feat: Spark L2 (#3715)

Co-authored-by: blackcoffeexbt <87530449+blackcoffeexbt@users.noreply.github.com> Co-authored-by: Vlad Stan <stan.v.vlad@gmail.com>
2026-02-25 07:54:18 +01:00
parent 7c28b58aaa
commit c102f10fab
8 changed files with 422 additions and 4 deletions
@@ -59,7 +59,7 @@ LNBITS_EXTENSIONS_DEFAULT_INSTALL="tpos"
 # LNBITS_EXT_GITHUB_TOKEN=github_pat_xxxxxxxxxxxxxxxxxx

 # which fundingsources are allowed in the admin ui
-# LNBITS_ALLOWED_FUNDING_SOURCES="VoidWallet, FakeWallet, CoreLightningWallet, CoreLightningRestWallet, LndRestWallet, EclairWallet, LndWallet, LnTipsWallet, LNPayWallet, LNbitsWallet, BlinkWallet, AlbyWallet, ZBDWallet, PhoenixdWallet, OpenNodeWallet, NWCWallet, BreezSdkWallet, BoltzWallet, StrikeWallet, CLNRestWallet"
+# LNBITS_ALLOWED_FUNDING_SOURCES="VoidWallet, FakeWallet, CoreLightningWallet, CoreLightningRestWallet, LndRestWallet, EclairWallet, LndWallet, LnTipsWallet, LNPayWallet, LNbitsWallet, BlinkWallet, AlbyWallet, ZBDWallet, PhoenixdWallet, OpenNodeWallet, NWCWallet, BreezSdkWallet, BoltzWallet, StrikeWallet, CLNRestWallet, SparkWallet, SparkL2Wallet"

 # uvicorn variable, allow https behind a proxy
 # IMPORTANT: this also needs the webserver to be configured to forward the headers
@@ -191,6 +191,8 @@ BOLTZ_CLIENT_MACAROON="/home/bob/.boltz/macaroons/admin.macaroon"
 # HEXSTRING instead of path also possible
 BOLTZ_CLIENT_CERT="/home/bob/.boltz/tls.cert"

+# TODO: add Spark
+
 # StrikeWallet
 STRIKE_API_ENDPOINT=https://api.strike.me/v1
 STRIKE_API_KEY=YOUR_STRIKE_API_KEY
@@ -50,6 +50,7 @@ Below is a side-by-side comparison of Lightning funding sources you can use with
 | **Blink**                      | Custodial                | ✅                  | Low                            | ❌                        | Low               | Provider-managed         | Easy              | Low                    | Transaction fees apply                       | Medium          | Third-party service; focuses on mobile integrations.                                       |
 | **ZBD**                        | Custodial                | ✅                  | Low                            | ❌                        | Low               | Provider-managed         | Easy              | Low                    | Transaction fees apply                       | Medium          | Gaming-focused payment platform.                                                           |
 | **Spark (CLN)**                | Self-custodial           | ❌                  | Higher                         | ✅                        | High              | Manual                   | Moderate          | High                   | Infrastructure cost and channel opening fees | High            | Web interface for CLN; requires Spark server setup.                                        |
+| **Spark (L2)**                 | Self-custodial           | ❌                  | Medium                         | ❌                        | Medium            | Automatic                | Easy              | Low                    | Minimal fees                                 | Medium          | Runs via Spark sidecar; seed-based self-custody.                                           |
 | **Cliche Wallet**              | Self-custodial           | ❌                  | Medium                         | ❌                        | Medium            | Manual                   | Moderate          | Moderate               | Minimal fees                                 | Medium          | Lightweight wallet; suitable for embedded systems.                                         |
 | **Strike**                     | Custodial                | ✅                  | Low                            | ❌                        | Low               | Provider-managed         | Easy              | Low                    | Transaction fees apply                       | Medium          | Third-party service; suitable for quick setups.                                            |
 | **LNPay**                      | Custodial                | ✅                  | Low                            | ❌                        | Low               | Provider-managed         | Easy              | Low                    | Transaction fees apply                       | Medium          | Third-party service; suitable for quick setups.                                            |
@@ -57,7 +58,9 @@ Below is a side-by-side comparison of Lightning funding sources you can use with
 | **LN.tips**                    | Custodial/Self-Custodial | Depends on provider | Medium                         | ❌                        | Low               | Provider-managed         | Moderate          | Low                    | Transaction fees may apply                   | Medium          | Simple hosted service; use LN.tips API as your backend.                                    |
 | **Fake Wallet**                | Testing (simulated)      | ❌                  | Low                            | ❌                        | N/A               | N/A                      | Easy              | Low                    | None (test only)                             | N/A             | For testing only; mints accounting units in LNbits (no real sats, unit name configurable). |

---
+## Spark (L2)
+
+Spark L2 uses a local Node.js sidecar to expose an HTTP API that LNbits can use as a funding source. It is self-custodial and secured by a standard mnemonic seed. You can let LNbits run the sidecar internally or run your own instance (see `https://github.com/lnbits/spark_sidecar`).

 ### Notes for readers

@@ -41,6 +41,7 @@ A backend wallet is selected and configured entirely through LNbits environment
 | [CoreLightning](#corelightning)                 | [LND (gRPC)](#lnd-grpc)               | [Blink](#blink)                                   |
 | [CoreLightning REST](#corelightning-rest)       | [LNbits](#lnbits)                     | [Alby](#alby)                                     |
 | [Spark (Core Lightning)](#spark-core-lightning) | [LNPay](#lnpay)                       | [Boltz](#boltz)                                   |
+| [Spark (L2)](#spark-l2)                         |                                       |                                                   |
 | [Cliche Wallet](#cliche-wallet)                 | [ZBD](#zbd)                           | [Phoenixd](#phoenixd)                             |
 | [Breez SDK](#breez-sdk)                         | [Breez Liquid SDK](#breez-liquid-sdk) | [Nostr Wallet Connect](#nostr-wallet-connect-nwc) |
 | [Strike](#strike)                               | [Eclair (ACINQ)](#eclair-acinq)       | [LN.tips](#lntips)                                |
@@ -52,7 +53,7 @@ A backend wallet is selected and configured entirely through LNbits environment

 ### CLNRest (using [runes](https://docs.corelightning.org/reference/lightning-createrune))

-[Core Lightning REST API docs](https://docs.corelightning.org/docs/rest)  
+[Core Lightning REST API docs](https://docs.corelightning.org/docs/rest)
 Should also work with the [Rust version of CLNRest](https://github.com/daywalker90/clnrest-rs)

 **Environment variables**
@@ -127,6 +128,47 @@ Old REST interface using [RTL c-lightning-REST](https://github.com/Ride-The-Ligh
 - `SPARK_URL`: `http://10.147.17.230:9737/rpc`
 - `SPARK_TOKEN`: `secret_access_key`

+## Spark (L2)
+
+Spark L2 is a self-custodial funding source that uses a small Node.js sidecar to talk to the Spark network and expose an HTTP API. You can let LNbits run the sidecar internally, or run it yourself and point LNbits at it.
+
+**Required env vars**
+
+- `LNBITS_BACKEND_WALLET_CLASS`: `SparkL2Wallet`
+
+**Internal sidecar (LNbits-managed)**
+
+- `SPARK_L2_INTERNAL_SIDECAR_VERSION`: `0.1.1`
+- `SPARK_L2_MNEMONIC`: `...` (optional; auto-generated if blank)
+- `SPARK_L2_NETWORK`: `MAINNET`
+
+Optional tuning:
+
+- `SPARK_L2_PAY_WAIT_MS`: `4000`
+- `SPARK_L2_PAY_POLL_MS`: `500`
+- `SPARK_L2_STREAM_KEEPALIVE_MS`: `15000`
+
+**External sidecar**
+
+- `SPARK_L2_EXTERNAL_ENDPOINT`: `http://127.0.0.1:8765`
+- `SPARK_L2_EXTERNAL_API_KEY`: `...` (if your sidecar requires auth)
+
+Example: run the sidecar manually (external mode)
+
+```bash
+git clone https://github.com/lnbits/spark_sidecar.git
+cd spark_sidecar
+npm install
+
+SPARK_MNEMONIC="bottom bottom bottom bottom bottom bottom bottom bottom bottom bottom bottom bottom" \
+SPARK_NETWORK=MAINNET \
+SPARK_SIDECAR_PORT=8765 \
+SPARK_PAY_WAIT_MS=20000 \
+node server.mjs
+```
+
+For testing, you can generate a 12-word mnemonic at `https://iancoleman.io/bip39/`. Store it securely — it controls your funds. Then select **Spark (L2)** as the funding source in LNbits.
+
 ## LND (REST)

 **Required env vars**
@@ -606,6 +606,15 @@ class SparkFundingSource(LNbitsSettings):
    spark_token: str | None = Field(default=None)


+class SparkL2FundingSource(LNbitsSettings):
+    spark_l2_network: str = Field(default="MAINNET")
+    spark_l2_external_endpoint: str | None = Field(default="http://localhost:8765")
+    spark_l2_external_api_key: str | None = Field(default=None)
+    spark_l2_pay_wait_ms: int = Field(default=4000, ge=0)
+    spark_l2_pay_poll_ms: int = Field(default=500, ge=0)
+    spark_l2_stream_keepalive_ms: int = Field(default=15000, ge=0)
+
+
 class LnTipsFundingSource(LNbitsSettings):
    lntips_api_endpoint: str | None = Field(default=None)
    lntips_api_key: str | None = Field(default=None)
@@ -711,6 +720,7 @@ class FundingSourcesSettings(
    PhoenixdFundingSource,
    OpenNodeFundingSource,
    SparkFundingSource,
+    SparkL2FundingSource,
    LnTipsFundingSource,
    NWCFundingSource,
    BreezSdkFundingSource,
@@ -1039,6 +1049,7 @@ class SuperUserSettings(LNbitsSettings):
            "FakeWallet",
            "LNPayWallet",
            "LNbitsWallet",
+            "SparkL2Wallet",
            "LnTipsWallet",
            "LndRestWallet",
            "LndWallet",
@@ -228,6 +228,43 @@ window.app.component('lnbits-admin-funding-sources', {
            spark_token: 'Token'
          }
        ],
+        [
+          'SparkL2Wallet',
+          'Spark (L2)',
+          {
+            spark_l2_external_endpoint: {
+              label: 'External Sidecar Endpoint',
+              hint: 'If specified then this endpoint will be used instead of the internal sidecar. Make sure to also specify the API key if your sidecar requires authentication.',
+              value: ''
+            },
+            spark_l2_external_api_key: {
+              label: 'External Sidecar API Key',
+              hint: 'API key for authenticating with the external sidecar if it requires authentication.',
+              value: ''
+            },
+            spark_l2_network: {
+              label: 'Network',
+              value: 'MAINNET',
+              hint: 'The network to use for the Spark wallet.',
+              advanced: true
+            },
+            spark_l2_pay_wait_ms: {
+              label: 'Payment Wait Time (ms)',
+              hint: 'The time to wait for a payment to be processed before considering it failed.',
+              advanced: true
+            },
+            spark_l2_pay_poll_ms: {
+              label: 'Payment Poll Time (ms)',
+              hint: 'The time to wait between polling for payment status updates.',
+              advanced: true
+            },
+            spark_l2_stream_keepalive_ms: {
+              label: 'Stream Keepalive Time (ms)',
+              hint: 'The time to wait between sending keepalive messages to the Spark sidecar to keep the connection open.',
+              advanced: true
+            }
+          }
+        ],
        [
          'NWCWallet',
          'Nostr Wallet Connect',
@@ -29,6 +29,7 @@ from .nwc import NWCWallet
 from .opennode import OpenNodeWallet
 from .phoenixd import PhoenixdWallet
 from .spark import SparkWallet
+from .sparkl2 import SparkL2Wallet
 from .strike import StrikeWallet
 from .void import VoidWallet
 from .zbd import ZBDWallet
@@ -75,6 +76,7 @@ __all__ = [
    "NWCWallet",
    "OpenNodeWallet",
    "PhoenixdWallet",
+    "SparkL2Wallet",
    "SparkWallet",
    "StrikeWallet",
    "VoidWallet",
@@ -0,0 +1,321 @@
+import asyncio
+import hashlib
+import json
+import uuid
+from collections.abc import AsyncGenerator
+from pathlib import Path
+from typing import Any, cast
+
+import httpx
+from bolt11 import decode as bolt11_decode
+from loguru import logger
+
+from lnbits.helpers import normalize_endpoint
+from lnbits.settings import settings
+
+from .base import (
+    InvoiceResponse,
+    PaymentFailedStatus,
+    PaymentPendingStatus,
+    PaymentResponse,
+    PaymentStatus,
+    PaymentSuccessStatus,
+    StatusResponse,
+    Wallet,
+)
+
+
+class SparkSidecarError(Exception):
+    pass
+
+
+class SparkL2Wallet(Wallet):
+    """
+    Spark L2 funding source via a local sidecar service.
+
+    Required settings/env:
+      - SPARK_L2_ENDPOINT (default http://127.0.0.1:8765)
+    Optional:
+      - SPARK_L2_API_KEY
+    """
+
+    def __init__(self):
+        self._status = "Initializing"
+        self._sidecar_path = Path(settings.lnbits_data_folder, "light_spark")
+
+        self.pending_invoices: list[str] = []
+
+        self.endpoint = "http://127.0.0.1:8765"
+        self._api_key = uuid.uuid4().hex
+
+        if settings.spark_l2_external_endpoint:
+            self.endpoint = normalize_endpoint(
+                cast(str, settings.spark_l2_external_endpoint)
+            )
+            logger.info(f"Using external Spark sidecar endpoint: {self.endpoint}")
+        else:
+            logger.error("No Spark sidecar endpoint configuration found.")
+
+        if settings.spark_l2_external_api_key:
+            self._api_key = cast(str, settings.spark_l2_external_api_key)
+            logger.info("Using external Spark sidecar API.")
+        else:
+            logger.warning("No Spark sidecar API key configured.")
+
+        headers = {"User-Agent": settings.user_agent, "X-Api-Key": self._api_key}
+
+        self.client = httpx.AsyncClient(
+            base_url=self.endpoint,
+            headers=headers,
+            timeout=60,
+        )
+
+    async def cleanup(self):
+        try:
+            await self.client.aclose()
+        except RuntimeError as e:
+            logger.warning(f"Error closing wallet connection: {e}")
+
+    async def status(self) -> StatusResponse:
+        try:
+            res = await self._request("POST", "/v1/balance")
+            balance_msat = res.get("balance_msat")
+            if balance_msat is not None:
+                return StatusResponse(None, int(balance_msat))
+            balance_sats = res.get("balance_sats")
+            if balance_sats is None:
+                return StatusResponse("Spark sidecar: missing balance.", 0)
+            return StatusResponse(None, int(balance_sats) * 1000)
+        except Exception as e:
+            logger.warning(e)
+            return StatusResponse(f"Spark sidecar status error: {e}", 0)
+
+    async def create_invoice(
+        self,
+        amount: int,
+        memo: str | None = None,
+        description_hash: bytes | None = None,
+        unhashed_description: bytes | None = None,
+        **kwargs,
+    ) -> InvoiceResponse:
+        expiry = kwargs.get("expiry")
+        expiry_secs = int(expiry) if expiry else None
+
+        description_hash_hex = None
+        if description_hash:
+            description_hash_hex = description_hash.hex()
+        elif unhashed_description:
+            description_hash_hex = hashlib.sha256(unhashed_description).hexdigest()
+
+        try:
+            payload = {
+                "amount_sats": int(amount),
+                "memo": (memo or "") if not description_hash_hex else None,
+                "description_hash": description_hash_hex,
+                "expiry_seconds": expiry_secs,
+            }
+            res = await self._request("POST", "/v1/invoices", payload)
+            bolt11 = res.get("payment_request")
+            checking_id = res.get("checking_id")
+            if not bolt11 or not checking_id:
+                return InvoiceResponse(
+                    ok=False,
+                    error_message="Spark sidecar invoice response missing fields.",
+                )
+            self.pending_invoices.append(checking_id)
+
+            return InvoiceResponse(
+                ok=True,
+                payment_request=bolt11,
+                checking_id=checking_id,
+                preimage=res.get("preimage", None),
+            )
+        except Exception as e:
+            return InvoiceResponse(ok=False, error_message=str(e))
+
+    async def pay_invoice(self, bolt11: str, fee_limit_msat: int) -> PaymentResponse:
+        try:
+            max_fee_sats = (int(fee_limit_msat) + 999) // 1000
+
+            payment_hash = None
+            try:
+                payment_hash = bolt11_decode(bolt11).payment_hash
+            except Exception as exc:
+                logger.warning(exc)
+                payment_hash = None
+            payload = {
+                "bolt11": bolt11,
+                "max_fee_sats": max_fee_sats,
+                "payment_hash": payment_hash,
+            }
+            res = await self._request("POST", "/v1/payments", payload)
+            checking_id = payment_hash or res.get("checking_id")
+            if not checking_id:
+                return PaymentResponse(
+                    ok=False,
+                    error_message="Spark sidecar payment response missing checking_id.",
+                )
+            status = res.get("status")
+            fee_msat = res.get("fee_msat")
+            ok = None
+            if status:
+                ok = self._map_payment_ok(status)
+            return PaymentResponse(
+                ok=ok,
+                checking_id=checking_id,
+                fee_msat=int(fee_msat) if fee_msat is not None else None,
+                preimage=res.get("preimage"),
+            )
+
+        except Exception as e:
+            return PaymentResponse(ok=False, error_message=str(e))
+
+    async def get_invoice_status(self, checking_id: str) -> PaymentStatus:
+        try:
+            res = await self._request("GET", f"/v1/invoices/{checking_id}")
+            status = res.get("status")
+            if not status:
+                return PaymentPendingStatus()
+            return self._map_invoice_status(status)
+        except Exception as exc:
+            logger.warning(exc)
+            return PaymentPendingStatus()
+
+    async def get_payment_status(self, checking_id: str) -> PaymentStatus:
+        try:
+            res = await self._request("GET", f"/v1/payments/{checking_id}")
+            status = res.get("status")
+            fee_msat = res.get("fee_msat")
+            preimage = res.get("preimage")
+            if not status:
+                return PaymentPendingStatus()
+            mapped = self._map_payment_status(status)
+            if mapped.success:
+                return PaymentSuccessStatus(
+                    fee_msat=int(fee_msat) if fee_msat is not None else None,
+                    preimage=preimage,
+                )
+            if mapped.failed:
+                return PaymentFailedStatus()
+            return PaymentPendingStatus()
+        except Exception as exc:
+            logger.warning(exc)
+            return PaymentPendingStatus()
+
+    async def paid_invoices_stream(self) -> AsyncGenerator[str, None]:
+        stream_path = "/v1/invoices/stream"
+        while settings.lnbits_running:
+            try:
+                async with self.client.stream("GET", stream_path, timeout=None) as r:
+                    if r.status_code in {404, 405}:
+                        logger.warning(
+                            "Spark sidecar invoice stream not available, "
+                            "falling back to polling."
+                        )
+                        async for checking_id in self._poll_pending_invoices():
+                            yield checking_id
+                        return
+                    r.raise_for_status()
+                    logger.info("connected to Spark sidecar invoice stream.")
+                    async for line in r.aiter_lines():
+                        if not line or not line.startswith("data:"):
+                            continue
+                        data = json.loads(line[5:].strip())
+                        checking_id = data.get("checking_id")
+                        if not checking_id:
+                            continue
+                        yield checking_id
+            except Exception as exc:
+                logger.error(
+                    "lost connection to Spark sidecar invoice stream: "
+                    f"'{exc}' retrying in 5 seconds"
+                )
+                await asyncio.sleep(5)
+
+    async def _request(
+        self, method: str, path: str, json_data: dict[str, Any] | None = None
+    ) -> dict[str, Any]:
+        error_message = None
+        try:
+            r = await self.client.request(method, path, json=json_data)
+            r.raise_for_status()
+            j = r.json()
+        except (httpx.RequestError, httpx.HTTPStatusError, json.JSONDecodeError) as exc:
+            if isinstance(exc, httpx.HTTPStatusError) and exc.response is not None:
+                try:
+                    error_json = exc.response.json()
+                    if "error" in error_json:
+                        error_message = error_json["error"]
+                except Exception as json_exc:
+                    logger.error(
+                        f"Failed to parse Spark error response as JSON: {json_exc}"
+                    )
+            raise SparkSidecarError(
+                error_message or f"Spark sidecar request error: '{exc}'"
+            ) from exc
+
+        if error_message or j.get("error"):
+            raise SparkSidecarError(
+                error_message or f"Spark sidecar error: {j['error']}"
+            )
+        return j
+
+    async def _poll_pending_invoices(self) -> AsyncGenerator[str, None]:
+        while settings.lnbits_running:
+            for invoice in list(self.pending_invoices):
+                try:
+                    status = await self.get_invoice_status(invoice)
+                    if status.paid:
+                        yield invoice
+                        self.pending_invoices.remove(invoice)
+                    elif status.failed:
+                        self.pending_invoices.remove(invoice)
+                except Exception as exc:
+                    logger.error(f"could not get status of invoice {invoice}: '{exc}' ")
+            await asyncio.sleep(5)
+
+    def _map_invoice_status(self, status: str) -> PaymentStatus:
+        success = {
+            "LIGHTNING_PAYMENT_RECEIVED",
+            "TRANSFER_COMPLETED",
+            "PAYMENT_PREIMAGE_RECOVERED",
+        }
+        failed = {
+            "TRANSFER_FAILED",
+            "PAYMENT_PREIMAGE_RECOVERING_FAILED",
+            "REFUND_SIGNING_FAILED",
+            "REFUND_SIGNING_COMMITMENTS_QUERYING_FAILED",
+            "TRANSFER_CREATION_FAILED",
+        }
+        if status in success:
+            return PaymentSuccessStatus()
+        if status in failed:
+            return PaymentFailedStatus()
+        return PaymentPendingStatus()
+
+    def _map_payment_status(self, status: str) -> PaymentStatus:
+        success = {
+            "LIGHTNING_PAYMENT_SUCCEEDED",
+            "TRANSFER_COMPLETED",
+            "PREIMAGE_PROVIDED",
+        }
+        failed = {
+            "LIGHTNING_PAYMENT_FAILED",
+            "TRANSFER_FAILED",
+            "PREIMAGE_PROVIDING_FAILED",
+            "USER_TRANSFER_VALIDATION_FAILED",
+            "USER_SWAP_RETURN_FAILED",
+        }
+        if status in success:
+            return PaymentSuccessStatus()
+        if status in failed:
+            return PaymentFailedStatus()
+        return PaymentPendingStatus()
+
+    def _map_payment_ok(self, status: str) -> bool | None:
+        mapped = self._map_payment_status(status)
+        if mapped.success:
+            return True
+        if mapped.failed:
+            return False
+        return None