breez-sdk-docs/src/guide/connecting_lsp.md

Connecting to an LSP

Based on the API key provided to the Breez SDK, a default LSP is selected for your node to provide liquidity to it. To get the information about the selected LSP you can do the following:

Rust

{{#include ../../snippets/rust/src/connecting_lsp.rs:get-lsp-info}}

Swift

do {
    let lspId = try sdk.lspId() 
    let lspInfo = try sdk.lspInfo()
} catch {
    // Handle error
}

Kotlin

try {
    val lspId = sdk.lspId()
    if (lspId != null) {
        val lspInfo = sdk.lspInfo()
    } else {
        // Handle no lsp id scenario
    }
} catch (e: Exception) {
    // Handle error
}

React Native

{{#include ../../snippets/react-native/connecting_lsp.ts:get-lsp-info}}

Dart

{{#include ../../snippets/dart_snippets/lib/connecting_lsp.dart:get-lsp-info}}

Python

try: 
    lsp_id = sdk_services.lsp_id()
    lsp_info = sdk_services.lsp_info()
   
except Exception as error:
    # Handle error

Go

{{#include ../../snippets/go/connecting_lsp.go:get-lsp-info}}

C#

{{#include ../../snippets/csharp/ConnectingLsp.cs:get-lsp-info}}

When you have selected an LSP you may then connect to it.

Rust

{{#include ../../snippets/rust/src/connecting_lsp.rs:connect-lsp}}

Swift

do {
    try sdk.connectLsp(lspId: lspId!)
} catch {
    // Handle error
}

Kotlin

try {
    sdk.connectLsp(lspId)
} catch (e: Exception) {
    // Handle error
}

React Native

{{#include ../../snippets/react-native/connecting_lsp.ts:connect-lsp}}

Dart

{{#include ../../snippets/dart_snippets/lib/connecting_lsp.dart:connect-lsp}}

Python

try: 
    sdk_services.connect_lsp(lsp_id)
except Exception as error:
    # Handle error

Go

{{#include ../../snippets/go/connecting_lsp.go:connect-lsp}}

C#

{{#include ../../snippets/csharp/ConnectingLsp.cs:connect-lsp}}

Channel Opening Fees

Some Breez SDK operations¹ may need opening a new channel with the LSP. The SDK supports the LSP2 dynamic fees spec² , which describes how these channel opening fees are handled.

For the client, the key points are:

• The LspInformation can be fetched at any point and includes a list of channel opening fees and the duration for which they are valid. The fees are sorted from cheapest to most expensive. The higher fees are typically also valid for longer.
• Depending on the application and use-case, the client may choose an appropriate fee and give it as an argument in the relevant Breez SDK method. If this fee argument is not provided, Breez SDK will choose an appropriate one instead.

The channel opening fees are provided in a structure³ that includes the conditions associated with these fees, like the minimum invoice amount or the date and time until when this opening fee is valid.

---

---

1. See the service methods receive_payment, receive_onchain or buy_bitcoin. ↩︎

2. https://github.com/BitcoinAndLightningLayerSpecs/lsp/tree/main/LSPS2 ↩︎

3. https://breez.github.io/breez-sdk/breez_sdk_core/struct.OpeningFeeParams.html ↩︎