# Troubleshooting

> Fixes for common BasicSwap problems: reindexing a coin, running on older Python versions, installing natively on Windows and reaching a node over an SSH tunnel.

This page collects fixes for problems that come up when installing or running BasicSwap, most of them from the project's own notes. If yours isn't here, ask in the [BasicSwap Matrix room](https://matrix.to/#/#basicswap:matrix.org) with the error from your terminal.

## A coin daemon won't start or its chain is corrupt

A crash or a full disk can leave a coin's blockchain database damaged, so its daemon stops at startup. Rebuilding the database with `-reindex` usually fixes it. With BasicSwap stopped, start only that coin with the extra option, and let it finish:

**From source**

```bash
export SWAP_DATADIR=$HOME/coinswaps
. $SWAP_DATADIR/venv/bin/activate
basicswap-run --datadir=$SWAP_DATADIR --startonlycoin=litecoin --extracoinopts="-reindex"
```

**Docker**

```bash
docker-compose run --rm swapclient basicswap-run --datadir=/coindata --startonlycoin=litecoin --extracoinopts="-reindex"
```

Reindexing reads the whole chain again and can take hours. When the daemon has caught up, stop it with `Ctrl + C` and start BasicSwap as usual.

To leave a broken coin out for now and trade the others, start BasicSwap with `--withoutcoin=` and that coin's name, or with `--withcoin=` and the list of coins to run. With Docker, add `--service-ports` so the web UI is still reachable:

```bash
docker-compose run --rm --service-ports swapclient basicswap-run --datadir=/coindata --withcoin=monero
```

## Use a different Python version

On an older distribution such as Debian 11, the system Python and its SQLite can be too old for BasicSwap. [uv](https://github.com/astral-sh/uv) can create the virtual environment with a newer Python instead. In the [source install](https://basicswapdex.com/docs/user-guides/install#build-basicswap), replace the `python3 -m venv` line with:

```bash
curl -LsSf https://astral.sh/uv/install.sh | sh
source $HOME/.local/bin/env
uv venv -p 3.10 "$SWAP_DATADIR/venv" --seed
```

then carry on with the remaining steps as written. The basicswap-bash installer already uses uv on its own whenever it finds it installed.

## Reaching BasicSwap on another computer

The safest way to use a BasicSwap that runs on another machine, such as a home server, is an SSH tunnel, which keeps the web UI private to that machine and lets SSH carry it to yours. Run this on the computer you browse on:

```bash
ssh -N -L 5555:localhost:12700 -L 11700:localhost:11700 user@BASICSWAP_HOST
```

Then open `http://localhost:5555` in your browser. The first port can be any free one, but the second, `11700`, carries the websocket that pushes live updates and has to match `wsport` in the server's `basicswap.json`.

To expose the web UI on the network directly instead, see [Reaching BasicSwap over a network](https://basicswapdex.com/docs/user-guides/web-ui-authentication#reaching-basicswap-over-a-network), which also explains the `403 Host not allowed` error.

## Using your own Monero node on another machine

You can point BasicSwap at a Monero node you run elsewhere, with or without an SSH tunnel. Stop BasicSwap and set these values under `chainclients.monero` in `basicswap.json`:

| Setting | Value |
|---|---|
| `connection_type` | `rpc` |
| `manage_daemon` | `false` |
| `manage_wallet_daemon` | `true` |
| `rpchost` | The node's address, or `localhost` through a tunnel |
| `rpcport` | The node's RPC port, for example `18089` |
| `rpcuser`, `rpcpassword` | The node's RPC login, if it has one |

On the node, a restricted RPC port with a login looks like this in `monerod.conf`, and the port needs to be open in the node's firewall as well:

```text
rpc-login=USER:PASSWORD
rpc-restricted-bind-port=18089
rpc-restricted-bind-ip=0.0.0.0
```

To keep the RPC port closed and use a tunnel instead, set `rpchost` to `localhost` and run this on the BasicSwap machine:

```bash
ssh -N -L 18089:localhost:18089 user@NODE_HOST
```

Test the connection from the BasicSwap machine with:

```bash
curl http://NODE_HOST:18089/json_rpc -u USER:PASSWORD --digest -d '{"jsonrpc":"2.0","id":"0","method":"get_info"}' -H 'Content-Type: application/json'
```

[Lightweight modes](https://basicswapdex.com/docs/user-guides/lightweight-modes#monero-remote-nodes) covers public remote nodes and when to trust one.

## Installing on Windows without WSL

You can install BasicSwap natively on Windows, but the project doesn't support it, and the [install guide](https://basicswapdex.com/docs/user-guides/install)'s WSL methods are the ones to use. If you still want to try, install [Git for Windows](https://gitforwindows.org) and [Python](https://www.python.org/downloads/windows/), open Git Bash as administrator, and run:

```bash
python -m venv c:\bsx_venv
c:/bsx_venv/scripts/activate
git clone https://github.com/basicswap/basicswap.git
cd basicswap
pip3 install -r requirements.txt --require-hashes && pip3 install .
basicswap-prepare.exe --help
```

## Errors during installation

Read the terminal output at each step. A step that fails, such as a missing package, a download that times out or a signature check that doesn't pass, rarely fixes itself later, and carrying on with the next steps anyway only makes the cause harder to find. Fix the first error you see, then run that step again.