25 KiB
(You have either followed the Quick Install on the readme (./install.sh) (RECOMMENDED), or have
followed a manual installation as per here).
(If you want to run Joinmarket-Qt, start with the walkthrough instead of this.)
Contents
-
Using the wallet-tool.py script
b. Funding Wallet and Displaying Balance
c. Spending from the wallet directly (without Coinjoin)
d. Recovering a Wallet from mnemonic
e. Recovering Mnemonic from a Wallet
h. Importing External Private Keys
Configuring for Bitcoin Core.
Bitcoin Core is required to use Joinmarket; note that the node can be pruned.
Configuring Joinmarket for Core is now reduced, since there is no longer any walletnotify used.
First thing to do: go into scripts/, and run:
(jmvenv)$ python wallet-tool.py generate
This should quit with an error, because the rpc is not configured. Open the newly created file joinmarket.cfg,
and edit:
[BLOCKCHAIN]
rpc_user = yourusername-as-in-bitcoin.conf
rpc_password = yourpassword-as-in-bitcoin.conf
rpc_host = localhost #default usually correct
rpc_port = 8332 # default for mainnet
Note, you can also use a cookie file by setting, in this section, a variable rpc_cookie_file to the location of the file, as an alternative to using user/password.
If you use Bitcoin Core's multiwallet feature, you can edit the value of rpc_wallet_file to your chosen wallet file.
Then retry the same generate command; it should now not error (see below).
If you still get rpc connection errors, make sure you can connect to your Core node using the command line first.
Using the wallet-tool.py script
This section leads you through the basics of creating, funding, recovering and displaying information about the Joinmarket wallet using the wallet-tool.py script. A reminder that, at this point, you should be on the command line and in the scripts/ subdirectory of the Joinmarket directory.
The Joinmarket wallet is hierarchical and deterministic, it can be entirely recovered from a single seed. At any point, you can use python wallet-tool.py --help on the command line for all options. We'll now go through all the main functions:
Creating a Wallet
Run wallet-tool.py with the generate method. Write down the 12 word seed on paper.
(jmvenv)$ python wallet-tool.py generate
Write down this wallet recovery mnemonic on paper:
matter aim multiply december stove march wolf nuclear yard boost worth supreme
Enter wallet encryption passphrase:
Reenter wallet encryption passphrase:
Input wallet file name (default: wallet.jmdat):
saved to wallet.jmdat
$
So far you have just created the wallet. But to do the next step, you'll need to see the addresses.
Run python wallet-tool.py wallet.jmdat (or replace the wallet name with whatever you chose). You'll get this message:
restart Bitcoin Core with -rescan or use bitcoin-cli rescanblockchain if you're recovering an existing wallet from backup seed
Otherwise just restart this joinmarket application.
Notice that here you don't need to rescan, because you are not "recovering an existing wallet" but creating a new one. Because it is new, none of the addresses are used yet. You only need to rescan (or use rescanblockchain as mentioned, which by the way can be a more efficient way of rescanning) if the addresses have been used ...
Funding Wallet and Displaying Balance
... so, ignore this, and just run python wallet-tool.py wallet.jmdat again. You should get a large output like this:
JM wallet
mixdepth 0 xpub6Crt4fcfpnrNxW45MzuV626z4fjddsuFGwRn1DXdpwnDkBMR12GKdBzW8euDqLSqRRv2eZmcJy8FSQLWEosC6wFZAZEv3FJMtvZ7W1CkQDi
external addresses m/49'/0'/0'/0 xpub6FQFAscJgwd8MXCcAT8A1hgx9vigrgVoXVNTAKHj2aK3NR2Zf1CbFNXD8G8X9dspGXLY9eiEzBWaypr24owJ8r1aTKgMbUZoTnQ36bBwQB3
m/49'/0'/0'/0/0 35SrGbUt9FpfA6xqKMpNaiTNyeuXagBi7Y 0.00000000 new
m/49'/0'/0'/0/1 39hc2xfA6i9kWZdXMwH4Pd9dWUvDKocGd3 0.00000000 new
m/49'/0'/0'/0/2 371MJcjFG4cEpz8RVdYb1L8PkA9tZYySGZ 0.00000000 new
m/49'/0'/0'/0/3 39eTy635wLCyBbphUTNnSB2V9LnvgdndNo 0.00000000 new
m/49'/0'/0'/0/4 33T8eNr54maWNZYQjoZwpLA2HGk7RJaLVb 0.00000000 new
m/49'/0'/0'/0/5 35kJoTSxHtQbKUg2jvjDVqcY9iXoH2cTqD 0.00000000 new
Balance: 0.00000000
internal addresses m/49'/0'/0'/1
Balance: 0.00000000
Balance for mixdepth 0: 0.00000000
mixdepth 1 xpub6Crt4fcfpnrP2GZnVuT1qi9aw9cpCuXcnGEjAKhaoWAHq5M4pWX64DNio3XHirY5uTCZCi6vTmaLjU5YQXbVsTjyEdCE2zn3S2fzBNFjxs8
external addresses m/49'/0'/1'/0 xpub6E2EnYy6yBXvE9U1nR5sSH58YiwbsKFZzaMkgMY5jrt2XFe4D5HVwikeTWyjuoczjQhJNezkwxrKAbUPMEDYHmbiaaiEAeXcL1yAcEAqtd7
m/49'/0'/1'/0/0 3DdhEr9GCoMDVRLNGAwi9rb8F4HQX8newY 0.00000000 new
m/49'/0'/1'/0/1 342XPkCQYzZkdUaB9TGPfVhf1iX55yE4gH 0.00000000 new
m/49'/0'/1'/0/2 33RaQJTn1P8KNUvNnPRFM19zHjPhzuyCqc 0.00000000 new
m/49'/0'/1'/0/3 3LydaxypMyYrbDFFp61f9rnZRcAJnZ5sv5 0.00000000 new
m/49'/0'/1'/0/4 36u2ykPy6Y9tg811B8XjYoPjpTtEg98RPd 0.00000000 new
m/49'/0'/1'/0/5 3AfSFczJEUN5RRbXirf8Pc74ve3ZaBVF8r 0.00000000 new
Balance: 0.00000000
internal addresses m/49'/0'/1'/1
Balance: 0.00000000
Balance for mixdepth 1: 0.00000000
mixdepth 2 xpub6Crt4fcfpnrP2Tjc95HKmSgaCpi9P9EM54B12XAUfdnyAyoftFpNyikSK4pBtsvqZAnj8grDFf61xDmAHYimQXvaQkoTY3h9G5BAxHuYgvn
external addresses m/49'/0'/2'/0 xpub6DrRZxJu5zEgxVMcrXmKGGeEQMgfh1MeZXvDXVYndqsqoFaJQUA94GbD1JX2p7Yw5NLcCUgg3WQXtXk5eP4vnNjGkDwA3FJoFFkE4PytauC
m/49'/0'/2'/0/0 39uPqzuW6CiyRSUvdrBYfaqSD2AtH2k4wf 0.00000000 new
m/49'/0'/2'/0/1 3FVYzJWE6g6kGj3hF7B5e7QpDQafBcUdnx 0.00000000 new
m/49'/0'/2'/0/2 3HjYatHB5tZFGcC2SUCBqT1zCM7AwgGE5r 0.00000000 new
m/49'/0'/2'/0/3 3CDco5iVa2iyEHGjXcAojsod6QDxeNedFg 0.00000000 new
m/49'/0'/2'/0/4 3LKaYFENU16ix8FngQk6m9VmQFGaATEeCu 0.00000000 new
m/49'/0'/2'/0/5 3B3TtgU6VgLF6BzQeG5znKZHpr3zgoftZC 0.00000000 new
Balance: 0.00000000
internal addresses m/49'/0'/2'/1
Balance: 0.00000000
Balance for mixdepth 2: 0.00000000
mixdepth 3 xpub6Crt4fcfpnrP5B7ysPePnY98sKaLAdu9yCbHpkodb6evSKhr4BWvpB7nQquPdzncTuhMxmUhEcVNuYpXQf9i6VN9DFYu3PgPMckuu4P7EeQ
external addresses m/49'/0'/3'/0 xpub6En2j7xGy2ihoYhpmTyDL1eER5B6rdas1HotoBiLbSXuXBMwZnjJTRefyJKVLUTfwDMgyATqZAwbZdKb8gQ8Fbno4XhUMPe6XBuN4LSsXN2
m/49'/0'/3'/0/0 3LhThkjSvYmmXLNLMcXghbvaoGgDitwfmi 0.00000000 new
m/49'/0'/3'/0/1 3LTwvukpZqsf9ghqnNQVu8szgScjoVnLdh 0.00000000 new
m/49'/0'/3'/0/2 35FRiSaZ6Yotr3YB3yX9JgqAbsxCnuTBfm 0.00000000 new
m/49'/0'/3'/0/3 3H7S5ZjYaWgSTXA1RFwGNytS2zsK1PfXoN 0.00000000 new
m/49'/0'/3'/0/4 33b8j2nPCFCWXb7wDHPRggUFoPJMwGQYYt 0.00000000 new
m/49'/0'/3'/0/5 3PE7fen989oPZn7XaRSAu3fvGN1P57SB9W 0.00000000 new
Balance: 0.00000000
internal addresses m/49'/0'/3'/1
Balance: 0.00000000
Balance for mixdepth 3: 0.00000000
mixdepth 4 xpub6Crt4fcfpnrP9pZBowaYjC7595HXETHFw2YnqtukLnqpfb4PWbhWwt5jPdskLo8ZZbHBnccexTJUArt4V8C7592K3LvsrYkrvsQMJFiPx8z
external addresses m/49'/0'/4'/0 xpub6E37s5W8C63FxsgcpMbH43ssUi8CQzfo3PrfSWfn9jKTYZgR4QZBCymJ8TPw3Vx5zoQ7aSgkqrEKr1NEerZuN8okV7w1JhNg2hoYEWohtT4
m/49'/0'/4'/0/0 39n1tYKnPQ47bgCmsPWDHxuk2Mxo6GE4LZ 0.00000000 new
m/49'/0'/4'/0/1 3BoLqHDSHdMHyrSEAP31bBzzw45bFwZhy7 0.00000000 new
m/49'/0'/4'/0/2 31mo7D9UDmoStafYcyHpwV9sWY7oP9jUVQ 0.00000000 new
m/49'/0'/4'/0/3 3JMVGEyZ5nyJR9NVsfNY93c34xx9rEtzmq 0.00000000 new
m/49'/0'/4'/0/4 3AdD86dw59Q5EGHVupkHzR8pM4sW45bKqX 0.00000000 new
m/49'/0'/4'/0/5 3Gu7jTxcmh5dHJXgCE7Z5fdMgUWuenE2GE 0.00000000 new
Balance: 0.00000000
internal addresses m/49'/0'/4'/1
Balance: 0.00000000
Balance for mixdepth 4: 0.00000000
Total balance: 0.00000000
The BIP32 xpub keys of each external branch are shown in case that is needed. The BIP32 derivation paths are also shown; for Joinmarket they are defined by BIP49; for more on this see below.
Bitcoins should be sent to empty external addresses (sometimes known as receive addresses). You'll notice in the above that while there are fields also for internal addresses, they are empty. That's because zero-balance internal addresses (also known as change addresses) are hidden by default. Using 'displayall' as the second argument will show all addresses in wallet, including empty used ones.
Read the instructions here before funding the wallet.
Once you've funded it, run python wallet-tool.py wallet.jmdat again, enter your passphrase, and you should see the deposited coins.
Spending from the wallet directly (without Coinjoin)
Note that Joinmarket's wallet supports spending to all address types, including legacy addresses ('1'), P2SH addresses ('3') and bech32 addresses ('bc1'). To learn more about how to spend directly without using CoinJoin, see here.
Recovering a Wallet from mnemonic
In the event of loss of encrypted wallet file, use the 12 word seed to recover by running wallet-tool.py with 'recover' as first argument:
(jmvenv)$python wallet-tool.py recover
Input mnemonic recovery phrase: matter aim multiply december stove march wolf nuclear yard boost worth supreme
Input mnemonic extension, leave blank if there isnt one:
Enter wallet file encryption passphrase:
Reenter wallet file encryption passphrase:
Input wallet file name (default: wallet.jmdat):
Write down this wallet recovery mnemonic
matter aim multiply december stove march wolf nuclear yard boost worth supreme
Recovered wallet OK
Help! I recovered but some of my money is missing
Try increasing the gap limit up from its default of 6. This is more likely to happen if you ran a yield generator bot for a while (see below).
(jmvenv)$ python wallet-tool.py -g 50 my-wallet-file.jmdat
Another possible cause is you were running the tumbler script and it was stopped halfway through, with your coins currently at mixing depth 8. In that case increase the maximum mixdepth:
(jmvenv)$ python wallet-tool.py -m 15 my-wallet-file.jmdat
Recovering a Wallet's Mnemonic Phrase
The showseed command will display the mnemonic for an existing wallet file, in case you've forgotten it. It is highly recommended to keep a written backup of this phrase, lest you forget it!
(jmvenv)$ python wallet-tool.py wallet.jmdat showseed
Recovering Private Keys
It is possible to recover a Joinmarket wallet in Trezor, Electrum or a number of other wallets, because it uses BIP49. But note that this is not ideal for privacy reasons (if you contact a server with your addresses), and also that because Joinmarket uses multiple accounts (=mixdepths), it may be more difficult than expected.
In difficult recovery situations, the -p command line flag can be used to print out private keys. Be very careful and consider this advanced usage:
...
JM wallet
mixdepth 0 xpub6Crt4fcfpnrNxW45MzuV626z4fjddsuFGwRn1DXdpwnDkBMR12GKdBzW8euDqLSqRRv2eZmcJy8FSQLWEosC6wFZAZEv3FJMtvZ7W1CkQDi
external addresses m/49'/0'/0'/0 xpub6FQFAscJgwd8MXCcAT8A1hgx9vigrgVoXVNTAKHj2aK3NR2Zf1CbFNXD8G8X9dspGXLY9eiEzBWaypr24owJ8r1aTKgMbUZoTnQ36bBwQB3
m/49'/0'/0'/0/0 35SrGbUt9FpfA6xqKMpNaiTNyeuXagBi7Y 0.00000000 new L4TDPLYgd77GcHWdLTCEhqqd3GM15Wp7PX7dw1YeyCeRb326hM8K
m/49'/0'/0'/0/1 39hc2xfA6i9kWZdXMwH4Pd9dWUvDKocGd3 0.00000000 new L26Y8v6fU3Nx8yaRhnkKAq3wi4TkaR5BgEXuDQNmR2nv2v7kVCd9
m/49'/0'/0'/0/2 371MJcjFG4cEpz8RVdYb1L8PkA9tZYySGZ 0.00000000 new KyLza1kdozCyGwt6rkwkhshaBHS8hhciB6mnneczrxtFYXTNeyYV
m/49'/0'/0'/0/3 39eTy635wLCyBbphUTNnSB2V9LnvgdndNo 0.00000000 new KyKugtGLD1RpA8ZURCPqJ74kWyh26JBnfPG1TtjzmBoS5E3wzWJK
m/49'/0'/0'/0/4 33T8eNr54maWNZYQjoZwpLA2HN4UJB2Gk7RJaLVb 0.00000000 new L3yjfeVyBCwTgUXpdPNKPK7RBQ6Xvc17LThvF3zKM2pQkWpEEcbo
m/49'/0'/0'/0/5 35kJoTSxHtQbKUg2jvjDVqcY9iXoH2cTqD 0.00000000 new L1QXi1KjVyTFQZGWeybjnnSN3sieYGeTQtTiYrwLJmJvhQ7EBzVL
Balance: 0.00000000
internal addresses m/49'/0'/0'/1
Balance: 0.00000000
Balance for mixdepth 0: 0.00000000
mixdepth 1 xpub6Crt4fcfpnrP2GZnVuT1qi9aw9cpCuXcnGEjAKhaoWAHq5M4pWX64DNio3XHirY5uTCZCi6vTmaLjU5YQXbVsTjyEdCE2zn3S2fzBNFjxs8
external addresses m/49'/0'/1'/0 xpub6E2EnYy6yBXvE9U1nR5sSH58YiwbsKFZzaMkgMY5jrt2XFe4D5HVwikeTWyjuoczjQhJNezkwxrKAbUPMEDYHmbiaaiEAeXcL1yAcEAqtd7
m/49'/0'/1'/0/0 3DdhEr9GCoMDVRLNGAwi9rb8F4HQX8newY 0.00000000 new KzNosXo1sDfSJr7JcyqwYqGzTKTgAeQ9iEfiWA5YVE3Y6Tn3iCJs
.... etc
The above method (-p) still requires synchronizing the JoinMarket wallet. In the case where this isn't possible, individual private keys can still be exported:
(jmvenv)$python wallet-tool.py -H "m/49'/0'/4'/0/0" wallet.jmdat dumpprivkey
Enter wallet decryption passphrase:
L1YPrEGNMwwfnvzBfAiPiPC4zb5s6Urpqnk88zNHgsYLHrq2Umss
... using the derivation path (m/...) as specified in the output as above; note the need to use double quotes around it.
Wallet History
The wallet transaction history can be displayed. Prints a summary for every transaction. If you have numpy/scipy installed it also calculates the effective interest rate you achieved as if your yield-generator was a savings account.
(jmvenv)$ python wallet-tool.py wallet.jmdat history
tx# timestamp type amount/btc balance-change/btc balance/btc coinjoin-n total-fees utxo-count mixdepth-from mixdepth-to
0 2016-04-20 21:37 deposit 0.15000000 +0.15000000 0.15000000 # # 1 # 0
1 2016-04-20 22:22 cj internal 0.02115585 +0.00006341 0.15006341 3 # 2 0 1
2 2016-04-20 23:27 cj internal 0.15046475 +0.00021085 0.15027426 4 # 3 0 1
3 2016-04-21 23:45 cj internal 0.01209051 +0.00003159 0.15030585 5 # 4 0 1
4 2016-04-21 00:07 cj internal 0.03120432 +0.00006307 0.15036892 3 # 5 1 2
5 2016-04-21 00:07 cj internal 0.05538475 +0.00017932 0.15054824 4 # 6 1 2
2016-04-21 18:55 best block is 000000000000000005009c707b2427224c784c6224a5c44ee449d93b727739e7
continuously compounded equivalent annual interest rate = 0.459494243045 %
(as if yield generator was a bank account)
$
You can create a csv file for opening with spreadsheet software:
(jmvenv)$ python wallet-tool.py --csv wallet.json history > history.csv
Importing External Private Keys
Individual private keys can be imported into JoinMarket wallets by using the 'importprivkey' method. Multiple private keys are imported by separating them with commas or spaces. Use the -M flag to control which mixing depth the private keys are imported into. Be warned that handling raw private keys like this is dangerous.
You should read the warnings and understand the non-intuitive behaviour before using.
With this and this page.
It is best to avoid importing private keys if you can.
(jmvenv)$ python wallet-tool.py -M 0 example.jmdat importprivkey
Enter wallet decryption passphrase:
WARNING: This imported key will not be recoverable with your 12 word mnemonic seed. Make sure you have backups.
WARNING: Handling of raw ECDSA bitcoin private keys can lead to non-intuitive behaviour and loss of funds.
Recommended instead is to use the 'sweep' feature of sendpayment.py
Enter private key(s) to import: KzHJDZrSmmwkZKdLNS8L91qGsL9By6b48deaZRExBg4vAiyiBE7V Kxo3mHpUcx6KcLsyGTETh3ZJHEeU73tNCwYM1Yk7MMoTcW4jZ7Mi L3SdjpTu8tGdtht74wwsUX37bqGmr44AoyvZSqvrhTieN2GhbP7e
Private key(s) successfully imported
$
What is the BIP32 wallet structure
The Mixing Depth Concept
The point of JoinMarket is to improve privacy. Merged transaction inputs are damaging to privacy because they provide evidence of common ownership. Each mixing depth is a different identity, coins are never merged in the same transaction across mixing depths, but may be merged within mixing depths. Coins move between mixing depths through coinjoins. A change output stays in the same mixing depth. This prevents the situation where a change output is merged with a coinjoin output in a later transaction, which would render the coinjoin easily unmixable.
An example of the different identities being used is to not leak a lower limit of your wallet balance. Imagine if someone pays you $10 and sees it combined with $1 million, they could deduce you own at least that much. If instead those two payments go to different mixing levels then this analysis becomes harder. As coins move up the mixing levels via coinjoin, their identity becomes more uncertain. To introduce more uncertainty, have the coins separated by more mixing levels. E.G. A coin in level 0 and a second coin with level 1 will be merged with one set of coinjoins between them, the second coin at level 5 will be merged with 5 sets of coinjoins.
BIP32 Structure
m - generated from seed
m/49' - purpose: this is specified by [BIP49](https://github.com/bitcoin/bips/blob/master/bip-0049.mediawiki) for P2SH-wrapped segwit P2WPKH addresses
m/49'/0' - coin type 0 : see [BIP44](https://github.com/bitcoin/bips/blob/master/bip-0044.mediawiki) which specifies this as the coin type for Bitcoin mainnet
m/49'/0'/n' - nth mixing depth (nth account) (as per BIP44)
m/49'/0'/n'/0/k - kth external address, for mixing depth n
m/49'/0'/n'/1/k - kth internal address, for mixing depth n
Note that the quote (') indicates hardened derivation. See BIP32 for technical details.
What is the Gap Limit?
With a deterministic wallet you create a sequence of bitcoin addresses and private keys from an initial seed. This list is the same every time it's generated, it means the entire wallet can be backed up by saving only the initial seed.
You can create as many addresses as you like, but not all of them will appear the blockchain. For instance I might create one especially for you to give me 1,000,000 BTC. That is (alas!) probably not going to be used so will likely never appear on the blockchain.
When you are starting JoinMarket it does not know which is the last address used. So you start at the beginning and see what is on the blockchain. Then you look for the next one in the sequence. The gap limit is how many misses you accept before you give up and stop looking. The same concept is used in other deterministic wallets like Electrum.
Try out a coinjoin; using sendpayment.py
Doing single coinjoins doesn't really achieve a significant privacy boost; so you can skip much of this if that's your only interest, and go here instead to learn about the tumbler script; but do read here about how to spend coins from the wallet..
A single coinjoin can make destination (payment) outputs unclear, and can degrade automated blockchain surveillance significantly. We recommend using these opportunistically when making payments but on no account rely on any specific privacy gain from doing so.
Single coinjoins can be done using the script sendpayment.py. As with all Joinmarket user scripts, use --help to see a full list of options.
Here is an example:
(jmvenv)$ python sendpayment.py wallet.jmdat 5000000 mprGzBA9rQk82Ly41TsmpQGa8UPpZb2w8c
This sends 5000000 satoshi (0.05btc) to the address mprGzBA9rQk82Ly41TsmpQGa8UPpZb2w8c (testnet), with the default 5-7 (randomized) other parties from the default 0-th mixing depth from the wallet contained in the file wallet.jmdat. This will take some time, since Joinmarket will connect to remote messaging servers and do end to end encrypted communication with other bots, and also you will be paying some fees (more on this later in this section).
No coinjoin, sending funds
Suppose you simply wanted to pay that address without coinjoin. Easy, just set the number of counterparties to zero:
(jmvenv)$ python sendpayment.py wallet.jmdat -N 0 5000000 mprGzBA9rQk82Ly41TsmpQGa8UPpZb2w8c
Other options such as "sweep", and network fees (see below) work the same when you set -N 0. This is your basic wallet function without CoinJoin.
Here is another example of a CoinJoin usage:
(jmvenv)$ python sendpayment.py -N 5 -m 1 wallet.jmdat 100000000 mprGzBA9rQk82Ly41TsmpQGa8UPpZb2w8c
Sends 1BTC (100 million satoshis) from mixing depth 1 (the second!), mixing with five other parties.
Setting the amount to zero will cause the bot to sweep. Meaning it will empty that mixing depth, calculating the coinjoin fee so that no coins are left.
(jmvenv)$ python sendpayment.py -N 7 wallet.jmdat 0 mprGzBA9rQk82Ly41TsmpQGa8UPpZb2w8c
... sends all coins in mixdepth 0 (default), minus whatever is needed as coinjoin and network fees, to the destination address, via a CoinJoin with 7 other parties. Note that CoinJoins that are sweeps are particularly powerful because no change is left behind to make future linkages.
Fee settings
There are two different types of fee; bitcoin network transaction fees and fees paid to counterparties for providing liquidity for coinjoins (that latter being the central idea of Joinmarket).
Bitcoin network fees.
This is controlled using the setting of tx_fees in the [POLICY] section in your joinmarket.cfg file in the current directory. If you set it to a number between 1 and 144 it is treated as the targeted number of blocks for confirmation; e.g. if you set it to 20 you are asking to use whatever Bitcoin Core things is a realistic fee to get confirmation within the next 20 blocks. By default it is 3. If you set it to a number > 144, don't set it lower than about 1200, it will be interpreted as "number of satoshis per kilobyte for the transaction fee". 1000 equates to 1 satoshi per byte (ignoring technical details of vbyte), which is usually the minimum fee that nodes on the network will relay. Note that Joinmarket will deliberately vary your choice randomly, in this case, by 20% either side, to avoid you watermarking all your transactions with the exact same fee rate. As an example, if you prefer to use an approximate rate of 20 sats/byte rather than rely on Bitcoin Core's estimated target for 3 or 6 blocks, then set tx_fees to 20000.
Note that some liquidity providers (Makers) will offer very small contributions to the tx fee, but mostly you should consider that you must pay the whole Bitcoin network fee yourself, as an instigator of a coinjoin (a Taker). Note also that if you set 7 counterparties, you are effectively paying for approximately 7 normal sized transactions; be cognizant of that!
CoinJoin fees.
Individual Makers will offer to do CoinJoin at different rates. Some set their fee as a percentage of the amount, and others set it as a fixed number of satoshis. Most set their rates very low, so in most (but not all) cases the overall CoinJoin fee will be lower than the bitcoin network fees discussed above. When starting to do a CoinJoin you will be prompted to set the maximum relative (percentage) and absolute (number of satoshis) fees that you're willing to accept from one participant; your bot will then choose randomly from those that are below at least one of those limits. Please read these instructions carefully and update your config file accordingly to avoid having to answer the questions repeatedly.
Note also that you can use 'schedule' files, but that's more advanced so ignore it for now; see the README under scripts/ for more details.