diff --git a/Cargo.lock b/Cargo.lock
index cb89c3f..27cbc39 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -345,6 +345,17 @@ version = "4.7.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "fbb36e985947064623dbd357f727af08ffd077f93d696782f3c56365fa2e2799"
 
+[[package]]
+name = "async-trait"
+version = "0.1.77"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c980ee35e870bd1a4d2c8294d4c04d0499e67bca1e4b5cefcc693c2fa00caea9"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.48",
+]
+
 [[package]]
 name = "atomic-waker"
 version = "1.1.2"
@@ -357,7 +368,7 @@ version = "0.16.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "fdb8867f378f33f78a811a8eb9bf108ad99430d7aad43315dd9319c827ef6247"
 dependencies = [
- "http",
+ "http 0.2.11",
  "log",
  "url",
  "wildmatch",
@@ -369,6 +380,64 @@ version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d468802bab17cbc0cc575e9b053f41e72aa36bfa6b7f55e3529ffa43161b97fa"
 
+[[package]]
+name = "axum"
+version = "0.7.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1236b4b292f6c4d6dc34604bb5120d85c3fe1d1aa596bd5cc52ca054d13e7b9e"
+dependencies = [
+ "async-trait",
+ "axum-core",
+ "base64 0.21.7",
+ "bytes",
+ "futures-util",
+ "http 1.0.0",
+ "http-body",
+ "http-body-util",
+ "hyper",
+ "hyper-util",
+ "itoa",
+ "matchit",
+ "memchr",
+ "mime",
+ "percent-encoding",
+ "pin-project-lite",
+ "rustversion",
+ "serde",
+ "serde_json",
+ "serde_path_to_error",
+ "serde_urlencoded",
+ "sha1",
+ "sync_wrapper",
+ "tokio",
+ "tokio-tungstenite",
+ "tower",
+ "tower-layer",
+ "tower-service",
+ "tracing",
+]
+
+[[package]]
+name = "axum-core"
+version = "0.4.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a15c63fd72d41492dc4f497196f5da1fb04fb7529e631d73630d1b491e47a2e3"
+dependencies = [
+ "async-trait",
+ "bytes",
+ "futures-util",
+ "http 1.0.0",
+ "http-body",
+ "http-body-util",
+ "mime",
+ "pin-project-lite",
+ "rustversion",
+ "sync_wrapper",
+ "tower-layer",
+ "tower-service",
+ "tracing",
+]
+
 [[package]]
 name = "backtrace"
 version = "0.3.69"
@@ -406,6 +475,18 @@ dependencies = [
  "local-ip-address",
 ]
 
+[[package]]
+name = "bevnet-relay"
+version = "0.2.0"
+dependencies = [
+ "axum",
+ "dashmap",
+ "futures",
+ "lazy_static",
+ "rand",
+ "tokio",
+]
+
 [[package]]
 name = "bevy"
 version = "0.12.1"
@@ -1227,6 +1308,15 @@ version = "0.1.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0d8c1fef690941d3e7788d328517591fecc684c084084702d6ff1641e993699a"
 
+[[package]]
+name = "block-buffer"
+version = "0.10.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3078c7629b62d3f0439517fa394996acacc5cbc91c5a20d8c658e77abd503a71"
+dependencies = [
+ "generic-array",
+]
+
 [[package]]
 name = "block-sys"
 version = "0.1.0-beta.1"
@@ -1604,6 +1694,19 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "dashmap"
+version = "5.5.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "978747c1d849a7d2ee5e8adc0159961c48fb7e5db2f06af6723b80123bb53856"
+dependencies = [
+ "cfg-if",
+ "hashbrown 0.14.3",
+ "lock_api",
+ "once_cell",
+ "parking_lot_core",
+]
+
 [[package]]
 name = "dasp_sample"
 version = "0.11.0"
@@ -1616,6 +1719,16 @@ version = "2.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7e962a19be5cfc3f3bf6dd8f61eb50107f356ad6270fbb3ed41476571db78be5"
 
+[[package]]
+name = "digest"
+version = "0.10.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9ed9a281f7bc9b7576e61468ba615a66a5c8cfdff42420a70aa82701a3b1e292"
+dependencies = [
+ "block-buffer",
+ "crypto-common",
+]
+
 [[package]]
 name = "dispatch"
 version = "0.2.0"
@@ -1889,12 +2002,48 @@ dependencies = [
  "percent-encoding",
 ]
 
+[[package]]
+name = "futures"
+version = "0.3.30"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "645c6916888f6cb6350d2550b80fb63e734897a8498abe35cfb732b6487804b0"
+dependencies = [
+ "futures-channel",
+ "futures-core",
+ "futures-executor",
+ "futures-io",
+ "futures-sink",
+ "futures-task",
+ "futures-util",
+]
+
+[[package]]
+name = "futures-channel"
+version = "0.3.30"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "eac8f7d7865dcb88bd4373ab671c8cf4508703796caa2b1985a9ca867b3fcb78"
+dependencies = [
+ "futures-core",
+ "futures-sink",
+]
+
 [[package]]
 name = "futures-core"
 version = "0.3.30"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "dfc6580bb841c5a68e9ef15c77ccc837b40a7504914d52e47b8b0e9bbda25a1d"
 
+[[package]]
+name = "futures-executor"
+version = "0.3.30"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a576fc72ae164fca6b9db127eaa9a9dda0d61316034f33a0a0d4eda41f02b01d"
+dependencies = [
+ "futures-core",
+ "futures-task",
+ "futures-util",
+]
+
 [[package]]
 name = "futures-io"
 version = "0.3.30"
@@ -1929,6 +2078,47 @@ dependencies = [
  "pin-project-lite",
 ]
 
+[[package]]
+name = "futures-macro"
+version = "0.3.30"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "87750cf4b7a4c0625b1529e4c543c2182106e4dedc60a2a6455e00d212c489ac"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.48",
+]
+
+[[package]]
+name = "futures-sink"
+version = "0.3.30"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9fb8e00e87438d937621c1c6269e53f536c14d3fbd6a042bb24879e57d474fb5"
+
+[[package]]
+name = "futures-task"
+version = "0.3.30"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "38d84fa142264698cdce1a9f9172cf383a0c82de1bddcf3092901442c4097004"
+
+[[package]]
+name = "futures-util"
+version = "0.3.30"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3d6401deb83407ab3da39eba7e33987a73c3df0c82b4bb5813ee871c19c41d48"
+dependencies = [
+ "futures-channel",
+ "futures-core",
+ "futures-io",
+ "futures-macro",
+ "futures-sink",
+ "futures-task",
+ "memchr",
+ "pin-project-lite",
+ "pin-utils",
+ "slab",
+]
+
 [[package]]
 name = "generic-array"
 version = "0.14.7"
@@ -2155,6 +2345,25 @@ dependencies = [
  "svg_fmt",
 ]
 
+[[package]]
+name = "h2"
+version = "0.4.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "31d030e59af851932b72ceebadf4a2b5986dba4c3b99dd2493f8273a0f151943"
+dependencies = [
+ "bytes",
+ "fnv",
+ "futures-core",
+ "futures-sink",
+ "futures-util",
+ "http 1.0.0",
+ "indexmap 2.2.2",
+ "slab",
+ "tokio",
+ "tokio-util",
+ "tracing",
+]
+
 [[package]]
 name = "hashbrown"
 version = "0.12.3"
@@ -2187,6 +2396,12 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "hermit-abi"
+version = "0.3.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d0c62115964e08cb8039170eb33c1d0e2388a256930279edca206fff675f82c3"
+
 [[package]]
 name = "hexasphere"
 version = "9.1.0"
@@ -2223,6 +2438,87 @@ dependencies = [
  "itoa",
 ]
 
+[[package]]
+name = "http"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b32afd38673a8016f7c9ae69e5af41a58f81b1d31689040f2f1959594ce194ea"
+dependencies = [
+ "bytes",
+ "fnv",
+ "itoa",
+]
+
+[[package]]
+name = "http-body"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1cac85db508abc24a2e48553ba12a996e87244a0395ce011e62b37158745d643"
+dependencies = [
+ "bytes",
+ "http 1.0.0",
+]
+
+[[package]]
+name = "http-body-util"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "41cb79eb393015dadd30fc252023adb0b2400a0caee0fa2a077e6e21a551e840"
+dependencies = [
+ "bytes",
+ "futures-util",
+ "http 1.0.0",
+ "http-body",
+ "pin-project-lite",
+]
+
+[[package]]
+name = "httparse"
+version = "1.8.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d897f394bad6a705d5f4104762e116a75639e470d80901eed05a860a95cb1904"
+
+[[package]]
+name = "httpdate"
+version = "1.0.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "df3b46402a9d5adb4c86a0cf463f42e19994e3ee891101b1841f30a545cb49a9"
+
+[[package]]
+name = "hyper"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fb5aa53871fc917b1a9ed87b683a5d86db645e23acb32c2e0785a353e522fb75"
+dependencies = [
+ "bytes",
+ "futures-channel",
+ "futures-util",
+ "h2",
+ "http 1.0.0",
+ "http-body",
+ "httparse",
+ "httpdate",
+ "itoa",
+ "pin-project-lite",
+ "tokio",
+]
+
+[[package]]
+name = "hyper-util"
+version = "0.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ca38ef113da30126bbff9cd1705f9273e15d45498615d138b0c20279ac7a76aa"
+dependencies = [
+ "bytes",
+ "futures-util",
+ "http 1.0.0",
+ "http-body",
+ "hyper",
+ "pin-project-lite",
+ "socket2",
+ "tokio",
+]
+
 [[package]]
 name = "idna"
 version = "0.5.0"
@@ -2571,6 +2867,12 @@ dependencies = [
  "regex-automata 0.1.10",
 ]
 
+[[package]]
+name = "matchit"
+version = "0.7.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0e7465ac9959cc2b1404e8e2367b43684a6d13790fe23056cc8c6c5a6b7bcb94"
+
 [[package]]
 name = "memchr"
 version = "2.7.1"
@@ -2601,6 +2903,12 @@ dependencies = [
  "paste",
 ]
 
+[[package]]
+name = "mime"
+version = "0.3.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6877bb514081ee2a7ff5ef9de3281f14a4dd4bceac4c09388074a6b5df8a139a"
+
 [[package]]
 name = "minimal-lexical"
 version = "0.2.1"
@@ -2819,6 +3127,16 @@ dependencies = [
  "autocfg",
 ]
 
+[[package]]
+name = "num_cpus"
+version = "1.16.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4161fcb6d602d4d2081af7c3a45852d875a03dd337a6bfdd6e06407b61342a43"
+dependencies = [
+ "hermit-abi",
+ "libc",
+]
+
 [[package]]
 name = "num_enum"
 version = "0.5.11"
@@ -3054,12 +3372,38 @@ dependencies = [
  "indexmap 2.2.2",
 ]
 
+[[package]]
+name = "pin-project"
+version = "1.1.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0302c4a0442c456bd56f841aee5c3bfd17967563f6fadc9ceb9f9c23cf3807e0"
+dependencies = [
+ "pin-project-internal",
+]
+
+[[package]]
+name = "pin-project-internal"
+version = "1.1.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "266c042b60c9c76b8d53061e52b2e0d1116abc57cefc8c5cd671619a56ac3690"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.48",
+]
+
 [[package]]
 name = "pin-project-lite"
 version = "0.2.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8afb450f006bf6385ca15ef45d71d2288452bc3683ce2e2cacc0d18e4be60b58"
 
+[[package]]
+name = "pin-utils"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8b870d8c151b6f2fb93e84a13146138f05d02ed11c7e7c54f8826aaaf7c9f184"
+
 [[package]]
 name = "piper"
 version = "0.2.1"
@@ -3313,6 +3657,12 @@ version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "08d43f7aa6b08d49f382cde6a7982047c3426db949b1424bc4b7ec9ae12c6ce2"
 
+[[package]]
+name = "rustversion"
+version = "1.0.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7ffc183a10b4478d04cbbbfc96d0873219d962dd5accaff2ffbd4ceb7df837f4"
+
 [[package]]
 name = "ruzstd"
 version = "0.4.0"
@@ -3376,6 +3726,39 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "serde_path_to_error"
+version = "0.1.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ebd154a240de39fdebcf5775d2675c204d7c13cf39a4c697be6493c8e734337c"
+dependencies = [
+ "itoa",
+ "serde",
+]
+
+[[package]]
+name = "serde_urlencoded"
+version = "0.7.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d3491c14715ca2294c4d6a88f15e84739788c1d030eed8c110436aafdaa2f3fd"
+dependencies = [
+ "form_urlencoded",
+ "itoa",
+ "ryu",
+ "serde",
+]
+
+[[package]]
+name = "sha1"
+version = "0.10.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e3bf829a2d51ab4a5ddf1352d8470c140cadc8301b2ae1789db023f01cedd6ba"
+dependencies = [
+ "cfg-if",
+ "cpufeatures",
+ "digest",
+]
+
 [[package]]
 name = "sharded-slab"
 version = "0.1.7"
@@ -3433,6 +3816,16 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "socket2"
+version = "0.5.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7b5fac59a5cb5dd637972e5fca70daf0523c9067fcdc4842f053dae04a18f8e9"
+dependencies = [
+ "libc",
+ "windows-sys 0.48.0",
+]
+
 [[package]]
 name = "spirv"
 version = "0.2.0+1.5.4"
@@ -3489,6 +3882,12 @@ dependencies = [
  "unicode-ident",
 ]
 
+[[package]]
+name = "sync_wrapper"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2047c6ded9c721764247e62cd3b03c09ffc529b2ba5b10ec482ae507a4a70160"
+
 [[package]]
 name = "sysinfo"
 version = "0.29.11"
@@ -3600,6 +3999,60 @@ version = "0.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1f3ccbac311fea05f86f61904b462b55fb3df8837a366dfc601a0161d0532f20"
 
+[[package]]
+name = "tokio"
+version = "1.36.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "61285f6515fa018fb2d1e46eb21223fff441ee8db5d0f1435e8ab4f5cdb80931"
+dependencies = [
+ "backtrace",
+ "bytes",
+ "libc",
+ "mio",
+ "num_cpus",
+ "pin-project-lite",
+ "socket2",
+ "tokio-macros",
+ "windows-sys 0.48.0",
+]
+
+[[package]]
+name = "tokio-macros"
+version = "2.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5b8a1e28f2deaa14e508979454cb3a223b10b938b45af148bc0986de36f1923b"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.48",
+]
+
+[[package]]
+name = "tokio-tungstenite"
+version = "0.21.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c83b561d025642014097b66e6c1bb422783339e0909e4429cde4749d1990bc38"
+dependencies = [
+ "futures-util",
+ "log",
+ "tokio",
+ "tungstenite",
+]
+
+[[package]]
+name = "tokio-util"
+version = "0.7.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5419f34732d9eb6ee4c3578b7989078579b7f039cbbb9ca2c4da015749371e15"
+dependencies = [
+ "bytes",
+ "futures-core",
+ "futures-sink",
+ "pin-project-lite",
+ "tokio",
+ "tracing",
+]
+
 [[package]]
 name = "toml_datetime"
 version = "0.6.5"
@@ -3628,12 +4081,41 @@ dependencies = [
  "winnow",
 ]
 
+[[package]]
+name = "tower"
+version = "0.4.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b8fa9be0de6cf49e536ce1851f987bd21a43b771b09473c3549a6c853db37c1c"
+dependencies = [
+ "futures-core",
+ "futures-util",
+ "pin-project",
+ "pin-project-lite",
+ "tokio",
+ "tower-layer",
+ "tower-service",
+ "tracing",
+]
+
+[[package]]
+name = "tower-layer"
+version = "0.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c20c8dbed6283a09604c3e69b4b7eeb54e298b8a600d4d5ecb5ad39de609f1d0"
+
+[[package]]
+name = "tower-service"
+version = "0.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b6bc1c9ce2b5135ac7f93c72918fc37feb872bdc6a5533a8b85eb4b86bfdae52"
+
 [[package]]
 name = "tracing"
 version = "0.1.40"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c3523ab5a71916ccf420eebdf5521fcef02141234bbc0b8a49f2fdc4544364ef"
 dependencies = [
+ "log",
  "pin-project-lite",
  "tracing-attributes",
  "tracing-core",
@@ -3717,6 +4199,25 @@ version = "0.20.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "17f77d76d837a7830fe1d4f12b7b4ba4192c1888001c7164257e4bc6d21d96b4"
 
+[[package]]
+name = "tungstenite"
+version = "0.21.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9ef1a641ea34f399a848dea702823bbecfb4c486f911735368f1f137cb8257e1"
+dependencies = [
+ "byteorder",
+ "bytes",
+ "data-encoding",
+ "http 1.0.0",
+ "httparse",
+ "log",
+ "rand",
+ "sha1",
+ "thiserror",
+ "url",
+ "utf-8",
+]
+
 [[package]]
 name = "twox-hash"
 version = "1.6.3"
@@ -3787,6 +4288,12 @@ dependencies = [
  "percent-encoding",
 ]
 
+[[package]]
+name = "utf-8"
+version = "0.7.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "09cc8ee72d2a9becf2f2febe0205bbed8fc6615b7cb429ad062dc7b7ddd036a9"
+
 [[package]]
 name = "uuid"
 version = "1.7.0"
diff --git a/crates/bevnet-relay/Cargo.toml b/crates/bevnet-relay/Cargo.toml
new file mode 100644
index 0000000..da48be0
--- /dev/null
+++ b/crates/bevnet-relay/Cargo.toml
@@ -0,0 +1,38 @@
+[package]
+name = "bevnet-relay"
+version = "0.2.0"
+edition = "2021"
+license = "GPL-3.0-or-later"
+description = "A relay server for bevnet."
+authors = ["Tipragot <contact@tipragot.fr>"]
+keywords = ["bevy", "network", "game"]
+categories = ["network-programming", "game-development"]
+
+[lints]
+workspace = true
+
+[dependencies]
+tokio = { version = "1.36.0", features = [
+    "macros",
+    "rt-multi-thread",
+], optional = true }
+axum = { version = "0.7.4", features = ["ws"], optional = true }
+lazy_static = { version = "1.4.0", optional = true }
+futures = { version = "0.3.30", optional = true }
+dashmap = { version = "5.5.3", optional = true }
+rand = { version = "0.8.5", optional = true }
+
+[features]
+default = []
+server = [
+    "dep:tokio",
+    "dep:axum",
+    "dep:lazy_static",
+    "dep:futures",
+    "dep:dashmap",
+    "dep:rand",
+]
+
+[[bin]]
+name = "server"
+required-features = ["server"]
diff --git a/crates/bevnet-relay/src/bin/server.rs b/crates/bevnet-relay/src/bin/server.rs
new file mode 100644
index 0000000..6bddbd1
--- /dev/null
+++ b/crates/bevnet-relay/src/bin/server.rs
@@ -0,0 +1,107 @@
+//! A relay server for bevnet.
+
+use axum::extract::ws::{Message, WebSocket};
+use axum::extract::WebSocketUpgrade;
+use axum::routing::get;
+use axum::Router;
+use dashmap::DashMap;
+use futures::{SinkExt, StreamExt};
+use lazy_static::lazy_static;
+use rand::Rng;
+use tokio::sync::mpsc::{channel, Receiver, Sender};
+use tokio::task::JoinHandle;
+use uuid::Uuid;
+
+lazy_static! {
+    static ref CLIENTS: DashMap<u32, Sender<Vec<u8>>> = DashMap::new();
+}
+
+#[tokio::main]
+async fn main() {
+    let app = Router::new().route(
+        "/relay",
+        get(|ws: WebSocketUpgrade| async { ws.on_upgrade(handle) }),
+    );
+    let listener = tokio::net::TcpListener::bind("0.0.0.0:80")
+        .await
+        .expect("failed to bind");
+    axum::serve(listener, app).await.expect("failed to serve");
+}
+
+/// Handle the websocket connection.
+async fn handle(socket: WebSocket) {
+    // Generate a new ID for the client.
+    let client_id: u32 = loop {
+        let id = rand::thread_rng().gen();
+        if !CLIENTS.contains_key(&id) {
+            break id;
+        }
+    };
+    println!("Client({}) connected", client_id);
+
+    // Add the client to the list of connected clients.
+    let (sender, receiver) = channel(128);
+    CLIENTS.insert(client_id, sender);
+
+    // Handle messages from the client.
+    let result = handle_socket(socket, client_id, receiver).await;
+
+    // Remove the client from the list of connected clients.
+    match result {
+        Ok(_) => println!("Client({}) disconnected", client_id),
+        Err(e) => {
+            CLIENTS.remove(&client_id);
+            println!("Client({}) disconnected: {}", client_id, e);
+        }
+    }
+}
+
+/// Error prone part of handling the websocket connection.
+async fn handle_socket(
+    mut socket: WebSocket,
+    client_id: u32,
+    mut receiver: Receiver<Vec<u8>>,
+) -> Result<(), axum::Error> {
+    // Send the client ID to the client.
+    socket
+        .send(Message::Binary(client_id.to_be_bytes().to_vec()))
+        .await?;
+
+    // Split the socket into sender and receiver.
+    let (mut writer, mut reader) = socket.split();
+
+    // Handle sending messages to the client.
+    let sending_task: JoinHandle<Result<(), axum::Error>> = tokio::spawn(async move {
+        while let Some(message) = receiver.recv().await {
+            writer
+                .send(Message::Binary(message))
+                .await
+                .map_err(axum::Error::new)?;
+        }
+        Ok(())
+    });
+
+    // Handle messages from the client.
+    while let Some(Ok(message)) = reader.next().await {
+        // Get the target ID from the message.
+        let mut data = message.into_data();
+        let id_start = data.len() - 4;
+        let target_id = u32::from_be_bytes(data[id_start..].try_into().map_err(axum::Error::new)?);
+
+        // Write the sender ID to the message.
+        for (i, byte) in client_id.to_be_bytes().into_iter().enumerate() {
+            data[id_start + i] = byte;
+        }
+
+        // Send the message to the target client.
+        if let Some(sender) = CLIENTS.get(&target_id) {
+            sender.send(data).await.map_err(axum::Error::new)?;
+        }
+    }
+
+    // Remove the client from the list of connected clients.
+    CLIENTS.remove(&client_id);
+
+    // Wait for the sender to finish.
+    sending_task.await.map_err(axum::Error::new)?
+}