cmd/loop: expose both taproot channel types

LND v0.21 added the production TAPROOT commitment type while SIMPLE_TAPROOT remains available as the legacy enum. The static open-channel CLI previously used "taproot" for SIMPLE_TAPROOT. Keep both choices available by renaming that legacy spelling to "simple-taproot" and mapping "taproot" to TAPROOT. This makes the CLI spelling match the channel type it requests while still leaving an explicit path for users that need SIMPLE_TAPROOT.
2026-08-13 12:33:03 +02:00 · 2026-06-20 18:33:48 -05:00 · 2026-06-20 18:33:48 -05:00 · 682d45405c
commit 682d45405c
parent 5d8a5019cf
8 changed files with 275 additions and 10 deletions
--- a/cmd/loop/openchannel.go
+++ b/cmd/loop/openchannel.go
@ -13,13 +13,11 @@ import (
 )

 const (
-	defaultUtxoMinConf = 1
-)
-
-var (
+	defaultUtxoMinConf       = 1
 	channelTypeTweakless     = "tweakless"
 	channelTypeAnchors       = "anchors"
-	channelTypeSimpleTaproot = "taproot"
+	channelTypeSimpleTaproot = "simple-taproot"
+	channelTypeTaproot       = "taproot"
 )

 var openChannelCommand = &cli.Command{
@ -137,9 +135,9 @@ var openChannelCommand = &cli.Command{
 		&cli.StringFlag{
 			Name: "channel_type",
 			Usage: fmt.Sprintf("(optional) the type of channel to "+
-				"propose to the remote peer (%q, %q, %q)",
+				"propose to the remote peer (%q, %q, %q, %q)",
 				channelTypeTweakless, channelTypeAnchors,
-				channelTypeSimpleTaproot),
+				channelTypeSimpleTaproot, channelTypeTaproot),
 		},
 		&cli.BoolFlag{
 			Name: "zero_conf",
@ -322,6 +320,7 @@ func openChannel(ctx context.Context, cmd *cli.Command) error {
 	switch channelType {
 	case "":
 		break
+
 	case channelTypeTweakless:
 		req.CommitmentType = lnrpc.CommitmentType_STATIC_REMOTE_KEY

@ -330,6 +329,10 @@ func openChannel(ctx context.Context, cmd *cli.Command) error {

 	case channelTypeSimpleTaproot:
 		req.CommitmentType = lnrpc.CommitmentType_SIMPLE_TAPROOT
+
+	case channelTypeTaproot:
+		req.CommitmentType = lnrpc.CommitmentType_TAPROOT
+
 	default:
 		return fmt.Errorf("unsupported channel type %v", channelType)
 	}
--- a/cmd/loop/testdata/sessions/static-openchannel/01_loop-static-openchannel-help.json
+++ b/cmd/loop/testdata/sessions/static-openchannel/01_loop-static-openchannel-help.json
@ -67,7 +67,7 @@
          "   --max_local_csv uint                    (optional) the maximum number of blocks that we will allow the remote peer to require we wait before accessing our funds in the case of a unilateral close. (default: 0)\n",
          "   --close_address string                  (optional) an address to enforce payout of our funds to on cooperative close. Note that if this value is set on channel open, you will *not* be able to cooperatively close to a different address.\n",
          "   --remote_max_value_in_flight_msat uint  (optional) the maximum value in msat that can be pending within the channel at any given time (default: 0)\n",
-          "   --channel_type string                   (optional) the type of channel to propose to the remote peer (\"tweakless\", \"anchors\", \"taproot\")\n",
+          "   --channel_type string                   (optional) the type of channel to propose to the remote peer (\"tweakless\", \"anchors\", \"simple-taproot\", \"taproot\")\n",
          "   --zero_conf                             (optional) whether a zero-conf channel open should be attempted. (default: false)\n",
          "   --scid_alias                            (optional) whether a scid-alias channel type should be negotiated. (default: false)\n",
          "   --remote_reserve_sats uint              (optional) the minimum number of satoshis we require the remote node to keep as a direct payment. If not specified, a default of 1% of the channel capacity will be used. (default: 0)\n",
--- a/cmd/loop/testdata/sessions/static-openchannel/07_loop-static-openchannel-taproot-success.json
+++ b/cmd/loop/testdata/sessions/static-openchannel/07_loop-static-openchannel-taproot-success.json
@ -0,0 +1,104 @@
+{
+  "metadata": {
+    "args": [
+      "/home/user/bin/loop",
+      "--rpcserver=localhost:11010",
+      "--loopdir=/redacted/loop",
+      "--tlscertpath=/redacted/loop/regtest/tls.cert",
+      "--macaroonpath=/redacted/loop/regtest/loop.macaroon",
+      "static",
+      "openchannel",
+      "--node_key",
+      "03465f68fd39358667678f8353a31e0d99475e3fd2fb4e58daf7dbfabe04c011f4",
+      "--fundmax",
+      "--utxo",
+      "89f6fd2ee96445c6e48278e7eaaca7de8e342904f20609ce72c0d27afb443e2d:1",
+      "--channel_type",
+      "taproot",
+      "--private",
+      "--network",
+      "regtest"
+    ],
+    "env": {},
+    "version": "0.33.2-beta commit=v0.33.2-beta-bump-lnd-21-a-7-g21019e684ed06e2267382f473dfeaafb81a33310 commit_hash=21019e684ed06e2267382f473dfeaafb81a33310",
+    "duration": 295879956,
+    "clock_start_unix": 1782002722
+  },
+  "events": [
+    {
+      "time_ms": 2,
+      "kind": "grpc",
+      "data": {
+        "method": "/looprpc.SwapClient/StaticOpenChannel",
+        "event": "request",
+        "message_type": "looprpc.StaticOpenChannelRequest",
+        "payload": {
+          "open_channel_request": {
+            "sat_per_vbyte": "0",
+            "node_pubkey": "A0ZfaP05NYZnZ4+DU6MeDZlHXj/S+05Y2vfb+r4EwBH0",
+            "node_pubkey_string": "",
+            "local_funding_amount": "0",
+            "push_sat": "0",
+            "target_conf": 0,
+            "sat_per_byte": "0",
+            "private": true,
+            "min_htlc_msat": "0",
+            "remote_csv_delay": 0,
+            "min_confs": 1,
+            "spend_unconfirmed": false,
+            "close_address": "",
+            "funding_shim": null,
+            "remote_max_value_in_flight_msat": "0",
+            "remote_max_htlcs": 0,
+            "max_local_csv": 0,
+            "commitment_type": "TAPROOT",
+            "zero_conf": false,
+            "scid_alias": false,
+            "base_fee": "0",
+            "fee_rate": "0",
+            "use_base_fee": false,
+            "use_fee_rate": false,
+            "remote_chan_reserve_sat": "0",
+            "fund_max": true,
+            "memo": "",
+            "outpoints": [
+              {
+                "txid_bytes": "",
+                "txid_str": "89f6fd2ee96445c6e48278e7eaaca7de8e342904f20609ce72c0d27afb443e2d",
+                "output_index": 1
+              }
+            ]
+          }
+        }
+      }
+    },
+    {
+      "time_ms": 295,
+      "kind": "grpc",
+      "data": {
+        "method": "/looprpc.SwapClient/StaticOpenChannel",
+        "event": "response",
+        "message_type": "looprpc.StaticOpenChannelResponse",
+        "payload": {
+          "channel_open_outpoint": "302a41b53946494306e415bdf4724e88b2cf2b37ad2f36dc075db00cc6499e9f:0"
+        }
+      }
+    },
+    {
+      "time_ms": 295,
+      "kind": "stdout",
+      "data": {
+        "lines": [
+          "{\n",
+          "    \"channel_open_outpoint\": \"302a41b53946494306e415bdf4724e88b2cf2b37ad2f36dc075db00cc6499e9f:0\"\n",
+          "}\n"
+        ]
+      }
+    },
+    {
+      "time_ms": 295,
+      "kind": "exit",
+      "data": {}
+    }
+  ]
+}
--- a/cmd/loop/testdata/sessions/static-openchannel/08_loop-static-openchannel-taproot-unsupported-lnd.json
+++ b/cmd/loop/testdata/sessions/static-openchannel/08_loop-static-openchannel-taproot-unsupported-lnd.json
@ -0,0 +1,106 @@
+{
+  "metadata": {
+    "args": [
+      "/home/user/bin/loop",
+      "--rpcserver=localhost:11010",
+      "--loopdir=/redacted/loop",
+      "--tlscertpath=/redacted/loop/regtest/tls.cert",
+      "--macaroonpath=/redacted/loop/regtest/loop.macaroon",
+      "static",
+      "openchannel",
+      "--node_key",
+      "026eca9330cc3e589505c4a240ea1f7f551e5765b1aae9040c6667141da657eae6",
+      "--fundmax",
+      "--utxo",
+      "dc942b3252ded50abc30ef4e8614d392ab0f091acab75fdd09e18a07f6ac36e6:0",
+      "--channel_type",
+      "taproot",
+      "--private",
+      "--network",
+      "regtest"
+    ],
+    "env": {},
+    "version": "0.33.3-beta commit= commit_hash=",
+    "run_error": "rpc error: code = Unknown desc = channel_type=taproot is not supported by the connected lnd; update LND to v0.21.0-beta or later to use this channel type: got error from server: rpc error: code = Unknown desc = unhandled request channel type 7",
+    "duration": 39639744,
+    "clock_start_unix": 1782158339
+  },
+  "events": [
+    {
+      "time_ms": 7,
+      "kind": "grpc",
+      "data": {
+        "method": "/looprpc.SwapClient/StaticOpenChannel",
+        "event": "request",
+        "message_type": "looprpc.StaticOpenChannelRequest",
+        "payload": {
+          "open_channel_request": {
+            "sat_per_vbyte": "0",
+            "node_pubkey": "Am7KkzDMPliVBcSiQOoff1UeV2WxqukEDGZnFB2mV+rm",
+            "node_pubkey_string": "",
+            "local_funding_amount": "0",
+            "push_sat": "0",
+            "target_conf": 0,
+            "sat_per_byte": "0",
+            "private": true,
+            "min_htlc_msat": "0",
+            "remote_csv_delay": 0,
+            "min_confs": 1,
+            "spend_unconfirmed": false,
+            "close_address": "",
+            "funding_shim": null,
+            "remote_max_value_in_flight_msat": "0",
+            "remote_max_htlcs": 0,
+            "max_local_csv": 0,
+            "commitment_type": "TAPROOT",
+            "zero_conf": false,
+            "scid_alias": false,
+            "base_fee": "0",
+            "fee_rate": "0",
+            "use_base_fee": false,
+            "use_fee_rate": false,
+            "remote_chan_reserve_sat": "0",
+            "fund_max": true,
+            "memo": "",
+            "outpoints": [
+              {
+                "txid_bytes": "",
+                "txid_str": "dc942b3252ded50abc30ef4e8614d392ab0f091acab75fdd09e18a07f6ac36e6",
+                "output_index": 0
+              }
+            ]
+          }
+        }
+      }
+    },
+    {
+      "time_ms": 39,
+      "kind": "grpc",
+      "data": {
+        "method": "/looprpc.SwapClient/StaticOpenChannel",
+        "event": "error",
+        "error": "rpc error: code = Unknown desc = channel_type=taproot is not supported by the connected lnd; update LND to v0.21.0-beta or later to use this channel type: got error from server: rpc error: code = Unknown desc = unhandled request channel type 7",
+        "status": {
+          "code": 2,
+          "message": "channel_type=taproot is not supported by the connected lnd; update LND to v0.21.0-beta or later to use this channel type: got error from server: rpc error: code = Unknown desc = unhandled request channel type 7"
+        }
+      }
+    },
+    {
+      "time_ms": 39,
+      "kind": "stderr",
+      "data": {
+        "lines": [
+          "[loop] rpc error: code = Unknown desc = channel_type=taproot is not supported by the connected lnd; update LND to v0.21.0-beta or later to use this channel type: got error from server: rpc error: code = Unknown desc = unhandled request channel type 7\n"
+        ]
+      }
+    },
+    {
+      "time_ms": 39,
+      "kind": "exit",
+      "data": {
+        "run_error": "rpc error: code = Unknown desc = channel_type=taproot is not supported by the connected lnd; update LND to v0.21.0-beta or later to use this channel type: got error from server: rpc error: code = Unknown desc = unhandled request channel type 7"
+      }
+    }
+  ]
+}
--- a/docs/loop.1
+++ b/docs/loop.1
@ -589,7 +589,7 @@ Open a channel to an existing peer.
 \fB--base_fee_msat\fP="": the base fee in milli-satoshis that will be charged for each forwarded HTLC, regardless of payment size (default: 0)

 .PP
-\fB--channel_type\fP="": (optional) the type of channel to propose to the remote peer ("tweakless", "anchors", "taproot")
+\fB--channel_type\fP="": (optional) the type of channel to propose to the remote peer ("tweakless", "anchors", "simple-taproot", "taproot")

 .PP
 \fB--close_address\fP="": (optional) an address to enforce payout of our funds to on cooperative close. Note that if this value is set on channel open, you will \fInot\fP be able to cooperatively close to a different address.
--- a/docs/loop.md
+++ b/docs/loop.md
@ -715,7 +715,7 @@ The following flags are supported:
 | `--max_local_csv="…"`                   | (optional) the maximum number of blocks that we will allow the remote peer to require we wait before accessing our funds in the case of a unilateral close                                                                                                                                                            | uint   |      `0`      |
 | `--close_address="…"`                   | (optional) an address to enforce payout of our funds to on cooperative close. Note that if this value is set on channel open, you will *not* be able to cooperatively close to a different address                                                                                                                    | string |
 | `--remote_max_value_in_flight_msat="…"` | (optional) the maximum value in msat that can be pending within the channel at any given time                                                                                                                                                                                                                         | uint   |      `0`      |
-| `--channel_type="…"`                    | (optional) the type of channel to propose to the remote peer ("tweakless", "anchors", "taproot")                                                                                                                                                                                                                      | string |
+| `--channel_type="…"`                    | (optional) the type of channel to propose to the remote peer ("tweakless", "anchors", "simple-taproot", "taproot")                                                                                                                                                                                                    | string |
 | `--zero_conf`                           | (optional) whether a zero-conf channel open should be attempted                                                                                                                                                                                                                                                       | bool   |    `false`    |
 | `--scid_alias`                          | (optional) whether a scid-alias channel type should be negotiated                                                                                                                                                                                                                                                     | bool   |    `false`    |
 | `--remote_reserve_sats="…"`             | (optional) the minimum number of satoshis we require the remote node to keep as a direct payment. If not specified, a default of 1% of the channel capacity will be used                                                                                                                                              | uint   |      `0`      |
--- a/staticaddr/openchannel/manager.go
+++ b/staticaddr/openchannel/manager.go
@ -368,6 +368,7 @@ func (m *Manager) OpenChannel(ctx context.Context,
 	if err == nil {
 		return chanOutpoint, nil
 	}
+	err = maybeWrapTaprootUnsupportedError(reqClone, err)

 	log.Infof("error opening channel: %v", err)

@ -782,6 +783,30 @@ func resolveCommitmentType(commitmentType lnrpc.CommitmentType) (
 	}
 }

+// maybeWrapTaprootUnsupportedError turns lnd's generic unknown channel type
+// error into a user-actionable message for Loop's production taproot channel
+// type.
+func maybeWrapTaprootUnsupportedError(req *lnrpc.OpenChannelRequest,
+	err error) error {
+
+	if err == nil || req.CommitmentType != lnrpc.CommitmentType_TAPROOT {
+		return err
+	}
+
+	errMsg := strings.ToLower(err.Error())
+	switch {
+	case strings.Contains(errMsg, "unhandled request channel type"),
+		strings.Contains(errMsg, "unknown channel type"),
+		strings.Contains(errMsg, "unsupported channel type"):
+
+		return fmt.Errorf("channel_type=taproot is not supported "+
+			"by the connected lnd; update LND to v0.21.0-beta "+
+			"or later to use this channel type: %w", err)
+	}
+
+	return err
+}
+
 // checkPsbtFlags make sure a request to open a channel doesn't set any
 // parameters that are incompatible with the PSBT funding flow.
 func checkPsbtFlags(req *lnrpc.OpenChannelRequest) error {
--- a/staticaddr/openchannel/manager_test.go
+++ b/staticaddr/openchannel/manager_test.go
@ -601,6 +601,33 @@ func TestResolveCommitmentType(t *testing.T) {
 	}
 }

+// TestMaybeWrapTaprootUnsupportedError verifies that generic old-lnd channel
+// type rejections become actionable for Loop users selecting production
+// taproot channels.
+func TestMaybeWrapTaprootUnsupportedError(t *testing.T) {
+	t.Parallel()
+
+	baseErr := errors.New("got error from server: rpc error: " +
+		"code = Unknown desc = unhandled request channel type 7")
+	req := &lnrpc.OpenChannelRequest{
+		CommitmentType: lnrpc.CommitmentType_TAPROOT,
+	}
+
+	err := maybeWrapTaprootUnsupportedError(req, baseErr)
+	require.ErrorContains(
+		t, err, "channel_type=taproot is not supported",
+	)
+	require.ErrorContains(
+		t, err, "update LND to v0.21.0-beta or later",
+	)
+	require.ErrorIs(t, err, baseErr)
+
+	req.CommitmentType = lnrpc.CommitmentType_SIMPLE_TAPROOT
+	err = maybeWrapTaprootUnsupportedError(req, baseErr)
+	require.ErrorIs(t, err, baseErr)
+	require.NotContains(t, err.Error(), "update LND")
+}
+
 // ---------------------------------------------------------------------------
 // Mock types for PSBT channel open flow tests.
 // ---------------------------------------------------------------------------