diff --git a/Cargo.lock b/Cargo.lock
index 4ea3fdd..eac29a4 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2,6 +2,12 @@
 # It is not intended for manual editing.
 version = 4
 
+[[package]]
+name = "adler2"
+version = "2.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "320119579fcad9c21884f5c4861d16174d0e06250625266f50fe6898340abefa"
+
 [[package]]
 name = "aho-corasick"
 version = "1.1.5"
@@ -205,8 +211,15 @@ name = "arr-subs"
 version = "0.1.0"
 dependencies = [
  "arr-core",
+ "arr-parse",
+ "reqwest",
+ "serde",
+ "serde_json",
  "thiserror",
  "tokio",
+ "tracing",
+ "wiremock",
+ "zip",
 ]
 
 [[package]]
@@ -433,6 +446,15 @@ version = "2.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "217698eaf96b4a3f0bc4f3662aaa55bdf913cd54d7204591faa790070c6d0853"
 
+[[package]]
+name = "crc32fast"
+version = "1.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8498c871161e1742aaa9d52551b2d6ebdd4c3d45a3be423e3728f33b955be550"
+dependencies = [
+ "cfg-if",
+]
+
 [[package]]
 name = "crossbeam-queue"
 version = "0.3.13"
@@ -589,6 +611,16 @@ version = "0.1.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d45db016d36b838f563236e9193d0ee6ce38f3f68b6c94e914b4929c96bbb890"
 
+[[package]]
+name = "flate2"
+version = "1.1.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "843fba2746e448b37e26a819579957415c8cef339bf08564fe8b7ddbd959573c"
+dependencies = [
+ "miniz_oxide",
+ "zlib-rs",
+]
+
 [[package]]
 name = "flume"
 version = "0.12.0"
@@ -1238,6 +1270,16 @@ dependencies = [
  "unicase",
 ]
 
+[[package]]
+name = "miniz_oxide"
+version = "0.8.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1fa76a2c86f704bdb222d66965fb3d63269ce38518b83cb0575fca855ebb6316"
+dependencies = [
+ "adler2",
+ "simd-adler32",
+]
+
 [[package]]
 name = "mio"
 version = "1.2.2"
@@ -1756,6 +1798,12 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "simd-adler32"
+version = "0.3.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3a219298ac11a56ea9a6d2120044824d6f01aeb034955e7af7bc16858527deea"
+
 [[package]]
 name = "slab"
 version = "0.4.12"
@@ -2315,6 +2363,12 @@ version = "0.2.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e421abadd41a4225275504ea4d6566923418b7f05506fbc9c0fe86ba7396114b"
 
+[[package]]
+name = "typed-path"
+version = "0.12.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8e28f89b80c87b8fb0cf04ab448d5dd0dd0ade2f8891bae878de66a75a28600e"
+
 [[package]]
 name = "typenum"
 version = "1.20.1"
@@ -2824,6 +2878,25 @@ dependencies = [
  "syn 3.0.3",
 ]
 
+[[package]]
+name = "zip"
+version = "8.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2d04a6b5381502aa6087c94c669499eb1602eb9c5e8198e534de571f7154809b"
+dependencies = [
+ "crc32fast",
+ "flate2",
+ "indexmap",
+ "memchr",
+ "typed-path",
+]
+
+[[package]]
+name = "zlib-rs"
+version = "0.6.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "34b31d188d9d685a4f9c7b46d6e36631b07058d2cfe190267adce54dc230bf12"
+
 [[package]]
 name = "zmij"
 version = "1.0.23"
diff --git a/Cargo.toml b/Cargo.toml
index 5dff684..12a051c 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -55,6 +55,7 @@ tracing = "0.1"
 tracing-subscriber = { version = "0.3", features = ["env-filter"] }
 url = "2"
 uuid = { version = "1", features = ["v4", "serde"] }
+zip = { version = "8", default-features = false, features = ["deflate-flate2-zlib-rs"] }
 
 # Test-only
 tempfile = "3"
diff --git a/crates/arr-subs/Cargo.toml b/crates/arr-subs/Cargo.toml
index bcabaff..a9efccb 100644
--- a/crates/arr-subs/Cargo.toml
+++ b/crates/arr-subs/Cargo.toml
@@ -19,10 +19,17 @@ translate-command = []
 
 [dependencies]
 arr-core.workspace = true
+arr-parse.workspace = true
+reqwest.workspace = true
+serde.workspace = true
+serde_json.workspace = true
 thiserror.workspace = true
+tracing.workspace = true
+zip.workspace = true
 
 [dev-dependencies]
 tokio = { workspace = true, features = ["macros", "rt-multi-thread"] }
+wiremock.workspace = true
 
 [lints]
 workspace = true
diff --git a/crates/arr-subs/src/error.rs b/crates/arr-subs/src/error.rs
index 6df7d43..55b5f8d 100644
--- a/crates/arr-subs/src/error.rs
+++ b/crates/arr-subs/src/error.rs
@@ -74,6 +74,17 @@ pub enum Error {
         #[source]
         source: std::io::Error,
     },
+
+    /// The provider could not be constructed: a bad base URL, or its HTTP
+    /// client failed to build. Always a caller bug — a hardcoded URL or a
+    /// test override — never a fact about the live service.
+    #[error("{provider} could not be configured: {detail}")]
+    Config {
+        /// The provider being constructed.
+        provider: ProviderId,
+        /// What went wrong, short enough to log.
+        detail: String,
+    },
 }
 
 impl Error {