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Roasbeef merged 1 commit into from
Mar 15, 2019
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docs: move out architecture diagram #15

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57 changes: 7 additions & 50 deletions README.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -43,56 +43,13 @@ problems. Community support is also available in the
[LND Slack](https://join.slack.com/t/lightningcommunity/shared_invite/enQtMzQ0OTQyNjE5NjU1LWRiMGNmOTZiNzU0MTVmYzc1ZGFkZTUyNzUwOGJjMjYwNWRkNWQzZWE3MTkwZjdjZGE5ZGNiNGVkMzI2MDU4ZTE)
.

## Loop Out Swap (off -> on-chain)

```
loop out 500
|
|
v
.-----------------------------.
| Loop CLI |
| ./cmd/loop |
| |
| |
| .-------------------. | .--------------. .---------------.
| | Loop Client (lib) | | | LND node | | Bitcoin node |
| | ./ |<-------------| |-------------------| |
| | | | | | on-chain | |
| | |------------->| | htlc | |
| | | | off-chain | | | |
| '-------------------' | htlc '--------------' '---------------'
'-----------------|-----------' | ^
| | |
| v |
| .--. .--.
| _ -( )- _ _ -( )- _
| .--,( ),--. .--,( ),--.
initiate| _.-( )-._ _.-( )-._
swap | ( LIGHTNING NETWORK ) ( BITCOIN NETWORK )
| '-._( )_.-' '-._( )_.-'
| '__,( ),__' '__,( ),__'
| - ._(__)_. - - ._(__)_. -
| | ^
| | |
v v |
.--------------------. off-chain .--------------. .---------------.
| Loop Server | htlc | LND node | | Bitcoin node |
| |<-------------| | | |
| | | | on-chain | |
| | | | htlc | |
| |--------------| |----------------->| |
| | | | | |
'--------------------' '--------------' '---------------'

```

## Setup

LND and the swaplet are using go modules. Make sure that the `GO111MODULE` env
variable is set to `on`.

In order to execute a swap, LND needs to be rebuilt with sub servers enabled.
## Setup and Install

LND and the loop client are using Go modules. Make sure that the `GO111MODULE`
env variable is set to `on`.

In order to execute a swap, LND will need to be rebuilt with sub servers
enabled.

### LND

Expand Down
67 changes: 67 additions & 0 deletions docs/architecture.md
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@@ -0,0 +1,67 @@
# Loop Architecture

Lightning Loop's architecture for orchestrating submarine swaps is based on a
client/server concept.

The client has a swap execution daemon `loopd` controlled by a CLI application
`loop` which uses a gRPC API. The client daemon initiates swaps and handles
their progress through swap phases. To manage keys and the connection to the
LN/BTC network layers the client daemon connects to a local lnd wallet.

Client daemons communicate with the Loop server daemon, which is opaque but
operates in a similar way. The server is not a trusted component in this
architecture; the client daemon validates that the terms of the swap are
acceptable and the server cannot access the swap funds unless the swap enters
the "complete" phase.

## Loop Out Swap (off -> on-chain)

Phases:

1. Initiation: Client queries for terms of a swap
2. Fee: Client sends a small fee HTLC that is unrestricted
3. Funding: Client sends a funding HTLC locked to a preimage they generate
4. Payment: Server sends the funds on-chain locked to the funding preimage hash
5. Complete: Client uses the preimage to take the on-chain funds.
6. Final: The server uses the on-chain-revealed preimage to claim funding HTLC

```
loop out 500
|
|
v
.-----------------------------.
| Loop CLI |
| ./cmd/loop |
| |
| |
| .-------------------. | .--------------. .---------------.
| | Loop Client (lib) | | | LND node | | Bitcoin node |
| | ./ |<-------------| |-------------------| |
| | | | | | on-chain | |
| | |------------->| | htlc | |
| | | | off-chain | | | |
| '-------------------' | htlc '--------------' '---------------'
'-----------------|-----------' | ^
| | |
| v |
| .--. .--.
| _ -( )- _ _ -( )- _
| .--,( ),--. .--,( ),--.
initiate| _.-( )-._ _.-( )-._
swap | ( LIGHTNING NETWORK ) ( BITCOIN NETWORK )
| '-._( )_.-' '-._( )_.-'
| '__,( ),__' '__,( ),__'
| - ._(__)_. - - ._(__)_. -
| | ^
| | |
v v |
.--------------------. off-chain .--------------. .---------------.
| Loop Server | htlc | LND node | | Bitcoin node |
| |<-------------| | | |
| | | | on-chain | |
| | | | htlc | |
| |--------------| |----------------->| |
| | | | | |
'--------------------' '--------------' '---------------'
```