did:cow, a proposal for an ID resolution method with most of the convenience of did:plc/did:web and the robustness of a public blockchain
API endpoint for resolving did:cow plus a simple web page (no edit feature yet)
+548
+101
web/app.py
+101
web/app.py
···
1
+
#!/usr/bin/env python3
2
+
"""did:cow resolution API"""
3
+
4
+
import json
5
+
import os
6
+
import sys
7
+
from pathlib import Path
8
+
9
+
from dotenv import load_dotenv
10
+
from fastapi import FastAPI, HTTPException
11
+
from fastapi.middleware.cors import CORSMiddleware
12
+
from fastapi.responses import JSONResponse
13
+
from web3 import Web3
14
+
15
+
# Load env and import helpers from CLI
16
+
load_dotenv(Path(__file__).parent.parent / "cli" / ".env")
17
+
sys.path.insert(0, str(Path(__file__).parent.parent / "cli"))
18
+
from cow import _controller_address, _parse_cow_did, _resolve_did_doc, _strip_did_prefix
19
+
20
+
_ABI_PATH = Path(__file__).parent.parent / "out" / "CowRegistry.sol" / "CowRegistry.json"
21
+
22
+
23
+
def _get_contract():
24
+
url = os.getenv("RPC_URL")
25
+
addr = os.getenv("CONTRACT_ADDRESS")
26
+
if not url or not addr:
27
+
raise RuntimeError("RPC_URL and CONTRACT_ADDRESS must be set")
28
+
w3 = Web3(Web3.HTTPProvider(url))
29
+
artifact = json.loads(_ABI_PATH.read_text())
30
+
contract = w3.eth.contract(
31
+
address=Web3.to_checksum_address(addr),
32
+
abi=artifact["abi"],
33
+
)
34
+
return w3, contract
35
+
36
+
37
+
app = FastAPI(title="did:cow resolver", docs_url="/api/docs", redoc_url=None)
38
+
39
+
app.add_middleware(
40
+
CORSMiddleware,
41
+
allow_origins=["*"],
42
+
allow_methods=["GET"],
43
+
allow_headers=["*"],
44
+
)
45
+
46
+
47
+
def _validate_cow_did(did: str):
48
+
"""Parse and validate a did:cow DID, raising HTTPException on failure."""
49
+
try:
50
+
return _parse_cow_did(did)
51
+
except Exception as e:
52
+
raise HTTPException(status_code=400, detail=str(e))
53
+
54
+
55
+
@app.get("/{did:path}/describe")
56
+
async def describe(did: str):
57
+
"""Return on-chain state for a did:cow DID without fetching the wrapped DID document."""
58
+
controller_hex, initial_wrapped = _validate_cow_did(did)
59
+
w3, contract = _get_contract()
60
+
controller_addr = _controller_address(controller_hex)
61
+
62
+
wrapped_did, controller = contract.functions.resolve(controller_addr, initial_wrapped).call()
63
+
64
+
if wrapped_did == "":
65
+
return {"status": "deactivated"}
66
+
67
+
cow_hash = contract.functions.calculateHash(controller_addr, initial_wrapped).call()
68
+
registered = contract.functions.cows(cow_hash).call()[1] # initialized bool
69
+
70
+
return {
71
+
"status": "active" if registered else "not registered on-chain",
72
+
"wrappedDid": wrapped_did,
73
+
"controller": controller,
74
+
}
75
+
76
+
77
+
@app.get("/{did:path}")
78
+
async def resolve_did(did: str):
79
+
"""Resolve a did:cow DID and return the modified DID document."""
80
+
controller_hex, initial_wrapped = _validate_cow_did(did)
81
+
w3, contract = _get_contract()
82
+
controller_addr = _controller_address(controller_hex)
83
+
84
+
wrapped_did, controller = contract.functions.resolve(controller_addr, initial_wrapped).call()
85
+
86
+
if wrapped_did == "":
87
+
raise HTTPException(status_code=404, detail="DID is deactivated")
88
+
89
+
try:
90
+
_, doc = _resolve_did_doc(_strip_did_prefix(wrapped_did))
91
+
except Exception as e:
92
+
raise HTTPException(status_code=502, detail=str(e))
93
+
94
+
chain_id = w3.eth.chain_id
95
+
doc["id"] = did
96
+
doc["did:cow"] = {
97
+
"controller": f"did:pkh:eip155:{chain_id}:{controller}",
98
+
"wrappedDid": wrapped_did,
99
+
}
100
+
101
+
return JSONResponse(content=doc)
+5
web/requirements.txt
+5
web/requirements.txt
+417
web/static/index.html
+417
web/static/index.html
···
1
+
<!DOCTYPE html>
2
+
<html lang="en">
3
+
<head>
4
+
<meta charset="UTF-8">
5
+
<meta name="viewport" content="width=device-width, initial-scale=1.0">
6
+
<title>did:cow</title>
7
+
<style>
8
+
* { box-sizing: border-box; margin: 0; padding: 0; }
9
+
10
+
body {
11
+
font-family: system-ui, -apple-system, sans-serif;
12
+
background: #f5f5f5;
13
+
color: #1a1a1a;
14
+
padding: 2rem;
15
+
}
16
+
17
+
header {
18
+
display: flex;
19
+
justify-content: space-between;
20
+
align-items: center;
21
+
margin-bottom: 2rem;
22
+
}
23
+
24
+
.header-left { display: flex; align-items: center; gap: 1.5rem; }
25
+
26
+
.cow-ascii {
27
+
font-family: monospace;
28
+
font-size: 0.7rem;
29
+
line-height: 1.3;
30
+
color: #6b7280;
31
+
white-space: pre;
32
+
user-select: none;
33
+
}
34
+
35
+
h1 { font-size: 1.5rem; font-weight: 700; }
36
+
h1 span { color: #6b7280; font-weight: 400; }
37
+
38
+
#connect-btn {
39
+
background: #1a1a1a;
40
+
color: #fff;
41
+
border: none;
42
+
padding: 0 1rem;
43
+
border-radius: 6px;
44
+
cursor: pointer;
45
+
font-size: 0.9rem;
46
+
height: 2.5rem;
47
+
}
48
+
#connect-btn:hover { background: #333; }
49
+
#connect-btn.connected { background: #166534; }
50
+
51
+
.card {
52
+
background: #fff;
53
+
border: 1px solid #e5e7eb;
54
+
border-radius: 8px;
55
+
padding: 1.5rem;
56
+
margin-bottom: 1.5rem;
57
+
}
58
+
59
+
.card h2 {
60
+
font-size: 1rem;
61
+
font-weight: 600;
62
+
margin-bottom: 1rem;
63
+
color: #374151;
64
+
}
65
+
66
+
.field { margin-bottom: 0.75rem; }
67
+
68
+
label {
69
+
display: block;
70
+
font-size: 0.8rem;
71
+
font-weight: 500;
72
+
color: #6b7280;
73
+
margin-bottom: 0.25rem;
74
+
text-transform: uppercase;
75
+
letter-spacing: 0.05em;
76
+
}
77
+
78
+
input[type="text"] {
79
+
width: 100%;
80
+
padding: 0.5rem 0.75rem;
81
+
border: 1px solid #d1d5db;
82
+
border-radius: 6px;
83
+
font-size: 0.95rem;
84
+
font-family: monospace;
85
+
height: 2.5rem;
86
+
}
87
+
input[type="text"]:focus {
88
+
outline: none;
89
+
border-color: #6b7280;
90
+
}
91
+
92
+
.row { display: flex; gap: 0.75rem; align-items: flex-end; }
93
+
.row .field { margin-bottom: 0; }
94
+
.row .field { flex: 1; }
95
+
96
+
button.action {
97
+
background: #1a1a1a;
98
+
color: #fff;
99
+
border: none;
100
+
padding: 0 1.25rem;
101
+
border-radius: 6px;
102
+
cursor: pointer;
103
+
font-size: 0.95rem;
104
+
height: 2.5rem;
105
+
white-space: nowrap;
106
+
}
107
+
button.action:hover { background: #333; }
108
+
button.action:disabled { background: #9ca3af; cursor: default; }
109
+
110
+
.result {
111
+
margin-top: 1rem;
112
+
padding: 1rem;
113
+
background: #f9fafb;
114
+
border: 1px solid #e5e7eb;
115
+
border-radius: 6px;
116
+
font-family: monospace;
117
+
font-size: 0.85rem;
118
+
white-space: pre-wrap;
119
+
word-break: break-all;
120
+
}
121
+
122
+
.result.error { background: #fef2f2; border-color: #fecaca; color: #dc2626; }
123
+
.result.success { background: #f0fdf4; border-color: #bbf7d0; }
124
+
125
+
.did-output {
126
+
margin-top: 1rem;
127
+
padding: 0.75rem 1rem;
128
+
background: #f0fdf4;
129
+
border: 1px solid #bbf7d0;
130
+
border-radius: 6px;
131
+
display: none;
132
+
}
133
+
134
+
.reveal-track {
135
+
position: relative;
136
+
display: flex;
137
+
align-items: center;
138
+
min-height: 5.5rem;
139
+
margin-bottom: 0.5rem;
140
+
}
141
+
142
+
#create-did-value {
143
+
font-family: monospace;
144
+
font-size: 1.2rem;
145
+
word-break: break-all;
146
+
width: 100%;
147
+
}
148
+
149
+
.running-cow {
150
+
position: absolute;
151
+
top: 0;
152
+
display: none;
153
+
pointer-events: none;
154
+
}
155
+
156
+
.running-cow pre {
157
+
transform: scaleX(-1);
158
+
font-family: monospace;
159
+
font-size: 0.85rem;
160
+
line-height: 1.3;
161
+
white-space: pre;
162
+
margin: 0;
163
+
}
164
+
165
+
.copy-btn {
166
+
background: none;
167
+
border: 1px solid #6b7280;
168
+
border-radius: 4px;
169
+
padding: 0.2rem 0.5rem;
170
+
font-size: 0.8rem;
171
+
cursor: pointer;
172
+
white-space: nowrap;
173
+
color: #374151;
174
+
}
175
+
.copy-btn:hover { background: #f3f4f6; }
176
+
177
+
.hint {
178
+
font-size: 0.8rem;
179
+
color: #6b7280;
180
+
margin-top: 0.5rem;
181
+
}
182
+
</style>
183
+
</head>
184
+
<body>
185
+
186
+
<header>
187
+
<div class="header-left">
188
+
<pre class="cow-ascii"
189
+
> ^__^
190
+
(oo)\_______
191
+
(__)\ )\/\
192
+
||----w |
193
+
|| ||</pre>
194
+
<h1>did:cow <span>Consensus Ownership Wrapper</span></h1>
195
+
</div>
196
+
<button id="connect-btn" onclick="connectWallet()">Connect wallet</button>
197
+
</header>
198
+
199
+
<!-- Resolve -->
200
+
<div class="card">
201
+
<h2>Resolve</h2>
202
+
<div class="row">
203
+
<div class="field">
204
+
<label>DID</label>
205
+
<input type="text" id="resolve-did" placeholder="did:cow:8BC101ABF5BcF8b6209FaaAD4D761C1ED14999Be:plc:pyzlzqt6b2nyrha7smfry6rv">
206
+
</div>
207
+
<button class="action" onclick="resolveDid()">Resolve</button>
208
+
</div>
209
+
<div id="resolve-result" class="result" style="display:none"></div>
210
+
</div>
211
+
212
+
<!-- Create -->
213
+
<div class="card">
214
+
<h2>Create</h2>
215
+
<p class="hint" style="margin-bottom:0.75rem">No transaction required — a did:cow identifier is formed from your controller address and wrapped DID.</p>
216
+
<div class="field">
217
+
<label>Controller address <span id="controller-hint" style="color:#166534;display:none">(your connected address)</span></label>
218
+
<input type="text" id="create-controller" placeholder="8BC101ABF5BcF8b6209FaaAD4D761C1ED14999Be">
219
+
</div>
220
+
<div class="field">
221
+
<label>Wrapped DID</label>
222
+
<input type="text" id="create-wrapped" placeholder="did:plc:pyzlzqt6b2nyrha7smfry6rv or plc:pyzlzqt6b2nyrha7smfry6rv">
223
+
</div>
224
+
<button class="action" onclick="createDid()">Construct DID</button>
225
+
<div id="create-output" class="did-output">
226
+
<div class="reveal-track">
227
+
<div class="running-cow" id="running-cow"><pre> ^__^
228
+
(oo)\_______
229
+
(__)\ )\/\
230
+
||----w |
231
+
|| ||</pre></div>
232
+
<span id="create-did-value"></span>
233
+
</div>
234
+
<button class="copy-btn" id="copy-btn" onclick="copyDid()" style="display:none">Copy</button>
235
+
</div>
236
+
<div id="create-error" class="result error" style="display:none"></div>
237
+
</div>
238
+
239
+
<script type="module">
240
+
const API_BASE = "https://cow.watch";
241
+
242
+
// ── Wallet ──────────────────────────────────────────────────────────────────
243
+
244
+
let connectedAddress = null;
245
+
246
+
window.connectWallet = async () => {
247
+
if (!window.ethereum) {
248
+
alert("No wallet detected. Install MetaMask or another browser wallet.");
249
+
return;
250
+
}
251
+
try {
252
+
const accounts = await window.ethereum.request({ method: "eth_requestAccounts" });
253
+
connectedAddress = accounts[0];
254
+
const btn = document.getElementById("connect-btn");
255
+
btn.textContent = connectedAddress.slice(0, 6) + "…" + connectedAddress.slice(-4);
256
+
btn.classList.add("connected");
257
+
258
+
// Pre-fill controller with checksummed address (strip 0x for did:cow format)
259
+
const controllerInput = document.getElementById("create-controller");
260
+
if (!controllerInput.value) {
261
+
controllerInput.value = toChecksumAddress(connectedAddress).slice(2);
262
+
}
263
+
document.getElementById("controller-hint").style.display = "inline";
264
+
} catch (e) {
265
+
console.error(e);
266
+
}
267
+
};
268
+
269
+
// EIP-55 checksum — minimal implementation
270
+
function toChecksumAddress(address) {
271
+
const addr = address.toLowerCase().replace("0x", "");
272
+
// Use the browser's SubtleCrypto to keccak would require a library;
273
+
// ethers is loaded below for this — call after ethers loads.
274
+
return address; // placeholder; replaced once ethers is available
275
+
}
276
+
277
+
// ── Resolve ─────────────────────────────────────────────────────────────────
278
+
279
+
window.resolveDid = async () => {
280
+
const did = document.getElementById("resolve-did").value.trim();
281
+
const el = document.getElementById("resolve-result");
282
+
el.style.display = "block";
283
+
el.className = "result";
284
+
el.textContent = "Resolving…";
285
+
286
+
try {
287
+
const resp = await fetch(`${API_BASE}/${encodeURIComponent(did)}`);
288
+
const body = await resp.json();
289
+
if (!resp.ok) {
290
+
el.className = "result error";
291
+
el.textContent = body.detail ?? JSON.stringify(body, null, 2);
292
+
} else {
293
+
el.className = "result success";
294
+
el.textContent = JSON.stringify(body, null, 2);
295
+
}
296
+
} catch (e) {
297
+
el.className = "result error";
298
+
el.textContent = `Network error: ${e.message}`;
299
+
}
300
+
};
301
+
302
+
// ── Create ──────────────────────────────────────────────────────────────────
303
+
304
+
window.createDid = () => {
305
+
const errorEl = document.getElementById("create-error");
306
+
const outputEl = document.getElementById("create-output");
307
+
errorEl.style.display = "none";
308
+
outputEl.style.display = "none";
309
+
310
+
let controller = document.getElementById("create-controller").value.trim();
311
+
let wrapped = document.getElementById("create-wrapped").value.trim();
312
+
313
+
// Strip leading 0x if present
314
+
if (controller.startsWith("0x") || controller.startsWith("0X")) {
315
+
controller = controller.slice(2);
316
+
}
317
+
318
+
// Strip leading did: if present
319
+
if (wrapped.startsWith("did:")) {
320
+
wrapped = wrapped.slice(4);
321
+
}
322
+
323
+
if (!controller) {
324
+
showCreateError("Controller address is required.");
325
+
return;
326
+
}
327
+
if (!/^[0-9a-fA-F]{40}$/.test(controller)) {
328
+
showCreateError("Controller must be a 40-character hex Ethereum address.");
329
+
return;
330
+
}
331
+
if (!wrapped) {
332
+
showCreateError("Wrapped DID is required.");
333
+
return;
334
+
}
335
+
if (!wrapped.includes(":")) {
336
+
showCreateError("Wrapped DID must include a method, e.g. plc:xxx or web:example.com");
337
+
return;
338
+
}
339
+
340
+
// EIP-55 checksum via ethers
341
+
let checksummed;
342
+
try {
343
+
checksummed = ethers.getAddress("0x" + controller).slice(2);
344
+
} catch (e) {
345
+
showCreateError("Invalid Ethereum address.");
346
+
return;
347
+
}
348
+
349
+
const did = `did:cow:${checksummed}:${wrapped}`;
350
+
animateCowReveal(did);
351
+
};
352
+
353
+
function animateCowReveal(did) {
354
+
const outputEl = document.getElementById("create-output");
355
+
const didEl = document.getElementById("create-did-value");
356
+
const cowEl = document.getElementById("running-cow");
357
+
const copyBtn = document.getElementById("copy-btn");
358
+
359
+
didEl.textContent = did;
360
+
didEl.style.clipPath = "inset(0 100% 0 0)";
361
+
cowEl.style.display = "block";
362
+
cowEl.style.left = "0px";
363
+
copyBtn.style.display = "none";
364
+
outputEl.style.display = "block";
365
+
366
+
const cowWidth = cowEl.offsetWidth;
367
+
const trackWidth = cowEl.parentElement.offsetWidth;
368
+
const travel = trackWidth - cowWidth; // tail goes from 0 to right edge
369
+
370
+
const duration = 5400;
371
+
const start = performance.now();
372
+
373
+
function frame(now) {
374
+
const t = Math.min((now - start) / duration, 1);
375
+
const eased = t < 0.5 ? 2 * t * t : -1 + (4 - 2 * t) * t;
376
+
const leftPx = eased * travel;
377
+
cowEl.style.left = leftPx + "px";
378
+
// reveal tracks the tail (left edge of cow) so text comes out behind it
379
+
const revealPct = (leftPx / trackWidth) * 100;
380
+
didEl.style.clipPath = `inset(0 ${100 - revealPct}% 0 0)`;
381
+
if (t < 1) {
382
+
requestAnimationFrame(frame);
383
+
} else {
384
+
didEl.style.clipPath = ""; // reveal the last bit hidden under the cow
385
+
copyBtn.style.display = "inline-block";
386
+
}
387
+
}
388
+
389
+
requestAnimationFrame(frame);
390
+
}
391
+
392
+
window.copyDid = () => {
393
+
const val = document.getElementById("create-did-value").textContent;
394
+
navigator.clipboard.writeText(val).then(() => {
395
+
const btn = document.querySelector(".copy-btn");
396
+
btn.textContent = "Copied!";
397
+
setTimeout(() => { btn.textContent = "Copy"; }, 1500);
398
+
});
399
+
};
400
+
401
+
function showCreateError(msg) {
402
+
const el = document.getElementById("create-error");
403
+
el.textContent = msg;
404
+
el.style.display = "block";
405
+
}
406
+
407
+
// ── Enter on resolve input ───────────────────────────────────────────────────
408
+
document.getElementById("resolve-did").addEventListener("keydown", e => {
409
+
if (e.key === "Enter") window.resolveDid();
410
+
});
411
+
</script>
412
+
413
+
<!-- ethers.js for EIP-55 checksum and future MetaMask tx signing -->
414
+
<script src="https://cdnjs.cloudflare.com/ajax/libs/ethers/6.13.4/ethers.umd.min.js"></script>
415
+
416
+
</body>
417
+
</html>
+23
web/web.py
+23
web/web.py
···
1
+
#!/usr/bin/env python3
2
+
"""Static file server for the did:cow web UI (dev use — in prod, copy to nginx webroot)."""
3
+
4
+
import http.server
5
+
import os
6
+
from pathlib import Path
7
+
8
+
PORT = 6667
9
+
DIRECTORY = Path(__file__).parent / "static"
10
+
11
+
12
+
class Handler(http.server.SimpleHTTPRequestHandler):
13
+
def __init__(self, *args, **kwargs):
14
+
super().__init__(*args, directory=str(DIRECTORY), **kwargs)
15
+
16
+
def log_message(self, format, *args):
17
+
print(f"{self.address_string()} {format % args}")
18
+
19
+
20
+
if __name__ == "__main__":
21
+
with http.server.HTTPServer(("", PORT), Handler) as httpd:
22
+
print(f"Serving {DIRECTORY} at http://localhost:{PORT}")
23
+
httpd.serve_forever()