diff --git a/Cargo.lock b/Cargo.lock
index 0e9fd42..feaad2a 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -274,7 +274,7 @@ dependencies = [
  "serde_json",
  "tokio",
  "tokio-stream",
- "tower",
+ "tower 0.5.2",
  "tracing",
  "url",
  "wasmtimer",
@@ -409,7 +409,7 @@ dependencies = [
  "serde_json",
  "thiserror 2.0.17",
  "tokio",
- "tower",
+ "tower 0.5.2",
  "tracing",
  "url",
  "wasmtimer",
@@ -425,7 +425,7 @@ dependencies = [
  "alloy-transport",
  "reqwest",
  "serde_json",
- "tower",
+ "tower 0.5.2",
  "tracing",
  "url",
 ]
@@ -856,7 +856,7 @@ dependencies = [
  "serde_urlencoded",
  "sync_wrapper",
  "tokio",
- "tower",
+ "tower 0.5.2",
  "tower-layer",
  "tower-service",
  "tracing",
@@ -906,7 +906,7 @@ dependencies = [
  "serde_urlencoded",
  "smallvec",
  "tokio",
- "tower",
+ "tower 0.5.2",
  "url",
 ]
 
@@ -929,7 +929,7 @@ dependencies = [
  "serde",
  "serde_json",
  "tokio",
- "tower",
+ "tower 0.5.2",
  "tower-http",
  "tracing",
  "tracing-subscriber",
@@ -1154,6 +1154,12 @@ dependencies = [
  "shlex",
 ]
 
+[[package]]
+name = "cesu8"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6d43a04d8753f35258c91f8ec639f792891f748a1edbd759cf1dcea3382ad83c"
+
 [[package]]
 name = "cfg-if"
 version = "1.0.4"
@@ -1235,6 +1241,16 @@ version = "1.0.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b05b61dc5112cbb17e4b6cd61790d9845d13888356391624cbe7e41efeac1e75"
 
+[[package]]
+name = "combine"
+version = "4.6.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ba5a308b75df32fe02788e748662718f03fde005016435c444eea572398219fd"
+dependencies = [
+ "bytes",
+ "memchr",
+]
+
 [[package]]
 name = "const-hex"
 version = "1.17.0"
@@ -1775,8 +1791,10 @@ dependencies = [
  "bytes",
  "clap",
  "eyre",
+ "fetcher-api",
  "flate2",
  "futures-util",
+ "jsonrpsee",
  "pin-project-lite",
  "reqwest",
  "serde",
@@ -1790,6 +1808,18 @@ dependencies = [
  "uuid",
 ]
 
+[[package]]
+name = "fetcher-api"
+version = "0.1.0"
+dependencies = [
+ "eyre",
+ "jsonrpsee",
+ "serde",
+ "serde_json",
+ "tokio",
+ "tracing",
+]
+
 [[package]]
 name = "ff"
 version = "0.13.1"
@@ -1965,6 +1995,12 @@ version = "0.3.31"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f90f7dce0722e95104fcb095585910c0977252f286e354b5e3bd38902cd99988"
 
+[[package]]
+name = "futures-timer"
+version = "3.0.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f288b0a4f20f9a56b5d1da57e2227c661b7b16168e2f72365f57b63326e29b24"
+
 [[package]]
 name = "futures-util"
 version = "0.3.31"
@@ -2534,6 +2570,28 @@ version = "1.0.15"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4a5f13b858c8d314ee3e8f639011f7ccefe71f97f96e50151fb991f267928e2c"
 
+[[package]]
+name = "jni"
+version = "0.21.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1a87aa2bb7d2af34197c04845522473242e1aa17c12f4935d5856491a7fb8c97"
+dependencies = [
+ "cesu8",
+ "cfg-if",
+ "combine",
+ "jni-sys",
+ "log",
+ "thiserror 1.0.69",
+ "walkdir",
+ "windows-sys 0.45.0",
+]
+
+[[package]]
+name = "jni-sys"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8eaf4bc02d17cbdd7ff4c7438cafcdf7fb9a4613313ad11b4f8fefe7d3fa0130"
+
 [[package]]
 name = "jobserver"
 version = "0.1.34"
@@ -2554,6 +2612,135 @@ dependencies = [
  "wasm-bindgen",
 ]
 
+[[package]]
+name = "jsonrpsee"
+version = "0.24.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e281ae70cc3b98dac15fced3366a880949e65fc66e345ce857a5682d152f3e62"
+dependencies = [
+ "jsonrpsee-core",
+ "jsonrpsee-proc-macros",
+ "jsonrpsee-server",
+ "jsonrpsee-types",
+ "jsonrpsee-ws-client",
+ "tokio",
+ "tracing",
+]
+
+[[package]]
+name = "jsonrpsee-client-transport"
+version = "0.24.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cc4280b709ac3bb5e16cf3bad5056a0ec8df55fa89edfe996361219aadc2c7ea"
+dependencies = [
+ "base64",
+ "futures-util",
+ "http",
+ "jsonrpsee-core",
+ "pin-project",
+ "rustls",
+ "rustls-pki-types",
+ "rustls-platform-verifier",
+ "soketto",
+ "thiserror 1.0.69",
+ "tokio",
+ "tokio-rustls",
+ "tokio-util",
+ "tracing",
+ "url",
+]
+
+[[package]]
+name = "jsonrpsee-core"
+version = "0.24.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "348ee569eaed52926b5e740aae20863762b16596476e943c9e415a6479021622"
+dependencies = [
+ "async-trait",
+ "bytes",
+ "futures-timer",
+ "futures-util",
+ "http",
+ "http-body",
+ "http-body-util",
+ "jsonrpsee-types",
+ "parking_lot",
+ "pin-project",
+ "rand 0.8.5",
+ "rustc-hash",
+ "serde",
+ "serde_json",
+ "thiserror 1.0.69",
+ "tokio",
+ "tokio-stream",
+ "tracing",
+]
+
+[[package]]
+name = "jsonrpsee-proc-macros"
+version = "0.24.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7398cddf5013cca4702862a2692b66c48a3bd6cf6ec681a47453c93d63cf8de5"
+dependencies = [
+ "heck",
+ "proc-macro-crate",
+ "proc-macro2",
+ "quote",
+ "syn 2.0.112",
+]
+
+[[package]]
+name = "jsonrpsee-server"
+version = "0.24.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "21429bcdda37dcf2d43b68621b994adede0e28061f816b038b0f18c70c143d51"
+dependencies = [
+ "futures-util",
+ "http",
+ "http-body",
+ "http-body-util",
+ "hyper",
+ "hyper-util",
+ "jsonrpsee-core",
+ "jsonrpsee-types",
+ "pin-project",
+ "route-recognizer",
+ "serde",
+ "serde_json",
+ "soketto",
+ "thiserror 1.0.69",
+ "tokio",
+ "tokio-stream",
+ "tokio-util",
+ "tower 0.4.13",
+ "tracing",
+]
+
+[[package]]
+name = "jsonrpsee-types"
+version = "0.24.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b0f05e0028e55b15dbd2107163b3c744cd3bb4474f193f95d9708acbf5677e44"
+dependencies = [
+ "http",
+ "serde",
+ "serde_json",
+ "thiserror 1.0.69",
+]
+
+[[package]]
+name = "jsonrpsee-ws-client"
+version = "0.24.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "78fc744f17e7926d57f478cf9ca6e1ee5d8332bf0514860b1a3cdf1742e614cc"
+dependencies = [
+ "http",
+ "jsonrpsee-client-transport",
+ "jsonrpsee-core",
+ "jsonrpsee-types",
+ "url",
+]
+
 [[package]]
 name = "k256"
 version = "0.13.4"
@@ -3503,7 +3690,7 @@ dependencies = [
  "tokio-native-tls",
  "tokio-rustls",
  "tokio-util",
- "tower",
+ "tower 0.5.2",
  "tower-http",
  "tower-service",
  "url",
@@ -3557,6 +3744,12 @@ dependencies = [
  "rustc-hex",
 ]
 
+[[package]]
+name = "route-recognizer"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "afab94fb28594581f62d981211a9a4d53cc8130bbcbbb89a0440d9b8e81a7746"
+
 [[package]]
 name = "ruint"
 version = "1.17.2"
@@ -3673,6 +3866,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "533f54bc6a7d4f647e46ad909549eda97bf5afc1585190ef692b4286b198bd8f"
 dependencies = [
  "aws-lc-rs",
+ "log",
  "once_cell",
  "ring",
  "rustls-pki-types",
@@ -3703,6 +3897,33 @@ dependencies = [
  "zeroize",
 ]
 
+[[package]]
+name = "rustls-platform-verifier"
+version = "0.5.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "19787cda76408ec5404443dc8b31795c87cd8fec49762dc75fa727740d34acc1"
+dependencies = [
+ "core-foundation 0.10.1",
+ "core-foundation-sys",
+ "jni",
+ "log",
+ "once_cell",
+ "rustls",
+ "rustls-native-certs",
+ "rustls-platform-verifier-android",
+ "rustls-webpki",
+ "security-framework 3.5.1",
+ "security-framework-sys",
+ "webpki-root-certs 0.26.11",
+ "windows-sys 0.52.0",
+]
+
+[[package]]
+name = "rustls-platform-verifier-android"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f87165f0995f63a9fbeea62b64d10b4d9d8e78ec6d7d51fb2125fda7bb36788f"
+
 [[package]]
 name = "rustls-webpki"
 version = "0.103.8"
@@ -3739,6 +3960,15 @@ version = "1.0.20"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "28d3b2b1366ec20994f1fd18c3c594f05c5dd4bc44d8bb0c1c632c8d6829481f"
 
+[[package]]
+name = "same-file"
+version = "1.0.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "93fc1dc3aaa9bfed95e02e6eadabb4baf7e3078b0bd1b4d7b6b0b68378900502"
+dependencies = [
+ "winapi-util",
+]
+
 [[package]]
 name = "schannel"
 version = "0.1.28"
@@ -3971,6 +4201,17 @@ dependencies = [
  "unsafe-libyaml",
 ]
 
+[[package]]
+name = "sha1"
+version = "0.10.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e3bf829a2d51ab4a5ddf1352d8470c140cadc8301b2ae1789db023f01cedd6ba"
+dependencies = [
+ "cfg-if",
+ "cpufeatures",
+ "digest 0.10.7",
+]
+
 [[package]]
 name = "sha2"
 version = "0.10.9"
@@ -4073,6 +4314,22 @@ dependencies = [
  "windows-sys 0.60.2",
 ]
 
+[[package]]
+name = "soketto"
+version = "0.8.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2e859df029d160cb88608f5d7df7fb4753fd20fdfb4de5644f3d8b8440841721"
+dependencies = [
+ "base64",
+ "bytes",
+ "futures",
+ "http",
+ "httparse",
+ "log",
+ "rand 0.8.5",
+ "sha1",
+]
+
 [[package]]
 name = "spec"
 version = "0.1.0"
@@ -4453,6 +4710,7 @@ checksum = "2efa149fe76073d6e8fd97ef4f4eca7b67f599660115591483572e406e165594"
 dependencies = [
  "bytes",
  "futures-core",
+ "futures-io",
  "futures-sink",
  "pin-project-lite",
  "tokio",
@@ -4488,6 +4746,21 @@ 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",
+ "tower-layer",
+ "tower-service",
+ "tracing",
+]
+
 [[package]]
 name = "tower"
 version = "0.5.2"
@@ -4517,7 +4790,7 @@ dependencies = [
  "http-body",
  "iri-string",
  "pin-project-lite",
- "tower",
+ "tower 0.5.2",
  "tower-layer",
  "tower-service",
  "tracing",
@@ -4755,6 +5028,16 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "walkdir"
+version = "2.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "29790946404f91d9c5d06f9874efddea1dc06c5efe94541a7d6863108e3a5e4b"
+dependencies = [
+ "same-file",
+ "winapi-util",
+]
+
 [[package]]
 name = "want"
 version = "0.3.1"
@@ -4884,6 +5167,24 @@ dependencies = [
  "wasm-bindgen",
 ]
 
+[[package]]
+name = "webpki-root-certs"
+version = "0.26.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "75c7f0ef91146ebfb530314f5f1d24528d7f0767efbfd31dce919275413e393e"
+dependencies = [
+ "webpki-root-certs 1.0.5",
+]
+
+[[package]]
+name = "webpki-root-certs"
+version = "1.0.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "36a29fc0408b113f68cf32637857ab740edfafdf460c326cd2afaa2d84cc05dc"
+dependencies = [
+ "rustls-pki-types",
+]
+
 [[package]]
 name = "webpki-roots"
 version = "1.0.4"
@@ -4909,6 +5210,15 @@ version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ac3b87c63620426dd9b991e5ce0329eff545bccbbb34f3be09ff6fb6ab51b7b6"
 
+[[package]]
+name = "winapi-util"
+version = "0.1.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c2a7b1c03c876122aa43f3020e6c3c3ee5c05081c9a00739faf7503aeba10d22"
+dependencies = [
+ "windows-sys 0.61.2",
+]
+
 [[package]]
 name = "winapi-x86_64-pc-windows-gnu"
 version = "0.4.0"
@@ -4985,6 +5295,15 @@ dependencies = [
  "windows-link",
 ]
 
+[[package]]
+name = "windows-sys"
+version = "0.45.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "75283be5efb2831d37ea142365f009c02ec203cd29a3ebecbc093d52315b66d0"
+dependencies = [
+ "windows-targets 0.42.2",
+]
+
 [[package]]
 name = "windows-sys"
 version = "0.52.0"
@@ -5012,6 +5331,21 @@ dependencies = [
  "windows-link",
 ]
 
+[[package]]
+name = "windows-targets"
+version = "0.42.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8e5180c00cd44c9b1c88adb3693291f1cd93605ded80c250a75d472756b4d071"
+dependencies = [
+ "windows_aarch64_gnullvm 0.42.2",
+ "windows_aarch64_msvc 0.42.2",
+ "windows_i686_gnu 0.42.2",
+ "windows_i686_msvc 0.42.2",
+ "windows_x86_64_gnu 0.42.2",
+ "windows_x86_64_gnullvm 0.42.2",
+ "windows_x86_64_msvc 0.42.2",
+]
+
 [[package]]
 name = "windows-targets"
 version = "0.52.6"
@@ -5045,6 +5379,12 @@ dependencies = [
  "windows_x86_64_msvc 0.53.1",
 ]
 
+[[package]]
+name = "windows_aarch64_gnullvm"
+version = "0.42.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "597a5118570b68bc08d8d59125332c54f1ba9d9adeedeef5b99b02ba2b0698f8"
+
 [[package]]
 name = "windows_aarch64_gnullvm"
 version = "0.52.6"
@@ -5057,6 +5397,12 @@ version = "0.53.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a9d8416fa8b42f5c947f8482c43e7d89e73a173cead56d044f6a56104a6d1b53"
 
+[[package]]
+name = "windows_aarch64_msvc"
+version = "0.42.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e08e8864a60f06ef0d0ff4ba04124db8b0fb3be5776a5cd47641e942e58c4d43"
+
 [[package]]
 name = "windows_aarch64_msvc"
 version = "0.52.6"
@@ -5069,6 +5415,12 @@ version = "0.53.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b9d782e804c2f632e395708e99a94275910eb9100b2114651e04744e9b125006"
 
+[[package]]
+name = "windows_i686_gnu"
+version = "0.42.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c61d927d8da41da96a81f029489353e68739737d3beca43145c8afec9a31a84f"
+
 [[package]]
 name = "windows_i686_gnu"
 version = "0.52.6"
@@ -5093,6 +5445,12 @@ version = "0.53.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "fa7359d10048f68ab8b09fa71c3daccfb0e9b559aed648a8f95469c27057180c"
 
+[[package]]
+name = "windows_i686_msvc"
+version = "0.42.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "44d840b6ec649f480a41c8d80f9c65108b92d89345dd94027bfe06ac444d1060"
+
 [[package]]
 name = "windows_i686_msvc"
 version = "0.52.6"
@@ -5105,6 +5463,12 @@ version = "0.53.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1e7ac75179f18232fe9c285163565a57ef8d3c89254a30685b57d83a38d326c2"
 
+[[package]]
+name = "windows_x86_64_gnu"
+version = "0.42.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8de912b8b8feb55c064867cf047dda097f92d51efad5b491dfb98f6bbb70cb36"
+
 [[package]]
 name = "windows_x86_64_gnu"
 version = "0.52.6"
@@ -5117,6 +5481,12 @@ version = "0.53.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9c3842cdd74a865a8066ab39c8a7a473c0778a3f29370b5fd6b4b9aa7df4a499"
 
+[[package]]
+name = "windows_x86_64_gnullvm"
+version = "0.42.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "26d41b46a36d453748aedef1486d5c7a85db22e56aff34643984ea85514e94a3"
+
 [[package]]
 name = "windows_x86_64_gnullvm"
 version = "0.52.6"
@@ -5129,6 +5499,12 @@ version = "0.53.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0ffa179e2d07eee8ad8f57493436566c7cc30ac536a3379fdf008f47f6bb7ae1"
 
+[[package]]
+name = "windows_x86_64_msvc"
+version = "0.42.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9aec5da331524158c6d1a4ac0ab1541149c0b9505fde06423b02f5ef0106b9f0"
+
 [[package]]
 name = "windows_x86_64_msvc"
 version = "0.52.6"
diff --git a/Cargo.toml b/Cargo.toml
index d43b332..39c02e4 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -8,6 +8,7 @@ members = [
     "crates/template",
     "crates/babel",
     "crates/fetcher",
+    "crates/fetcher-api",
     "crates/cosmos-keys"
 ]
 
@@ -17,6 +18,7 @@ runtime-docker-compose = { path = "crates/runtime-docker-compose" }
 runtime-trait = { path = "crates/runtime-trait" }
 catalog = { path = "crates/catalog" }
 template = { path = "crates/template" }
+fetcher-api = { path = "crates/fetcher-api" }
 cosmos-keys = { path = "crates/cosmos-keys" }
 
 serde = { version = "1.0", features = ["derive"] }
@@ -32,5 +34,6 @@ tinytemplate = "1.2"
 askama = "0.14.0"
 clap = { version = "4.5", features = ["derive"] }
 reqwest = { version = "0.12", default-features = false }
+jsonrpsee = { version = "0.24", features = ["server", "ws-client", "macros"] }
 tracing = "0.1"
 tracing-subscriber = "0.3"
diff --git a/crates/fetcher-api/Cargo.toml b/crates/fetcher-api/Cargo.toml
new file mode 100644
index 0000000..aca33c7
--- /dev/null
+++ b/crates/fetcher-api/Cargo.toml
@@ -0,0 +1,12 @@
+[package]
+name = "fetcher-api"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+jsonrpsee = { workspace = true }
+tokio = { workspace = true }
+serde = { workspace = true }
+serde_json = { workspace = true }
+eyre = { workspace = true }
+tracing = "0.1"
diff --git a/crates/fetcher-api/src/lib.rs b/crates/fetcher-api/src/lib.rs
new file mode 100644
index 0000000..07635ae
--- /dev/null
+++ b/crates/fetcher-api/src/lib.rs
@@ -0,0 +1,22 @@
+use jsonrpsee::{core::SubscriptionResult, proc_macros::rpc};
+use serde::{Deserialize, Serialize};
+
+/// Progress message sent over WebSocket
+#[derive(Debug, Clone, Serialize, Deserialize)]
+#[serde(tag = "type")]
+pub enum ProgressMessage {
+    /// Total size is known
+    SetTotal { total: u64 },
+    /// Progress update
+    Update { downloaded: u64, total: Option<u64> },
+    /// Download finished
+    Finished,
+}
+
+/// JSON-RPC API for fetcher progress tracking
+#[rpc(server, client)]
+pub trait FetcherProgressApi {
+    /// Subscribe to download progress updates via WebSocket
+    #[subscription(name = "subscribeProgress", item = ProgressMessage)]
+    async fn subscribe_progress(&self) -> SubscriptionResult;
+}
diff --git a/crates/fetcher/Cargo.toml b/crates/fetcher/Cargo.toml
index 0f1bc2c..6fd61b4 100644
--- a/crates/fetcher/Cargo.toml
+++ b/crates/fetcher/Cargo.toml
@@ -16,6 +16,9 @@ pin-project-lite = "0.2"
 bytes = "1.0"
 uuid = { version = "1.0", features = ["v4"] }
 eyre = { workspace = true }
+fetcher-api = { workspace = true }
+jsonrpsee = { workspace = true }
+
 url = "2.5"
 flate2 = "1.0"
 tar = "0.4"
diff --git a/crates/fetcher/README.md b/crates/fetcher/README.md
new file mode 100644
index 0000000..77723c8
--- /dev/null
+++ b/crates/fetcher/README.md
@@ -0,0 +1,11 @@
+# Fetcher
+
+A lightweight tool to fetch files from HTTP/HTTPS sources with progress tracking, checksum verification, and automatic extraction of tar.gz archives.
+
+## WebSocket Progress Server
+
+Enable the WebSocket server with `--ws` to stream real-time progress updates via JSON-RPC (default: `127.0.0.1:7070`).
+
+```bash
+echo '{"jsonrpc":"2.0","method":"subscribeProgress","params":[],"id":1}' | websocat ws://127.0.0.1:7070
+```
diff --git a/crates/fetcher/bin/main.rs b/crates/fetcher/bin/main.rs
index c888561..9e58ce3 100644
--- a/crates/fetcher/bin/main.rs
+++ b/crates/fetcher/bin/main.rs
@@ -1,7 +1,8 @@
 use clap::Parser;
-use fetcher::{ConsoleProgressTracker, fetch_with_progress, verify_checksum};
+use fetcher::{ConsoleProgressTracker, fetch_with_progress, verify_checksum, MultiProgressTracker};
 use std::path::PathBuf;
 use std::process;
+use std::sync::Arc;
 
 #[derive(Parser, Debug)]
 #[command(name = "fetcher")]
@@ -20,6 +21,18 @@ struct Args {
     /// Skip download if file exists and checksum matches (requires --checksum)
     #[arg(long, requires = "checksum")]
     skip_if_valid_checksum: bool,
+
+    /// Enable WebSocket progress server
+    #[arg(long)]
+    ws: bool,
+
+    /// Port for WebSocket server (default: 7070)
+    #[arg(long, default_value = "7070")]
+    ws_port: u16,
+
+    /// Bind address for WebSocket server (default: 127.0.0.1)
+    #[arg(long, default_value = "0.0.0.0")]
+    ws_bind_address: String,
 }
 
 #[tokio::main]
@@ -55,7 +68,32 @@ async fn main() {
         }
     }
 
-    let mut progress = ConsoleProgressTracker::new();
+    // Build progress tracker with console, and optionally WebSocket
+    let mut progress = MultiProgressTracker::new().add_tracker(ConsoleProgressTracker::new());
+
+    // Start WebSocket server if enabled
+    let _ws_server_handle = if args.ws {
+        use fetcher::websocket::{start_progress_server, WebSocketProgressTracker};
+        use fetcher_api::ProgressMessage;
+        use tokio::sync::broadcast;
+
+        let addr = format!("{}:{}", args.ws_bind_address, args.ws_port)
+            .parse()
+            .expect("Invalid bind address");
+
+        let (tx, _rx) = broadcast::channel::<ProgressMessage>(100);
+        let tx = Arc::new(tx);
+
+        let handle = start_progress_server(addr, tx.clone())
+            .await
+            .expect("Failed to start WebSocket server");
+
+        progress = progress.add_tracker(WebSocketProgressTracker::new(tx));
+
+        Some(handle)
+    } else {
+        None
+    };
 
     if let Err(e) = fetch_with_progress(
         &args.source,
diff --git a/crates/fetcher/src/lib.rs b/crates/fetcher/src/lib.rs
index c2cbe14..c154b6f 100644
--- a/crates/fetcher/src/lib.rs
+++ b/crates/fetcher/src/lib.rs
@@ -12,6 +12,8 @@ use tokio::io::{AsyncRead, ReadBuf};
 use url::Url;
 use uuid::Uuid;
 
+pub mod websocket;
+
 #[derive(Debug, Clone, Copy, PartialEq)]
 enum ArchiveFormat {
     TarGz,
@@ -95,6 +97,44 @@ impl ProgressTracker for ConsoleProgressTracker {
     }
 }
 
+/// A progress tracker that forwards updates to multiple trackers
+pub struct MultiProgressTracker {
+    trackers: Vec<Box<dyn ProgressTracker>>,
+}
+
+impl MultiProgressTracker {
+    pub fn new() -> Self {
+        Self {
+            trackers: Vec::new(),
+        }
+    }
+
+    pub fn add_tracker<T: ProgressTracker + 'static>(mut self, tracker: T) -> Self {
+        self.trackers.push(Box::new(tracker));
+        self
+    }
+}
+
+impl ProgressTracker for MultiProgressTracker {
+    fn set_total(&mut self, total: u64) {
+        for tracker in &mut self.trackers {
+            tracker.set_total(total);
+        }
+    }
+
+    fn update(&mut self, downloaded: u64) {
+        for tracker in &mut self.trackers {
+            tracker.update(downloaded);
+        }
+    }
+
+    fn finish(&mut self) {
+        for tracker in &mut self.trackers {
+            tracker.finish();
+        }
+    }
+}
+
 pub async fn fetch(source: &str, destination: &PathBuf, checksum: Option<String>) -> Result<()> {
     fetch_with_progress(source, destination, &mut NoOpProgressTracker, checksum).await
 }
diff --git a/crates/fetcher/src/websocket.rs b/crates/fetcher/src/websocket.rs
new file mode 100644
index 0000000..1a429ae
--- /dev/null
+++ b/crates/fetcher/src/websocket.rs
@@ -0,0 +1,106 @@
+use fetcher_api::{FetcherProgressApiServer, ProgressMessage};
+use jsonrpsee::core::SubscriptionResult;
+use std::sync::Arc;
+use tokio::sync::broadcast;
+
+use crate::ProgressTracker;
+
+/// Progress tracker that sends updates to a WebSocket broadcast channel
+pub struct WebSocketProgressTracker {
+    total: Option<u64>,
+    tx: Arc<broadcast::Sender<ProgressMessage>>,
+}
+
+impl WebSocketProgressTracker {
+    pub fn new(tx: Arc<broadcast::Sender<ProgressMessage>>) -> Self {
+        Self { total: None, tx }
+    }
+}
+
+impl ProgressTracker for WebSocketProgressTracker {
+    fn set_total(&mut self, total: u64) {
+        self.total = Some(total);
+        let _ = self.tx.send(ProgressMessage::SetTotal { total });
+    }
+
+    fn update(&mut self, downloaded: u64) {
+        let _ = self.tx.send(ProgressMessage::Update {
+            downloaded,
+            total: self.total,
+        });
+    }
+
+    fn finish(&mut self) {
+        let _ = self.tx.send(ProgressMessage::Finished);
+    }
+}
+
+/// Implementation of the Fetcher Progress RPC server
+pub struct FetcherProgressServer {
+    progress_tx: Arc<broadcast::Sender<ProgressMessage>>,
+}
+
+impl FetcherProgressServer {
+    pub fn new(progress_tx: Arc<broadcast::Sender<ProgressMessage>>) -> Self {
+        Self { progress_tx }
+    }
+}
+
+#[jsonrpsee::core::async_trait]
+impl FetcherProgressApiServer for FetcherProgressServer {
+    async fn subscribe_progress(
+        &self,
+        pending: jsonrpsee::PendingSubscriptionSink,
+    ) -> SubscriptionResult {
+        let sink = match pending.accept().await {
+            Ok(sink) => sink,
+            Err(err) => {
+                tracing::error!("failed to accept subscription: {err}");
+                return Err(err.to_string().into());
+            }
+        };
+
+        let mut rx = self.progress_tx.subscribe();
+
+        tokio::spawn(async move {
+            loop {
+                match rx.recv().await {
+                    Ok(msg) => {
+                        let subscription_msg =
+                            jsonrpsee::SubscriptionMessage::from_json(&msg).unwrap();
+                        let result = sink.send(subscription_msg).await;
+                        if result.is_err() {
+                            break;
+                        }
+                    }
+                    Err(broadcast::error::RecvError::Lagged(n)) => {
+                        tracing::warn!("Progress subscriber lagged by {} messages", n);
+                    }
+                    Err(broadcast::error::RecvError::Closed) => {
+                        break;
+                    }
+                }
+            }
+            tracing::debug!("Progress subscription ended");
+        });
+
+        Ok(())
+    }
+}
+
+/// Start the WebSocket progress server
+pub async fn start_progress_server(
+    addr: std::net::SocketAddr,
+    progress_tx: Arc<broadcast::Sender<ProgressMessage>>,
+) -> Result<jsonrpsee::server::ServerHandle, Box<dyn std::error::Error>> {
+    use jsonrpsee::server::Server;
+
+    let server = Server::builder().build(addr).await?;
+
+    let progress_server = FetcherProgressServer::new(progress_tx);
+    let handle = server.start(progress_server.into_rpc());
+
+    tracing::info!("Progress WebSocket server listening on {}", addr);
+
+    Ok(handle)
+}