functionality updates

Cargo.toml

@@ -2,6 +2,7 @@
 name = "coap-hello-udp"
 version = "0.1.0"
 edition = "2024"
+default-run = "coap-hello-udp"
 
 [dependencies]
 coap-lite = "0.13.3"

README.md

@@ -46,20 +46,19 @@ cargo run --release --bin coap-hello-udp
 cargo run --release --bin bridge
 ```
 
-Then open <http://localhost:8080/> for a test console with a name field and a
-button per route. Every response shows both the CoAP code and the HTTP status
-it was mapped to; the raw CoAP code is also returned in an `X-Coap-Code` header.
+Every response shows the CoAP code mapped onto an HTTP status, with the raw
+CoAP code returned verbatim in an `X-Coap-Code` header.
 
 These are now ordinary URLs — clickable, curl-able, bookmarkable:
 
 | URL                                              | Response                     |
 |--------------------------------------------------|------------------------------|
-| `http://localhost:8080/`                          | the test console             |
+| `http://localhost:8080/`                          | the CoAP reference page      |
 | `http://localhost:8080/hello`                     | `Hello, World!`              |
 | `http://localhost:8080/hello?name=Imran`          | `Hello, Imran!`              |
 | `http://localhost:8080/health`                    | `{"status":"ok","uptime":12}`|
 
-POST needs a body, so it is easiest from the console page or curl:
+POST needs a body, so use curl:
 
 ```bash
 curl -X POST -d "Imran" http://localhost:8080/hello
@@ -104,7 +103,7 @@ decoding.
 | `src/lib.rs`        | Shared CoAP client used by the CLI and the bridge.       |
 | `src/bin/client.rs` | CLI client for smoke tests.                              |
 | `src/bin/bridge.rs` | HTTP -> CoAP proxy so a browser can reach the server.    |
-| `static/index.html` | The browser test console the bridge serves at `/`.       |
+| `static/index.html` | CoAP reference page: routes, codes, copyable commands.   |
 | `nodejs/`           | The earlier Node.js version, kept for reference.         |
 
 ## Config

coap-inspect.py

@@ -0,0 +1,200 @@
+#!/usr/bin/env python3
+"""Send one CoAP request over UDP and show both datagrams byte by byte.
+
+    ./coap-inspect.py get "/hello?name=Imran"
+    ./coap-inspect.py post /hello Imran
+    ./coap-inspect.py get /health
+
+No CoAP library: the packet is built and decoded right here, so every byte on
+screen is accounted for. COAP_HOST / COAP_PORT retarget it (127.0.0.1:5683).
+"""
+import os
+import random
+import socket
+import sys
+import time
+
+TYPES = {0: "CON confirmable", 1: "NON non-confirmable", 2: "ACK acknowledgement", 3: "RST reset"}
+METHODS = {"get": 1, "post": 2, "put": 3, "delete": 4}
+CODES = {
+    "0.00": "Empty", "0.01": "GET", "0.02": "POST", "0.03": "PUT", "0.04": "DELETE",
+    "2.01": "Created", "2.02": "Deleted", "2.03": "Valid", "2.04": "Changed", "2.05": "Content",
+    "4.00": "Bad Request", "4.04": "Not Found", "4.05": "Method Not Allowed",
+    "5.00": "Internal Server Error",
+}
+OPTIONS = {3: "Uri-Host", 7: "Uri-Port", 11: "Uri-Path", 12: "Content-Format", 15: "Uri-Query", 17: "Accept"}
+FORMATS = {0: "text/plain", 50: "application/json"}
+
+TTY = sys.stdout.isatty()
+
+
+def bold(text):
+    return f"\033[1m{text}\033[0m" if TTY else text
+
+
+def encode_option(delta, value):
+    """One option: a byte of 4-bit delta + 4-bit length, then any extended bytes, then the value."""
+    def nibble(n):
+        if n < 13:
+            return n, b""
+        if n < 269:
+            return 13, bytes([n - 13])
+        return 14, (n - 269).to_bytes(2, "big")
+
+    d, d_ext = nibble(delta)
+    l, l_ext = nibble(len(value))
+    return bytes([(d << 4) | l]) + d_ext + l_ext + value
+
+
+def build_request(method, path, query, payload):
+    token = os.urandom(4)
+    header = bytes([(1 << 6) | (0 << 4) | len(token), METHODS[method]])  # ver 1, CON, TKL, code
+    header += random.randrange(1 << 16).to_bytes(2, "big") + token        # message id, token
+
+    # Options must be in ascending number order; each stores the gap from the previous one.
+    options = [(11, s.encode()) for s in path.split("/") if s]
+    options += [(15, q.encode()) for q in query.split("&") if q]
+    body, last = b"", 0
+    for number, value in options:
+        body += encode_option(number - last, value)
+        last = number
+    if payload:
+        body += b"\xff" + payload
+    return header + body
+
+
+def decode(pkt):
+    """Return (rows, meta). Each row is (start, end, field, meaning) over pkt[start:end]."""
+    if len(pkt) < 4:
+        raise ValueError(f"{len(pkt)} bytes is shorter than the 4-byte CoAP header")
+
+    rows = []
+    b0 = pkt[0]
+    ver, typ, tkl = b0 >> 6, (b0 >> 4) & 0b11, b0 & 0b1111
+    rows.append((0, 1, "ver|type|tkl",
+                 f"{ver:02b} {typ:02b} {tkl:04b} -> version {ver}, {TYPES[typ]}, token {tkl} bytes"))
+
+    cls, detail = pkt[1] >> 5, pkt[1] & 0b11111
+    code = f"{cls}.{detail:02d}"
+    rows.append((1, 2, "code", f"{cls:03b} {detail:05b} -> {code} {CODES.get(code, '')}"))
+
+    mid = int.from_bytes(pkt[2:4], "big")
+    rows.append((2, 4, "message id", f"{mid} (0x{mid:04x})"))
+
+    token = pkt[4:4 + tkl]
+    if tkl:
+        rows.append((4, 4 + tkl, "token", f"0x{token.hex()}"))
+
+    i, number = 4 + tkl, 0
+    while i < len(pkt):
+        if pkt[i] == 0xFF:
+            body = pkt[i + 1:]
+            rows.append((i, i + 1, "payload marker", "0xff -> the rest is the body"))
+            rows.append((i + 1, len(pkt), "payload",
+                         f"{len(body)} bytes: {body.decode('utf-8', 'replace')}"))
+            break
+
+        start = i
+        delta, length = pkt[i] >> 4, pkt[i] & 0b1111
+        i += 1
+        extended = []
+        for which, n in (("delta", delta), ("length", length)):
+            if n == 13:
+                n, i = pkt[i] + 13, i + 1
+            elif n == 14:
+                n, i = int.from_bytes(pkt[i:i + 2], "big") + 269, i + 2
+            extended.append(n)
+        delta, length = extended
+        number += delta
+        value = pkt[i:i + length]
+        i += length
+
+        if number in (12, 17):
+            n = int.from_bytes(value, "big") if value else 0
+            shown = f"{n} = {FORMATS.get(n, 'unknown format')}"
+        else:
+            shown = f'"{value.decode("utf-8", "replace")}"'
+        rows.append((start, i, OPTIONS.get(number, f"option {number}"),
+                     f"delta {delta} -> option {number}, {length} bytes: {shown}"))
+
+    return rows, {"type": typ, "code": code, "mid": mid, "token": token}
+
+
+def show(title, pkt):
+    print(bold(f"\n{title}  ({len(pkt)} bytes)"))
+
+    print(bold("\n  hex + ascii"))
+    for off in range(0, len(pkt), 16):
+        chunk = pkt[off:off + 16]
+        hexes = " ".join(f"{b:02x}" for b in chunk)
+        text = "".join(chr(b) if 32 <= b < 127 else "." for b in chunk)
+        print(f"  {off:04x}  {hexes:<47}  |{text}|")
+
+    print(bold("\n  binary"))
+    for off in range(0, len(pkt), 4):
+        chunk = pkt[off:off + 4]
+        bits = " ".join(f"{b:08b}" for b in chunk)
+        text = "".join(chr(b) if 32 <= b < 127 else "." for b in chunk)
+        print(f"  {off:04x}  {bits:<35}  |{text}|")
+
+    rows, meta = decode(pkt)
+    print(bold("\n  fields"))
+    print(f"  {'byte':<7} {'hex':<24} {'field':<15} meaning")
+    for start, end, field, meaning in rows:
+        span = f"{start}" if end - start == 1 else f"{start}-{end - 1}"
+        hexes = pkt[start:end].hex(" ")
+        if len(hexes) > 23:
+            hexes = hexes[:20] + "..."
+        print(f"  {span:<7} {hexes:<24} {field:<15} {meaning}")
+    return meta
+
+
+def main():
+    args = sys.argv[1:]
+    if not args or args[0].lower() not in METHODS:
+        print(__doc__.strip())
+        return 2
+
+    method = args[0].lower()
+    target = args[1] if len(args) > 1 else "/hello"
+    payload = args[2].encode() if len(args) > 2 else b""
+    path, _, query = target.partition("?")
+    host = os.environ.get("COAP_HOST", "127.0.0.1")
+    port = int(os.environ.get("COAP_PORT", "5683"))
+
+    request = build_request(method, path, query, payload)
+
+    sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)  # SOCK_DGRAM = UDP
+    sock.settimeout(3)
+    sock.connect((host, port))
+    local = "%s:%d" % sock.getsockname()
+
+    req = show(f">>> REQUEST   udp {local} -> {host}:{port}", request)
+    sent_at = time.perf_counter()
+    sock.send(request)
+    try:
+        response = sock.recv(1152)
+    except socket.timeout:
+        print(f"\nno reply within 3s - is the CoAP server running on {host}:{port}?")
+        return 1
+    except ConnectionRefusedError:
+        print(f"\nport unreachable - nothing is listening on udp {host}:{port}")
+        return 1
+    elapsed = (time.perf_counter() - sent_at) * 1000
+
+    res = show(f"<<< RESPONSE  udp {host}:{port} -> {local}", response)
+
+    print(bold("\n  exchange"))
+    print(f"  request   {TYPES[req['type']].split()[0]}  {req['code']}  mid 0x{req['mid']:04x}  "
+          f"token 0x{req['token'].hex()}  {len(request)} bytes")
+    print(f"  response  {TYPES[res['type']].split()[0]}  {res['code']}  mid 0x{res['mid']:04x}  "
+          f"token 0x{res['token'].hex()}  {len(response)} bytes  after {elapsed:.2f} ms")
+    same_mid = "yes" if req["mid"] == res["mid"] else "NO"
+    same_token = "yes" if req["token"] == res["token"] else "NO"
+    kind = " (piggybacked: the ACK carries the answer)" if res["type"] == 2 else ""
+    print(f"  message id matches: {same_mid}   token matches: {same_token}{kind}")
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main())

healthcheck.sh

@@ -0,0 +1,31 @@
+#!/usr/bin/env bash
+# Liveness check for the CoAP server. Exits 0 if healthy, 1 if not.
+#   ./healthcheck.sh          quiet, for cron/systemd/monitoring
+#   ./healthcheck.sh -v       print what it found
+# Retargets with COAP_HOST / COAP_PORT.
+
+CLIENT=${CLIENT:-$(dirname "$0")/target/release/client}
+verbose=false; [[ $1 == -v ]] && verbose=true
+say() { $verbose && echo "$@"; }
+
+host=${COAP_HOST:-127.0.0.1}; port=${COAP_PORT:-5683}
+
+[[ -x $CLIENT ]] || { echo "healthcheck: no client binary at $CLIENT (cargo build --release)"; exit 1; }
+
+reply=$("$CLIENT" get /health 2>&1)
+
+# A bound socket proves nothing on UDP - the round trip is the real test.
+if [[ $reply != "<- 2.05 "* ]]; then
+  echo "UNHEALTHY: coap://$host:$port/health -> ${reply:-no reply}"
+  exit 1
+fi
+
+body=${reply#<- 2.05 }
+if [[ $body != *'"status":"ok"'* ]]; then
+  echo "UNHEALTHY: unexpected body from coap://$host:$port/health -> $body"
+  exit 1
+fi
+
+uptime=$(sed -n 's/.*"uptime":\([0-9]*\).*/\1/p' <<<"$body")
+say "HEALTHY: coap://$host:$port up ${uptime}s (code 2.05)"
+exit 0

nodejs/client.js

@@ -1,32 +0,0 @@
-'use strict';
-
-// Tiny CLI client:
-//   node client.js get /hello?name=Imran
-//   node client.js post /hello Imran
-//   node client.js get /health
-
-const coap = require('coap');
-
-const [, , methodArg = 'get', pathArg = '/hello', payload] = process.argv;
-
-const req = coap.request({
-  host: process.env.COAP_HOST || 'localhost',
-  port: Number(process.env.COAP_PORT) || 5683,
-  pathname: pathArg.split('?')[0],
-  query: pathArg.split('?')[1] || '',
-  method: methodArg.toUpperCase(),
-  confirmable: true,
-});
-
-req.on('response', (res) => {
-  console.log(`<- ${res.code} ${res.payload.toString()}`);
-  process.exit(0);
-});
-
-req.on('error', (err) => {
-  console.error('request failed:', err.message);
-  process.exit(1);
-});
-
-if (payload) req.write(payload);
-req.end();

nodejs/package-lock.json

@@ -1,309 +0,0 @@
-{
-  "name": "coapwithudp",
-  "version": "1.0.0",
-  "lockfileVersion": 3,
-  "requires": true,
-  "packages": {
-    "": {
-      "name": "coapwithudp",
-      "version": "1.0.0",
-      "license": "ISC",
-      "dependencies": {
-        "coap": "^1.6.0"
-      }
-    },
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-      "license": "MIT",
-      "dependencies": {
-        "undici-types": "~8.3.0"
-      }
-    },
-    "node_modules/@types/readable-stream": {
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-        "process": "^0.11.10",
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-          "type": "consulting",
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-      "license": "MIT",
-      "dependencies": {
-        "safe-buffer": "~5.2.0"
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-    "node_modules/undici-types": {
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-      "license": "MIT"
-    }
-  }
-}

nodejs/package.json

@@ -1,16 +0,0 @@
-{
-  "name": "coap-hello-udp",
-  "version": "1.0.0",
-  "main": "server.js",
-  "scripts": {
-    "start": "node server.js",
-    "client": "node client.js"
-  },
-  "keywords": [],
-  "author": "",
-  "license": "ISC",
-  "description": "Minimal CoAP-over-UDP hello world server with GET/POST routes",
-  "dependencies": {
-    "coap": "^1.6.0"
-  }
-}

nodejs/server.js

@@ -1,102 +0,0 @@
-'use strict';
-
-const coap = require('coap');
-
-const PORT = Number(process.env.COAP_PORT) || 5683;
-const HOST = process.env.COAP_HOST || '0.0.0.0';
-
-// --- helpers ---------------------------------------------------------------
-
-const TEXT = 'text/plain';
-const JSON_FMT = 'application/json';
-
-/** Split "/hello?name=Bob" into ["/hello", "name=Bob"]. */
-function splitUrl(url) {
-  const i = url.indexOf('?');
-  const path = (i === -1 ? url : url.slice(0, i)).replace(/\/+$/, '') || '/';
-  return [path, i === -1 ? '' : url.slice(i + 1)];
-}
-
-/** Pull a name out of "?name=Bob" style queries. */
-function nameFromQuery(query) {
-  return new URLSearchParams(query || '').get('name');
-}
-
-/** Pull a name out of a POST body: raw text or {"name":"Bob"}. */
-function nameFromBody(buf) {
-  const body = buf.toString('utf8').trim();
-  if (!body) return null;
-  if (body.startsWith('{')) {
-    try {
-      const parsed = JSON.parse(body);
-      return typeof parsed.name === 'string' ? parsed.name.trim() : null;
-    } catch {
-      return null;
-    }
-  }
-  return body;
-}
-
-function greet(name) {
-  return `Hello, ${name && name.length ? name : 'World'}!`;
-}
-
-function send(res, code, payload, format = TEXT) {
-  res.code = code;
-  res.setOption('Content-Format', format);
-  res.end(typeof payload === 'string' ? payload : JSON.stringify(payload));
-}
-
-// --- routes ----------------------------------------------------------------
-// key: "METHOD /path"
-
-const routes = {
-  'GET /hello': (req, res) => {
-    send(res, '2.05', greet(nameFromQuery(req.query)));
-  },
-
-  'POST /hello': (req, res) => {
-    const name = nameFromBody(req.payload) || nameFromQuery(req.query);
-    if (!name) {
-      return send(res, '4.00', 'Bad Request: send a name as the payload');
-    }
-    send(res, '2.01', greet(name));
-  },
-
-  'GET /health': (_req, res) => {
-    send(res, '2.05', { status: 'ok', uptime: Math.round(process.uptime()) }, JSON_FMT);
-  },
-};
-
-// --- server ----------------------------------------------------------------
-
-const server = coap.createServer({ type: 'udp4' });
-
-server.on('request', (req, res) => {
-  const [path, query] = splitUrl(req.url);
-  req.query = query; // node-coap only gives us req.url on the server side
-  const key = `${req.method} ${path}`;
-  const handler = routes[key];
-
-  console.log(`${req.method} ${req.url} from ${req.rsinfo.address}:${req.rsinfo.port}`);
-
-  if (!handler) return send(res, '4.04', `Not Found: ${path}`);
-
-  try {
-    handler(req, res);
-  } catch (err) {
-    console.error('handler error:', err);
-    send(res, '5.00', 'Internal Server Error');
-  }
-});
-
-server.on('error', (err) => console.error('server error:', err));
-
-server.listen(PORT, HOST, () => {
-  console.log(`CoAP server (UDP) listening on coap://${HOST}:${PORT}`);
-  console.log('  GET  /hello?name=Imran');
-  console.log('  POST /hello   (payload: Imran  |  {"name":"Imran"})');
-  console.log('  GET  /health');
-});
-
-process.on('SIGINT', () => server.close(() => process.exit(0)));

src/main.rs

@@ -269,6 +269,7 @@ mod tests {
     }
 
     #[test]
+    
     fn reads_name_from_text_and_json_payloads() {
         assert_eq!(name_from_payload(b"Imran").as_deref(), Some("Imran"));
         assert_eq!(

static/index.html

@@ -3,7 +3,7 @@
 <head>
 <meta charset="utf-8">
 <meta name="viewport" content="width=device-width, initial-scale=1">
-<title>CoAP Hello — Test Console</title>
+<title>CoAP Hello — UDP Reference</title>
 <style>
   :root {
     color-scheme: light dark;
@@ -23,112 +23,144 @@
     margin: 0; padding: 2rem 1.25rem; background: var(--bg); color: var(--fg);
     font: 15px/1.55 ui-sans-serif, system-ui, -apple-system, "Segoe UI", sans-serif;
   }
-  main { max-width: 640px; margin: 0 auto; }
+  main { max-width: 680px; margin: 0 auto; }
   h1 { font-size: 1.4rem; margin: 0 0 .35rem; letter-spacing: -.01em; }
   .sub { color: var(--muted); margin: 0 0 1.75rem; font-size: .9rem; }
   .card {
     background: var(--card); border: 1px solid var(--border);
     border-radius: 10px; padding: 1.25rem; margin-bottom: 1rem;
   }
+  h2 { font-size: .82rem; text-transform: uppercase; letter-spacing: .06em;
+       color: var(--muted); margin: 0 0 .7rem; }
   label { display: block; font-weight: 600; font-size: .82rem; margin-bottom: .4rem; }
   input {
     width: 100%; padding: .6rem .7rem; font: inherit; border-radius: 7px;
     border: 1px solid var(--border); background: var(--bg); color: var(--fg);
   }
   input:focus { outline: 2px solid var(--accent); outline-offset: 1px; }
-  .row { display: flex; gap: .5rem; flex-wrap: wrap; margin-top: .85rem; }
-  button {
-    font: inherit; font-weight: 600; padding: .55rem 1rem; border-radius: 7px;
-    border: 1px solid var(--border); background: var(--bg); color: var(--fg); cursor: pointer;
-  }
-  button:hover { border-color: var(--accent); color: var(--accent); }
-  button.primary { background: var(--accent); border-color: var(--accent); color: #fff; }
-  button.primary:hover { opacity: .88; color: #fff; }
+  .hint { color: var(--muted); font-size: .82rem; margin: .8rem 0 0; }
+  .cmd { display: flex; gap: .5rem; align-items: stretch; margin-top: .55rem; }
+  .cmd pre { flex: 1; margin: 0; }
   pre {
     background: var(--code-bg); border: 1px solid var(--border); border-radius: 7px;
-    padding: .8rem; overflow-x: auto; margin: 0;
+    padding: .7rem .8rem; overflow-x: auto; margin: 0;
     font: 13px/1.5 ui-monospace, SFMono-Regular, Menlo, monospace;
   }
-  .status { font-weight: 600; }
-  .status.ok { color: var(--ok); }
-  .status.err { color: var(--err); }
-  h2 { font-size: .82rem; text-transform: uppercase; letter-spacing: .06em;
-       color: var(--muted); margin: 0 0 .7rem; }
-  .hint { color: var(--muted); font-size: .82rem; margin: .8rem 0 0; }
+  button {
+    font: inherit; font-size: .8rem; font-weight: 600; padding: .35rem .7rem;
+    border-radius: 7px; border: 1px solid var(--border);
+    background: var(--bg); color: var(--muted); cursor: pointer; white-space: nowrap;
+  }
+  button:hover { border-color: var(--accent); color: var(--accent); }
+  button.copied { color: var(--ok); border-color: var(--ok); }
+  .what { font-size: .8rem; color: var(--muted); margin: 1rem 0 .1rem; }
+  .what:first-of-type { margin-top: 0; }
+  table { width: 100%; border-collapse: collapse; font-size: .87rem; }
+  th, td { text-align: left; padding: .4rem .5rem; border-bottom: 1px solid var(--border); }
+  th { font-size: .74rem; text-transform: uppercase; letter-spacing: .05em;
+       color: var(--muted); font-weight: 600; }
+  tr:last-child td { border-bottom: none; }
+  td.code { font: 13px ui-monospace, SFMono-Regular, Menlo, monospace; white-space: nowrap; }
+  .ok { color: var(--ok); font-weight: 600; }
+  .err { color: var(--err); font-weight: 600; }
   code { background: var(--code-bg); padding: .1em .35em; border-radius: 4px;
          font: 13px ui-monospace, SFMono-Regular, Menlo, monospace; }
+  a { color: var(--accent); }
 </style>
 </head>
 <body>
 <main>
-  <h1>CoAP Hello — Test Console</h1>
-  <p class="sub">This page talks HTTP to a local bridge, which reissues each
-     call as CoAP over UDP and shows you the raw response code.</p>
+  <h1>CoAP Hello — UDP Reference</h1>
+  <p class="sub">This server speaks CoAP over UDP only, so there is nothing here
+     for a browser to call. Type a name and copy the command for the client you
+     use — the page is static and works straight off disk.</p>
 
   <div class="card">
     <label for="name">Name</label>
-    <input id="name" value="Imran" autocomplete="off" placeholder="leave blank for &quot;World&quot;">
-    <div class="row">
-      <button class="primary" data-act="get">GET /hello</button>
-      <button data-act="post">POST /hello</button>
-      <button data-act="json">POST (JSON body)</button>
-      <button data-act="health">GET /health</button>
-      <button data-act="notfound">GET /nope</button>
-    </div>
-    <p class="hint">Or hit an endpoint directly:
-       <a href="/hello?name=Imran">/hello?name=Imran</a> ·
-       <a href="/health">/health</a></p>
+    <input id="name" value="Imran" autocomplete="off" spellcheck="false"
+           placeholder="leave blank for &quot;World&quot;">
+
+    <p class="what">Bundled client — <code>cargo build --release</code> first</p>
+    <div class="cmd"><pre id="c-get"></pre><button data-copy="c-get">Copy</button></div>
+    <div class="cmd"><pre id="c-post"></pre><button data-copy="c-post">Copy</button></div>
+    <div class="cmd"><pre id="c-json"></pre><button data-copy="c-json">Copy</button></div>
+    <div class="cmd"><pre id="c-health"></pre><button data-copy="c-health">Copy</button></div>
+
+    <p class="what">Any other CoAP client, e.g. <a href="https://www.npmjs.com/package/coap-cli">coap-cli</a></p>
+    <div class="cmd"><pre id="c-cli"></pre><button data-copy="c-cli">Copy</button></div>
+
+    <p class="hint">Set <code>COAP_HOST</code> / <code>COAP_PORT</code> to point at
+       another server; both default to <code>127.0.0.1:5683</code>.</p>
   </div>
 
   <div class="card">
-    <h2>Response</h2>
-    <p id="status" class="status">—</p>
-    <pre id="out">Pick an action above.</pre>
+    <h2>Routes</h2>
+    <table>
+      <thead><tr><th>Request</th><th>Code</th><th>Response</th></tr></thead>
+      <tbody>
+        <tr><td class="code">GET /hello</td><td class="code ok">2.05</td><td class="code">Hello, World!</td></tr>
+        <tr><td class="code">GET /hello?name=…</td><td class="code ok">2.05</td><td class="code">Hello, …!</td></tr>
+        <tr><td class="code">POST /hello</td><td class="code ok">2.01</td><td class="code">Hello, &lt;payload&gt;!</td></tr>
+        <tr><td class="code">GET /health</td><td class="code ok">2.05</td><td class="code">{"status":"ok","uptime":12}</td></tr>
+        <tr><td class="code">POST /hello (empty)</td><td class="code err">4.00</td><td class="code">Bad Request</td></tr>
+        <tr><td class="code">GET /nope</td><td class="code err">4.04</td><td class="code">Not Found</td></tr>
+        <tr><td class="code">PUT /hello</td><td class="code err">4.05</td><td class="code">Method Not Allowed</td></tr>
+      </tbody>
+    </table>
+    <p class="hint">CoAP writes response codes as <code>class.detail</code>:
+       <code>2.05</code> is HTTP's 200, <code>4.04</code> its 404.
+       <code>POST /hello</code> takes raw text or <code>{"name":"…"}</code>.</p>
+  </div>
+
+  <div class="card">
+    <h2>Scripts</h2>
+    <p class="what">Full request/response suite against a running server</p>
+    <div class="cmd"><pre id="c-test">./test-coap.sh</pre><button data-copy="c-test">Copy</button></div>
+    <p class="what">Liveness check — exit 0 healthy, 1 not</p>
+    <div class="cmd"><pre id="c-health-sh">./healthcheck.sh -v</pre><button data-copy="c-health-sh">Copy</button></div>
+    <p class="what">Start the server</p>
+    <div class="cmd"><pre id="c-run">cargo run --release</pre><button data-copy="c-run">Copy</button></div>
   </div>
 </main>
 
 <script>
   const $ = (id) => document.getElementById(id);
+  const shell = (s) => "'" + String(s).replace(/'/g, `'\\''`) + "'";
 
-  async function call(method, path, body) {
-    $('status').textContent = '…';
-    $('status').className = 'status';
-    $('out').textContent = '';
-    try {
-      const res = await fetch(path, {
-        method,
-        body,
-        headers: body ? { 'Content-Type': 'text/plain' } : undefined,
-      });
-      const text = await res.text();
-      const coap = res.headers.get('X-Coap-Code') || '—';
-      $('status').textContent = `CoAP ${coap}  ·  HTTP ${res.status}`;
-      $('status').className = 'status ' + (res.ok ? 'ok' : 'err');
-      $('out').textContent = `${method} ${path}\n${body ? 'body: ' + body + '\n' : ''}\n${text || '(empty)'}`;
-    } catch (err) {
-      $('status').textContent = 'Request failed';
-      $('status').className = 'status err';
-      $('out').textContent = String(err) + '\n\nIs the bridge still running?';
-    }
-  }
-
-  document.querySelectorAll('button[data-act]').forEach((btn) => {
-    btn.addEventListener('click', () => {
+  function render() {
     const name = $('name').value.trim();
-      switch (btn.dataset.act) {
-        case 'get':
-          return call('GET', '/hello' + (name ? '?name=' + encodeURIComponent(name) : ''));
-        case 'post':
-          return call('POST', '/hello', name || '');
-        case 'json':
-          return call('POST', '/hello', JSON.stringify({ name }));
-        case 'health':
-          return call('GET', '/health');
-        case 'notfound':
-          return call('GET', '/nope');
+    const q = name ? '/hello?name=' + encodeURIComponent(name) : '/hello';
+    const who = name || 'Imran';
+
+    $('c-get').textContent    = `./target/release/client get ${shell(q)}`;
+    $('c-post').textContent   = `./target/release/client post /hello ${shell(who)}`;
+    $('c-json').textContent   = `./target/release/client post /hello ${shell(JSON.stringify({ name: who }))}`;
+    $('c-health').textContent = `./target/release/client get /health`;
+    $('c-cli').textContent    = `coap get ${shell('coap://localhost:5683' + q)}`;
   }
+
+  document.querySelectorAll('button[data-copy]').forEach((btn) => {
+    btn.addEventListener('click', async () => {
+      const text = $(btn.dataset.copy).textContent;
+      try {
+        await navigator.clipboard.writeText(text);
+      } catch {
+        // file:// and non-secure origins deny the clipboard API; fall back.
+        const ta = document.createElement('textarea');
+        ta.value = text;
+        document.body.appendChild(ta);
+        ta.select();
+        document.execCommand('copy');
+        ta.remove();
+      }
+      btn.textContent = 'Copied';
+      btn.classList.add('copied');
+      setTimeout(() => { btn.textContent = 'Copy'; btn.classList.remove('copied'); }, 1200);
     });
   });
+
+  $('name').addEventListener('input', render);
+  render();
 </script>
 </body>
 </html>