How do I install the Netcat Async skill?

Run npx skillmds add majiayu000/netcat-async in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

Is Netcat Async safe to use?

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Which AI agents work with Netcat Async?

This skill is tagged as working with Claude Code, Claude.ai, OpenAI Codex. SKILL.md is an open format, so most agents that read a skills directory can load it too.

Is Netcat Async free to use?

Yes. Installing skills from SkillMD is free, and the skill stays under its author's original license.

Who published Netcat Async?

majiayu000 (@majiayu000) published this skill. Their other Agent Skills are listed on their SkillMD profile.

Netcat Async by majiayu000 — Agent Skill

Name: Netcat Async
Rating: 4.5 (4 reviews)
Author: majiayu000

Netcat Async

Maintain bidirectional netcat-style TCP communications with persistent asynchronous input/output. Use when Codex must keep a connection open across multiple commands, send messages while receiving background output, inspect connection logs, or safely start/stop reusable sessions for protocol testing, CTF services, debugging sockets, or interactive line-based services.

majiayu000 3e62c8a 2 files · 3.2 KB Updated Sep 9, 2026 567 repo stars

File contents

OpenCROW I/O - Netcat Async

Prefer the opencrow-netcat-mcp server for session lifecycle, reads, and writes. Fall back to scripts/ncx only when you need to inspect or debug the backend directly.

MCP First

Use toolbox_info, toolbox_verify, and toolbox_capabilities first.
Use the generic session tools:
- session_start
- session_send
- session_read
- session_status
- session_stop
Keep one named session per target flow so the MCP server can report stable artifacts under /tmp/codex-nc-async/<name>/.

Use scripts/ncx to manage long-lived TCP sessions instead of one-shot nc invocations when you are operating outside MCP.

Workflow

Start a named session.
Send one or more payloads while the daemon keeps receiving output asynchronously.
Read logs (tail for recent data, follow for streaming).
Stop the session when done.

Commands

# Start session
scripts/ncx start --name demo --host 127.0.0.1 --port 9001

# Send text (append newline for line-oriented protocols)
scripts/ncx send --name demo --data 'ping' --newline

# Read latest output
scripts/ncx read --name demo --tail 40

# Follow output live
scripts/ncx read --name demo --follow

# Check metadata and process state
scripts/ncx status --name demo

# Stop session
scripts/ncx stop --name demo

Operational Rules

Use one session per target/service flow (--name scoped per host+port interaction).
Prefer --newline for interactive text protocols.
Read with --tail before --follow to avoid missing context.
Stop sessions explicitly to avoid stale daemons.
If status reports running: false, inspect daemon.log and restart.

Files and State

Session state lives at /tmp/codex-nc-async/<name>/:

io.log: timestamped TX/RX events
rx.raw: raw received bytes
daemon.log: daemon stdout/stderr
meta.json: session metadata
pid: daemon PID

References

For usage patterns and recovery steps, read references/patterns.md.

---name: netcat-asyncdescription: Maintain bidirectional netcat-style TCP communications with persistent asynchronous input/output. Use when Codex must keep a connection open across multiple commands, send messages while receiving background output, inspect connection logs, or safely start/stop reusable sessions for protocol testing, CTF services, debugging sockets, or interactive line-based services.--- # OpenCROW I/O - Netcat Async Prefer the `opencrow-netcat-mcp` server for session lifecycle, reads, and writes. Fall back to `scripts/ncx` only when you need to inspect or debug the backend directly. ## MCP First - Use `toolbox_info`, `toolbox_verify`, and `toolbox_capabilities` first. - Use the generic session tools: - `session_start` - `session_send` - `session_read` - `session_status` - `session_stop` - Keep one named session per target flow so the MCP server can report stable artifacts under `/tmp/codex-nc-async/<name>/`. Use `scripts/ncx` to manage long-lived TCP sessions instead of one-shot `nc` invocations when you are operating outside MCP. ## Workflow 1. Start a named session. 2. Send one or more payloads while the daemon keeps receiving output asynchronously. 3. Read logs (`tail` for recent data, `follow` for streaming). 4. Stop the session when done. ## Commands ```bash # Start session scripts/ncx start --name demo --host 127.0.0.1 --port 9001 # Send text (append newline for line-oriented protocols) scripts/ncx send --name demo --data 'ping' --newline # Read latest output scripts/ncx read --name demo --tail 40 # Follow output live scripts/ncx read --name demo --follow # Check metadata and process state scripts/ncx status --name demo # Stop session scripts/ncx stop --name demo ``` ## Operational Rules - Use one session per target/service flow (`--name` scoped per host+port interaction). - Prefer `--newline` for interactive text protocols. - Read with `--tail` before `--follow` to avoid missing context. - Stop sessions explicitly to avoid stale daemons. - If `status` reports `running: false`, inspect `daemon.log` and restart. ## Files and State Session state lives at `/tmp/codex-nc-async/<name>/`: - `io.log`: timestamped TX/RX events - `rx.raw`: raw received bytes - `daemon.log`: daemon stdout/stderr - `meta.json`: session metadata - `pid`: daemon PID ## References - For usage patterns and recovery steps, read `references/patterns.md`.

Frequently asked questions