diff --git a/Cargo.lock b/Cargo.lock
index f2799a7b69..b566a0e2e8 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2034,7 +2034,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "778e2ac28f6c47af28e4907f13ffd1e1ddbd400980a9abd7c8df189bf578a5ad"
 dependencies = [
  "libc",
- "windows-sys 0.60.2",
+ "windows-sys 0.52.0",
 ]
 
 [[package]]
@@ -4286,7 +4286,7 @@ dependencies = [
  "once_cell",
  "socket2 0.6.4",
  "tracing",
- "windows-sys 0.60.2",
+ "windows-sys 0.52.0",
 ]
 
 [[package]]
@@ -4675,7 +4675,7 @@ dependencies = [
  "errno",
  "libc",
  "linux-raw-sys 0.9.4",
- "windows-sys 0.60.2",
+ "windows-sys 0.52.0",
 ]
 
 [[package]]
@@ -5344,9 +5344,8 @@ dependencies = [
 
 [[package]]
 name = "soroban-builtin-sdk-macros"
-version = "28.0.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "86ffd329211a50add3965a8f4a8f70e24fc5c8268c945566ab963029b12dce40"
+version = "29.0.0"
+source = "git+https://github.com/stellar/rs-soroban-env?rev=de68ee914401e70d3d8350a4d004c0442943324e#de68ee914401e70d3d8350a4d004c0442943324e"
 dependencies = [
  "itertools 0.13.0",
  "proc-macro2",
@@ -5449,9 +5448,8 @@ dependencies = [
 
 [[package]]
 name = "soroban-env-common"
-version = "28.0.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "610bb12ee937a56c2b629f8eb16efb7e47607cba4e79ab0c24132b9a53dd19a0"
+version = "29.0.0"
+source = "git+https://github.com/stellar/rs-soroban-env?rev=de68ee914401e70d3d8350a4d004c0442943324e#de68ee914401e70d3d8350a4d004c0442943324e"
 dependencies = [
  "arbitrary",
  "crate-git-revision 0.0.9",
@@ -5468,9 +5466,8 @@ dependencies = [
 
 [[package]]
 name = "soroban-env-guest"
-version = "28.0.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7d383176b27bb286f718ab0ff5713bd9b01132089151266359bd9b20f38684cf"
+version = "29.0.0"
+source = "git+https://github.com/stellar/rs-soroban-env?rev=de68ee914401e70d3d8350a4d004c0442943324e#de68ee914401e70d3d8350a4d004c0442943324e"
 dependencies = [
  "soroban-env-common",
  "static_assertions",
@@ -5478,9 +5475,8 @@ dependencies = [
 
 [[package]]
 name = "soroban-env-host"
-version = "28.0.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "36d7e5920c200939164cc58038224e2d90d7e2fabbfa505d6e2129d648dce7e2"
+version = "29.0.0"
+source = "git+https://github.com/stellar/rs-soroban-env?rev=de68ee914401e70d3d8350a4d004c0442943324e#de68ee914401e70d3d8350a4d004c0442943324e"
 dependencies = [
  "ark-bls12-381",
  "ark-bn254",
@@ -5515,9 +5511,8 @@ dependencies = [
 
 [[package]]
 name = "soroban-env-macros"
-version = "28.0.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "077600bb175ea54592c1ac5983b8fb34ec9ab7a65f298af11d687b61e9d646a4"
+version = "29.0.0"
+source = "git+https://github.com/stellar/rs-soroban-env?rev=de68ee914401e70d3d8350a4d004c0442943324e#de68ee914401e70d3d8350a4d004c0442943324e"
 dependencies = [
  "itertools 0.13.0",
  "proc-macro2",
@@ -5535,8 +5530,7 @@ version = "28.0.0"
 [[package]]
 name = "soroban-ledger-snapshot"
 version = "28.0.0-rc.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9e68b020e9838df2affe8488998943b81d183c7ea4990691a863b39c13d3516e"
+source = "git+https://github.com/stellar/rs-soroban-sdk?rev=7093a641145329526b221e683fbb5e74f9710053#7093a641145329526b221e683fbb5e74f9710053"
 dependencies = [
  "serde",
  "serde_json",
@@ -5549,8 +5543,7 @@ dependencies = [
 [[package]]
 name = "soroban-sdk"
 version = "28.0.0-rc.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "864a530b8a1eb07c364f3f4b2f069b737ae87df203fd290baebddb9119f2dfe5"
+source = "git+https://github.com/stellar/rs-soroban-sdk?rev=7093a641145329526b221e683fbb5e74f9710053#7093a641145329526b221e683fbb5e74f9710053"
 dependencies = [
  "arbitrary",
  "bytes-lit",
@@ -5566,15 +5559,16 @@ dependencies = [
  "soroban-env-host",
  "soroban-ledger-snapshot",
  "soroban-sdk-macros",
+ "soroban-spec",
  "stellar-strkey 0.0.16",
+ "stellar-xdr",
  "visibility",
 ]
 
 [[package]]
 name = "soroban-sdk-macros"
 version = "28.0.0-rc.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d66c2bfe91c8ec2179dcab5284ee99215d9271fed2eb8b9819bcd45001ac861f"
+source = "git+https://github.com/stellar/rs-soroban-sdk?rev=7093a641145329526b221e683fbb5e74f9710053#7093a641145329526b221e683fbb5e74f9710053"
 dependencies = [
  "darling 0.20.11",
  "heck 0.5.0",
@@ -5584,7 +5578,6 @@ dependencies = [
  "quote",
  "sha2 0.10.9",
  "soroban-env-common",
- "soroban-spec",
  "soroban-spec-rust",
  "stellar-xdr",
  "syn 2.0.118",
@@ -5593,11 +5586,9 @@ dependencies = [
 [[package]]
 name = "soroban-spec"
 version = "28.0.0-rc.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2f20e3c44fa7939fece5c8988efa7c9e062ab5596ae7497035a2bc59ffd48816"
+source = "git+https://github.com/stellar/rs-soroban-sdk?rev=7093a641145329526b221e683fbb5e74f9710053#7093a641145329526b221e683fbb5e74f9710053"
 dependencies = [
  "base64 0.22.1",
- "sha2 0.10.9",
  "stellar-xdr",
  "thiserror 1.0.69",
  "wasmparser 0.116.1",
@@ -5606,8 +5597,7 @@ dependencies = [
 [[package]]
 name = "soroban-spec-rust"
 version = "28.0.0-rc.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "43eb9293928c35e949818f83fe5eacfe0cf45ebb32552304aaea66279b7c8403"
+source = "git+https://github.com/stellar/rs-soroban-sdk?rev=7093a641145329526b221e683fbb5e74f9710053#7093a641145329526b221e683fbb5e74f9710053"
 dependencies = [
  "prettyplease",
  "proc-macro2",
@@ -5705,8 +5695,7 @@ dependencies = [
 [[package]]
 name = "soroban-token-sdk"
 version = "28.0.0-rc.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b7053541ed1cf2cbfc78625d2b619c496c0748d20d75aee019b2f68169386f4c"
+source = "git+https://github.com/stellar/rs-soroban-sdk?rev=7093a641145329526b221e683fbb5e74f9710053#7093a641145329526b221e683fbb5e74f9710053"
 dependencies = [
  "soroban-sdk",
 ]
@@ -5714,8 +5703,7 @@ dependencies = [
 [[package]]
 name = "soroban-token-spec"
 version = "28.0.0-rc.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "27fe6acb049550f221fcb294c8ca3ede0e89609ea3d480c63b84b8cf4197c416"
+source = "git+https://github.com/stellar/rs-soroban-sdk?rev=7093a641145329526b221e683fbb5e74f9710053#7093a641145329526b221e683fbb5e74f9710053"
 dependencies = [
  "soroban-sdk",
  "soroban-token-sdk",
@@ -5724,8 +5712,7 @@ dependencies = [
 [[package]]
 name = "soroban-wasmi"
 version = "0.31.1-soroban.20.0.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "710403de32d0e0c35375518cb995d4fc056d0d48966f2e56ea471b8cb8fc9719"
+source = "git+https://github.com/stellar/wasmi?rev=0ed3f3dee30dc41ebe21972399e0a73a41944aa0#0ed3f3dee30dc41ebe21972399e0a73a41944aa0"
 dependencies = [
  "smallvec",
  "spin",
@@ -5765,8 +5752,7 @@ checksum = "a2eb9349b6444b326872e140eb1cf5e7c522154d69e7a0ffb0fb81c06b37543f"
 [[package]]
 name = "stellar-asset-spec"
 version = "28.0.0-rc.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4194d1b54a5337c277a0656c2d4da940439f9eb3f2e17a919bc686a870429250"
+source = "git+https://github.com/stellar/rs-soroban-sdk?rev=7093a641145329526b221e683fbb5e74f9710053#7093a641145329526b221e683fbb5e74f9710053"
 dependencies = [
  "soroban-sdk",
  "soroban-token-sdk",
@@ -5882,8 +5868,7 @@ dependencies = [
 [[package]]
 name = "stellar-xdr"
 version = "28.0.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f93d09ff8b9f919b084f664003c4c546ac66a76affd5429460dbe29f4b326f8e"
+source = "git+https://github.com/stellar/rs-stellar-xdr?rev=9c6c2f8c09b678d1ebed87b3f41f621068badcf4#9c6c2f8c09b678d1ebed87b3f41f621068badcf4"
 dependencies = [
  "arbitrary",
  "base64 0.22.1",
@@ -6071,7 +6056,7 @@ dependencies = [
  "getrandom 0.3.3",
  "once_cell",
  "rustix 1.0.8",
- "windows-sys 0.60.2",
+ "windows-sys 0.52.0",
 ]
 
 [[package]]
@@ -7091,15 +7076,13 @@ dependencies = [
 
 [[package]]
 name = "wasmi_arena"
-version = "0.4.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "104a7f73be44570cac297b3035d76b169d6599637631cf37a1703326a0727073"
+version = "0.4.0"
+source = "git+https://github.com/stellar/wasmi?rev=0ed3f3dee30dc41ebe21972399e0a73a41944aa0#0ed3f3dee30dc41ebe21972399e0a73a41944aa0"
 
 [[package]]
 name = "wasmi_core"
 version = "0.13.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dcf1a7db34bff95b85c261002720c00c3a6168256dcb93041d3fa2054d19856a"
+source = "git+https://github.com/stellar/wasmi?rev=0ed3f3dee30dc41ebe21972399e0a73a41944aa0#0ed3f3dee30dc41ebe21972399e0a73a41944aa0"
 dependencies = [
  "downcast-rs",
  "libm",
diff --git a/Cargo.toml b/Cargo.toml
index 023d794096..76b6384b0a 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -121,6 +121,26 @@ testcontainers = "0.27.2"
 httpmock = "0.7.0"
 astral-tokio-tar = "0.6.0"
 
+[patch.crates-io]
+# Pending https://github.com/stellar/rs-stellar-xdr/pull/566, which widens the
+# user-defined type name limit so that a fully qualified type name fits. Pinned
+# to the same rev rs-soroban-sdk#1970 uses so the graph has one stellar-xdr.
+stellar-xdr = { git = "https://github.com/stellar/rs-stellar-xdr", rev = "9c6c2f8c09b678d1ebed87b3f41f621068badcf4" }
+# Pending https://github.com/stellar/rs-soroban-sdk/pull/1970, which names
+# user-defined types in contract specs by their fully qualified path.
+soroban-spec = { git = "https://github.com/stellar/rs-soroban-sdk", rev = "7093a641145329526b221e683fbb5e74f9710053" }
+soroban-spec-rust = { git = "https://github.com/stellar/rs-soroban-sdk", rev = "7093a641145329526b221e683fbb5e74f9710053" }
+soroban-sdk = { git = "https://github.com/stellar/rs-soroban-sdk", rev = "7093a641145329526b221e683fbb5e74f9710053" }
+soroban-token-sdk = { git = "https://github.com/stellar/rs-soroban-sdk", rev = "7093a641145329526b221e683fbb5e74f9710053" }
+stellar-asset-spec = { git = "https://github.com/stellar/rs-soroban-sdk", rev = "7093a641145329526b221e683fbb5e74f9710053" }
+soroban-ledger-snapshot = { git = "https://github.com/stellar/rs-soroban-sdk", rev = "7093a641145329526b221e683fbb5e74f9710053" }
+# Pending https://github.com/stellar/rs-soroban-env/pull/1733, which adapts the
+# host to the XDR constants that rs-stellar-xdr#580 changes from u64 to u32.
+# rs-soroban-sdk#1970 is on that 29.x line, so pin to the same rev it uses.
+soroban-env-common = { git = "https://github.com/stellar/rs-soroban-env", rev = "de68ee914401e70d3d8350a4d004c0442943324e" }
+soroban-env-guest = { git = "https://github.com/stellar/rs-soroban-env", rev = "de68ee914401e70d3d8350a4d004c0442943324e" }
+soroban-env-host = { git = "https://github.com/stellar/rs-soroban-env", rev = "de68ee914401e70d3d8350a4d004c0442943324e" }
+
 [profile.release]
 overflow-checks = true
 
diff --git a/Makefile b/Makefile
index 397040e81d..9f1ddbd4ea 100644
--- a/Makefile
+++ b/Makefile
@@ -39,7 +39,7 @@ build:
 	cargo build
 
 build-test-wasms:
-	SOROBAN_SDK_BUILD_SYSTEM_SUPPORTS_SPEC_SHAKING_V2=1 cargo build --package 'test_*' --profile test-wasms --target wasm32v1-none
+	SOROBAN_SDK_BUILD_SYSTEM_SUPPORTS_SPEC_SHAKING_V2=1 SOROBAN_SDK_BUILD_SYSTEM_SUPPORTS_REDUCING_FULL_NAMES=1 cargo build --package 'test_*' --profile test-wasms --target wasm32v1-none
 
 build-test: build-test-wasms build-fixtures install
 
diff --git a/cmd/crates/soroban-spec-tools/src/contract.rs b/cmd/crates/soroban-spec-tools/src/contract.rs
index bf877dccc1..89ef225fd6 100644
--- a/cmd/crates/soroban-spec-tools/src/contract.rs
+++ b/cmd/crates/soroban-spec-tools/src/contract.rs
@@ -316,7 +316,7 @@ fn indent(s: &str, n: usize) -> String {
         .join("\n")
 }
 
-fn format_name(lib: &StringM<80>, name: &StringM<60>) -> String {
+fn format_name(lib: &StringM<80>, name: &StringM<{ crate::UDT_NAME_LIMIT }>) -> String {
     if lib.is_empty() {
         sanitize(&name.to_utf8_string_lossy())
     } else {
diff --git a/cmd/crates/soroban-spec-tools/src/event.rs b/cmd/crates/soroban-spec-tools/src/event.rs
index 496cdb1ccf..3cd5fc1df6 100644
--- a/cmd/crates/soroban-spec-tools/src/event.rs
+++ b/cmd/crates/soroban-spec-tools/src/event.rs
@@ -294,7 +294,7 @@ mod tests {
         ScSpecEventV0 {
             doc: StringM::default(),
             lib: StringM::default(),
-            name: make_symbol(name),
+            name: name.try_into().unwrap(),
             prefix_topics: prefix_topics
                 .into_iter()
                 .map(make_symbol)
diff --git a/cmd/crates/soroban-spec-tools/src/lib.rs b/cmd/crates/soroban-spec-tools/src/lib.rs
index bccf21828a..9563c38407 100644
--- a/cmd/crates/soroban-spec-tools/src/lib.rs
+++ b/cmd/crates/soroban-spec-tools/src/lib.rs
@@ -12,7 +12,7 @@ use stellar_xdr::{
     ScSpecTypeTuple, ScSpecTypeUdt, ScSpecTypeVec, ScSpecUdtEnumV0, ScSpecUdtErrorEnumCaseV0,
     ScSpecUdtErrorEnumV0, ScSpecUdtStructV0, ScSpecUdtUnionCaseTupleV0, ScSpecUdtUnionCaseV0,
     ScSpecUdtUnionCaseVoidV0, ScSpecUdtUnionV0, ScString, ScSymbol, ScVal, ScVec, StringM,
-    UInt128Parts, UInt256Parts, Uint256, VecM,
+    UInt128Parts, UInt256Parts, Uint256, VecM, SC_SPEC_TYPE_NAME_LIMIT,
 };
 
 pub mod contract;
@@ -25,6 +25,12 @@ pub mod wasm;
 pub use contract::sanitize;
 pub use verify::SpecWarning;
 
+/// The XDR limit on the length of a user-defined type name
+/// ([`SC_SPEC_TYPE_NAME_LIMIT`]), as the `u32` that `StringM`'s const generic
+/// expects.
+#[allow(clippy::cast_possible_truncation)]
+pub const UDT_NAME_LIMIT: u32 = SC_SPEC_TYPE_NAME_LIMIT as u32;
+
 #[derive(thiserror::Error, Debug)]
 pub enum Error {
     #[error("an unknown error occurred")]
@@ -372,7 +378,7 @@ impl Spec {
         Ok(val)
     }
 
-    fn parse_udt(&self, name: &StringM<60>, value: &Value) -> Result<ScVal, Error> {
+    fn parse_udt(&self, name: &StringM<UDT_NAME_LIMIT>, value: &Value) -> Result<ScVal, Error> {
         let name = &name.to_utf8_string_lossy();
         match (self.find(name)?, value) {
             (ScSpecEntry::UdtStructV0(strukt), Value::Object(map)) => {
@@ -649,7 +655,11 @@ impl Spec {
     /// # Panics
     ///
     /// May panic
-    pub fn udt_to_json(&self, name: &StringM<60>, sc_obj: &ScVal) -> Result<Value, Error> {
+    pub fn udt_to_json(
+        &self,
+        name: &StringM<UDT_NAME_LIMIT>,
+        sc_obj: &ScVal,
+    ) -> Result<Value, Error> {
         let name = &name.to_utf8_string_lossy();
         let udt = self.find(name)?;
         Ok(match (sc_obj, udt) {
@@ -2345,7 +2355,7 @@ mod tests {
         ScSpecEventV0 {
             doc: StringM::default(),
             lib: StringM::default(),
-            name: ScSymbol(name.try_into().unwrap()),
+            name: name.try_into().unwrap(),
             prefix_topics: VecM::default(),
             params: VecM::default(),
             data_format: stellar_xdr::ScSpecEventDataFormat::SingleValue,
diff --git a/cmd/crates/soroban-test/tests/it/build.rs b/cmd/crates/soroban-test/tests/it/build.rs
index 84c42fd32c..0e1605269e 100644
--- a/cmd/crates/soroban-test/tests/it/build.rs
+++ b/cmd/crates/soroban-test/tests/it/build.rs
@@ -736,7 +736,11 @@ fn parent_path() -> String {
 }
 
 fn with_flags(expected: &str) -> String {
-    const ENV_VAR: &str = "SOROBAN_SDK_BUILD_SYSTEM_SUPPORTS_SPEC_SHAKING_V2=1";
+    // Serialized in sorted key order, so REDUCING_FULL_NAMES precedes SPEC_SHAKING_V2.
+    const ENV_VARS: &str = concat!(
+        "SOROBAN_SDK_BUILD_SYSTEM_SUPPORTS_REDUCING_FULL_NAMES=1 ",
+        "SOROBAN_SDK_BUILD_SYSTEM_SUPPORTS_SPEC_SHAKING_V2=1"
+    );
 
     let cargo_home = home::cargo_home().unwrap();
     let registry_prefix = cargo_home.join("registry").join("src");
@@ -747,7 +751,7 @@ fn with_flags(expected: &str) -> String {
     let vec: Vec<_> = if env::var("RUSTFLAGS").is_ok() {
         expected
             .split('\n')
-            .map(|x| format!("{ENV_VAR} {x}"))
+            .map(|x| format!("{ENV_VARS} {x}"))
             .collect()
     } else {
         expected
@@ -755,7 +759,7 @@ fn with_flags(expected: &str) -> String {
             .map(|x| {
                 let rustflags_value = format!("--remap-path-prefix={registry_prefix}=");
                 let escaped_value = escape(std::borrow::Cow::Borrowed(&rustflags_value));
-                format!("CARGO_BUILD_RUSTFLAGS={escaped_value} {ENV_VAR} {x}")
+                format!("CARGO_BUILD_RUSTFLAGS={escaped_value} {ENV_VARS} {x}")
             })
             .collect()
     };
diff --git a/cmd/soroban-cli/src/commands/contract/arg_parsing.rs b/cmd/soroban-cli/src/commands/contract/arg_parsing.rs
index c97cfa551f..6ffdb34436 100644
--- a/cmd/soroban-cli/src/commands/contract/arg_parsing.rs
+++ b/cmd/soroban-cli/src/commands/contract/arg_parsing.rs
@@ -1074,7 +1074,8 @@ mod tests {
         };
 
         // Build a minimal Spec with a union type: enum MyEnum { Unit }
-        let union_name: StringM<60> = "MyEnum".try_into().unwrap();
+        let union_name: StringM<{ soroban_spec_tools::UDT_NAME_LIMIT }> =
+            "MyEnum".try_into().unwrap();
         let case_name: StringM<60> = "Unit".try_into().unwrap();
         let spec = Spec(Some(vec![ScSpecEntry::UdtUnionV0(ScSpecUdtUnionV0 {
             doc: StringM::default(),
@@ -1123,7 +1124,8 @@ mod tests {
             ScSpecUdtUnionCaseV0, ScSpecUdtUnionCaseVoidV0, ScSpecUdtUnionV0, StringM,
         };
 
-        let union_name: StringM<60> = "MyEnum".try_into().unwrap();
+        let union_name: StringM<{ soroban_spec_tools::UDT_NAME_LIMIT }> =
+            "MyEnum".try_into().unwrap();
         let spec = Spec(Some(vec![ScSpecEntry::UdtUnionV0(ScSpecUdtUnionV0 {
             doc: StringM::default(),
             lib: StringM::default(),
@@ -1190,7 +1192,7 @@ mod tests {
         use stellar_xdr::{
             ScSpecEntry, ScSpecTypeUdt, ScSpecUdtStructFieldV0, ScSpecUdtStructV0, StringM,
         };
-        let struct_name: StringM<60> = name.try_into().unwrap();
+        let struct_name: StringM<{ soroban_spec_tools::UDT_NAME_LIMIT }> = name.try_into().unwrap();
         let fields_xdr: Vec<ScSpecUdtStructFieldV0> = fields
             .iter()
             .map(|(n, t)| ScSpecUdtStructFieldV0 {
@@ -1324,7 +1326,8 @@ mod tests {
             ScSpecUdtUnionV0, StringM,
         };
 
-        let union_name: StringM<60> = "Choice".try_into().unwrap();
+        let union_name: StringM<{ soroban_spec_tools::UDT_NAME_LIMIT }> =
+            "Choice".try_into().unwrap();
         let spec = Spec(Some(vec![ScSpecEntry::UdtUnionV0(ScSpecUdtUnionV0 {
             doc: StringM::default(),
             lib: StringM::default(),
@@ -1362,7 +1365,8 @@ mod tests {
             ScSpecUdtUnionV0, StringM,
         };
 
-        let union_name: StringM<60> = "OneOf".try_into().unwrap();
+        let union_name: StringM<{ soroban_spec_tools::UDT_NAME_LIMIT }> =
+            "OneOf".try_into().unwrap();
         let spec = Spec(Some(vec![ScSpecEntry::UdtUnionV0(ScSpecUdtUnionV0 {
             doc: StringM::default(),
             lib: StringM::default(),
diff --git a/cmd/soroban-cli/src/commands/contract/build.rs b/cmd/soroban-cli/src/commands/contract/build.rs
index 5a00d1894b..ab0e5f57af 100644
--- a/cmd/soroban-cli/src/commands/contract/build.rs
+++ b/cmd/soroban-cli/src/commands/contract/build.rs
@@ -346,6 +346,11 @@ impl Cmd {
             // optimization using markers.
             cmd.env("SOROBAN_SDK_BUILD_SYSTEM_SUPPORTS_SPEC_SHAKING_V2", "1");
 
+            // Set env var to inform the SDK that this CLI reduces fully
+            // qualified user-defined type names in the spec down to their
+            // simple names.
+            cmd.env("SOROBAN_SDK_BUILD_SYSTEM_SUPPORTS_REDUCING_FULL_NAMES", "1");
+
             let cmd_str = serialize_command(&cmd);
 
             if self.print_commands_only {
@@ -366,6 +371,7 @@ impl Cmd {
 
                 self.inject_meta(&target_file_path)?;
                 Self::filter_spec(&target_file_path)?;
+                Self::reduce_spec(&print, &p.name, &target_file_path)?;
 
                 let final_path = if let Some(out_dir) = &self.out_dir {
                     fs::create_dir_all(out_dir).map_err(Error::CreatingOutDir)?;
@@ -535,6 +541,65 @@ impl Cmd {
         fs::write(target_file_path, new_wasm).map_err(Error::WritingWasmFile)
     }
 
+    /// Reduces user-defined type names in the contract spec to their simple
+    /// form, rewriting the `contractspecv0` section in place.
+    ///
+    /// Contract specs may name user-defined types by their fully qualified path
+    /// (e.g. `my_contract::inner::State`). This follows each to its simple name
+    /// (e.g. `State`), rewriting every reference, so the on-chain spec and every
+    /// downstream tool see the short names. Names that would collide are
+    /// disambiguated with a numeric suffix, which is warned about.
+    ///
+    /// Runs after `filter_spec` so only the entries that survive shaking are
+    /// reduced, but is otherwise independent of spec shaking.
+    fn reduce_spec(print: &Print, name: &str, target_file_path: &PathBuf) -> Result<(), Error> {
+        use soroban_spec_tools::contract::Spec;
+        use soroban_spec_tools::wasm::replace_custom_section;
+
+        let wasm_bytes = fs::read(target_file_path).map_err(Error::ReadingWasmFile)?;
+        let spec = Spec::new(&wasm_bytes)?;
+
+        let reduced = soroban_spec::reduce::reduce(&spec.spec);
+
+        // If every name was already simple, leave the wasm untouched.
+        if reduced.renames().all(|r| !r.renamed()) {
+            return Ok(());
+        }
+
+        let collisions: Vec<_> = reduced.renames().filter(|r| r.collision()).collect();
+        if !collisions.is_empty() {
+            use std::fmt::Write as _;
+            let mut msg = format!(
+                "{name}: reduced type names collided and were disambiguated with a numeric suffix:"
+            );
+            for rename in collisions {
+                let _ = write!(
+                    msg,
+                    "\n    {} -> {}",
+                    String::from_utf8_lossy(&rename.from),
+                    String::from_utf8_lossy(&rename.to),
+                );
+            }
+            print.warnln(msg);
+        }
+
+        // Encode the reduced entries and replace the contractspecv0 section.
+        let mut reduced_xdr = Vec::new();
+        let mut writer = Limited::new(
+            Cursor::new(&mut reduced_xdr),
+            Limits::depth(XDR_DEPTH_LIMIT),
+        );
+        for entry in reduced.into_entries() {
+            entry.write_xdr(&mut writer)?;
+        }
+
+        let new_wasm = replace_custom_section(&wasm_bytes, "contractspecv0", &reduced_xdr)
+            .map_err(|e| Error::WasmParsing(e.to_string()))?;
+
+        fs::remove_file(target_file_path).map_err(Error::DeletingArtifact)?;
+        fs::write(target_file_path, new_wasm).map_err(Error::WritingWasmFile)
+    }
+
     fn encoded_new_meta(&self) -> Result<Vec<u8>, Error> {
         let mut new_meta: Vec<ScMetaEntry> = Vec::new();
 
@@ -936,6 +1001,46 @@ mod tests {
         assert!(Cmd::try_parse_from(["build", "--pull"]).is_err());
     }
 
+    #[test]
+    fn reduce_spec_shortens_qualified_names_in_wasm() {
+        use soroban_spec_tools::contract::Spec;
+        use soroban_spec_tools::wasm::replace_custom_section;
+        use stellar_xdr::{ScSpecEntry, ScSpecUdtStructV0, VecM};
+
+        // A spec with a single struct whose name is fully qualified.
+        let entry = ScSpecEntry::UdtStructV0(ScSpecUdtStructV0 {
+            doc: StringM::default(),
+            lib: StringM::default(),
+            name: "mycrate::mymod::MyType".to_string().try_into().unwrap(),
+            fields: VecM::default(),
+        });
+        let mut spec_xdr = Vec::new();
+        entry
+            .write_xdr(&mut Limited::new(
+                Cursor::new(&mut spec_xdr),
+                Limits::depth(XDR_DEPTH_LIMIT),
+            ))
+            .unwrap();
+
+        // Embed the spec in a minimal (empty) wasm module and write it out.
+        let wasm = replace_custom_section(b"\0asm\x01\0\0\0", "contractspecv0", &spec_xdr).unwrap();
+        let path =
+            env::temp_dir().join(format!("reduce_spec_test_{}.wasm", std::process::id()));
+        fs::write(&path, &wasm).unwrap();
+
+        Cmd::reduce_spec(&Print::new(true), "pkg", &path).unwrap();
+
+        let out = fs::read(&path).unwrap();
+        fs::remove_file(&path).ok();
+        let spec = Spec::new(&out).unwrap();
+
+        assert_eq!(spec.spec.len(), 1);
+        let ScSpecEntry::UdtStructV0(s) = &spec.spec[0] else {
+            panic!("expected a struct entry, got {:?}", spec.spec[0]);
+        };
+        assert_eq!(s.name.to_vec(), b"MyType".to_vec());
+    }
+
     #[test]
     fn serialize_command_shell_escapes_args_with_metacharacters() {
         let raw_arg = "--manifest-path=/path/to/contract;touch PWNED;#/Cargo.toml";
diff --git a/cmd/soroban-cli/src/commands/contract/info/interface.rs b/cmd/soroban-cli/src/commands/contract/info/interface.rs
index a2dfa1de38..2ab2aaf1c7 100644
--- a/cmd/soroban-cli/src/commands/contract/info/interface.rs
+++ b/cmd/soroban-cli/src/commands/contract/info/interface.rs
@@ -65,6 +65,8 @@ impl Cmd {
             }
         };
 
+        // Type names in the spec are already reduced to simple names during
+        // `contract build`, so show the spec as it is stored in the contract.
         let res = match self.output {
             InfoOutput::XdrBase64 => base64,
             InfoOutput::Json => serde_json::to_string(&spec)?,
diff --git a/deny.toml b/deny.toml
index dd05ae3b5b..6ae9eaf1b2 100644
--- a/deny.toml
+++ b/deny.toml
@@ -231,7 +231,15 @@ allow-registry = ["https://github.com/rust-lang/crates.io-index"]
 # List of URLs for allowed Git repositories
 allow-git = [
   # Only used by the unpublished doc-gen crate, temporarily until PR is merged: https://github.com/ConnorGray/clap-markdown/pull/48
-  "https://github.com/ConnorGray/clap-markdown?rev=42956b342cef3325d9060fc43995d595e7c8aa66"
+  "https://github.com/ConnorGray/clap-markdown?rev=42956b342cef3325d9060fc43995d595e7c8aa66",
+
+  # Temporary patches, remove once merged and released:
+  # https://github.com/stellar/rs-stellar-xdr/pull/566, which widens the
+  # user-defined type name limit so a fully qualified type name fits.
+  "https://github.com/stellar/rs-stellar-xdr?rev=82677e1dfe49b6b94fc6440d9c58be74d2a33bff",
+  # https://github.com/stellar/rs-soroban-sdk/pull/1970, which names
+  # user-defined types in contract specs by their fully qualified path.
+  "https://github.com/stellar/rs-soroban-sdk?rev=788b536af88a1b0a4d473dc8050b6a44c668e80e",
 ]
 
 [sources.allow-org]