diff --git a/Cargo.lock b/Cargo.lock
index e7702f044..ca04c6379 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -28,6 +28,17 @@ dependencies = [
  "cpufeatures",
 ]
 
+[[package]]
+name = "ahash"
+version = "0.7.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "891477e0c6a8957309ee5c45a6368af3ae14bb510732d2684ffa19af310920f9"
+dependencies = [
+ "getrandom",
+ "once_cell",
+ "version_check",
+]
+
 [[package]]
 name = "ahash"
 version = "0.8.11"
@@ -35,6 +46,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e89da841a80418a9b391ebaea17f5c112ffaaa96f621d2c285b5174da76b9011"
 dependencies = [
  "cfg-if",
+ "getrandom",
  "once_cell",
  "version_check",
  "zerocopy",
@@ -136,9 +148,40 @@ dependencies = [
 
 [[package]]
 name = "anyhow"
-version = "1.0.87"
+version = "1.0.89"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "10f00e1f6e58a40e807377c75c6a7f97bf9044fab57816f2414e6f5f4499d7b8"
+checksum = "86fdf8605db99b54d3cd748a44c6d04df638eb5dafb219b135d0149bd0db01f6"
+
+[[package]]
+name = "apollo-compiler"
+version = "1.0.0-beta.22"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6feccaf8fab00732a73dd3a40e4aaa7a1106ceef3c0bfbc591c4e0ba27e07774"
+dependencies = [
+ "ahash 0.8.11",
+ "apollo-parser 0.8.2",
+ "ariadne",
+ "indexmap 2.5.0",
+ "rowan",
+ "serde",
+ "serde_json_bytes",
+ "thiserror",
+ "triomphe",
+ "typed-arena",
+ "uuid",
+]
+
+[[package]]
+name = "apollo-composition"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0b66ac0639701b5dcf6004d5df0030a7836cbb334f80713f644562e5c37559fa"
+dependencies = [
+ "apollo-compiler",
+ "apollo-federation",
+ "apollo-federation-types",
+ "either",
+]
 
 [[package]]
 name = "apollo-encoder"
@@ -150,6 +193,33 @@ dependencies = [
  "thiserror",
 ]
 
+[[package]]
+name = "apollo-federation"
+version = "2.0.0-alpha.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "22ca57e70fa00d8c0f8f01152dd79c648313e78b06c9cf455c4c49bba3a2b1e4"
+dependencies = [
+ "apollo-compiler",
+ "derive_more",
+ "either",
+ "http 0.2.12",
+ "indexmap 2.5.0",
+ "itertools 0.13.0",
+ "lazy_static",
+ "multimap",
+ "nom",
+ "petgraph",
+ "serde",
+ "serde_json",
+ "serde_json_bytes",
+ "strum",
+ "strum_macros",
+ "thiserror",
+ "time",
+ "tracing",
+ "url",
+]
+
 [[package]]
 name = "apollo-federation-types"
 version = "0.14.1"
@@ -167,6 +237,34 @@ dependencies = [
  "url",
 ]
 
+[[package]]
+name = "apollo-language-server"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4cbc734271268fcf9e542e0793f63db202036609ec562fce517075313a3cb4b7"
+dependencies = [
+ "apollo-compiler",
+ "apollo-composition",
+ "apollo-federation",
+ "apollo-federation-types",
+ "apollo-parser 0.8.2",
+ "debounced",
+ "futures",
+ "indexmap 2.5.0",
+ "itertools 0.13.0",
+ "lsp-types",
+ "memoize",
+ "once_cell",
+ "ropey",
+ "semver",
+ "serde",
+ "serde_json",
+ "tokio",
+ "tower-lsp",
+ "tracing",
+ "url",
+]
+
 [[package]]
 name = "apollo-parser"
 version = "0.7.7"
@@ -210,8 +308,9 @@ version = "0.4.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "44055e597c674aef7cb903b2b9f6e4cba1277ed0d2d61dae7cd52d7ffa81f8e2"
 dependencies = [
+ "concolor",
  "unicode-width",
- "yansi 1.0.1",
+ "yansi",
 ]
 
 [[package]]
@@ -404,9 +503,9 @@ dependencies = [
 
 [[package]]
 name = "async-process"
-version = "2.2.4"
+version = "2.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a8a07789659a4d385b79b18b9127fc27e1a59e1e89117c78c5ea3b806f016374"
+checksum = "63255f1dc2381611000436537bbedfe83183faa303a5a0edaf191edef06526bb"
 dependencies = [
  "async-channel 2.3.1",
  "async-io",
@@ -419,7 +518,6 @@ dependencies = [
  "futures-lite",
  "rustix",
  "tracing",
- "windows-sys 0.59.0",
 ]
 
 [[package]]
@@ -563,6 +661,17 @@ version = "1.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1505bd5d3d116872e7271a6d4e16d81d0c8570876c8de68093a09ac269d8aac0"
 
+[[package]]
+name = "auto_impl"
+version = "1.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3c87f3f15e7794432337fc718554eaa4dc8f04c9677a950ffe366f20a162ae42"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.77",
+]
+
 [[package]]
 name = "autocfg"
 version = "1.3.0"
@@ -819,7 +928,7 @@ version = "0.49.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8e8e463fceca5674287f32d252fb1d94083758b8709c160efae66d263e5f4eba"
 dependencies = [
- "ahash",
+ "ahash 0.8.11",
  "cached_proc_macro",
  "cached_proc_macro_types",
  "hashbrown 0.14.5",
@@ -899,9 +1008,9 @@ dependencies = [
 
 [[package]]
 name = "cc"
-version = "1.1.18"
+version = "1.1.19"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b62ac837cdb5cb22e10a256099b4fc502b1dfe560cb282963a974d7abd80e476"
+checksum = "2d74707dde2ba56f86ae90effb3b43ddd369504387e718014de010cec7959800"
 dependencies = [
  "jobserver",
  "libc",
@@ -1050,6 +1159,26 @@ dependencies = [
  "unreachable",
 ]
 
+[[package]]
+name = "concolor"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0b946244a988c390a94667ae0e3958411fa40cc46ea496a929b263d883f5f9c3"
+dependencies = [
+ "bitflags 1.3.2",
+ "concolor-query",
+ "is-terminal",
+]
+
+[[package]]
+name = "concolor-query"
+version = "0.3.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "88d11d52c3d7ca2e6d0040212be9e4dbbcd78b6447f535b6b561f449427944cf"
+dependencies = [
+ "windows-sys 0.45.0",
+]
+
 [[package]]
 name = "concurrent-queue"
 version = "2.5.0"
@@ -1078,6 +1207,12 @@ version = "0.3.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7c74b8349d32d297c9134b8c88677813a227df8f779daa29bfc29c183fe3dca6"
 
+[[package]]
+name = "convert_case"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6245d59a3e82a7fc217c5828a6692dbc6dfb63a0c8c90495621f7b9d79704a0e"
+
 [[package]]
 name = "cookie"
 version = "0.17.0"
@@ -1498,6 +1633,16 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "debounced"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "107e5cd9b5163c19751e53eef634cae25cf5ed5f6d0c81125feaa92e43703cc7"
+dependencies = [
+ "futures-timer",
+ "futures-util",
+]
+
 [[package]]
 name = "deflate64"
 version = "0.1.9"
@@ -1572,6 +1717,19 @@ dependencies = [
  "syn 1.0.109",
 ]
 
+[[package]]
+name = "derive_more"
+version = "0.99.18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5f33878137e4dafd7fa914ad4e259e18a4e8e532b9617a2d0150262bf53abfce"
+dependencies = [
+ "convert_case",
+ "proc-macro2",
+ "quote",
+ "rustc_version",
+ "syn 2.0.77",
+]
+
 [[package]]
 name = "dialoguer"
 version = "0.11.0"
@@ -2318,6 +2476,9 @@ name = "hashbrown"
 version = "0.12.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8a9ee70c43aaf417c914396645a0fa852624801b24ebb7ae78fe8272889ac888"
+dependencies = [
+ "ahash 0.7.8",
+]
 
 [[package]]
 name = "hashbrown"
@@ -2325,7 +2486,7 @@ version = "0.14.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e5274423e17b7c9fc20b6e7e208532f9b19825d82dfd615708b70edd83df41f1"
 dependencies = [
- "ahash",
+ "ahash 0.8.11",
  "allocator-api2",
 ]
 
@@ -2680,9 +2841,9 @@ dependencies = [
 
 [[package]]
 name = "iana-time-zone"
-version = "0.1.60"
+version = "0.1.61"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e7ffbb5a1b541ea2561f8c41c087286cc091e21e556a4f09a8f6cbf17b69b141"
+checksum = "235e081f3925a06703c2d0117ea8b91f042756fd6e7a6e5d901e8ca1a996b220"
 dependencies = [
  "android_system_properties",
  "core-foundation-sys",
@@ -2859,9 +3020,9 @@ checksum = "187674a687eed5fe42285b40c6291f9a01517d415fad1c3cbc6a9f778af7fcd4"
 
 [[package]]
 name = "iri-string"
-version = "0.7.2"
+version = "0.7.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7f5f6c2df22c009ac44f6f1499308e7a3ac7ba42cd2378475cc691510e1eef1b"
+checksum = "3e0f755bd3806e06ad4f366f92639415d99a339a2c7ecf8c26ccea2097c11cb6"
 dependencies = [
  "memchr",
  "serde",
@@ -2932,6 +3093,19 @@ dependencies = [
  "wasm-bindgen",
 ]
 
+[[package]]
+name = "jsonpath-rust"
+version = "0.3.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "06cc127b7c3d270be504572364f9569761a180b981919dd0d87693a7f5fb7829"
+dependencies = [
+ "pest",
+ "pest_derive",
+ "regex",
+ "serde_json",
+ "thiserror",
+]
+
 [[package]]
 name = "jsonwebtoken"
 version = "9.3.0"
@@ -3189,6 +3363,15 @@ dependencies = [
  "logos-codegen",
 ]
 
+[[package]]
+name = "lru"
+version = "0.7.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e999beba7b6e8345721bd280141ed958096a2e4abdf74f67ff4ce49b4b54e47a"
+dependencies = [
+ "hashbrown 0.12.3",
+]
+
 [[package]]
 name = "lru-cache"
 version = "0.1.2"
@@ -3198,6 +3381,19 @@ dependencies = [
  "linked-hash-map",
 ]
 
+[[package]]
+name = "lsp-types"
+version = "0.94.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c66bfd44a06ae10647fe3f8214762e9369fd4248df1350924b4ef9e770a85ea1"
+dependencies = [
+ "bitflags 1.3.2",
+ "serde",
+ "serde_json",
+ "serde_repr",
+ "url",
+]
+
 [[package]]
 name = "lychee-lib"
 version = "0.15.1"
@@ -3315,6 +3511,29 @@ version = "2.7.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "78ca9ab1a0babb1e7d5695e3530886289c18cf2f87ec19a575a0abdce112e3a3"
 
+[[package]]
+name = "memoize"
+version = "0.4.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5df4051db13d0816cf23196d3baa216385ae099339f5d0645a8d9ff2305e82b8"
+dependencies = [
+ "lazy_static",
+ "lru",
+ "memoize-inner",
+]
+
+[[package]]
+name = "memoize-inner"
+version = "0.4.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "27bdece7e91f0d1e33df7b46ec187a93ea0d4e642113a1039ac8bfdd4a3273ac"
+dependencies = [
+ "lazy_static",
+ "proc-macro2",
+ "quote",
+ "syn 1.0.109",
+]
+
 [[package]]
 name = "mime"
 version = "0.3.17"
@@ -3420,6 +3639,15 @@ dependencies = [
  "tokio",
 ]
 
+[[package]]
+name = "multimap"
+version = "0.10.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "defc4c55412d89136f966bbb339008b474350e5e6e78d2714439c386b3137a03"
+dependencies = [
+ "serde",
+]
+
 [[package]]
 name = "nanorand"
 version = "0.7.0"
@@ -3621,6 +3849,15 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "num_threads"
+version = "0.1.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5c7398b9c8b70908f6371f47ed36737907c87c52af34c268fed0bf0ceb92ead9"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "object"
 version = "0.36.4"
@@ -3902,6 +4139,51 @@ version = "2.3.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e3148f5046208a5d56bcfc03053e3ca6334e51da8dfb19b6cdc8b306fae3283e"
 
+[[package]]
+name = "pest"
+version = "2.7.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9c73c26c01b8c87956cea613c907c9d6ecffd8d18a2a5908e5de0adfaa185cea"
+dependencies = [
+ "memchr",
+ "thiserror",
+ "ucd-trie",
+]
+
+[[package]]
+name = "pest_derive"
+version = "2.7.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "664d22978e2815783adbdd2c588b455b1bd625299ce36b2a99881ac9627e6d8d"
+dependencies = [
+ "pest",
+ "pest_generator",
+]
+
+[[package]]
+name = "pest_generator"
+version = "2.7.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a2d5487022d5d33f4c30d91c22afa240ce2a644e87fe08caad974d4eab6badbe"
+dependencies = [
+ "pest",
+ "pest_meta",
+ "proc-macro2",
+ "quote",
+ "syn 2.0.77",
+]
+
+[[package]]
+name = "pest_meta"
+version = "2.7.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0091754bbd0ea592c4deb3a122ce8ecbb0753b738aa82bc055fcc2eccc8d8174"
+dependencies = [
+ "once_cell",
+ "pest",
+ "sha2",
+]
+
 [[package]]
 name = "petgraph"
 version = "0.6.5"
@@ -3910,6 +4192,8 @@ checksum = "b4c5cc86750666a3ed20bdaf5ca2a0344f9c67674cae0515bec2da16fbaa47db"
 dependencies = [
  "fixedbitset",
  "indexmap 2.5.0",
+ "serde",
+ "serde_derive",
 ]
 
 [[package]]
@@ -4101,12 +4385,12 @@ dependencies = [
 
 [[package]]
 name = "pretty_assertions"
-version = "1.4.0"
+version = "1.4.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "af7cee1a6c8a5b9208b3cb1061f10c0cb689087b3d8ce85fb9d2dd7a29b6ba66"
+checksum = "3ae130e2f271fbc2ac3a40fb1d07180839cdbbe443c7a27e1e3c13c5cac0116d"
 dependencies = [
  "diff",
- "yansi 0.5.1",
+ "yansi",
 ]
 
 [[package]]
@@ -4267,9 +4551,9 @@ checksum = "d3edd4d5d42c92f0a659926464d4cce56b562761267ecf0f469d85b7de384175"
 
 [[package]]
 name = "redox_syscall"
-version = "0.5.3"
+version = "0.5.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2a908a6e00f1fdd0dfd9c0eb08ce85126f6d8bbda50017e74bc4a4b7d4a926a4"
+checksum = "0884ad60e090bf1345b93da0a5de8923c93884cd03f40dfcfddd3b4bee661853"
 dependencies = [
  "bitflags 2.6.0",
 ]
@@ -4473,12 +4757,23 @@ dependencies = [
  "uuid",
 ]
 
+[[package]]
+name = "ropey"
+version = "1.6.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "93411e420bcd1a75ddd1dc3caf18c23155eda2c090631a85af21ba19e97093b5"
+dependencies = [
+ "smallvec",
+ "str_indices",
+]
+
 [[package]]
 name = "rover"
-version = "0.26.2"
+version = "0.27.0-alpha.0"
 dependencies = [
  "anyhow",
  "apollo-federation-types",
+ "apollo-language-server",
  "apollo-parser 0.8.2",
  "assert-json-diff",
  "assert_cmd",
@@ -4548,6 +4843,7 @@ dependencies = [
  "tokio-stream",
  "toml",
  "tower 0.5.1",
+ "tower-lsp",
  "tracing",
  "tracing-test",
  "url",
@@ -4747,9 +5043,9 @@ dependencies = [
 
 [[package]]
 name = "rustix"
-version = "0.38.36"
+version = "0.38.37"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3f55e80d50763938498dd5ebb18647174e0c76dc38c5505294bb224624f30f36"
+checksum = "8acb788b847c24f28525660c4d7758620a7210875711f79e7f663cc152726811"
 dependencies = [
  "bitflags 2.6.0",
  "errno",
@@ -4939,12 +5235,28 @@ version = "1.0.128"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6ff5456707a1de34e7e37f2a6fd3d3f808c318259cbd01ab6377795054b483d8"
 dependencies = [
+ "indexmap 2.5.0",
  "itoa",
  "memchr",
  "ryu",
  "serde",
 ]
 
+[[package]]
+name = "serde_json_bytes"
+version = "0.2.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0ecd92a088fb2500b2f146c9ddc5da9950bb7264d3f00932cd2a6fb369c26c46"
+dependencies = [
+ "ahash 0.8.11",
+ "bytes",
+ "indexmap 2.5.0",
+ "jsonpath-rust",
+ "regex",
+ "serde",
+ "serde_json",
+]
+
 [[package]]
 name = "serde_json_traversal"
 version = "0.2.0"
@@ -4971,6 +5283,17 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "serde_repr"
+version = "0.1.19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6c64451ba24fc7a6a2d60fc75dd9c83c90903b19028d4eff35e88fc1e86564e9"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.77",
+]
+
 [[package]]
 name = "serde_spanned"
 version = "0.6.7"
@@ -5321,6 +5644,18 @@ dependencies = [
  "wsl",
 ]
 
+[[package]]
+name = "stable_deref_trait"
+version = "1.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a8f112729512f8e442d81f95a8a7ddf2b7c6b8a1a6f509a95864142b30cab2d3"
+
+[[package]]
+name = "str_indices"
+version = "0.4.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e9557cb6521e8d009c51a8666f09356f4b817ba9ba0981a305bd86aee47bd35c"
+
 [[package]]
 name = "str_inflector"
 version = "0.12.0"
@@ -5622,7 +5957,9 @@ checksum = "5dfd88e563464686c916c7e46e623e520ddc6d79fa6641390f2e3fa86e83e885"
 dependencies = [
  "deranged",
  "itoa",
+ "libc",
  "num-conv",
+ "num_threads",
  "powerfmt",
  "serde",
  "time-core",
@@ -5860,6 +6197,40 @@ version = "0.3.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "121c2a6cda46980bb0fcd1647ffaf6cd3fc79a013de288782836f6df9c48780e"
 
+[[package]]
+name = "tower-lsp"
+version = "0.20.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d4ba052b54a6627628d9b3c34c176e7eda8359b7da9acd497b9f20998d118508"
+dependencies = [
+ "async-trait",
+ "auto_impl",
+ "bytes",
+ "dashmap",
+ "futures",
+ "httparse",
+ "lsp-types",
+ "memchr",
+ "serde",
+ "serde_json",
+ "tokio",
+ "tokio-util",
+ "tower 0.4.13",
+ "tower-lsp-macros",
+ "tracing",
+]
+
+[[package]]
+name = "tower-lsp-macros"
+version = "0.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "84fd902d4e0b9a4b27f2f440108dc034e1758628a9b702f8ec61ad66355422fa"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.77",
+]
+
 [[package]]
 name = "tower-service"
 version = "0.3.3"
@@ -5964,6 +6335,16 @@ dependencies = [
  "syn 2.0.77",
 ]
 
+[[package]]
+name = "triomphe"
+version = "0.1.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e6631e42e10b40c0690bf92f404ebcfe6e1fdb480391d15f17cc8e96eeed5369"
+dependencies = [
+ "serde",
+ "stable_deref_trait",
+]
+
 [[package]]
 name = "trust-dns-proto"
 version = "0.21.2"
@@ -6034,6 +6415,12 @@ dependencies = [
  "syn 2.0.77",
 ]
 
+[[package]]
+name = "typed-arena"
+version = "2.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6af6ae20167a9ece4bcb41af5b80f8a1f1df981f6391189ce00fd257af04126a"
+
 [[package]]
 name = "typed-builder"
 version = "0.18.2"
@@ -6060,6 +6447,12 @@ version = "1.17.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "42ff0bf0c66b8238c6f3b578df37d0b7848e55df8577b3f74f92a69acceeb825"
 
+[[package]]
+name = "ucd-trie"
+version = "0.1.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ed646292ffc8188ef8ea4d1e0e0150fb15a5c2e12ad9b8fc191ae7a8a7f3c4b9"
+
 [[package]]
 name = "unicase"
 version = "2.7.0"
@@ -6077,9 +6470,9 @@ checksum = "08f95100a766bf4f8f28f90d77e0a5461bbdb219042e7679bebe79004fed8d75"
 
 [[package]]
 name = "unicode-ident"
-version = "1.0.12"
+version = "1.0.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3354b9ac3fae1ff6755cb6db53683adb661634f67557942dea4facebec0fee4b"
+checksum = "e91b56cd4cadaeb79bbf1a5645f6b4f8dc5bde8834ad5894a8db35fda9efa1fe"
 
 [[package]]
 name = "unicode-normalization"
@@ -6155,6 +6548,7 @@ checksum = "81dfa00651efa65069b0b6b651f4aaa31ba9e3c3ce0137aaad053604ee7e0314"
 dependencies = [
  "getrandom",
  "serde",
+ "wasm-bindgen",
 ]
 
 [[package]]
@@ -6418,6 +6812,15 @@ dependencies = [
  "windows-targets 0.52.6",
 ]
 
+[[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 = "0.48.0"
@@ -6445,6 +6848,21 @@ dependencies = [
  "windows-targets 0.52.6",
 ]
 
+[[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 = "0.48.5"
@@ -6476,6 +6894,12 @@ dependencies = [
  "windows_x86_64_msvc 0.52.6",
 ]
 
+[[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 = "0.48.5"
@@ -6488,6 +6912,12 @@ version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "32a4622180e7a0ec044bb555404c800bc9fd9ec262ec147edd5989ccd0c02cd3"
 
+[[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 = "0.48.5"
@@ -6500,6 +6930,12 @@ version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "09ec2a7bb152e2252b53fa7803150007879548bc709c039df7627cabbd05d469"
 
+[[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 = "0.48.5"
@@ -6518,6 +6954,12 @@ version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0eee52d38c090b3caa76c563b86c3a4bd71ef1a819287c19d586d7334ae8ed66"
 
+[[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 = "0.48.5"
@@ -6530,6 +6972,12 @@ version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "240948bc05c5e7c6dabba28bf89d89ffce3e303022809e73deaefe4f6ec56c66"
 
+[[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 = "0.48.5"
@@ -6542,6 +6990,12 @@ version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "147a5c80aabfbf0c7d901cb5895d1de30ef2907eb21fbbab29ca94c5b08b1a78"
 
+[[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 = "0.48.5"
@@ -6554,6 +7008,12 @@ version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "24d5b23dc417412679681396f2b49f3de8c1473deb516bd34410872eff51ed0d"
 
+[[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 = "0.48.5"
@@ -6667,12 +7127,6 @@ dependencies = [
  "linked-hash-map",
 ]
 
-[[package]]
-name = "yansi"
-version = "0.5.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "09041cd90cf85f7f8b2df60c646f853b7f535ce68f85244eb6731cf89fa498ec"
-
 [[package]]
 name = "yansi"
 version = "1.0.1"
diff --git a/Cargo.toml b/Cargo.toml
index da2593e4e..c469553b3 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -11,7 +11,7 @@ license-file = "./LICENSE"
 name = "rover"
 readme = "README.md"
 repository = "https://github.com/apollographql/rover/"
-version = "0.26.2"
+version = "0.27.0-alpha.0"
 default-run = "rover"
 
 publish = false
@@ -70,6 +70,12 @@ apollo-encoder = "0.8"
 
 # https://github.com/apollographql/federation-rs
 apollo-federation-types = "0.14.1"
+# apollo-federation-types = { path = "../federation-rs/apollo-federation-types" }
+# apollo-federation-types = { git = "https://github.com/apollographql/federation-rs.git", branch = "connectors"}
+
+# https://github.com/mdg-private/language-server
+apollo-language-server = { version = "0.1.1", default-features = false, features = ["tokio"] }
+# apollo-language-server = { path = "../language-server/crates/language-server-core", default-features = false, features = ["tokio"] }
 
 # crates.io dependencies
 anyhow = "1"
@@ -165,10 +171,11 @@ zip = "2.0"
 ### rover specific dependencies
 [dependencies]
 anyhow = { workspace = true }
-assert_fs = { workspace = true }
-async-trait = { workspace = true }
 apollo-federation-types = { workspace = true }
+apollo-language-server = { workspace = true }
 apollo-parser = { workspace = true }
+assert_fs = { workspace = true }
+async-trait = { workspace = true }
 billboard = { workspace = true }
 binstall = { workspace = true }
 buildstructor = { workspace = true }
@@ -217,6 +224,7 @@ tokio = { workspace = true, features = ["rt", "rt-multi-thread", "macros", "proc
 tokio-stream = { workspace = true }
 toml = { workspace = true }
 tower = { workspace = true }
+tower-lsp = { version = "0.20.0" }
 tracing = { workspace = true }
 which = { workspace = true }
 uuid = { workspace = true }
diff --git a/crates/rover-client/package-lock.json b/crates/rover-client/package-lock.json
index 0937ec0ec..2671aab9e 100644
--- a/crates/rover-client/package-lock.json
+++ b/crates/rover-client/package-lock.json
@@ -448,9 +448,9 @@
       }
     },
     "node_modules/@eslint-community/regexpp": {
-      "version": "4.11.0",
-      "resolved": "https://registry.npmjs.org/@eslint-community/regexpp/-/regexpp-4.11.0.tgz",
-      "integrity": "sha512-G/M/tIiMrTAxEWRfLfQJMmGNX28IxBg4PBz8XqQhqUHLFI6TL2htpIB1iQCj144V5ee/JaKyT9/WZ0MGZWfA7A==",
+      "version": "4.11.1",
+      "resolved": "https://registry.npmjs.org/@eslint-community/regexpp/-/regexpp-4.11.1.tgz",
+      "integrity": "sha512-m4DVN9ZqskZoLU5GlWZadwDnYo3vAEydiUayB9widCl9ffWx2IvPnp6n3on5rJmziJSw9Bv+Z3ChDVdMwXCY8Q==",
       "dev": true,
       "license": "MIT",
       "engines": {
@@ -1101,9 +1101,9 @@
       "license": "MIT"
     },
     "node_modules/@types/node": {
-      "version": "22.5.4",
-      "resolved": "https://registry.npmjs.org/@types/node/-/node-22.5.4.tgz",
-      "integrity": "sha512-FDuKUJQm/ju9fT/SeX/6+gBzoPzlVCzfzmGkwKvRHQVxi4BntVbyIwf6a4Xn62mrvndLiml6z/UBXIdEVjQLXg==",
+      "version": "22.5.5",
+      "resolved": "https://registry.npmjs.org/@types/node/-/node-22.5.5.tgz",
+      "integrity": "sha512-Xjs4y5UPO/CLdzpgR6GirZJx36yScjh73+2NlLlkFRSoQN8B0DpfXPdZGnvVmLRLOsqDpOfTNv7D9trgGhmOIA==",
       "dev": true,
       "license": "MIT",
       "dependencies": {
@@ -1511,9 +1511,9 @@
       }
     },
     "node_modules/electron-to-chromium": {
-      "version": "1.5.18",
-      "resolved": "https://registry.npmjs.org/electron-to-chromium/-/electron-to-chromium-1.5.18.tgz",
-      "integrity": "sha512-1OfuVACu+zKlmjsNdcJuVQuVE61sZOLbNM4JAQ1Rvh6EOj0/EUKhMJjRH73InPlXSh8HIJk1cVZ8pyOV/FMdUQ==",
+      "version": "1.5.23",
+      "resolved": "https://registry.npmjs.org/electron-to-chromium/-/electron-to-chromium-1.5.23.tgz",
+      "integrity": "sha512-mBhODedOXg4v5QWwl21DjM5amzjmI1zw9EPrPK/5Wx7C8jt33bpZNrC7OhHUG3pxRtbLpr3W2dXT+Ph1SsfRZA==",
       "dev": true,
       "license": "ISC",
       "peer": true
diff --git a/deny.toml b/deny.toml
index 708521cef..aca4b27bd 100644
--- a/deny.toml
+++ b/deny.toml
@@ -58,6 +58,24 @@ version = "*"
 expression = "(Apache-2.0 OR MIT) AND BSD-3-Clause"
 license-files = [{ path = "COPYRIGHT", hash = 0x39f8ad31 }]
 
+[[licenses.clarify]]
+name = "apollo-language-server"
+version = "*"
+expression = "Elastic-2.0"
+license-files = [{ path = "LICENSE.md", hash = 0x5fc4a573 }]
+
+[[licenses.exceptions]]
+name = "apollo-language-server"
+allow = ["Elastic-2.0"]
+
+[[licenses.exceptions]]
+name = "apollo-federation"
+allow = ["Elastic-2.0"]
+
+[[licenses.exceptions]]
+name = "apollo-composition"
+allow = ["Elastic-2.0"]
+
 # This section is considered when running `cargo deny check bans`.
 # More documentation about the 'bans' section can be found here:
 # https://embarkstudios.github.io/cargo-deny/checks/bans/cfg.html
diff --git a/installers/binstall/scripts/nix/install.sh b/installers/binstall/scripts/nix/install.sh
index db4b54d79..410d8931e 100755
--- a/installers/binstall/scripts/nix/install.sh
+++ b/installers/binstall/scripts/nix/install.sh
@@ -20,7 +20,7 @@ BINARY_DOWNLOAD_PREFIX="https://github.com/apollographql/rover/releases/download
 # Rover version defined in root cargo.toml
 # Note: this line is built automatically
 # in build.rs. Don't touch it!
-PACKAGE_VERSION="v0.26.2"
+PACKAGE_VERSION="v0.27.0-alpha.0"
 
 download_binary_and_run_installer() {
     downloader --check
diff --git a/installers/binstall/scripts/windows/install.ps1 b/installers/binstall/scripts/windows/install.ps1
index 543f74d6e..90163ef42 100644
--- a/installers/binstall/scripts/windows/install.ps1
+++ b/installers/binstall/scripts/windows/install.ps1
@@ -14,7 +14,7 @@
 # version found in Rover's Cargo.toml
 # Note: this line is built automatically
 # in build.rs. Don't touch it!
-$package_version = 'v0.26.2'
+$package_version = 'v0.27.0-alpha.0'
 
 function Install-Binary($rover_install_args) {
   $old_erroractionpreference = $ErrorActionPreference
diff --git a/installers/npm/package-lock.json b/installers/npm/package-lock.json
index 164c61bbd..c2f5065c7 100644
--- a/installers/npm/package-lock.json
+++ b/installers/npm/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "@apollo/rover",
-  "version": "0.26.2",
+  "version": "0.27.0-alpha.0",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "@apollo/rover",
-      "version": "0.26.2",
+      "version": "0.27.0-alpha.0",
       "hasInstallScript": true,
       "license": "MIT",
       "dependencies": {
@@ -1238,9 +1238,9 @@
       }
     },
     "node_modules/@types/node": {
-      "version": "22.5.4",
-      "resolved": "https://registry.npmjs.org/@types/node/-/node-22.5.4.tgz",
-      "integrity": "sha512-FDuKUJQm/ju9fT/SeX/6+gBzoPzlVCzfzmGkwKvRHQVxi4BntVbyIwf6a4Xn62mrvndLiml6z/UBXIdEVjQLXg==",
+      "version": "22.5.5",
+      "resolved": "https://registry.npmjs.org/@types/node/-/node-22.5.5.tgz",
+      "integrity": "sha512-Xjs4y5UPO/CLdzpgR6GirZJx36yScjh73+2NlLlkFRSoQN8B0DpfXPdZGnvVmLRLOsqDpOfTNv7D9trgGhmOIA==",
       "dev": true,
       "license": "MIT",
       "dependencies": {
@@ -1916,9 +1916,9 @@
       }
     },
     "node_modules/electron-to-chromium": {
-      "version": "1.5.18",
-      "resolved": "https://registry.npmjs.org/electron-to-chromium/-/electron-to-chromium-1.5.18.tgz",
-      "integrity": "sha512-1OfuVACu+zKlmjsNdcJuVQuVE61sZOLbNM4JAQ1Rvh6EOj0/EUKhMJjRH73InPlXSh8HIJk1cVZ8pyOV/FMdUQ==",
+      "version": "1.5.23",
+      "resolved": "https://registry.npmjs.org/electron-to-chromium/-/electron-to-chromium-1.5.23.tgz",
+      "integrity": "sha512-mBhODedOXg4v5QWwl21DjM5amzjmI1zw9EPrPK/5Wx7C8jt33bpZNrC7OhHUG3pxRtbLpr3W2dXT+Ph1SsfRZA==",
       "dev": true,
       "license": "ISC"
     },
diff --git a/installers/npm/package.json b/installers/npm/package.json
index a878e5392..daae9c41b 100644
--- a/installers/npm/package.json
+++ b/installers/npm/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@apollo/rover",
-  "version": "0.26.2",
+  "version": "0.27.0-alpha.0",
   "description": "The new Apollo CLI",
   "main": "index.js",
   "bin": {
diff --git a/src/cli.rs b/src/cli.rs
index 89a204865..79508e4cb 100644
--- a/src/cli.rs
+++ b/src/cli.rs
@@ -235,6 +235,8 @@ impl Rover {
             Command::Explain(command) => command.run(),
             Command::PersistedQueries(command) => command.run(self.get_client_config()?).await,
             Command::License(command) => command.run(self.get_client_config()?).await,
+            #[cfg(feature = "composition-js")]
+            Command::Lsp(command) => command.run(self.get_client_config()?).await,
         }
     }
 
@@ -437,6 +439,10 @@ pub enum Command {
 
     /// Commands for fetching offline licenses
     License(command::License),
+
+    /// Start the language server
+    #[cfg(feature = "composition-js")]
+    Lsp(command::Lsp),
 }
 
 #[derive(Default, ValueEnum, Debug, Serialize, Clone, Copy, Eq, PartialEq)]
diff --git a/src/command/lsp/README.md b/src/command/lsp/README.md
new file mode 100644
index 000000000..355e93584
--- /dev/null
+++ b/src/command/lsp/README.md
@@ -0,0 +1,14 @@
+# Build / configuration
+
+1. Clone mdg-private/language-server repo (adjacent to this repo, the language
+   server dependency is currently specified as a path in Cargo.toml)
+   > apollo-language-server-core = { path = "../language-server/crates/language-server-core" }
+2. From this repo, run `cargo update -p apollo-language-server-core` to
+   build/rebuild changes made to the language server.
+3. To rebuild the rover binary, run `cargo build`
+4. Build is located at `target/debug/rover`
+
+In case you're looking to sanity check the binary, there's a sample `input.txt`
+file you can paste into stdin to see if the binary is working as expected. I'm
+not sure why it breaks when I try to redirect the input from a file, but it
+works as expected when I paste the contents of the file into stdin.
diff --git a/src/command/lsp/input.txt b/src/command/lsp/input.txt
new file mode 100644
index 000000000..bc938633e
--- /dev/null
+++ b/src/command/lsp/input.txt
@@ -0,0 +1,9 @@
+Content-Length: 75
+
+{"jsonrpc":"2.0","method":"initialize","params":{"capabilities":{}},"id":0}Content-Length: 185
+
+{"jsonrpc":"2.0","method":"textDocument/didOpen","params":{"textDocument":{"uri":"file:///path/to/file","version":1,"languageId":"apollo-graphql","text":"type Query { hello: Strin }"}}}Content-Length: 180
+
+{"jsonrpc":"2.0","method":"textDocument/didChange","params":{"textDocument":{"uri":"file:///path/to/file","version":2},"contentChanges":[{"text":"type Query { hello: String! }"}]}}Content-Length: 178
+
+{"jsonrpc":"2.0","method":"textDocument/didChange","params":{"textDocument":{"uri":"file:///path/to/file","version":3},"contentChanges":[{"text":"type Query { hello: Strin }"}]}}Content-Length: 0
\ No newline at end of file
diff --git a/src/command/lsp/mod.rs b/src/command/lsp/mod.rs
new file mode 100644
index 000000000..96c5166a0
--- /dev/null
+++ b/src/command/lsp/mod.rs
@@ -0,0 +1,162 @@
+use core::panic;
+
+use apollo_federation_types::{
+    config::{FederationVersion, SupergraphConfig},
+    javascript::SubgraphDefinition,
+    rover::BuildErrors,
+};
+use apollo_language_server::{ApolloLanguageServer, Config};
+use clap::Parser;
+use futures::{channel::mpsc::Receiver, StreamExt};
+use serde::Serialize;
+use tower_lsp::Server;
+
+use super::supergraph::compose::Compose;
+use crate::{
+    options::PluginOpts,
+    utils::{
+        client::StudioClientConfig, parsers::FileDescriptorType,
+        supergraph_config::resolve_supergraph_yaml,
+    },
+    RoverOutput, RoverResult,
+};
+
+#[derive(Debug, Serialize, Parser)]
+pub struct Lsp {
+    #[clap(flatten)]
+    pub(crate) opts: LspOpts,
+}
+
+#[derive(Clone, Debug, Serialize, Parser)]
+pub struct LspOpts {
+    #[clap(flatten)]
+    pub plugin_opts: PluginOpts,
+
+    /// The relative path to the supergraph configuration file. You can pass `-` to use stdin instead of a file.
+    #[serde(skip_serializing)]
+    #[arg(long = "supergraph-config")]
+    supergraph_yaml: Option<FileDescriptorType>,
+}
+
+impl Lsp {
+    pub async fn run(&self, client_config: StudioClientConfig) -> RoverResult<RoverOutput> {
+        self.opts
+            .plugin_opts
+            .prompt_for_license_accept(&client_config)?;
+
+        run_lsp(client_config, &self.opts).await;
+        Ok(RoverOutput::EmptySuccess)
+    }
+}
+
+async fn run_lsp(client_config: StudioClientConfig, lsp_opts: &LspOpts) {
+    let (service, socket, receiver) = ApolloLanguageServer::build_service(Config {
+        root_uri: "".into(),
+        enable_auto_composition: true,
+        force_federation: false,
+        disable_telemetry: false,
+    });
+
+    let language_server = service.inner().clone();
+
+    tokio::spawn(run_composer_in_thread(
+        receiver,
+        lsp_opts.clone(),
+        client_config,
+        language_server,
+    ));
+
+    let stdin = tokio::io::stdin();
+    let stdout = tokio::io::stdout();
+    let server = Server::new(stdin, stdout, socket);
+    server.serve(service).await;
+}
+
+async fn run_composer_in_thread(
+    mut receiver: Receiver<Vec<SubgraphDefinition>>,
+    lsp_opts: LspOpts,
+    client_config: StudioClientConfig,
+    language_server: ApolloLanguageServer,
+) {
+    let composer = Compose::new(lsp_opts.plugin_opts.clone());
+    let federation_version =
+        dbg!(get_federation_version(lsp_opts.clone(), client_config.clone()).await);
+    match composer
+        .maybe_install_supergraph(None, client_config.clone(), federation_version.clone())
+        .await
+    {
+        Ok(_) => {}
+        Err(err) => {
+            panic!("Failed to install supergraph plugin: {:?}", err);
+        }
+    };
+
+    while let Some(mut definitions) = receiver.next().await {
+        while let Some(next_definitions) = receiver.try_next().ok().flatten() {
+            definitions = next_definitions
+        }
+        tracing::info!("Received message: {:?}", definitions);
+        dbg!(&definitions);
+
+        let mut supergraph_config = SupergraphConfig::from(definitions);
+        supergraph_config.set_federation_version(federation_version.clone());
+
+        match composer
+            .compose(None, client_config.clone(), &mut supergraph_config, None)
+            .await
+        {
+            Ok(RoverOutput::CompositionResult(composition_output)) => {
+                dbg!(&composition_output);
+                language_server
+                    .composition_did_update(
+                        Some(composition_output.supergraph_sdl),
+                        composition_output
+                            .hints
+                            .into_iter()
+                            .map(Into::into)
+                            .collect(),
+                        None,
+                    )
+                    .await
+            }
+            Err(rover_error) => {
+                dbg!(&rover_error);
+                let build_errors: BuildErrors = rover_error.into();
+                dbg!(&build_errors);
+                language_server
+                    .composition_did_update(
+                        None,
+                        build_errors.into_iter().map(Into::into).collect(),
+                        None,
+                    )
+                    .await
+            }
+            _ => panic!("Expected CompositionResult"),
+        }
+    }
+}
+
+async fn get_federation_version(
+    lsp_opts: LspOpts,
+    client_config: StudioClientConfig,
+) -> FederationVersion {
+    if let Some(supergraph_yaml) = &lsp_opts.supergraph_yaml {
+        if let Ok(supergraph_config) = resolve_supergraph_yaml(
+            supergraph_yaml,
+            client_config.clone(),
+            &lsp_opts.plugin_opts.profile,
+            true,
+        )
+        .await
+        {
+            supergraph_config
+                .get_federation_version()
+                .unwrap_or(FederationVersion::LatestFedTwo)
+        } else {
+            tracing::warn!("Failed to resolve supergraph yaml");
+            FederationVersion::LatestFedTwo
+        }
+    } else {
+        FederationVersion::LatestFedTwo
+    }
+}
diff --git a/src/command/mod.rs b/src/command/mod.rs
index 481cb9487..43b98059f 100644
--- a/src/command/mod.rs
+++ b/src/command/mod.rs
@@ -9,6 +9,8 @@ mod graph;
 mod info;
 pub(crate) mod install;
 mod license;
+#[cfg(feature = "composition-js")]
+mod lsp;
 pub(crate) mod output;
 mod persisted_queries;
 mod readme;
@@ -28,6 +30,8 @@ pub use graph::Graph;
 pub use info::Info;
 pub use install::Install;
 pub use license::License;
+#[cfg(feature = "composition-js")]
+pub use lsp::Lsp;
 pub use output::RoverOutput;
 pub use persisted_queries::PersistedQueries;
 pub use readme::Readme;
diff --git a/src/error/mod.rs b/src/error/mod.rs
index 2ed9a0611..a00e80c9c 100644
--- a/src/error/mod.rs
+++ b/src/error/mod.rs
@@ -156,3 +156,15 @@ impl<E: Into<anyhow::Error>> From<E> for RoverError {
         Self::new(error)
     }
 }
+
+impl From<RoverError> for BuildErrors {
+    fn from(rover_error: RoverError) -> Self {
+        match rover_error.error.downcast_ref::<RoverClientError>() {
+            Some(RoverClientError::BuildErrors { source, .. }) => BuildErrors {
+                build_errors: source.build_errors.clone(),
+                is_config: source.is_config,
+            },
+            _ => panic!("Expected RoverClientError::BuildErrors"),
+        }
+    }
+}