pinggy-tunnel – skill DevOps & Hạ tầng cho agent AI

Pinggy Tunnel Skill

Expose a local service (dev server, webhook receiver, MCP endpoint, demo) to the public internet using a Pinggy SSH reverse tunnel. No daemon to install — the user's stock SSH client connects to a.pinggy.io:443 and Pinggy hands back a public HTTP/HTTPS URL.

Free tier: 60-minute tunnels, random subdomain, no signup. Pro tier ($3/mo) is an opt-in with a token.

When to Use

• User asks to "expose this locally", "share my dev server", "make this URL public", "tunnel port N", "get a public URL for a webhook"
• Need to receive a webhook callback during a local task (Stripe, GitHub, Discord, AgentMail)
• Sharing a one-off HTTP demo (MCP server, Ollama/vLLM endpoint, dashboard) with a remote party
• The host has SSH but no cloudflared / ngrok binary, and installing one would be overkill

If the host already has cloudflared configured, prefer the cloudflared-quick-tunnel skill — Cloudflare quick tunnels don't expire after 60 minutes.

Prerequisites

• ssh on PATH (ssh -V). Default on Linux, macOS, and Windows 10+. No other install.
• A local service listening on 127.0.0.1:<port> before the tunnel starts. Pinggy will return URLs but they'll 502 until the local origin is up.

Optional:

• PINGGY_TOKEN env var for paid Pro features (persistent subdomain, custom domain, multiple tunnels, no 60-minute cap). Free tier needs no credentials.

Quick Reference

# Plain HTTP/HTTPS tunnel for port 8000 (free tier)
ssh -p 443 -o StrictHostKeyChecking=no -o ServerAliveInterval=30 \
    -R0:localhost:8000 [email protected]

# TCP tunnel (databases, raw SSH, etc.)
ssh -p 443 -o StrictHostKeyChecking=no -R0:localhost:5432 [email protected]

# TLS tunnel (Pinggy can't decrypt — bring your own certs at origin)
ssh -p 443 -o StrictHostKeyChecking=no -R0:localhost:443 [email protected]

# Basic auth gate (b:user:pass)
ssh -p 443 -o StrictHostKeyChecking=no -R0:localhost:8000 \
    "b:admin:[email protected]"

# Bearer token gate (k:token)
ssh -p 443 -o StrictHostKeyChecking=no -R0:localhost:8000 \
    "k:[email protected]"

# IP whitelist (w:CIDR)
ssh -p 443 -o StrictHostKeyChecking=no -R0:localhost:8000 \
    "w:203.0.113.0/[email protected]"

# Enable CORS + force HTTPS redirect
ssh -p 443 -o StrictHostKeyChecking=no -R0:localhost:8000 \
    "co+x:[email protected]"

# Pro tier (persistent URL, no 60-min cap)
ssh -p 443 -o StrictHostKeyChecking=no -R0:localhost:8000 "$PINGGY_TOKEN+a.pinggy.io"

Procedure — Start a Tunnel and Get the URL

The model SHOULD use the terminal tool. The tunnel must stay alive for the duration of the share, so run it as a background process and parse the public URL from stdout.

1. Confirm a local origin is up

curl -sI http://127.0.0.1:8000/ | head -1
# expect HTTP/1.x 200 (or any non-connection-refused response)

If nothing is listening yet, start it first (e.g. python -m http.server 8000 --bind 127.0.0.1). Pinggy will happily return a URL pointed at nothing — the user will see 502 until the origin comes up.

2. Launch the tunnel as a background process

Use terminal(background=True) and capture output to a logfile (Pinggy prints the URLs on stdout, then keeps the connection open):

LOG=~/.hermes/cache/scratch/pinggy-8000.log
nohup ssh -p 443 \
    -o StrictHostKeyChecking=no \
    -o UserKnownHostsFile=/dev/null \
    -o ServerAliveInterval=30 \
    -o ServerAliveCountMax=3 \
    -R0:localhost:8000 [email protected] \
    > "$LOG" 2>&1 &
echo $! > ~/.hermes/cache/scratch/pinggy-8000.pid

StrictHostKeyChecking=no + UserKnownHostsFile=/dev/null skips the first-run host-key prompt. ServerAliveInterval=30 keeps the SSH session from getting torn down by an idle NAT.

3. Parse the URL out of the log

sleep 4
grep -oE 'https://[a-z0-9-]+\.[a-z]+\.pinggy\.link' ~/.hermes/cache/scratch/pinggy-8000.log | head -1

Expected output looks like:

You are not authenticated.
Your tunnel will expire in 60 minutes.
http://yqycl-98-162-69-48.a.free.pinggy.link
https://yqycl-98-162-69-48.a.free.pinggy.link

Hand the https://...pinggy.link URL to the user.

4. Verify

curl -sI https://<the-url>/ | head -3
# expect 200/302/whatever the local origin actually returns

If you get 502 Bad Gateway, the SSH session is up but the local origin isn't listening — fix step 1 first.

5. Teardown

kill "$(cat ~/.hermes/cache/scratch/pinggy-8000.pid)"
# or, if the pid file got lost:
pkill -f 'ssh -p 443 .* free@a\.pinggy\.io'

If you have a session_id from terminal(background=True), prefer process(action='kill', session_id=...).

Access Control via Username Keywords

Pinggy stacks control flags into the SSH username separated by +. Always quote the whole user@host argument when it contains a +:

| Keyword | Effect |

|---------|--------|

| b:user:pass | HTTP Basic auth gate |

| k:token | Bearer-token header gate (Authorization: Bearer <token>) |

| w:CIDR | IP whitelist (single IP or CIDR, repeatable) |

| co | Add Access-Control-Allow-Origin: * (CORS) |

| x:https | Force HTTPS — auto-redirect HTTP to HTTPS |

| a:Name:Value | Add request header |

| u:Name:Value | Update request header |

| r:Name | Remove request header |

| qr | Print a QR code of the URL to stdout (handy for mobile sharing) |

Combine freely: "b:admin:secret+co+x:[email protected]".

Web Debugger (optional)

Pinggy can mirror the inbound traffic to localhost:4300 for inspection. Add a local forward to the SSH command:

ssh -p 443 -L4300:localhost:4300 -R0:localhost:8000 [email protected]

Then open http://localhost:4300 in a browser to see live request/response pairs.

Pitfalls

• 60-minute hard cap on the free tier. The SSH session terminates at the 60-minute mark; the URL goes dead. For longer shares, either use PINGGY_TOKEN (Pro) or auto-restart with a shell loop (note that the URL changes on every restart for free-tier).
• Free-tier URL is random and changes on restart. Don't bookmark it, don't paste it into a config file. Re-parse from the log each time.
• Concurrent free tunnels are limited to one per source IP. Starting a second tunnel from the same machine usually kills the first. Pro tier lifts this.
• + in usernames must be quoted. Bare ssh ... b:admin:[email protected] works in bash but breaks under shells that treat + specially or when assembled programmatically. Always wrap in double quotes.
• Don't tunnel anything sensitive without an access-control flag. A bare HTTP tunnel is reachable by anyone with the URL. Use b:, k:, or w: for non-public services.
• process(action='log') may miss SSH banner output. Pinggy prints the URLs and then the SSH session goes interactive. Always redirect to a logfile and grep the file directly — same pattern as cloudflared-quick-tunnel.
• Host-key prompt on first run. Default OpenSSH config asks the user to accept Pinggy's host key. Always pass -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null for unattended runs.
• TCP and TLS tunnels return a <subdomain>.a.pinggy.online:<port> pair, not an https URL. Parse with a different regex (tcp:// and a port). Don't assume every Pinggy tunnel is HTTP.
• Pro mode requires the token as the username, not a flag. Use "$PINGGY_TOKEN+a.pinggy.io" (no free@). With a token you can also add :persistent for a stable subdomain — see pinggy.io/docs/.

Recipes

Composite patterns combining a local origin with a Pinggy tunnel. Each recipe is self-contained — start the origin, start the tunnel, parse the URL, hand it back to the user.

Recipe 1 — Receive a webhook callback

Use this when an external service (Stripe, GitHub, Discord, AgentMail, etc.) needs to POST to a publicly reachable URL during a local task.

# 1. Tiny capturing server: every request gets appended to ~/.hermes/cache/scratch/webhook-hits.log
cat >~/.hermes/cache/scratch/webhook-server.py <<'PY'
import http.server, json, datetime, pathlib
LOG = pathlib.Path("~/.hermes/cache/scratch/webhook-hits.log").expanduser()
class H(http.server.BaseHTTPRequestHandler):
    def _capture(self):
        n = int(self.headers.get("content-length") or 0)
        body = self.rfile.read(n).decode("utf-8", "replace") if n else ""
        rec = {"t": datetime.datetime.utcnow().isoformat(), "path": self.path,
               "method": self.command, "headers": dict(self.headers), "body": body}
        with LOG.open("a") as f: f.write(json.dumps(rec) + "\n")
        self.send_response(200); self.send_header("content-type","application/json")
        self.end_headers(); self.wfile.write(b'{"ok":true}\n')
    def do_GET(self): self._capture()
    def do_POST(self): self._capture()
    def log_message(self,*a,**k): pass
http.server.HTTPServer(("127.0.0.1", 18080), H).serve_forever()
PY
nohup python ~/.hermes/cache/scratch/webhook-server.py >~

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