" height="20" /></a>

Terminal check:

terminal

curl -fsSL https://agentarmorhq.com/api/cli | node --input-type=module - check "r3bl-org-r3bl-open-core"

Share with your security lead

Need sign-off to use r3bl-open-core? Copy this note for Slack, a ticket or a pull request.

### AgentArmorHQ Security Review Memo: r3bl-open-core
- **Listing URL:** https://agentarmorhq.com/skills/r3bl-org-r3bl-open-core
- **Type:** App connector
- **Risk Grade:** Grade C (Moderate risk signals)
- **Outside Security Advisories on File:** 0
- **Public Adoption:** 486 GitHub stars

#### Permission & Blast-Radius Signals
- **Local files:** Reads & writes local folders
- **Command execution:** Runs shell or system commands
- **Network reach:** Connects to outside service API
- **Credentials:** No API token required
- **Package source:** GitHub (r3bl-org/r3bl-open-core)

#### Recommended Hardened Setup
- **Source Repo:** https://github.com/r3bl-org/r3bl-open-core
- **Controls:** Pin an exact version in `.mcp.json`, scope access to a single workspace folder, and use a least-privilege read-only token where supported.

_Based on public adoption and transparency signals as of Oct 19, 2026. Our opinion, not a code audit or security guarantee._

Key facts

Type: App connector
Publisher: r3bl-org
Source code: github.com/r3bl-org/r3bl-open-core
Est. context load: ~900 tokens / turn (~5 tool schemas, 0.45% of 200k context)
Popularity: 486 GitHub stars
Last updated: 2026-10-29
Last graded: 2026-10-19

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