staticaddr: multi-address support

.golangci.yml

@@ -3,7 +3,7 @@ run:
   go: "1.26"
 
   # timeout for analysis
-  timeout: 4m
+  timeout: 8m
 
 linters:
   default: all

README.md

@@ -64,6 +64,28 @@ To execute a Loop In:
 loop in <amt_in_satoshis>
 ```
 
+### Static Address Recovery
+Loop now keeps at most one encrypted immutable recovery backup per paid L402
+generation in the active network data directory. A backup is written only after
+Loop has both the paid `l402.token` and the concrete static-address parameters
+for that generation.
+
+The backup is encrypted with a key derived by the backing `lnd` wallet. It is
+therefore only useful with that same `lnd` instance, or with an `lnd` restored
+from the same seed/key material. The Loop backup file alone is not enough to
+recover static-address access.
+
+Existing static-address users get this backup backfilled on the next startup
+with the upgraded client. A fresh install that has no local L402 or
+static-address state first checks for an existing recovery backup in the active
+network directory. If none is restored, startup materializes the initial
+paid-L402/static-address generation and writes its backup.
+
+The follow-up multi-address work is expected to keep this one-backup-per-L402
+model and use the deterministic receive/change key-family metadata already
+stored in the backup. See [recovery/README.md](./recovery/README.md) for the
+full recovery model and the planned multi-address outlook.
+
 ### More info
 
 - [Loop FAQs](./docs/faqs.md)

cmd/loop/main.go

@@ -97,7 +97,8 @@ var (
 		monitorCommand, quoteCommand, listAuthCommand, fetchL402Command,
 		listSwapsCommand, swapInfoCommand, getLiquidityParamsCommand,
 		setLiquidityRuleCommand, suggestSwapCommand, setParamsCommand,
-		getInfoCommand, abandonSwapCommand, reservationsCommands,
+		getInfoCommand, abandonSwapCommand, recoverCommand,
+		reservationsCommands,
 		instantOutCommand, listInstantOutsCommand, stopCommand,
 		printManCommand, printMarkdownCommand,
 	}

cmd/loop/recover.go

@@ -0,0 +1,50 @@
+package main
+
+import (
+	"context"
+
+	"github.com/lightninglabs/loop/looprpc"
+	"github.com/urfave/cli/v3"
+)
+
+var recoverCommand = &cli.Command{
+	Name:  "recover",
+	Usage: "restore static address and L402 state from a local backup file",
+	Description: "Restores the local static-address state and L402 token " +
+		"from an encrypted backup file. If --backup_file is omitted, " +
+		"loopd selects the latest decryptable active-network backup " +
+		"candidate and fully validates it before restoring state.",
+	Flags: []cli.Flag{
+		&cli.StringFlag{
+			Name: "backup_file",
+			Usage: "path to an encrypted backup file; if omitted, " +
+				"loopd selects and validates the latest active-network " +
+				"backup candidate",
+		},
+	},
+	Action: runRecover,
+}
+
+func runRecover(ctx context.Context, cmd *cli.Command) error {
+	if cmd.NArg() > 0 {
+		return showCommandHelp(ctx, cmd)
+	}
+
+	client, cleanup, err := getClient(cmd)
+	if err != nil {
+		return err
+	}
+	defer cleanup()
+
+	resp, err := client.Recover(
+		ctx, &looprpc.RecoverRequest{
+			BackupFile: cmd.String("backup_file"),
+		},
+	)
+	if err != nil {
+		return err
+	}
+
+	printRespJSON(resp)
+	return nil
+}