mevcat

mevcat is a lightweight tool for interating with various MEV APIs, in the spirit of nc(1).

Installation

$ cargo install mevcat

Usage

$ mevcat -h
Lightweight tool for interacting with MEV APIs

Usage: mevcat [OPTIONS] [ENDPOINT]

Arguments:
  [ENDPOINT]  Remote host to submit RPCs to

Options:
  -l, --listen <LISTEN>  Start an MEV server instance
  -p, --port <PORT>      Port number to use
  -s, --suffix <SUFFIX>  URL suffix to bind to
  -m, --method <METHOD>  RPC verb to use (client-mode only)
  -r, --raw              Send standard input to the remote host
  -h, --help             Print help
  -V, --version          Print version

There are two modes: client and server.

Client Mode

When operating in client mode, mevcat accepts a JSON RPC payload from standard input and submits it to the provided RPC endpoint. The RPC method to use is specified via -m (the default is eth_sendBundle).

$ mevcat https://rpc.beaverbuild.org
{"txs":["0x02f8b20181948449bdee618501dcd6500083016b93942dabcea55a12d73191aece59f508b191fb68adac80b844095ea7b300000000000000000000000054e44dbb92dba848ace27f44c0cb4268981ef1cc00000000000000000000000000000000000000000000000052616e065f6915ebc080a0c497b6e53d7cb78e68c37f6186c8bb9e1b8a55c3e22462163495979b25c2caafa052769811779f438b73159c4cc6a05a889da8c1a16e432c2e37e3415c9a0b9887"],"blockNumber":"0x1361bd3"}
{"bundleHash":"0xfc53193c7eb836aa28c45f11db07e41429b3b580c632e18ab37d1b92d66df641"}

Raw mode (-r) will simply POST the entire (line-delimited) contents of standard input to the endpoint (note that -m will be ignored here).

$ mevcat -r https://rpc.beaverbuild.org
{"jsonrpc":"2.0","id":1,"method":"eth_sendBundle","params":[{"txs":["0x02f8b20181948449bdee618501dcd6500083016b93942dabcea55a12d73191aece59f508b191fb68adac80b844095ea7b300000000000000000000000054e44dbb92dba848ace27f44c0cb4268981ef1cc00000000000000000000000000000000000000000000000052616e065f6915ebc080a0c497b6e53d7cb78e68c37f6186c8bb9e1b8a55c3e22462163495979b25c2caafa052769811779f438b73159c4cc6a05a889da8c1a16e432c2e37e3415c9a0b9887"],"blockNumber":"0x1361bd3"}]}
{"id":1,"jsonrpc":"2.0","result":{"bundleHash":"0xfc53193c7eb836aa28c45f11db07e41429b3b580c632e18ab37d1b92d66df641"}}

Server Mode

In server mode, mevcat listens on the specified socket for incoming JSON RPC submissions (think nc -l). It exposes the EthBundleApi.

$ RUST_LOG=info mevcat -l 0.0.0.0:3000
 2025-01-27T01:01:35.422Z INFO  mevcat > Bound to 0.0.0.0:3000
 2025-01-27T01:01:52.746Z INFO  mevcat > Received bundle: EthSendBundle { txs: [], block_number: 0, min_timestamp: None, max_timestamp: None, reverting_tx_hashes: [], replacement_uuid: None }