fix: populate lnurl/lnurl_url in nostr-transport handlers (#1)

The HTTP views populate `link.lnurl` and `link.lnurl_url` from
`request.url_for(...)`; the nostr-transport RPC handlers had no
`Request` and so left both fields as `None`. Consumers (ATMs over
nostr) were forced to provision a separate `LNBITS_HTTP_URL` env var
and compose the LNURL callback themselves.

Add `helpers.create_lnurl_from_baseurl(link)` that mirrors
`create_lnurl` but composes the callback URL from
`settings.lnbits_baseurl` instead, and thread it through the
create/get/update/list RPC handlers via a `_populate_lnurl` shim
so the response shape matches the HTTP path. Encoding errors are
swallowed (fields stay `None`) so a misconfigured baseurl falls
back to current behavior rather than failing the RPC.

Closes #1.

helpers.py

@@ -1,4 +1,5 @@
 from fastapi import Request
+from lnbits.settings import settings
 from lnurl import Lnurl
 from lnurl import encode as lnurl_encode
 from shortuuid import uuid
@@ -26,3 +27,28 @@ def create_lnurl(link: WithdrawLink, req: Request) -> Lnurl:
             f"Error creating LNURL with url: `{url!s}`, "
             "check your webserver proxy configuration."
         ) from e
+
+
+def create_lnurl_from_baseurl(link: WithdrawLink) -> Lnurl:
+    """
+    Same shape as `create_lnurl`, but composes the callback URL from
+    `settings.lnbits_baseurl` instead of a FastAPI `Request`. Used by
+    the nostr-transport RPC handlers, which have no HTTP request to
+    derive a base URL from.
+    """
+    base = settings.lnbits_baseurl.rstrip("/")
+    if link.is_unique:
+        usescssv = link.usescsv.split(",")
+        tohash = link.id + link.unique_hash + usescssv[link.number]
+        multihash = uuid(name=tohash)
+        url = f"{base}/withdraw/api/v1/lnurl/{link.unique_hash}/{multihash}"
+    else:
+        url = f"{base}/withdraw/api/v1/lnurl/{link.unique_hash}"
+
+    try:
+        return lnurl_encode(url)
+    except Exception as e:
+        raise ValueError(
+            f"Error creating LNURL with url: `{url!s}`, "
+            "check your `LNBITS_BASEURL` configuration."
+        ) from e

transport_rpcs.py

@@ -20,12 +20,11 @@ link_id:...})` enforce ownership without core importing this module.
 
 from __future__ import annotations
 
-from shortuuid import uuid
-
 from lnbits.core.crud.wallets import get_wallets
 from lnbits.core.models import Account
 from lnbits.core.models.wallets import WalletTypeInfo
 from lnbits.core.services.nostr_transport.models import NostrRpcRequest
+from shortuuid import uuid
 
 from .crud import (
     create_withdraw_link,
@@ -34,7 +33,8 @@ from .crud import (
     get_withdraw_links,
     update_withdraw_link,
 )
-from .models import CreateWithdrawData
+from .helpers import create_lnurl_from_baseurl
+from .models import CreateWithdrawData, WithdrawLink
 
 
 async def handle_lnurlw_create_link(
@@ -43,7 +43,7 @@ async def handle_lnurlw_create_link(
     body = request.body or {}
     data = CreateWithdrawData(**body)
     link = await create_withdraw_link(data, auth.wallet.id)
-    return _to_dict(link)
+    return _to_dict(_populate_lnurl(link))
 
 
 async def handle_lnurlw_get_link(
@@ -51,7 +51,7 @@ async def handle_lnurlw_get_link(
 ) -> dict:
     link_id = _require_id(request)
     link = await _require_owned_link(link_id, auth.wallet.id)
-    return _to_dict(link)
+    return _to_dict(_populate_lnurl(link))
 
 
 async def handle_lnurlw_update_link(
@@ -77,7 +77,7 @@ async def handle_lnurlw_update_link(
         if k in _MUTABLE:
             setattr(link, k, v)
     updated = await update_withdraw_link(link)
-    return _to_dict(updated)
+    return _to_dict(_populate_lnurl(updated))
 
 
 async def handle_lnurlw_delete_link(
@@ -89,9 +89,7 @@ async def handle_lnurlw_delete_link(
     return {"ok": True}
 
 
-async def handle_lnurlw_list_links(
-    auth: Account, request: NostrRpcRequest
-) -> dict:
+async def handle_lnurlw_list_links(auth: Account, request: NostrRpcRequest) -> dict:
     """List withdraw links across all wallets owned by the calling account.
     Useful for ATMs to re-discover their links after a reconnect.
 
@@ -114,7 +112,7 @@ async def handle_lnurlw_list_links(
 
     page = await get_withdraw_links(wallet_ids, limit, offset)
     return {
-        "data": [_to_dict(link) for link in page.data],
+        "data": [_to_dict(_populate_lnurl(link)) for link in page.data],
         "total": page.total,
     }
 
@@ -199,12 +197,29 @@ async def _require_owned_link(link_id: str, wallet_id: str):
     if link is None:
         raise ValueError(f"withdraw: link not found: {link_id}")
     if link.wallet != wallet_id:
-        raise PermissionError(
-            "withdraw: link does not belong to caller's wallet"
-        )
+        raise PermissionError("withdraw: link does not belong to caller's wallet")
+    return link
+
+
+def _populate_lnurl(link: WithdrawLink) -> WithdrawLink:
+    """
+    Compose `lnurl` / `lnurl_url` from `settings.lnbits_baseurl` so
+    nostr-transport responses match the HTTP `views_api` shape, where
+    these fields are populated from `request.url_for(...)`. Without
+    this, consumers (ATMs, etc.) would have to re-derive the callback
+    URL themselves from a separately-provisioned LNbits HTTPS URL —
+    duplicating state LNbits already knows. See aiolabs/withdraw#1.
+    """
+    try:
+        encoded = create_lnurl_from_baseurl(link)
+        link.lnurl = str(encoded.bech32)
+        link.lnurl_url = str(encoded.url)
+    except ValueError:
+        pass
     return link
 
 
 def _to_dict(link) -> dict:
     import json
+
     return json.loads(link.json())