Module htlc 

Direct HTLC API

This module exposes the outgoing contract of the LNv2 module as a plain HTLC between two clients of the same federation, without any Lightning gateway involvement. This enables atomic swaps with counterparties outside the federation’s Lightning infrastructure, e.g. swaps with other chains or currencies.

The funder locks ecash to the counterparty’s claim key via LightningClientModule::create_htlc. The counterparty verifies the funding via LightningClientModule::await_htlc_funded and resolves the HTLC with the preimage via LightningClientModule::claim_htlc, which reveals the preimage to the funder via LightningClientModule::await_htlc_resolution. A failed HTLC is either cancelled cooperatively before its expiration with the counterparty’s forfeit signature via LightningClientModule::cancel_htlc, or refunded unilaterally after its expiration via LightningClientModule::refund_htlc.

All coordination data - the contract, its funding outpoint and the forfeit signature - is exchanged between the two parties out of band; the CLI and the JSON representation of this data are documented in docs/lightning_module_v2.md. The contract expiration is measured in block count as tracked by the federation’s consensus, not in unix time.

Structs

CreateHtlcOperationMeta

Metadata of an operation funding a direct HTLC via LightningClientModule::create_htlc.

HtlcSpend 🔒

The parameters of a transaction spending a direct HTLC; see LightningClientModule::spend_htlc. The witness is the action taken on the contract, from which the operation id and the operation meta of the spend are derived.

SpendHtlcOperationMeta

Metadata of an operation spending a direct HTLC: a claim via LightningClientModule::claim_htlc, a refund via LightningClientModule::refund_htlc or a cancellation via LightningClientModule::cancel_htlc.

Enums

HtlcError

Errors of the direct HTLC operations; see LightningClientModule::create_htlc.

Functions

is_transient 🔒

Whether a federation error is caused by connection failures only, such that retrying the request may succeed.