diff --git a/.gitmodules b/.gitmodules
index 140d3658f..4d0319357 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -49,6 +49,9 @@
 [submodule "src/rust/soroban/p27"]
 	path = src/rust/soroban/p27
 	url = https://github.com/stellar/rs-soroban-env.git
+[submodule "src/rust/soroban/p28"]
+	path = src/rust/soroban/p28
+	url = https://github.com/stellar/rs-soroban-env.git
 [submodule "lib/gperftools"]
 	path = lib/gperftools
 	url = https://github.com/gperftools/gperftools.git
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 6cd924cd2..010955454 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -116,7 +116,7 @@ See https://clang.llvm.org/docs/AddressSanitizer.html for more information.
 
 *Note*: ASan will ignore any memory errors in Rust code unless you build with
 Rust's ASan support. And building with Rust's ASan support requires configuring
-with `--enable-unified-rust-unsafe-for-production`. See below on "unified Rust
+with `--enable-fastdev-unsafe-for-production`. See below on "fastdev Rust
 builds".
 
 *Note*: Rust's ASan support also requires a nightly compiler and the rust-src
@@ -156,7 +156,7 @@ See https://clang.llvm.org/docs/ThreadSanitizer.html for more information.
 *Note*: Since Rust code is run on multiple threads and those threads are
 launched _from C++_ TSan will report races in Rust code unless you build with
 Rust's TSan support. And building with Rust's TSan support requires configuring
-with `--enable-unified-rust-unsafe-for-production`.
+with `--enable-fastdev-unsafe-for-production`.
 
 *Note*: Rust's ASan support also requires a nightly compiler and the rust-src
 component. Install these with:
@@ -294,7 +294,7 @@ files. You should then inspect to see that only the transactions you expected to
 see change did so. If so, commit the changes as a new set of baselines for
 future tests.
 
-## Unified and non-unified Rust builds
+## Fastdev and non-unified Rust builds
 
 As of protocol 20, some components of stellar-core are written in Rust (notably
 soroban).
@@ -331,23 +331,29 @@ and it _usually_ works. But there are two cases you might not want it.
      the stdlib and producing some sort of link-time dependency on crates that
      are only used as procedural macros).
 
-For both of these cases, we've added the ability to (optionally) switch back to
-the normal way Rust expects you to build a crate that links multiple versions of
-a dependency: with a single "unified" cargo invocation, at the top level. There
-are two different ways to enable this:
+For both of these cases, we've added a fastdev mode that switches back to the
+normal way Rust expects you to build a crate, with a single cargo invocation at
+the top level and only the current and next Soroban hosts compiled in. There are
+two different ways to enable this:
 
-  - By configuring with `--enable-unified-rust-unsafe-for-production`, if one
-    wants to _build_ a stellar-core with unified rust.
+  - By configuring with `--enable-fastdev-unsafe-for-production`, if one wants
+    to _build_ a stellar-core with fastdev rust.
 
-  - By toggling the "unified" feature flag in the IDE (eg. using the "Rust
+  - By toggling the "fastdev" feature flag in the IDE (eg. using the "Rust
     Feature Toggler" editor extension in VS code) if one merely wants to _edit_
-    a stellar-core with unified rust.
+    a stellar-core with fastdev rust.
 
 The configure flag has got such a long and unwieldy name because _it will build
-soroban with slightly different versions of transitive dependencies_, a
-configuration we do _not_ want to ship in production builds.
+soroban with fewer host versions and slightly different versions of transitive
+dependencies_, a configuration we do _not_ want to ship in production builds.
 
 It is fine for debugging though. In practice those different versions of
 transitive dependencies are rarely "all that different". You will _probably_ not
 be able to observe any differences. We just don't want to chance it in
 production.
+
+To reduce the set of possible configurations and flags, fastdev also acts as
+a superset of `--enable-next-protocol-version-unsafe-for-production` (i.e. it
+also turns on the `next` feature and links in whatever the next-protocol soroban
+host is).
+
diff --git a/Cargo.lock b/Cargo.lock
index 45ecdbd1a..e4245019a 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -464,6 +464,17 @@ dependencies = [
  "serde_json",
 ]
 
+[[package]]
+name = "crate-git-revision"
+version = "0.0.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "54851b5b3f24621804b1cded2820975623c205e3055d2d44031cdb1237339ac8"
+dependencies = [
+ "serde",
+ "serde_derive",
+ "serde_json",
+]
+
 [[package]]
 name = "crypto-bigint"
 version = "0.5.5"
@@ -1440,8 +1451,19 @@ dependencies = [
 
 [[package]]
 name = "soroban-builtin-sdk-macros"
-version = "26.1.2"
-source = "git+https://github.com/stellar/rs-soroban-env?rev=c0e58f94ff2983a09440cef6a54253349fd3c4db#c0e58f94ff2983a09440cef6a54253349fd3c4db"
+version = "27.0.0"
+source = "git+https://github.com/stellar/rs-soroban-env?rev=883fd56374fc619afaa4c4c7489563555b7173f2#883fd56374fc619afaa4c4c7489563555b7173f2"
+dependencies = [
+ "itertools 0.13.0",
+ "proc-macro2",
+ "quote",
+ "syn 2.0.39",
+]
+
+[[package]]
+name = "soroban-builtin-sdk-macros"
+version = "27.0.0"
+source = "git+https://github.com/stellar/rs-soroban-env?rev=b03d2563f3a08d51095a19bdbb6d90364b8ce04a#b03d2563f3a08d51095a19bdbb6d90364b8ce04a"
 dependencies = [
  "itertools 0.13.0",
  "proc-macro2",
@@ -1454,7 +1476,7 @@ name = "soroban-env-common"
 version = "21.2.2"
 source = "git+https://github.com/stellar/rs-soroban-env?rev=7eeddd897cfb0f700f938b0c8d6f0541150d1fcb#7eeddd897cfb0f700f938b0c8d6f0541150d1fcb"
 dependencies = [
- "crate-git-revision",
+ "crate-git-revision 0.0.6",
  "ethnum",
  "num-derive",
  "num-traits",
@@ -1470,7 +1492,7 @@ name = "soroban-env-common"
 version = "22.0.0"
 source = "git+https://github.com/stellar/rs-soroban-env?rev=1cd8b8dca9aeeca9ce45b129cd923992b32dc258#1cd8b8dca9aeeca9ce45b129cd923992b32dc258"
 dependencies = [
- "crate-git-revision",
+ "crate-git-revision 0.0.6",
  "ethnum",
  "num-derive",
  "num-traits",
@@ -1486,7 +1508,7 @@ name = "soroban-env-common"
 version = "23.0.0"
 source = "git+https://github.com/stellar/rs-soroban-env?rev=688bc34e6cd15c71742139e625268c7f30f55a92#688bc34e6cd15c71742139e625268c7f30f55a92"
 dependencies = [
- "crate-git-revision",
+ "crate-git-revision 0.0.6",
  "ethnum",
  "num-derive",
  "num-traits",
@@ -1502,7 +1524,7 @@ name = "soroban-env-common"
 version = "24.0.0"
 source = "git+https://github.com/stellar/rs-soroban-env?rev=a37eeda815e626f416eff13f2eacb32a8b0c3729#a37eeda815e626f416eff13f2eacb32a8b0c3729"
 dependencies = [
- "crate-git-revision",
+ "crate-git-revision 0.0.6",
  "ethnum",
  "num-derive",
  "num-traits",
@@ -1518,7 +1540,7 @@ name = "soroban-env-common"
 version = "25.0.0"
 source = "git+https://github.com/stellar/rs-soroban-env?rev=0a0c2df704edeb3cdafabfcc759eddccd6775337#0a0c2df704edeb3cdafabfcc759eddccd6775337"
 dependencies = [
- "crate-git-revision",
+ "crate-git-revision 0.0.6",
  "ethnum",
  "num-derive",
  "num-traits",
@@ -1534,8 +1556,7 @@ name = "soroban-env-common"
 version = "26.0.0"
 source = "git+https://github.com/stellar/rs-soroban-env?rev=b351f88a468d3b9e1d6de53d5b0ca585f6b7dadb#b351f88a468d3b9e1d6de53d5b0ca585f6b7dadb"
 dependencies = [
- "arbitrary",
- "crate-git-revision",
+ "crate-git-revision 0.0.6",
  "ethnum",
  "num-derive",
  "num-traits",
@@ -1548,17 +1569,34 @@ dependencies = [
 
 [[package]]
 name = "soroban-env-common"
-version = "26.1.2"
-source = "git+https://github.com/stellar/rs-soroban-env?rev=c0e58f94ff2983a09440cef6a54253349fd3c4db#c0e58f94ff2983a09440cef6a54253349fd3c4db"
+version = "27.0.0"
+source = "git+https://github.com/stellar/rs-soroban-env?rev=883fd56374fc619afaa4c4c7489563555b7173f2#883fd56374fc619afaa4c4c7489563555b7173f2"
 dependencies = [
- "crate-git-revision",
+ "crate-git-revision 0.0.9",
  "ethnum",
  "num-derive",
  "num-traits",
- "soroban-env-macros 26.1.2",
+ "soroban-env-macros 27.0.0 (git+https://github.com/stellar/rs-soroban-env?rev=883fd56374fc619afaa4c4c7489563555b7173f2)",
  "soroban-wasmi",
  "static_assertions",
- "stellar-xdr 26.0.0",
+ "stellar-xdr 27.0.0",
+ "wasmparser",
+]
+
+[[package]]
+name = "soroban-env-common"
+version = "27.0.0"
+source = "git+https://github.com/stellar/rs-soroban-env?rev=b03d2563f3a08d51095a19bdbb6d90364b8ce04a#b03d2563f3a08d51095a19bdbb6d90364b8ce04a"
+dependencies = [
+ "arbitrary",
+ "crate-git-revision 0.0.6",
+ "ethnum",
+ "num-derive",
+ "num-traits",
+ "soroban-env-macros 27.0.0 (git+https://github.com/stellar/rs-soroban-env?rev=b03d2563f3a08d51095a19bdbb6d90364b8ce04a)",
+ "soroban-wasmi",
+ "static_assertions",
+ "stellar-xdr 27.0.0",
  "wasmparser",
 ]
 
@@ -1772,8 +1810,44 @@ dependencies = [
 
 [[package]]
 name = "soroban-env-host"
-version = "26.1.2"
-source = "git+https://github.com/stellar/rs-soroban-env?rev=c0e58f94ff2983a09440cef6a54253349fd3c4db#c0e58f94ff2983a09440cef6a54253349fd3c4db"
+version = "27.0.0"
+source = "git+https://github.com/stellar/rs-soroban-env?rev=883fd56374fc619afaa4c4c7489563555b7173f2#883fd56374fc619afaa4c4c7489563555b7173f2"
+dependencies = [
+ "ark-bls12-381 0.5.0",
+ "ark-bn254 0.5.0",
+ "ark-ec 0.5.0",
+ "ark-ff 0.5.0",
+ "ark-serialize 0.5.0",
+ "curve25519-dalek",
+ "ecdsa",
+ "ed25519-dalek",
+ "elliptic-curve",
+ "generic-array",
+ "getrandom",
+ "hex-literal",
+ "hmac",
+ "k256",
+ "num-derive",
+ "num-integer",
+ "num-traits",
+ "p256",
+ "rand",
+ "rand_chacha",
+ "sec1",
+ "sha2",
+ "sha3",
+ "soroban-builtin-sdk-macros 27.0.0 (git+https://github.com/stellar/rs-soroban-env?rev=883fd56374fc619afaa4c4c7489563555b7173f2)",
+ "soroban-env-common 27.0.0 (git+https://github.com/stellar/rs-soroban-env?rev=883fd56374fc619afaa4c4c7489563555b7173f2)",
+ "soroban-wasmi",
+ "static_assertions",
+ "stellar-strkey 0.0.13",
+ "wasmparser",
+]
+
+[[package]]
+name = "soroban-env-host"
+version = "27.0.0"
+source = "git+https://github.com/stellar/rs-soroban-env?rev=b03d2563f3a08d51095a19bdbb6d90364b8ce04a#b03d2563f3a08d51095a19bdbb6d90364b8ce04a"
 dependencies = [
  "ark-bls12-381 0.5.0",
  "ark-bn254 0.5.0",
@@ -1798,8 +1872,8 @@ dependencies = [
  "sec1",
  "sha2",
  "sha3",
- "soroban-builtin-sdk-macros 26.1.2",
- "soroban-env-common 26.1.2",
+ "soroban-builtin-sdk-macros 27.0.0 (git+https://github.com/stellar/rs-soroban-env?rev=b03d2563f3a08d51095a19bdbb6d90364b8ce04a)",
+ "soroban-env-common 27.0.0 (git+https://github.com/stellar/rs-soroban-env?rev=b03d2563f3a08d51095a19bdbb6d90364b8ce04a)",
  "soroban-wasmi",
  "static_assertions",
  "stellar-strkey 0.0.13",
@@ -1892,25 +1966,39 @@ dependencies = [
 
 [[package]]
 name = "soroban-env-macros"
-version = "26.1.2"
-source = "git+https://github.com/stellar/rs-soroban-env?rev=c0e58f94ff2983a09440cef6a54253349fd3c4db#c0e58f94ff2983a09440cef6a54253349fd3c4db"
+version = "27.0.0"
+source = "git+https://github.com/stellar/rs-soroban-env?rev=883fd56374fc619afaa4c4c7489563555b7173f2#883fd56374fc619afaa4c4c7489563555b7173f2"
 dependencies = [
  "itertools 0.13.0",
  "proc-macro2",
  "quote",
  "serde",
  "serde_json",
- "stellar-xdr 26.0.0",
+ "stellar-xdr 27.0.0",
+ "syn 2.0.39",
+]
+
+[[package]]
+name = "soroban-env-macros"
+version = "27.0.0"
+source = "git+https://github.com/stellar/rs-soroban-env?rev=b03d2563f3a08d51095a19bdbb6d90364b8ce04a#b03d2563f3a08d51095a19bdbb6d90364b8ce04a"
+dependencies = [
+ "itertools 0.13.0",
+ "proc-macro2",
+ "quote",
+ "serde",
+ "serde_json",
+ "stellar-xdr 27.0.0",
  "syn 2.0.39",
 ]
 
 [[package]]
 name = "soroban-fuzz-targets"
-version = "26.0.0"
-source = "git+https://github.com/stellar/rs-soroban-env?rev=b351f88a468d3b9e1d6de53d5b0ca585f6b7dadb#b351f88a468d3b9e1d6de53d5b0ca585f6b7dadb"
+version = "27.0.0"
+source = "git+https://github.com/stellar/rs-soroban-env?rev=b03d2563f3a08d51095a19bdbb6d90364b8ce04a#b03d2563f3a08d51095a19bdbb6d90364b8ce04a"
 dependencies = [
  "arbitrary",
- "soroban-env-host 26.0.0",
+ "soroban-env-host 27.0.0 (git+https://github.com/stellar/rs-soroban-env?rev=b03d2563f3a08d51095a19bdbb6d90364b8ce04a)",
  "soroban-synth-wasm",
  "soroban-wasmi",
  "wasm-smith",
@@ -1918,21 +2006,21 @@ dependencies = [
 
 [[package]]
 name = "soroban-synth-wasm"
-version = "26.0.0"
-source = "git+https://github.com/stellar/rs-soroban-env?rev=b351f88a468d3b9e1d6de53d5b0ca585f6b7dadb#b351f88a468d3b9e1d6de53d5b0ca585f6b7dadb"
+version = "27.0.0"
+source = "git+https://github.com/stellar/rs-soroban-env?rev=b03d2563f3a08d51095a19bdbb6d90364b8ce04a#b03d2563f3a08d51095a19bdbb6d90364b8ce04a"
 dependencies = [
  "arbitrary",
- "soroban-env-common 26.0.0",
- "soroban-env-macros 26.0.0",
- "stellar-xdr 26.0.0",
+ "soroban-env-common 27.0.0 (git+https://github.com/stellar/rs-soroban-env?rev=b03d2563f3a08d51095a19bdbb6d90364b8ce04a)",
+ "soroban-env-macros 27.0.0 (git+https://github.com/stellar/rs-soroban-env?rev=b03d2563f3a08d51095a19bdbb6d90364b8ce04a)",
+ "stellar-xdr 27.0.0",
  "wasm-encoder",
  "wasmparser",
 ]
 
 [[package]]
 name = "soroban-test-wasms"
-version = "26.0.0"
-source = "git+https://github.com/stellar/rs-soroban-env?rev=b351f88a468d3b9e1d6de53d5b0ca585f6b7dadb#b351f88a468d3b9e1d6de53d5b0ca585f6b7dadb"
+version = "27.0.0"
+source = "git+https://github.com/stellar/rs-soroban-env?rev=b03d2563f3a08d51095a19bdbb6d90364b8ce04a#b03d2563f3a08d51095a19bdbb6d90364b8ce04a"
 
 [[package]]
 name = "soroban-wasmi"
@@ -1987,7 +2075,8 @@ dependencies = [
  "soroban-env-host 24.0.0",
  "soroban-env-host 25.0.0",
  "soroban-env-host 26.0.0",
- "soroban-env-host 26.1.2",
+ "soroban-env-host 27.0.0 (git+https://github.com/stellar/rs-soroban-env?rev=883fd56374fc619afaa4c4c7489563555b7173f2)",
+ "soroban-env-host 27.0.0 (git+https://github.com/stellar/rs-soroban-env?rev=b03d2563f3a08d51095a19bdbb6d90364b8ce04a)",
  "soroban-fuzz-targets",
  "soroban-synth-wasm",
  "soroban-test-wasms",
@@ -2015,7 +2104,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "12d2bf45e114117ea91d820a846fd1afbe3ba7d717988fee094ce8227a3bf8bd"
 dependencies = [
  "base32",
- "crate-git-revision",
+ "crate-git-revision 0.0.6",
  "thiserror",
 ]
 
@@ -2025,7 +2114,7 @@ version = "0.0.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5e3aa3ed00e70082cb43febc1c2afa5056b9bb3e348bbb43d0cd0aa88a611144"
 dependencies = [
- "crate-git-revision",
+ "crate-git-revision 0.0.6",
  "data-encoding",
  "thiserror",
 ]
@@ -2036,7 +2125,7 @@ version = "0.0.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ee1832fb50c651ad10f734aaf5d31ca5acdfb197a6ecda64d93fcdb8885af913"
 dependencies = [
- "crate-git-revision",
+ "crate-git-revision 0.0.6",
  "data-encoding",
 ]
 
@@ -2047,7 +2136,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2675a71212ed39a806e415b0dbf4702879ff288ec7f5ee996dda42a135512b50"
 dependencies = [
  "base64 0.13.1",
- "crate-git-revision",
+ "crate-git-revision 0.0.6",
  "escape-bytes",
  "hex",
  "stellar-strkey 0.0.8",
@@ -2060,7 +2149,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "20c2130275cc730d042b3082f51145f0486f5a543d6d72fced02ed9048b82b57"
 dependencies = [
  "base64 0.13.1",
- "crate-git-revision",
+ "crate-git-revision 0.0.6",
  "escape-bytes",
  "hex",
  "stellar-strkey 0.0.9",
@@ -2074,7 +2163,7 @@ checksum = "89d2848e1694b0c8db81fd812bfab5ea71ee28073e09ccc45620ef3cf7a75a9b"
 dependencies = [
  "base64 0.22.1",
  "cfg_eval",
- "crate-git-revision",
+ "crate-git-revision 0.0.6",
  "escape-bytes",
  "ethnum",
  "hex",
@@ -2090,7 +2179,7 @@ checksum = "4ceec163a64a9ed03359dab3b73ca556251020edc0103bae7073a38eb1708ab5"
 dependencies = [
  "base64 0.22.1",
  "cfg_eval",
- "crate-git-revision",
+ "crate-git-revision 0.0.6",
  "escape-bytes",
  "ethnum",
  "hex",
@@ -2105,7 +2194,7 @@ source = "git+https://github.com/stellar/rs-stellar-xdr?rev=89cc1cbadf1b9a168438
 dependencies = [
  "base64 0.22.1",
  "cfg_eval",
- "crate-git-revision",
+ "crate-git-revision 0.0.6",
  "escape-bytes",
  "ethnum",
  "hex",
@@ -2119,10 +2208,9 @@ version = "26.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "fea3195594b044ea3a5b05906f81d945480825f00db4e3ae7d77526bf546ff3a"
 dependencies = [
- "arbitrary",
  "base64 0.22.1",
  "cfg_eval",
- "crate-git-revision",
+ "crate-git-revision 0.0.6",
  "escape-bytes",
  "ethnum",
  "hex",
@@ -2136,7 +2224,9 @@ version = "27.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "05ff843326969bdf1ef673dcdba94c08f4a3c8f1e58d6e6ef39b1bd4f749179a"
 dependencies = [
- "crate-git-revision",
+ "arbitrary",
+ "base64 0.22.1",
+ "crate-git-revision 0.0.6",
  "escape-bytes",
  "ethnum",
  "hex",
diff --git a/Cargo.toml b/Cargo.toml
index b4017c618..d1e263949 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -12,3 +12,10 @@ lto = true
 # (or you can build with `make RUST_PROFILE=dev` to get them built with
 # debug-and-no-opt).
 debug = true
+
+[profile.fastdev]
+inherits = "release"
+lto = false
+debug = "line-tables-only"
+codegen-units = 16
+split-debuginfo = "unpacked"
diff --git a/configure.ac b/configure.ac
index 76cc59523..01ed39746 100644
--- a/configure.ac
+++ b/configure.ac
@@ -97,10 +97,24 @@ AX_APPEND_COMPILE_FLAGS($WFLAGS)
 AX_APPEND_COMPILE_FLAGS([-pthread])
 AC_LANG_POP(C)
 
-AC_ARG_ENABLE(unified-rust-unsafe-for-production,
-    AS_HELP_STRING([--enable-unified-rust-unsafe-for-production],
-        [Build rust crates as a single cargo library, risking version drift]))
-AM_CONDITIONAL(UNIFIED_RUST, [test "x$enable_unified_rust_unsafe_for_production" = "xyes"])
+AC_ARG_ENABLE(fastdev-unsafe-for-production,
+    AS_HELP_STRING([--enable-fastdev-unsafe-for-production],
+        [Build in fast development mode UNSAFE FOR PRODUCTION]))
+AS_IF([test "x$enable_fastdev_unsafe_for_production" = "xyes"], [
+  AC_MSG_NOTICE([enabling fastdev build profile UNSAFE FOR PRODUCTION])
+  fastdev_cxx_version=`$CXX --version 2>/dev/null`
+  case "$fastdev_cxx_version" in
+    *clang*)
+      CXXFLAGS="$CXXFLAGS -gline-tables-only"
+      AC_MSG_NOTICE([added -gline-tables-only to CXXFLAGS])
+      ;;
+    *)
+      AC_MSG_ERROR([fastdev build requires clang compiler])
+      ;;
+  esac
+])
+AM_CONDITIONAL(ENABLE_FASTDEV_UNSAFE_FOR_PRODUCTION,
+    [test "x$enable_fastdev_unsafe_for_production" = "xyes"])
 
 unset sanitizeopts
 
@@ -110,8 +124,8 @@ AC_ARG_ENABLE([asan],
 AS_IF([test "x$enable_asan" = "xyes"], [
   AC_MSG_NOTICE([ Enabling asan, see https://clang.llvm.org/docs/AddressSanitizer.html ])
 
-  AS_IF([test "xyes" != "x$enable_unified_rust_unsafe_for_production"], [
-    AC_MSG_WARN(Asan will not instrument rust without --enable-unified-rust-unsafe-for-production)
+  AS_IF([test "xyes" != "x$enable_fastdev_unsafe_for_production"], [
+    AC_MSG_WARN(Asan will not instrument rust without --enable-fastdev-unsafe-for-production)
   ])
 
   sanitizeopts="address"
@@ -134,8 +148,8 @@ AC_ARG_ENABLE([threadsanitizer],
 AS_IF([test "x$enable_threadsanitizer" = "xyes"], [
   AC_MSG_NOTICE([ enabling thread-sanitizer, see https://clang.llvm.org/docs/ThreadSanitizer.html ])
 
-  AS_IF([test "xyes" != "x$enable_unified_rust_unsafe_for_production"], [
-    AC_MSG_ERROR(Enabling tsan requires --enable-unified-rust-unsafe-for-production)
+  AS_IF([test "xyes" != "x$enable_fastdev_unsafe_for_production"], [
+    AC_MSG_ERROR(Enabling tsan requires --enable-fastdev-unsafe-for-production)
   ])
   AS_IF([test x != "x$sanitizeopts"], [
     AC_MSG_ERROR(Cannot enable multiple sanitizers at once)
@@ -558,6 +572,12 @@ AM_CONDITIONAL(USE_SPDLOG, [test x$enable_spdlog != xno])
 AC_ARG_ENABLE(next-protocol-version-unsafe-for-production,
     AS_HELP_STRING([--enable-next-protocol-version-unsafe-for-production],
         [Enable next protocol version UNSAFE FOR PRODUCTION]))
+AS_IF([test "x$enable_fastdev_unsafe_for_production" = "xyes"], [
+  AS_IF([test "x$enable_next_protocol_version_unsafe_for_production" != "xyes"], [
+    AC_MSG_NOTICE([enabling next protocol version due to fastdev build profile])
+  ])
+  enable_next_protocol_version_unsafe_for_production=yes
+])
 AM_CONDITIONAL(ENABLE_NEXT_PROTOCOL_VERSION_UNSAFE_FOR_PRODUCTION,
     [test x$enable_next_protocol_version_unsafe_for_production = xyes])
 
diff --git a/src/Makefile.am b/src/Makefile.am
index e33128a57..180ff8052 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -77,6 +77,12 @@ else
 CARGO_FEATURE_NEXT =
 endif
 
+if ENABLE_FASTDEV_UNSAFE_FOR_PRODUCTION
+CARGO_FEATURE_FASTDEV = --features fastdev
+else
+CARGO_FEATURE_FASTDEV =
+endif
+
 main/XDRFilesSha256.cpp: $(SRC_X_FILES) Makefile $(top_srcdir)/hash-xdrs.sh
 	$(top_srcdir)/hash-xdrs.sh $(top_srcdir)/src/protocol-curr >$@
 
@@ -131,11 +137,12 @@ stellar_core_SOURCES += $(GENERATED_XDRQUERY_SOURCES) util/xdrquery/XDRQueryPars
 BUILT_SOURCES += rust/RustBridge.h $(GENERATED_RUST_SOURCES)
 stellar_core_SOURCES += rust/RustBridge.h $(GENERATED_RUST_SOURCES)
 
-if UNIFIED_RUST
-RUST_TOOLCHAIN_CHANNEL=nightly
-else
 RUST_TOOLCHAIN_FILE=$(top_srcdir)/rust-toolchain.toml
-RUST_TOOLCHAIN_CHANNEL=$(shell sed -n 's/channel *= *"\([^"]*\)"/\1/p' $(RUST_TOOLCHAIN_FILE))
+RUST_TOOLCHAIN_FILE_CHANNEL=$(shell sed -n 's/channel *= *"\([^"]*\)"/\1/p' $(RUST_TOOLCHAIN_FILE))
+if ENABLE_FASTDEV_UNSAFE_FOR_PRODUCTION
+RUST_TOOLCHAIN_CHANNEL=$(if $(findstring -fsanitize=,$(CXXFLAGS)),nightly,$(RUST_TOOLCHAIN_FILE_CHANNEL))
+else
+RUST_TOOLCHAIN_CHANNEL=$(RUST_TOOLCHAIN_FILE_CHANNEL)
 endif
 CARGO=cargo +$(RUST_TOOLCHAIN_CHANNEL)
 RUSTC_WRAPPER=@RUSTC_WRAPPER@
@@ -151,22 +158,27 @@ RUST_BUILD_DIR=$(top_builddir)/src/rust
 RUST_BIN_DIR=$(RUST_BUILD_DIR)/bin
 RUST_TARGET_DIR=$(top_builddir)/target
 RUST_CXXBRIDGE=$(RUST_BIN_DIR)/cxxbridge
+
+if ENABLE_FASTDEV_UNSAFE_FOR_PRODUCTION
+RUST_PROFILE=fastdev
+else
 RUST_PROFILE=release
+endif
 
 check-rust-profile: Makefile
 	@case "$(RUST_PROFILE)" in \
-		release|dev) ;; \
-		*) echo "Error: RUST_PROFILE must be 'release' or 'dev', got '$(RUST_PROFILE)'" >&2; exit 1;; \
+		release|dev|fastdev) ;; \
+		*) echo "Error: RUST_PROFILE must be 'release', 'dev', or 'fastdev', got '$(RUST_PROFILE)'" >&2; exit 1;; \
 	esac
 
 # Of course, RUST_PROFILE can't be used as an argument directly because cargo
 # doesn't let you pass --debug, that's the default! you can only pass --release.
 # So we have to derive a new variable here.
-RUST_PROFILE_ARG := $(if $(findstring release,$(RUST_PROFILE)),--release,)
+RUST_PROFILE_ARG := $(if $(findstring fastdev,$(RUST_PROFILE)),--profile fastdev,$(if $(findstring release,$(RUST_PROFILE)),--release,))
 
 # Also for even more nonsense reasons the debug profile name is actually `dev`
 # but only in the command line, the target subdirectory gets called `debug`.
-RUST_PROFILE_DIR := $(if $(findstring release,$(RUST_PROFILE)),release,debug)
+RUST_PROFILE_DIR := $(if $(findstring fastdev,$(RUST_PROFILE)),fastdev,$(if $(findstring release,$(RUST_PROFILE)),release,debug))
 
 RUST_DEP_TREE_STAMP=$(RUST_BUILD_DIR)/src/dep-trees/equal-trees.stamp
 SOROBAN_LIBS_STAMP=$(RUST_BUILD_DIR)/soroban/soroban-libs.stamp
@@ -201,7 +213,11 @@ SOROBAN_BUILD_DIR=$(abspath $(RUST_BUILD_DIR))/soroban
 # variable empty (and include or exclude submodules from the list of
 # ALL_SOROBAN_PROTOCOLS as you see fit).
 
-ALL_SOROBAN_PROTOCOLS=p21 p22 p23 p24 p25 p26 p27
+if ENABLE_FASTDEV_UNSAFE_FOR_PRODUCTION
+ALL_SOROBAN_PROTOCOLS=p27 p28
+else
+ALL_SOROBAN_PROTOCOLS=p21 p22 p23 p24 p25 p26 p27 p28
+endif
 WIP_SOROBAN_PROTOCOL=
 
 CARGO_XDR_FEATURE_FLAGS =
@@ -287,23 +303,23 @@ $(SOROBAN_BUILD_DIR)/%/target/git-state.txt: $(top_srcdir)/.git/modules/src/rust
 	printf '%s\n' "$$state" > $@.tmp; \
 	if cmp -s $@.tmp $@; then rm -f $@.tmp; else mv -f $@.tmp $@; fi
 
-# The "unified" rust build is a special non-production mode that builds all of
+# The fastdev rust build is a special non-production mode that builds all of
 # the rust dependencies of librust_stellar_core.a through a single cargo
 # invocation, which is actually the "normal" way cargo operates, but which also
 # has the negative side effect of resolving (merging) different point releases
 # and pre-release minor versions across transitive dependencies, which means we
 # can't control the _exact_ transitive dependencies as well as we'd like.
 #
-# So we only use the unified rust build for certain special cases such as
+# So we only use the fastdev rust build for certain special cases such as
 # testing with asan/tsan (they seem to only work well when built this way) and
 # use the non-unified build (with separate .a files for each separate soroban
 # version) for production builds.
 
-if UNIFIED_RUST
+if ENABLE_FASTDEV_UNSAFE_FOR_PRODUCTION
 
-# In the unified build, we have to pass the --target flag. This actually breaks
+# In the fastdev build, we have to pass the --target flag. This actually breaks
 # the non-unified build, so we wind up setting LIBRUST_STELLAR_CORE separately
-# in unified and non-unified builds.
+# in fastdev and non-unified builds.
 RUST_TARGET=$(shell rustc -vV | sed -n 's/host: //p')
 LIBRUST_STELLAR_CORE=$(RUST_TARGET_DIR)/$(RUST_TARGET)/$(RUST_PROFILE_DIR)/librust_stellar_core.a
 
@@ -323,14 +339,13 @@ $(LIBRUST_STELLAR_CORE): $(RUST_HOST_DEPFILES) $(SRC_RUST_FILES) Makefile $(RUST
 		$(CARGOFLAGS_BUILDSTD) \
 		--package stellar-core \
 		--target $(RUST_TARGET) \
-		--features unified \
 		$(RUST_PROFILE_ARG) \
 		--locked \
 		--target-dir $(abspath $(RUST_TARGET_DIR)) \
-		$(CARGO_FEATURE_TRACY) $(CARGO_FEATURE_NEXT) $(CARGO_FEATURE_TESTUTILS)
+		$(CARGO_FEATURE_FASTDEV) $(CARGO_FEATURE_TRACY) $(CARGO_FEATURE_NEXT) $(CARGO_FEATURE_TESTUTILS)
 	ranlib $@
 
-else # !UNIFIED_RUST
+else # !ENABLE_FASTDEV_UNSAFE_FOR_PRODUCTION
 
 # This next build command looks a little weird but it's necessary. We have to
 # provide an auxiliary metadata string (using RUSTFLAGS=-Cmetadata=$*)
@@ -444,7 +459,7 @@ $(LIBRUST_STELLAR_CORE): $(RUST_HOST_DEPFILES) $(SRC_RUST_FILES) $(ALL_SOROBAN_L
 		$(ALL_SOROBAN_DEPEND_ARGS)
 	ranlib $@
 
-endif # UNIFIED_RUST
+endif # ENABLE_FASTDEV_UNSAFE_FOR_PRODUCTION
 
 stellar_core_LDADD += $(LIBRUST_STELLAR_CORE) -ldl
 
diff --git a/src/herder/test/HerderTests.cpp b/src/herder/test/HerderTests.cpp
index 15d3282d4..885ff6f14 100644
--- a/src/herder/test/HerderTests.cpp
+++ b/src/herder/test/HerderTests.cpp
@@ -1042,7 +1042,15 @@ TEST_CASE("txset", "[herder][txset]")
 {
     SECTION("generalized tx set protocol")
     {
-        testTxSet(static_cast<uint32>(SOROBAN_PROTOCOL_VERSION));
+        uint32_t generalizedTxSetProtocolVersion =
+            static_cast<uint32>(SOROBAN_PROTOCOL_VERSION);
+#ifdef ENABLE_NEXT_PROTOCOL_VERSION_UNSAFE_FOR_PRODUCTION
+        // Fastdev only links recent Soroban hosts, and this test just needs a
+        // generalized-txset-capable protocol.
+        generalizedTxSetProtocolVersion =
+            Config::CURRENT_LEDGER_PROTOCOL_VERSION - 1;
+#endif
+        testTxSet(generalizedTxSetProtocolVersion);
     }
     SECTION("protocol current")
     {
@@ -1450,6 +1458,12 @@ TEST_CASE("txset base fee", "[herder][txset]")
                            uint32_t expNotChargedAccounts = 0) {
         cfg.LEDGER_PROTOCOL_VERSION = protocolVersion;
         cfg.TESTING_UPGRADE_LEDGER_PROTOCOL_VERSION = protocolVersion;
+                if (!testutil::isTestApplicationProtocolVersionSupported(cfg))
+                {
+                    SUCCEED("Skipping historical Soroban protocol test: requested "
+                        "protocol is not linked in this build");
+                    return;
+                }
         VirtualClock clock;
         Application::pointer app = createTestApplication(clock, cfg);
 
@@ -1671,7 +1685,7 @@ TEST_CASE("tx set hits overlay byte limit during construction",
 {
     Config cfg(getTestConfig());
     cfg.TESTING_UPGRADE_LEDGER_PROTOCOL_VERSION =
-        static_cast<uint32_t>(SOROBAN_PROTOCOL_VERSION);
+        Config::CURRENT_LEDGER_PROTOCOL_VERSION;
     auto max = std::numeric_limits<uint32_t>::max();
     cfg.TESTING_UPGRADE_MAX_TX_SET_SIZE = max;
     // Pre-create enough genesis accounts for the test
diff --git a/src/herder/test/TransactionQueueTests.cpp b/src/herder/test/TransactionQueueTests.cpp
index ec2b84a06..4ed79984d 100644
--- a/src/herder/test/TransactionQueueTests.cpp
+++ b/src/herder/test/TransactionQueueTests.cpp
@@ -1430,6 +1430,15 @@ TEST_CASE("TransactionQueue Key Filtering", "[soroban][transactionqueue]")
     }
     SECTION("protocol version 24")
     {
+        auto cfg = getTestConfig();
+        cfg.TESTING_UPGRADE_LEDGER_PROTOCOL_VERSION = 24;
+        if (!testutil::isTestApplicationProtocolVersionSupported(cfg))
+        {
+            SUCCEED("Skipping historical Soroban protocol test: requested "
+                    "protocol is not linked in this build");
+            return;
+        }
+
         SECTION("should filter")
         {
             for (auto const& keyToFilter : keysToFilterP24)
diff --git a/src/herder/test/TxSetTests.cpp b/src/herder/test/TxSetTests.cpp
index 87216f3ce..bcf61ed69 100644
--- a/src/herder/test/TxSetTests.cpp
+++ b/src/herder/test/TxSetTests.cpp
@@ -482,6 +482,12 @@ testGeneralizedTxSetXDRConversion(ProtocolVersion protocolVersion)
     cfg.TESTING_UPGRADE_LEDGER_PROTOCOL_VERSION =
         static_cast<uint32_t>(protocolVersion);
     cfg.GENESIS_TEST_ACCOUNT_COUNT = 10000;
+    if (!testutil::isTestApplicationProtocolVersionSupported(cfg))
+    {
+        SUCCEED("Skipping historical Soroban protocol test: requested "
+                "protocol is not linked in this build");
+        return;
+    }
     bool isParallelSoroban = protocolVersionStartsFrom(
         cfg.LEDGER_PROTOCOL_VERSION, PARALLEL_SOROBAN_PHASE_PROTOCOL_VERSION);
 
@@ -1064,6 +1070,16 @@ TEST_CASE("generalized tx set XDR conversion", "[txset]")
 TEST_CASE("applicable txset validation - Soroban phase version is correct",
           "[txset][soroban]")
 {
+    auto historicalCfg = getTestConfig();
+    historicalCfg.TESTING_UPGRADE_LEDGER_PROTOCOL_VERSION =
+        static_cast<uint32_t>(PARALLEL_SOROBAN_PHASE_PROTOCOL_VERSION) - 1;
+    if (!testutil::isTestApplicationProtocolVersionSupported(historicalCfg))
+    {
+        SUCCEED("Skipping historical Soroban protocol test: requested "
+                "protocol is not linked in this build");
+        return;
+    }
+
     auto runTest = [](uint32_t protocolVersion,
                       bool useParallelSorobanPhase) -> TxSetValidationResult {
         VirtualClock clock;
@@ -2497,10 +2513,15 @@ runParallelTxSetBuildingTest(bool variableStageCount)
 
     VirtualClock clock;
     auto cfg = getTestConfig();
-    cfg.LEDGER_PROTOCOL_VERSION =
-        static_cast<uint32_t>(PARALLEL_SOROBAN_PHASE_PROTOCOL_VERSION);
-    cfg.TESTING_UPGRADE_LEDGER_PROTOCOL_VERSION =
+    uint32_t testLedgerProtocolVersion =
         static_cast<uint32_t>(PARALLEL_SOROBAN_PHASE_PROTOCOL_VERSION);
+#ifdef ENABLE_NEXT_PROTOCOL_VERSION_UNSAFE_FOR_PRODUCTION
+    // Fastdev only links recent Soroban hosts, so avoid forcing this test
+    // through the first historical parallel-Soroban protocol in next builds.
+    testLedgerProtocolVersion = Config::CURRENT_LEDGER_PROTOCOL_VERSION - 1;
+#endif
+    cfg.LEDGER_PROTOCOL_VERSION = testLedgerProtocolVersion;
+    cfg.TESTING_UPGRADE_LEDGER_PROTOCOL_VERSION = testLedgerProtocolVersion;
     cfg.SOROBAN_PHASE_MIN_STAGE_COUNT = variableStageCount ? 1 : STAGE_COUNT;
     cfg.SOROBAN_PHASE_MAX_STAGE_COUNT = STAGE_COUNT;
     // Temporary set the limits override very high in order for the upgrades
diff --git a/src/herder/test/UpgradesTests.cpp b/src/herder/test/UpgradesTests.cpp
index 4894af432..18bb5d6c9 100644
--- a/src/herder/test/UpgradesTests.cpp
+++ b/src/herder/test/UpgradesTests.cpp
@@ -1047,6 +1047,12 @@ TEST_CASE("upgrades affect in-memory Soroban state state size",
     auto cfg = getTestConfig();
     cfg.TESTING_UPGRADE_LEDGER_PROTOCOL_VERSION = 22;
     cfg.USE_CONFIG_FOR_GENESIS = true;
+    if (!testutil::isTestApplicationProtocolVersionSupported(cfg))
+    {
+        SUCCEED("Skipping historical Soroban protocol test: requested "
+                "protocol is not linked in this build");
+        return;
+    }
 
     uint32_t const windowSize = 15;
     uint32_t const samplePeriod = 4;
@@ -3892,6 +3898,12 @@ TEST_CASE("protocol 23 upgrade sets default SCP timing values", "[upgrades]")
     VirtualClock clock;
     auto cfg = getTestConfig(0, Config::TESTDB_IN_MEMORY);
     cfg.TESTING_UPGRADE_LEDGER_PROTOCOL_VERSION = 22;
+    if (!testutil::isTestApplicationProtocolVersionSupported(cfg))
+    {
+        SUCCEED("Skipping historical Soroban protocol test: requested "
+                "protocol is not linked in this build");
+        return;
+    }
 
     auto app = createTestApplication(clock, cfg);
     auto& lm = app->getLedgerManager();
@@ -4043,6 +4055,12 @@ TEST_CASE("p24 upgrade fixes corrupted hot archive entries",
     Config cfg(getTestConfig());
     cfg.USE_CONFIG_FOR_GENESIS = true;
     cfg.TESTING_UPGRADE_LEDGER_PROTOCOL_VERSION = corruptedProtocolVersion;
+    if (!testutil::isTestApplicationProtocolVersionSupported(cfg))
+    {
+        SUCCEED("Skipping historical Soroban protocol test: requested "
+                "protocol is not linked in this build");
+        return;
+    }
     auto app = createTestApplication(clock, cfg);
     gIsProductionNetwork = true;
     overrideSorobanNetworkConfigForTest(*app);
diff --git a/src/rust/Cargo.toml b/src/rust/Cargo.toml
index b67966797..be8e16cb1 100644
--- a/src/rust/Cargo.toml
+++ b/src/rust/Cargo.toml
@@ -98,27 +98,35 @@ tracy-client = { version = "=0.17.0", features = [
 # makes it difficult to use an IDE to work on this crate since the IDE will not
 # be able to resolve the hosts to anything at all. So we keep some _optional_
 # copies of the host dependencies here, and allow enabling them with the
-# `unified` feature here.
+# `fastdev` feature here.
 #
 # To reiterate: the soroban-env-host-p{21,22,23}... dependency blocks listed
 # here are NOT part of the default build. The default build relies on the
 # versions pinned as git submodules.
 #
-# However, you can _manually_ switch the default build by enabling the `unified`
+# However, you can _manually_ switch the default build by enabling the `fastdev`
 # feature using a feature-toggle in an IDE (eg. using the VS Code "Rust Feature
 # Toggler" extension), and the build system (src/Makefile.am) can be configured
-# to use the `unified` feature if you configure with
-# --enable-unified-rust-unsafe-for-production.
+# to use the `fastdev` feature if you configure with
+# --enable-fastdev-unsafe-for-production.
 #
-# If you do a unified build, be careful to reset any changes the IDE makes to
+# If you do a fastdev build, be careful to reset any changes the IDE makes to
 # Cargo.lock! The unified build will re-resolve transitive dependencies and
 # unify them, perturbing the contents of the lockfile.
 
+[dependencies.soroban-env-host-p28]
+version = "=27.0.0"
+git = "https://github.com/stellar/rs-soroban-env"
+package = "soroban-env-host"
+rev = "883fd56374fc619afaa4c4c7489563555b7173f2"
+optional = true
+features = ["next"]
+
 [dependencies.soroban-env-host-p27]
-version = "=26.1.2"
+version = "=27.0.0"
 git = "https://github.com/stellar/rs-soroban-env"
 package = "soroban-env-host"
-rev = "c0e58f94ff2983a09440cef6a54253349fd3c4db"
+rev = "b03d2563f3a08d51095a19bdbb6d90364b8ce04a"
 optional = true
 
 [dependencies.soroban-env-host-p26]
@@ -167,14 +175,14 @@ optional = true
 # supported host, since test material usually just grows over time.
 
 [dependencies.soroban-test-wasms]
-version = "=26.0.0"
+version = "=27.0.0"
 git = "https://github.com/stellar/rs-soroban-env"
-rev = "b351f88a468d3b9e1d6de53d5b0ca585f6b7dadb"
+rev = "b03d2563f3a08d51095a19bdbb6d90364b8ce04a"
 
 [dependencies.soroban-synth-wasm]
-version = "=26.0.0"
+version = "=27.0.0"
 git = "https://github.com/stellar/rs-soroban-env"
-rev = "b351f88a468d3b9e1d6de53d5b0ca585f6b7dadb"
+rev = "b03d2563f3a08d51095a19bdbb6d90364b8ce04a"
 
 # The soroban-fuzz-targets crate will actually pull in _its own copy_ of the
 # soroban host (or at least unify with one of the versions above if you're doing
@@ -182,9 +190,9 @@ rev = "b351f88a468d3b9e1d6de53d5b0ca585f6b7dadb"
 # soroban is updated -- it should track the highest protocol available (or
 # at least whichever one you want to fuzz).
 [dependencies.soroban-fuzz-targets]
-version = "=26.0.0"
+version = "=27.0.0"
 git = "https://github.com/stellar/rs-soroban-env"
-rev = "b351f88a468d3b9e1d6de53d5b0ca585f6b7dadb"
+rev = "b03d2563f3a08d51095a19bdbb6d90364b8ce04a"
 optional = true
 
 [dependencies.stellar-quorum-analyzer]
@@ -194,15 +202,11 @@ rev = "f67e9e2f080c2cc1a332d894c42277c64845e257"
 
 [features]
 
-# Turn on the optional unified build. This is typically only useful in an IDE or when
+# Turn on the optional fastdev build. This is typically only useful in an IDE or when
 # orchestrated by the build system. See note above and in docs/CONTRIBUTING.md.
-unified = ["dep:soroban-env-host-p21",
-           "dep:soroban-env-host-p22",
-           "dep:soroban-env-host-p23",
-           "dep:soroban-env-host-p24",
-           "dep:soroban-env-host-p25",
-           "dep:soroban-env-host-p26",
-           "dep:soroban-env-host-p27"]
+fastdev = ["dep:soroban-env-host-p27",
+           "dep:soroban-env-host-p28",
+           "next"]
 
 tracy = ["dep:tracy-client"]
 
diff --git a/src/rust/soroban/p28 b/src/rust/soroban/p28
new file mode 160000
index 000000000..883fd5637
--- /dev/null
+++ b/src/rust/soroban/p28
@@ -0,0 +1 @@
+Subproject commit 883fd56374fc619afaa4c4c7489563555b7173f2
diff --git a/src/rust/src/dep-trees/p28-expect.txt b/src/rust/src/dep-trees/p28-expect.txt
new file mode 100644
index 000000000..2ccc9a9ba
--- /dev/null
+++ b/src/rust/src/dep-trees/p28-expect.txt
@@ -0,0 +1,311 @@
+soroban-env-host v27.0.0 (src/rust/soroban/p28/soroban-env-host)
+├── ark-bls12-381 v0.5.0
+│   ├── ark-ec v0.5.0
+│   │   ├── ahash v0.8.11
+│   │   │   ├── cfg-if v1.0.0
+│   │   │   ├── once_cell v1.19.0
+│   │   │   └── zerocopy v0.7.35
+│   │   │       └── zerocopy-derive v0.7.35 (proc-macro)
+│   │   │           ├── proc-macro2 v1.0.69
+│   │   │           │   └── unicode-ident v1.0.9
+│   │   │           ├── quote v1.0.33
+│   │   │           │   └── proc-macro2 v1.0.69 (*)
+│   │   │           └── syn v2.0.39
+│   │   │               ├── proc-macro2 v1.0.69 (*)
+│   │   │               ├── quote v1.0.33 (*)
+│   │   │               └── unicode-ident v1.0.9
+│   │   │   [build-dependencies]
+│   │   │   └── version_check v0.9.4
+│   │   ├── ark-ff v0.5.0
+│   │   │   ├── ark-ff-asm v0.5.0 (proc-macro)
+│   │   │   │   ├── quote v1.0.33 (*)
+│   │   │   │   └── syn v2.0.39 (*)
+│   │   │   ├── ark-ff-macros v0.5.0 (proc-macro)
+│   │   │   │   ├── num-bigint v0.4.4
+│   │   │   │   │   ├── num-integer v0.1.45
+│   │   │   │   │   │   └── num-traits v0.2.17
+│   │   │   │   │   │       [build-dependencies]
+│   │   │   │   │   │       └── autocfg v1.1.0
+│   │   │   │   │   │   [build-dependencies]
+│   │   │   │   │   │   └── autocfg v1.1.0
+│   │   │   │   │   └── num-traits v0.2.17 (*)
+│   │   │   │   │   [build-dependencies]
+│   │   │   │   │   └── autocfg v1.1.0
+│   │   │   │   ├── num-traits v0.2.17 (*)
+│   │   │   │   ├── proc-macro2 v1.0.69 (*)
+│   │   │   │   ├── quote v1.0.33 (*)
+│   │   │   │   └── syn v2.0.39 (*)
+│   │   │   ├── ark-serialize v0.5.0
+│   │   │   │   ├── ark-serialize-derive v0.5.0 (proc-macro)
+│   │   │   │   │   ├── proc-macro2 v1.0.69 (*)
+│   │   │   │   │   ├── quote v1.0.33 (*)
+│   │   │   │   │   └── syn v2.0.39 (*)
+│   │   │   │   ├── ark-std v0.5.0
+│   │   │   │   │   ├── num-traits v0.2.17
+│   │   │   │   │   │   [build-dependencies]
+│   │   │   │   │   │   └── autocfg v1.1.0
+│   │   │   │   │   └── rand v0.8.5
+│   │   │   │   │       ├── libc v0.2.176
+│   │   │   │   │       ├── rand_chacha v0.3.1
+│   │   │   │   │       │   ├── ppv-lite86 v0.2.17
+│   │   │   │   │       │   └── rand_core v0.6.4
+│   │   │   │   │       │       └── getrandom v0.2.11
+│   │   │   │   │       │           ├── cfg-if v1.0.0
+│   │   │   │   │       │           ├── js-sys v0.3.64
+│   │   │   │   │       │           │   └── wasm-bindgen v0.2.100
+│   │   │   │   │       │           │       ├── cfg-if v1.0.0
+│   │   │   │   │       │           │       ├── once_cell v1.19.0
+│   │   │   │   │       │           │       ├── rustversion v1.0.14 (proc-macro)
+│   │   │   │   │       │           │       └── wasm-bindgen-macro v0.2.100 (proc-macro)
+│   │   │   │   │       │           │           ├── quote v1.0.33 (*)
+│   │   │   │   │       │           │           └── wasm-bindgen-macro-support v0.2.100
+│   │   │   │   │       │           │               ├── proc-macro2 v1.0.69 (*)
+│   │   │   │   │       │           │               ├── quote v1.0.33 (*)
+│   │   │   │   │       │           │               ├── syn v2.0.39 (*)
+│   │   │   │   │       │           │               ├── wasm-bindgen-backend v0.2.100
+│   │   │   │   │       │           │               │   ├── bumpalo v3.13.0
+│   │   │   │   │       │           │               │   ├── log v0.4.19
+│   │   │   │   │       │           │               │   ├── proc-macro2 v1.0.69 (*)
+│   │   │   │   │       │           │               │   ├── quote v1.0.33 (*)
+│   │   │   │   │       │           │               │   ├── syn v2.0.39 (*)
+│   │   │   │   │       │           │               │   └── wasm-bindgen-shared v0.2.100
+│   │   │   │   │       │           │               │       └── unicode-ident v1.0.9
+│   │   │   │   │       │           │               └── wasm-bindgen-shared v0.2.100 (*)
+│   │   │   │   │       │           ├── libc v0.2.176
+│   │   │   │   │       │           ├── wasi v0.11.0+wasi-snapshot-preview1
+│   │   │   │   │       │           └── wasm-bindgen v0.2.100 (*)
+│   │   │   │   │       └── rand_core v0.6.4 (*)
+│   │   │   │   ├── arrayvec v0.7.6
+│   │   │   │   ├── digest v0.10.7
+│   │   │   │   │   ├── block-buffer v0.10.4
+│   │   │   │   │   │   └── generic-array v0.14.7
+│   │   │   │   │   │       ├── typenum v1.16.0
+│   │   │   │   │   │       └── zeroize v1.8.1
+│   │   │   │   │   │           └── zeroize_derive v1.4.2 (proc-macro)
+│   │   │   │   │   │               ├── proc-macro2 v1.0.69 (*)
+│   │   │   │   │   │               ├── quote v1.0.33 (*)
+│   │   │   │   │   │               └── syn v2.0.39 (*)
+│   │   │   │   │   │       [build-dependencies]
+│   │   │   │   │   │       └── version_check v0.9.4
+│   │   │   │   │   ├── const-oid v0.9.2
+│   │   │   │   │   ├── crypto-common v0.1.6
+│   │   │   │   │   │   ├── generic-array v0.14.7 (*)
+│   │   │   │   │   │   └── typenum v1.16.0
+│   │   │   │   │   └── subtle v2.5.0
+│   │   │   │   └── num-bigint v0.4.4 (*)
+│   │   │   ├── ark-std v0.5.0 (*)
+│   │   │   ├── arrayvec v0.7.6
+│   │   │   ├── digest v0.10.7 (*)
+│   │   │   ├── educe v0.6.0 (proc-macro)
+│   │   │   │   ├── enum-ordinalize v4.3.2
+│   │   │   │   │   └── enum-ordinalize-derive v4.3.2 (proc-macro)
+│   │   │   │   │       ├── proc-macro2 v1.0.69 (*)
+│   │   │   │   │       ├── quote v1.0.33 (*)
+│   │   │   │   │       └── syn v2.0.39 (*)
+│   │   │   │   ├── proc-macro2 v1.0.69 (*)
+│   │   │   │   ├── quote v1.0.33 (*)
+│   │   │   │   └── syn v2.0.39 (*)
+│   │   │   ├── itertools v0.13.0
+│   │   │   │   └── either v1.8.1
+│   │   │   ├── num-bigint v0.4.4 (*)
+│   │   │   ├── num-traits v0.2.17 (*)
+│   │   │   ├── paste v1.0.12 (proc-macro)
+│   │   │   └── zeroize v1.8.1 (*)
+│   │   ├── ark-poly v0.5.0
+│   │   │   ├── ahash v0.8.11 (*)
+│   │   │   ├── ark-ff v0.5.0 (*)
+│   │   │   ├── ark-serialize v0.5.0 (*)
+│   │   │   ├── ark-std v0.5.0 (*)
+│   │   │   ├── educe v0.6.0 (proc-macro) (*)
+│   │   │   ├── fnv v1.0.7
+│   │   │   └── hashbrown v0.15.5
+│   │   │       └── allocator-api2 v0.2.21
+│   │   ├── ark-serialize v0.5.0 (*)
+│   │   ├── ark-std v0.5.0 (*)
+│   │   ├── educe v0.6.0 (proc-macro) (*)
+│   │   ├── fnv v1.0.7
+│   │   ├── hashbrown v0.15.5 (*)
+│   │   ├── itertools v0.13.0 (*)
+│   │   ├── num-bigint v0.4.4 (*)
+│   │   ├── num-integer v0.1.45
+│   │   │   └── num-traits v0.2.17 (*)
+│   │   │   [build-dependencies]
+│   │   │   └── autocfg v1.1.0
+│   │   ├── num-traits v0.2.17 (*)
+│   │   └── zeroize v1.8.1 (*)
+│   ├── ark-ff v0.5.0 (*)
+│   ├── ark-serialize v0.5.0 (*)
+│   └── ark-std v0.5.0 (*)
+├── ark-bn254 v0.5.0
+│   ├── ark-ec v0.5.0 (*)
+│   ├── ark-ff v0.5.0 (*)
+│   └── ark-std v0.5.0 (*)
+├── ark-ec v0.5.0 (*)
+├── ark-ff v0.5.0 (*)
+├── ark-serialize v0.5.0 (*)
+├── curve25519-dalek v4.1.3
+│   ├── cfg-if v1.0.0
+│   ├── cpufeatures v0.2.8
+│   │   └── libc v0.2.176
+│   ├── curve25519-dalek-derive v0.1.0 (proc-macro)
+│   │   ├── proc-macro2 v1.0.69 (*)
+│   │   ├── quote v1.0.33 (*)
+│   │   └── syn v2.0.39 (*)
+│   ├── digest v0.10.7 (*)
+│   ├── fiat-crypto v0.2.5
+│   ├── subtle v2.5.0
+│   └── zeroize v1.8.1 (*)
+│   [build-dependencies]
+│   └── rustc_version v0.4.0
+│       └── semver v1.0.17
+├── ecdsa v0.16.9
+│   ├── der v0.7.6
+│   │   ├── const-oid v0.9.2
+│   │   └── zeroize v1.8.1 (*)
+│   ├── digest v0.10.7 (*)
+│   ├── elliptic-curve v0.13.8
+│   │   ├── base16ct v0.2.0
+│   │   ├── crypto-bigint v0.5.2
+│   │   │   ├── generic-array v0.14.7 (*)
+│   │   │   ├── rand_core v0.6.4 (*)
+│   │   │   ├── subtle v2.5.0
+│   │   │   └── zeroize v1.8.1 (*)
+│   │   ├── digest v0.10.7 (*)
+│   │   ├── ff v0.13.0
+│   │   │   ├── rand_core v0.6.4 (*)
+│   │   │   └── subtle v2.5.0
+│   │   ├── generic-array v0.14.7 (*)
+│   │   ├── group v0.13.0
+│   │   │   ├── ff v0.13.0 (*)
+│   │   │   ├── rand_core v0.6.4 (*)
+│   │   │   └── subtle v2.5.0
+│   │   ├── rand_core v0.6.4 (*)
+│   │   ├── sec1 v0.7.2
+│   │   │   ├── base16ct v0.2.0
+│   │   │   ├── der v0.7.6 (*)
+│   │   │   ├── generic-array v0.14.7 (*)
+│   │   │   ├── subtle v2.5.0
+│   │   │   └── zeroize v1.8.1 (*)
+│   │   ├── subtle v2.5.0
+│   │   └── zeroize v1.8.1 (*)
+│   ├── rfc6979 v0.4.0
+│   │   ├── hmac v0.12.1
+│   │   │   └── digest v0.10.7 (*)
+│   │   └── subtle v2.5.0
+│   └── signature v2.1.0
+│       ├── digest v0.10.7 (*)
+│       └── rand_core v0.6.4 (*)
+├── ed25519-dalek v2.1.1
+│   ├── curve25519-dalek v4.1.3 (*)
+│   ├── ed25519 v2.2.2
+│   │   └── signature v2.1.0 (*)
+│   ├── rand_core v0.6.4 (*)
+│   ├── sha2 v0.10.9
+│   │   ├── cfg-if v1.0.0
+│   │   ├── cpufeatures v0.2.8 (*)
+│   │   └── digest v0.10.7 (*)
+│   ├── subtle v2.5.0
+│   └── zeroize v1.8.1 (*)
+├── elliptic-curve v0.13.8 (*)
+├── generic-array v0.14.7 (*)
+├── getrandom v0.2.11 (*)
+├── hex-literal v0.4.1
+├── hmac v0.12.1 (*)
+├── k256 v0.13.4
+│   ├── cfg-if v1.0.0
+│   ├── ecdsa v0.16.9 (*)
+│   ├── elliptic-curve v0.13.8 (*)
+│   └── sha2 v0.10.9 (*)
+├── num-derive v0.4.1 (proc-macro)
+│   ├── proc-macro2 v1.0.69 (*)
+│   ├── quote v1.0.33 (*)
+│   └── syn v2.0.39 (*)
+├── num-integer v0.1.45 (*)
+├── num-traits v0.2.17 (*)
+├── p256 v0.13.2
+│   ├── ecdsa v0.16.9 (*)
+│   ├── elliptic-curve v0.13.8 (*)
+│   ├── primeorder v0.13.3
+│   │   └── elliptic-curve v0.13.8 (*)
+│   └── sha2 v0.10.9 (*)
+├── rand v0.8.5 (*)
+├── rand_chacha v0.3.1 (*)
+├── sec1 v0.7.2 (*)
+├── sha2 v0.10.9 (*)
+├── sha3 v0.10.8
+│   ├── digest v0.10.7 (*)
+│   └── keccak v0.1.4
+│       └── cpufeatures v0.2.8 (*)
+├── soroban-builtin-sdk-macros v27.0.0 (proc-macro) (src/rust/soroban/p28/soroban-builtin-sdk-macros)
+│   ├── itertools v0.13.0
+│   │   └── either v1.8.1
+│   ├── proc-macro2 v1.0.69 (*)
+│   ├── quote v1.0.33 (*)
+│   └── syn v2.0.39 (*)
+├── soroban-env-common v27.0.0 (src/rust/soroban/p28/soroban-env-common)
+│   ├── ethnum v1.5.3
+│   ├── num-derive v0.4.1 (proc-macro) (*)
+│   ├── num-traits v0.2.17 (*)
+│   ├── soroban-env-macros v27.0.0 (proc-macro) (src/rust/soroban/p28/soroban-env-macros)
+│   │   ├── itertools v0.13.0 (*)
+│   │   ├── proc-macro2 v1.0.69 (*)
+│   │   ├── quote v1.0.33 (*)
+│   │   ├── serde v1.0.192
+│   │   │   └── serde_derive v1.0.192 (proc-macro)
+│   │   │       ├── proc-macro2 v1.0.69 (*)
+│   │   │       ├── quote v1.0.33 (*)
+│   │   │       └── syn v2.0.39 (*)
+│   │   ├── serde_json v1.0.108
+│   │   │   ├── itoa v1.0.6
+│   │   │   ├── ryu v1.0.13
+│   │   │   └── serde v1.0.192 (*)
+│   │   ├── stellar-xdr v27.0.0
+│   │   │   ├── escape-bytes v0.1.1
+│   │   │   ├── ethnum v1.5.3
+│   │   │   ├── hex v0.4.3
+│   │   │   ├── sha2 v0.10.9 (*)
+│   │   │   └── stellar-strkey v0.0.13
+│   │   │       └── data-encoding v2.6.0
+│   │   │       [build-dependencies]
+│   │   │       └── crate-git-revision v0.0.6
+│   │   │           ├── serde v1.0.192 (*)
+│   │   │           ├── serde_derive v1.0.192 (proc-macro) (*)
+│   │   │           └── serde_json v1.0.108 (*)
+│   │   │   [build-dependencies]
+│   │   │   └── crate-git-revision v0.0.6 (*)
+│   │   └── syn v2.0.39 (*)
+│   ├── soroban-wasmi v0.31.1-soroban.20.0.1 (https://github.com/stellar/wasmi?rev=0ed3f3dee30dc41ebe21972399e0a73a41944aa0#0ed3f3de)
+│   │   ├── smallvec v1.13.2
+│   │   ├── spin v0.9.8
+│   │   ├── wasmi_arena v0.4.0 (https://github.com/stellar/wasmi?rev=0ed3f3dee30dc41ebe21972399e0a73a41944aa0#0ed3f3de)
+│   │   ├── wasmi_core v0.13.0 (https://github.com/stellar/wasmi?rev=0ed3f3dee30dc41ebe21972399e0a73a41944aa0#0ed3f3de)
+│   │   │   ├── downcast-rs v1.2.0
+│   │   │   ├── libm v0.2.8
+│   │   │   ├── num-traits v0.2.17 (*)
+│   │   │   └── paste v1.0.12 (proc-macro)
+│   │   └── wasmparser-nostd v0.100.2
+│   │       └── indexmap-nostd v0.4.0
+│   ├── static_assertions v1.1.0
+│   ├── stellar-xdr v27.0.0
+│   │   ├── base64 v0.22.1
+│   │   ├── escape-bytes v0.1.1
+│   │   ├── ethnum v1.5.3
+│   │   ├── hex v0.4.3
+│   │   ├── sha2 v0.10.9 (*)
+│   │   └── stellar-strkey v0.0.13 (*)
+│   │   [build-dependencies]
+│   │   └── crate-git-revision v0.0.6 (*)
+│   └── wasmparser v0.116.1
+│       ├── indexmap v2.0.2
+│       │   ├── equivalent v1.0.1
+│       │   └── hashbrown v0.14.1
+│       └── semver v1.0.17
+│   [build-dependencies]
+│   └── crate-git-revision v0.0.9
+│       ├── serde v1.0.192 (*)
+│       ├── serde_derive v1.0.192 (proc-macro) (*)
+│       └── serde_json v1.0.108 (*)
+├── soroban-wasmi v0.31.1-soroban.20.0.1 (https://github.com/stellar/wasmi?rev=0ed3f3dee30dc41ebe21972399e0a73a41944aa0#0ed3f3de) (*)
+├── static_assertions v1.1.0
+├── stellar-strkey v0.0.13 (*)
+└── wasmparser v0.116.1 (*)
diff --git a/src/rust/src/soroban_module_cache.rs b/src/rust/src/soroban_module_cache.rs
index 9270b46c7..e8e0b221e 100644
--- a/src/rust/src/soroban_module_cache.rs
+++ b/src/rust/src/soroban_module_cache.rs
@@ -16,25 +16,43 @@
 
 use crate::{
     rust_bridge::CxxBuf,
-    soroban_proto_all::{get_host_module_for_protocol, p23, p24, p25, p26, p27, protocol_agnostic},
+    soroban_proto_all::{get_host_module_for_protocol, p27, protocol_agnostic},
 };
 
+#[cfg(not(feature = "fastdev"))]
+use crate::soroban_proto_all::{p23, p24, p25, p26};
+
+#[cfg(feature = "next")]
+use crate::soroban_proto_all::p28;
+
 pub(crate) struct SorobanModuleCache {
+    #[cfg(not(feature = "fastdev"))]
     pub(crate) p23_cache: p23::soroban_proto_any::ProtocolSpecificModuleCache,
+    #[cfg(not(feature = "fastdev"))]
     pub(crate) p24_cache: p24::soroban_proto_any::ProtocolSpecificModuleCache,
+    #[cfg(not(feature = "fastdev"))]
     pub(crate) p25_cache: p25::soroban_proto_any::ProtocolSpecificModuleCache,
+    #[cfg(not(feature = "fastdev"))]
     pub(crate) p26_cache: p26::soroban_proto_any::ProtocolSpecificModuleCache,
     pub(crate) p27_cache: p27::soroban_proto_any::ProtocolSpecificModuleCache,
+    #[cfg(feature = "next")]
+    pub(crate) p28_cache: p28::soroban_proto_any::ProtocolSpecificModuleCache,
 }
 
 impl SorobanModuleCache {
     fn new() -> Result<Self, Box<dyn std::error::Error>> {
         Ok(Self {
+            #[cfg(not(feature = "fastdev"))]
             p23_cache: p23::soroban_proto_any::ProtocolSpecificModuleCache::new()?,
+            #[cfg(not(feature = "fastdev"))]
             p24_cache: p24::soroban_proto_any::ProtocolSpecificModuleCache::new()?,
+            #[cfg(not(feature = "fastdev"))]
             p25_cache: p25::soroban_proto_any::ProtocolSpecificModuleCache::new()?,
+            #[cfg(not(feature = "fastdev"))]
             p26_cache: p26::soroban_proto_any::ProtocolSpecificModuleCache::new()?,
             p27_cache: p27::soroban_proto_any::ProtocolSpecificModuleCache::new()?,
+            #[cfg(feature = "next")]
+            p28_cache: p28::soroban_proto_any::ProtocolSpecificModuleCache::new()?,
         })
     }
     pub fn compile(
@@ -42,25 +60,36 @@ impl SorobanModuleCache {
         ledger_protocol: u32,
         _wasm: &[u8],
     ) -> Result<(), Box<dyn std::error::Error>> {
-        match ledger_protocol {
+        let hm = get_host_module_for_protocol(ledger_protocol, ledger_protocol)?;
+        match hm.max_proto {
+            #[cfg(not(feature = "fastdev"))]
             23 => self.p23_cache.compile(_wasm),
+            #[cfg(not(feature = "fastdev"))]
             24 => self.p24_cache.compile(_wasm),
+            #[cfg(not(feature = "fastdev"))]
             25 => self.p25_cache.compile(_wasm),
+            #[cfg(not(feature = "fastdev"))]
             26 => self.p26_cache.compile(_wasm),
             27 => self.p27_cache.compile(_wasm),
             #[cfg(feature = "next")]
-            28 => self.p27_cache.compile(_wasm),
+            28 => self.p28_cache.compile(_wasm),
             // Add other protocols here as needed.
             _ => Err(protocol_agnostic::make_error("unsupported protocol")),
         }
     }
     pub fn shallow_clone(&self) -> Result<Box<Self>, Box<dyn std::error::Error>> {
         Ok(Box::new(Self {
+            #[cfg(not(feature = "fastdev"))]
             p23_cache: self.p23_cache.shallow_clone()?,
+            #[cfg(not(feature = "fastdev"))]
             p24_cache: self.p24_cache.shallow_clone()?,
+            #[cfg(not(feature = "fastdev"))]
             p25_cache: self.p25_cache.shallow_clone()?,
+            #[cfg(not(feature = "fastdev"))]
             p26_cache: self.p26_cache.shallow_clone()?,
             p27_cache: self.p27_cache.shallow_clone()?,
+            #[cfg(feature = "next")]
+            p28_cache: self.p28_cache.shallow_clone()?,
         }))
     }
 
@@ -69,19 +98,31 @@ impl SorobanModuleCache {
             .as_ref()
             .try_into()
             .map_err(|_| "Invalid contract-code key length")?;
+        #[cfg(not(feature = "fastdev"))]
         self.p23_cache.evict(&_hash)?;
+        #[cfg(not(feature = "fastdev"))]
         self.p24_cache.evict(&_hash)?;
+        #[cfg(not(feature = "fastdev"))]
         self.p25_cache.evict(&_hash)?;
+        #[cfg(not(feature = "fastdev"))]
         self.p26_cache.evict(&_hash)?;
         self.p27_cache.evict(&_hash)?;
+        #[cfg(feature = "next")]
+        self.p28_cache.evict(&_hash)?;
         Ok(())
     }
     pub fn clear(&self) -> Result<(), Box<dyn std::error::Error>> {
+        #[cfg(not(feature = "fastdev"))]
         self.p23_cache.clear()?;
+        #[cfg(not(feature = "fastdev"))]
         self.p24_cache.clear()?;
+        #[cfg(not(feature = "fastdev"))]
         self.p25_cache.clear()?;
+        #[cfg(not(feature = "fastdev"))]
         self.p26_cache.clear()?;
         self.p27_cache.clear()?;
+        #[cfg(feature = "next")]
+        self.p28_cache.clear()?;
         Ok(())
     }
 
@@ -94,14 +135,19 @@ impl SorobanModuleCache {
             .as_ref()
             .try_into()
             .map_err(|_| "Invalid contract-code key length")?;
-        match protocol {
+        let hm = get_host_module_for_protocol(protocol, protocol)?;
+        match hm.max_proto {
+            #[cfg(not(feature = "fastdev"))]
             23 => self.p23_cache.contains_module(&_hash),
+            #[cfg(not(feature = "fastdev"))]
             24 => self.p24_cache.contains_module(&_hash),
+            #[cfg(not(feature = "fastdev"))]
             25 => self.p25_cache.contains_module(&_hash),
+            #[cfg(not(feature = "fastdev"))]
             26 => self.p26_cache.contains_module(&_hash),
             27 => self.p27_cache.contains_module(&_hash),
             #[cfg(feature = "next")]
-            28 => self.p27_cache.contains_module(&_hash),
+            28 => self.p28_cache.contains_module(&_hash),
             _ => Err(protocol_agnostic::make_error("unsupported protocol")),
         }
     }
@@ -109,16 +155,20 @@ impl SorobanModuleCache {
         &self,
         ledger_protocol: u32,
     ) -> Result<u64, Box<dyn std::error::Error>> {
-        #[allow(unused_mut)]
+        let hm = get_host_module_for_protocol(ledger_protocol, ledger_protocol)?;
         let mut bytes = 0;
-        match ledger_protocol {
+        match hm.max_proto {
+            #[cfg(not(feature = "fastdev"))]
             23 => bytes = bytes.max(self.p23_cache.get_wasm_bytes_input()?),
+            #[cfg(not(feature = "fastdev"))]
             24 => bytes = bytes.max(self.p24_cache.get_wasm_bytes_input()?),
+            #[cfg(not(feature = "fastdev"))]
             25 => bytes = bytes.max(self.p25_cache.get_wasm_bytes_input()?),
+            #[cfg(not(feature = "fastdev"))]
             26 => bytes = bytes.max(self.p26_cache.get_wasm_bytes_input()?),
             27 => bytes = bytes.max(self.p27_cache.get_wasm_bytes_input()?),
             #[cfg(feature = "next")]
-            28 => bytes = bytes.max(self.p27_cache.get_wasm_bytes_input()?),
+            28 => bytes = bytes.max(self.p28_cache.get_wasm_bytes_input()?),
             _ => return Err(protocol_agnostic::make_error("unsupported protocol")),
         }
         Ok(bytes)
diff --git a/src/rust/src/soroban_proto_all.rs b/src/rust/src/soroban_proto_all.rs
index ccdc46786..3cf22a6dd 100644
--- a/src/rust/src/soroban_proto_all.rs
+++ b/src/rust/src/soroban_proto_all.rs
@@ -32,10 +32,10 @@ use crate::RustBuf;
 // We also alias the latest soroban as soroban_curr to help reduce churn in code
 // that's just "always supposed to use the latest".
 
-//#[cfg(not(feature = "next"))]
+#[cfg(not(feature = "next"))]
 pub(crate) use p27 as soroban_curr;
-//#[cfg(feature = "next")]
-//pub(crate) use p28 as soroban_curr;
+#[cfg(feature = "next")]
+pub(crate) use p28 as soroban_curr;
 
 // We also pin some protocol _agnostic_ definitions that are technically
 // implemented by a specific version of soroban, but which is protocol-stable
@@ -43,13 +43,182 @@ pub(crate) use p27 as soroban_curr;
 // only compatible with with, say, a rust Dyn interface like Box<dyn Error>).
 pub(crate) mod protocol_agnostic {
     pub(crate) fn make_error(msg: &'static str) -> Box<dyn std::error::Error> {
-        super::p24::soroban_proto_any::CoreHostError::General(msg.into()).into()
+        super::soroban_curr::soroban_proto_any::CoreHostError::General(msg.into()).into()
     }
 
     // The i128 functions are protocol-agnostic because they're too simple to
     // ever plausibly change. If they ever _do_ change we can switch this (and
     // the callers) to pass a protocol number but it seems unlikely.
-    pub(crate) use super::p24::soroban_env_host::xdr::int128_helpers;
+    pub(crate) use super::soroban_curr::soroban_env_host::xdr::int128_helpers;
+}
+
+#[cfg(feature = "next")]
+#[path = "."]
+pub(crate) mod p28 {
+    pub(crate) extern crate soroban_env_host_p28;
+    use crate::{
+        bridge::rust_bridge::CxxLedgerEntryRentChange,
+        rust_bridge::{
+            CxxFeeConfiguration, CxxRentFeeConfiguration, CxxRentWriteFeeConfiguration,
+            CxxTransactionResources,
+        },
+        SorobanModuleCache,
+    };
+    use soroban_env_host::{
+        budget::Budget,
+        e2e_invoke::{self, InvokeHostFunctionResult},
+        fees::{
+            compute_rent_write_fee_per_1kb, FeeConfiguration, LedgerEntryRentChange,
+            RentFeeConfiguration, RentWriteFeeConfiguration, TransactionResources,
+        },
+        vm::wasm_module_memory_cost,
+        xdr::{ContractCodeEntry, DiagnosticEvent},
+        HostError, LedgerInfo, TraceHook,
+    };
+    pub(crate) use soroban_env_host_p28 as soroban_env_host;
+
+    pub(crate) mod soroban_proto_any;
+
+    pub(crate) use soroban_env_host::{CompilationContext, ErrorHandler, ModuleCache};
+
+    pub(crate) const fn get_version_pre_release(v: &soroban_env_host::Version) -> u32 {
+        v.interface.pre_release
+    }
+
+    pub(crate) const fn get_version_protocol(v: &soroban_env_host::Version) -> u32 {
+        v.interface.protocol
+    }
+
+    pub(crate) fn get_xdr_base_git_rev() -> String {
+        soroban_env_host::xdr::VERSION.xdr.to_string()
+    }
+    pub(crate) fn get_xdr_pkg_ver() -> String {
+        soroban_env_host::xdr::VERSION.pkg.to_string()
+    }
+    pub(crate) fn get_xdr_git_rev() -> String {
+        soroban_env_host::xdr::VERSION.rev.to_string()
+    }
+    pub(crate) fn get_xdr_features() -> Vec<String> {
+        soroban_env_host::xdr::VERSION
+            .features
+            .iter()
+            .map(|s| s.to_string())
+            .collect()
+    }
+
+    pub fn invoke_host_function_with_trace_hook_and_module_cache<
+        T: AsRef<[u8]>,
+        I: ExactSizeIterator<Item = T>,
+    >(
+        budget: &Budget,
+        enable_diagnostics: bool,
+        encoded_host_fn: T,
+        encoded_resources: T,
+        restored_rw_entry_indices: &[u32],
+        encoded_source_account: T,
+        encoded_auth_entries: I,
+        ledger_info: LedgerInfo,
+        encoded_ledger_entries: I,
+        encoded_ttl_entries: I,
+        base_prng_seed: T,
+        diagnostic_events: &mut Vec<DiagnosticEvent>,
+        trace_hook: Option<TraceHook>,
+        module_cache: &SorobanModuleCache,
+    ) -> Result<InvokeHostFunctionResult, HostError> {
+        e2e_invoke::invoke_host_function(
+            budget,
+            enable_diagnostics,
+            encoded_host_fn,
+            encoded_resources,
+            restored_rw_entry_indices,
+            encoded_source_account,
+            encoded_auth_entries,
+            ledger_info,
+            encoded_ledger_entries,
+            encoded_ttl_entries,
+            base_prng_seed,
+            diagnostic_events,
+            trace_hook,
+            Some(module_cache.p28_cache.module_cache.clone()),
+        )
+    }
+
+    pub(crate) fn wasm_module_memory_cost_wrapper(
+        budget: &Budget,
+        contract_code_entry: &ContractCodeEntry,
+    ) -> Result<u64, HostError> {
+        wasm_module_memory_cost(budget, contract_code_entry)
+    }
+
+    pub(crate) fn compute_rent_write_fee_per_1kb_wrapper(
+        bucket_list_size: i64,
+        fee_config: CxxRentWriteFeeConfiguration,
+    ) -> i64 {
+        compute_rent_write_fee_per_1kb(bucket_list_size, &fee_config.into())
+    }
+
+    pub(crate) fn convert_transaction_resources(
+        value: &CxxTransactionResources,
+    ) -> TransactionResources {
+        TransactionResources {
+            instructions: value.instructions,
+            disk_read_entries: value.disk_read_entries,
+            write_entries: value.write_entries,
+            disk_read_bytes: value.disk_read_bytes,
+            write_bytes: value.write_bytes,
+            contract_events_size_bytes: value.contract_events_size_bytes,
+            transaction_size_bytes: value.transaction_size_bytes,
+        }
+    }
+
+    impl From<CxxRentWriteFeeConfiguration> for RentWriteFeeConfiguration {
+        fn from(value: CxxRentWriteFeeConfiguration) -> Self {
+            Self {
+                state_target_size_bytes: value.state_target_size_bytes,
+                rent_fee_1kb_state_size_low: value.rent_fee_1kb_state_size_low,
+                rent_fee_1kb_state_size_high: value.rent_fee_1kb_state_size_high,
+                state_size_rent_fee_growth_factor: value.state_size_rent_fee_growth_factor,
+            }
+        }
+    }
+
+    pub(crate) fn convert_rent_fee_configuration(
+        value: &CxxRentFeeConfiguration,
+    ) -> RentFeeConfiguration {
+        RentFeeConfiguration {
+            fee_per_rent_1kb: value.fee_per_rent_1kb,
+            fee_per_write_1kb: value.fee_per_write_1kb,
+            fee_per_write_entry: value.fee_per_write_entry,
+            persistent_rent_rate_denominator: value.persistent_rent_rate_denominator,
+            temporary_rent_rate_denominator: value.temporary_rent_rate_denominator,
+        }
+    }
+
+    pub(crate) fn convert_fee_configuration(value: CxxFeeConfiguration) -> FeeConfiguration {
+        FeeConfiguration {
+            fee_per_instruction_increment: value.fee_per_instruction_increment,
+            fee_per_disk_read_entry: value.fee_per_disk_read_entry,
+            fee_per_write_entry: value.fee_per_write_entry,
+            fee_per_disk_read_1kb: value.fee_per_disk_read_1kb,
+            fee_per_write_1kb: value.fee_per_write_1kb,
+            fee_per_historical_1kb: value.fee_per_historical_1kb,
+            fee_per_contract_event_1kb: value.fee_per_contract_event_1kb,
+            fee_per_transaction_size_1kb: value.fee_per_transaction_size_1kb,
+        }
+    }
+
+    pub(crate) fn convert_ledger_entry_rent_change(
+        value: &CxxLedgerEntryRentChange,
+    ) -> LedgerEntryRentChange {
+        LedgerEntryRentChange {
+            is_persistent: value.is_persistent,
+            is_code_entry: value.is_code_entry,
+            old_size_bytes: value.old_size_bytes,
+            new_size_bytes: value.new_size_bytes,
+            old_live_until_ledger: value.old_live_until_ledger,
+            new_live_until_ledger: value.new_live_until_ledger,
+        }
+    }
 }
 
 #[path = "."]
@@ -220,6 +389,7 @@ pub(crate) mod p27 {
     }
 }
 
+#[cfg(not(feature = "fastdev"))]
 #[path = "."]
 pub(crate) mod p26 {
     pub(crate) extern crate soroban_env_host_p26;
@@ -392,6 +562,7 @@ pub(crate) mod p26 {
     }
 }
 
+#[cfg(not(feature = "fastdev"))]
 #[path = "."]
 pub(crate) mod p25 {
     pub(crate) extern crate soroban_env_host_p25;
@@ -565,6 +736,7 @@ pub(crate) mod p25 {
     }
 }
 
+#[cfg(not(feature = "fastdev"))]
 #[path = "."]
 pub(crate) mod p24 {
     pub(crate) extern crate soroban_env_host_p24;
@@ -738,6 +910,7 @@ pub(crate) mod p24 {
     }
 }
 
+#[cfg(not(feature = "fastdev"))]
 #[path = "."]
 pub(crate) mod p23 {
     pub(crate) extern crate soroban_env_host_p23;
@@ -911,6 +1084,7 @@ pub(crate) mod p23 {
     }
 }
 
+#[cfg(not(feature = "fastdev"))]
 #[path = "."]
 pub(crate) mod p22 {
     pub(crate) extern crate soroban_env_host_p22;
@@ -1118,6 +1292,7 @@ pub(crate) mod p22 {
     }
 }
 
+#[cfg(not(feature = "fastdev"))]
 #[path = "."]
 pub(crate) mod p21 {
     pub(crate) extern crate soroban_env_host_p21;
@@ -1345,7 +1520,10 @@ pub fn check_sensible_soroban_config_for_protocol(core_max_proto: u32) {
             "host modules are not in ascending order"
         );
     }
-    assert!(HOST_MODULES.last().unwrap().max_proto >= core_max_proto);
+    let max_host_module_proto = HOST_MODULES.last().unwrap().max_proto;
+    dbg!(max_host_module_proto);
+    dbg!(core_max_proto);
+    assert!(max_host_module_proto >= core_max_proto);
 }
 
 // The remainder of the file is implementations of functions
@@ -1462,13 +1640,21 @@ macro_rules! proto_versioned_functions_for_module {
 // NB: this list should be in ascending order. Out of order will cause
 // an assert to fail in the by-protocol-number lookup function below.
 const HOST_MODULES: &'static [HostModule] = &[
+    #[cfg(not(feature = "fastdev"))]
     proto_versioned_functions_for_module!(p21),
+    #[cfg(not(feature = "fastdev"))]
     proto_versioned_functions_for_module!(p22),
+    #[cfg(not(feature = "fastdev"))]
     proto_versioned_functions_for_module!(p23),
+    #[cfg(not(feature = "fastdev"))]
     proto_versioned_functions_for_module!(p24),
+    #[cfg(not(feature = "fastdev"))]
     proto_versioned_functions_for_module!(p25),
+    #[cfg(not(feature = "fastdev"))]
     proto_versioned_functions_for_module!(p26),
     proto_versioned_functions_for_module!(p27),
+    #[cfg(feature = "next")]
+    proto_versioned_functions_for_module!(p28),
 ];
 
 pub(crate) fn get_host_module_for_protocol(
@@ -1495,13 +1681,27 @@ pub(crate) fn get_host_module_for_protocol(
 
 #[test]
 fn protocol_dispatches_as_expected() {
-    assert_eq!(get_host_module_for_protocol(20, 20).unwrap().max_proto, 21);
-    assert_eq!(get_host_module_for_protocol(21, 21).unwrap().max_proto, 21);
-    assert_eq!(get_host_module_for_protocol(22, 22).unwrap().max_proto, 22);
-    assert_eq!(get_host_module_for_protocol(23, 23).unwrap().max_proto, 23);
-    assert_eq!(get_host_module_for_protocol(24, 24).unwrap().max_proto, 24);
-    assert_eq!(get_host_module_for_protocol(25, 25).unwrap().max_proto, 25);
-    assert_eq!(get_host_module_for_protocol(26, 26).unwrap().max_proto, 26);
+    #[cfg(not(feature = "fastdev"))]
+    {
+        assert_eq!(get_host_module_for_protocol(20, 20).unwrap().max_proto, 21);
+        assert_eq!(get_host_module_for_protocol(21, 21).unwrap().max_proto, 21);
+        assert_eq!(get_host_module_for_protocol(22, 22).unwrap().max_proto, 22);
+        assert_eq!(get_host_module_for_protocol(23, 23).unwrap().max_proto, 23);
+        assert_eq!(get_host_module_for_protocol(24, 24).unwrap().max_proto, 24);
+        assert_eq!(get_host_module_for_protocol(25, 25).unwrap().max_proto, 25);
+        assert_eq!(get_host_module_for_protocol(26, 26).unwrap().max_proto, 26);
+    }
+
+    #[cfg(feature = "fastdev")]
+    {
+        assert_eq!(get_host_module_for_protocol(20, 20).unwrap().max_proto, 27);
+        assert_eq!(get_host_module_for_protocol(27, 27).unwrap().max_proto, 27);
+    }
+
+    #[cfg(all(feature = "fastdev", feature = "next"))]
+    {
+        assert_eq!(get_host_module_for_protocol(28, 28).unwrap().max_proto, 28);
+    }
 
     // No protocols past the max known.
     let last_proto = HOST_MODULES.last().unwrap().max_proto;
diff --git a/src/rust/src/soroban_proto_any.rs b/src/rust/src/soroban_proto_any.rs
index da08c0749..52f5c64f9 100644
--- a/src/rust/src/soroban_proto_any.rs
+++ b/src/rust/src/soroban_proto_any.rs
@@ -10,7 +10,7 @@ use crate::{
         InvokeHostFunctionOutput, RustBuf, SorobanVersionInfo, XDRFileHash,
     },
 };
-use log::{debug, error, trace, warn};
+use log::{debug, error, trace};
 use std::{fmt::Display, io::Cursor, panic, rc::Rc, time::Instant};
 
 // This module (soroban_proto_any) is bound to _multiple locations_ in the
diff --git a/src/rust/src/soroban_test_extra_protocol.rs b/src/rust/src/soroban_test_extra_protocol.rs
index ec5e8c787..1b876252b 100644
--- a/src/rust/src/soroban_test_extra_protocol.rs
+++ b/src/rust/src/soroban_test_extra_protocol.rs
@@ -8,10 +8,13 @@ use std::str::FromStr;
 
 use crate::{
     log::partition::TX,
-    soroban_proto_all::{get_host_module_for_protocol, p22, HostModule},
+    soroban_proto_all::{get_host_module_for_protocol, HostModule},
     CxxBuf, CxxLedgerInfo, CxxRentFeeConfiguration, InvokeHostFunctionOutput, RustBuf,
     SorobanModuleCache,
 };
+
+#[cfg(not(feature = "fastdev"))]
+use crate::soroban_proto_all::p22;
 use log::{info, warn};
 
 pub(super) fn maybe_invoke_host_function_again_and_compare_outputs(
@@ -80,12 +83,14 @@ pub(super) fn maybe_invoke_host_function_again_and_compare_outputs(
     }
 }
 
+#[cfg_attr(feature = "fastdev", allow(unused_variables))]
 fn modify_resources_for_extra_test_execution(
     instruction_limit: &mut u32,
     resources_buf: &mut CxxBuf,
     new_protocol: u32,
 ) -> Result<(), Box<dyn std::error::Error>> {
     match new_protocol {
+        #[cfg(not(feature = "fastdev"))]
         22 => {
             use p22::soroban_proto_any::{
                 inplace_modify_cxxbuf_encoded_type, xdr::SorobanResources,
diff --git a/src/test/TestUtils.cpp b/src/test/TestUtils.cpp
index c588bf82e..0a5d48d8c 100644
--- a/src/test/TestUtils.cpp
+++ b/src/test/TestUtils.cpp
@@ -6,6 +6,7 @@
 #include "herder/TxSetFrame.h"
 #include "ledger/ImmutableLedgerView.h"
 #include "ledger/test/LedgerTestUtils.h"
+#include "rust/RustBridge.h"
 #include "simulation/LoadGenerator.h"
 #include "simulation/Simulation.h"
 #include "test/TxTests.h"
@@ -16,12 +17,120 @@
 #include "work/WorkScheduler.h"
 #include "xdrpp/marshal.h"
 
+#include <algorithm>
+#include <sstream>
+
 namespace stellar
 {
 
 namespace testutil
 {
 
+bool isTestApplicationProtocolVersionSupported(Config const& cfg);
+
+namespace
+{
+bool
+isProtocolBackedByLinkedSorobanHost(uint32_t protocolVersion,
+                                    std::vector<uint32_t> const& hostProtocols)
+{
+    if (protocolVersionIsBefore(protocolVersion, SOROBAN_PROTOCOL_VERSION))
+    {
+        return true;
+    }
+
+    auto selectedHost = std::find_if(
+        hostProtocols.begin(), hostProtocols.end(),
+        [&](uint32_t hostProtocol) { return protocolVersion <= hostProtocol; });
+    if (selectedHost == hostProtocols.end())
+    {
+        return false;
+    }
+
+    // Protocol 20 is serviced by the p21 host. All later Soroban protocols
+    // should have their own linked host in non-fastdev builds.
+    return protocolVersion == static_cast<uint32_t>(SOROBAN_PROTOCOL_VERSION)
+               ? *selectedHost == static_cast<uint32_t>(ProtocolVersion::V_21)
+               : *selectedHost == protocolVersion;
+}
+
+std::string
+joinProtocolVersions(std::vector<uint32_t> const& protocolVersions)
+{
+    std::ostringstream out;
+    for (size_t i = 0; i < protocolVersions.size(); ++i)
+    {
+        if (i != 0)
+        {
+            out << ", ";
+        }
+        out << protocolVersions[i];
+    }
+    return out.str();
+}
+}
+
+void
+validateTestApplicationProtocolVersion(Config const& cfg)
+{
+    if (isTestApplicationProtocolVersionSupported(cfg))
+    {
+        return;
+    }
+
+    auto const protocolVersion = cfg.TESTING_UPGRADE_LEDGER_PROTOCOL_VERSION;
+    std::vector<uint32_t> hostProtocols;
+    auto rustVersions = rust_bridge::get_soroban_version_info(
+        Config::CURRENT_LEDGER_PROTOCOL_VERSION);
+    for (auto const& host : rustVersions)
+    {
+        hostProtocols.emplace_back(host.env_max_proto);
+    }
+
+    std::ostringstream msg;
+    msg << "Test application requested genesis ledger protocol "
+        << protocolVersion
+        << ", but this binary does not have the matching Soroban host linked. "
+        << "Linked Soroban host protocols: ["
+        << joinProtocolVersions(hostProtocols)
+        << "]. This usually means the build is using fastdev/unified Rust "
+        << "mode, where historical Soroban protocols are collapsed to a newer "
+        << "host and can fail later with opaque Soroban invocation errors. "
+        << "Use a linked protocol for this test, or rebuild without fastdev "
+        << "when testing historical Soroban protocol behavior.";
+    throw std::runtime_error(msg.str());
+}
+
+bool
+isTestApplicationProtocolVersionSupported(Config const& cfg)
+{
+    if (!cfg.USE_CONFIG_FOR_GENESIS)
+    {
+        return true;
+    }
+
+    auto const protocolVersion = cfg.TESTING_UPGRADE_LEDGER_PROTOCOL_VERSION;
+    if (protocolVersionIsBefore(protocolVersion, SOROBAN_PROTOCOL_VERSION))
+    {
+        return true;
+    }
+
+    std::vector<uint32_t> hostProtocols;
+    auto rustVersions = rust_bridge::get_soroban_version_info(
+        Config::CURRENT_LEDGER_PROTOCOL_VERSION);
+    for (auto const& host : rustVersions)
+    {
+        hostProtocols.emplace_back(host.env_max_proto);
+    }
+
+    if (isProtocolBackedByLinkedSorobanHost(protocolVersion, hostProtocols))
+    {
+        return true;
+    }
+
+    return false;
+}
+
 void
 crankSome(VirtualClock& clock)
 {
diff --git a/src/test/TestUtils.h b/src/test/TestUtils.h
index b8b8a24de..0a9e4a955 100644
--- a/src/test/TestUtils.h
+++ b/src/test/TestUtils.h
@@ -34,6 +34,9 @@ std::vector<Asset> getInvalidAssets(SecretKey const& issuer);
 
 int32_t computeMultiplier(LedgerEntry const& le);
 
+bool isTestApplicationProtocolVersionSupported(Config const& cfg);
+void validateTestApplicationProtocolVersion(Config const& cfg);
+
 template <class BucketT> class BucketListDepthModifier
 {
     BUCKET_TYPE_ASSERT(BucketT);
@@ -90,6 +93,7 @@ std::shared_ptr<T>
 createTestApplication(VirtualClock& clock, Config const& cfg, Args&&... args,
                       bool newDB = true, bool startApp = true)
 {
+    testutil::validateTestApplicationProtocolVersion(cfg);
     Config c2(cfg);
     c2.adjust();
     auto app = Application::create<T, Args...>(
diff --git a/src/transactions/test/FrozenLedgerKeysTests.cpp b/src/transactions/test/FrozenLedgerKeysTests.cpp
index 26f689967..c5d1166c2 100644
--- a/src/transactions/test/FrozenLedgerKeysTests.cpp
+++ b/src/transactions/test/FrozenLedgerKeysTests.cpp
@@ -150,6 +150,12 @@ TEST_CASE("frozen ledger keys config setting does not exist prior to p26",
     cfg.LEDGER_PROTOCOL_VERSION = static_cast<uint32_t>(ProtocolVersion::V_25);
     cfg.TESTING_UPGRADE_LEDGER_PROTOCOL_VERSION =
         static_cast<uint32_t>(ProtocolVersion::V_25);
+    if (!testutil::isTestApplicationProtocolVersionSupported(cfg))
+    {
+        SUCCEED("Skipping historical Soroban protocol test: requested "
+                "protocol is not linked in this build");
+        return;
+    }
     auto app = createTestApplication(clock, cfg);
     auto root = app->getRoot();
     CheckValidLedgerViewWrapper ledgerView(*app);
@@ -166,6 +172,12 @@ TEST_CASE("freeze bypass txs config setting does not exist prior to p26",
     cfg.LEDGER_PROTOCOL_VERSION = static_cast<uint32_t>(ProtocolVersion::V_25);
     cfg.TESTING_UPGRADE_LEDGER_PROTOCOL_VERSION =
         static_cast<uint32_t>(ProtocolVersion::V_25);
+    if (!testutil::isTestApplicationProtocolVersionSupported(cfg))
+    {
+        SUCCEED("Skipping historical Soroban protocol test: requested "
+                "protocol is not linked in this build");
+        return;
+    }
     auto app = createTestApplication(clock, cfg);
     auto root = app->getRoot();
     CheckValidLedgerViewWrapper ledgerView(*app);
diff --git a/src/transactions/test/InvokeHostFunctionTests.cpp b/src/transactions/test/InvokeHostFunctionTests.cpp
index 13166c0c8..945c0b615 100644
--- a/src/transactions/test/InvokeHostFunctionTests.cpp
+++ b/src/transactions/test/InvokeHostFunctionTests.cpp
@@ -70,6 +70,30 @@ checkResults(TransactionResultSet& r, int expectedSuccess, int expectedFailed)
     REQUIRE(expectedFailed == expectedFailed);
 };
 
+uint32_t
+getParallelSorobanTestProtocolVersion()
+{
+    uint32_t testLedgerProtocolVersion =
+        static_cast<uint32_t>(PARALLEL_SOROBAN_PHASE_PROTOCOL_VERSION);
+#ifdef ENABLE_NEXT_PROTOCOL_VERSION_UNSAFE_FOR_PRODUCTION
+    // Fastdev only links recent Soroban hosts, so avoid forcing these tests
+    // through the first historical parallel-Soroban protocol in next builds.
+    testLedgerProtocolVersion = Config::CURRENT_LEDGER_PROTOCOL_VERSION - 1;
+#endif
+    return testLedgerProtocolVersion;
+}
+
+bool
+isSorobanProtocolLinked(Config const& cfg, ProtocolVersion protocolVersion)
+{
+    auto sorobanProtocolCfg = cfg;
+    sorobanProtocolCfg.USE_CONFIG_FOR_GENESIS = true;
+    sorobanProtocolCfg.TESTING_UPGRADE_LEDGER_PROTOCOL_VERSION =
+        static_cast<uint32_t>(protocolVersion);
+    return testutil::isTestApplicationProtocolVersionSupported(
+        sorobanProtocolCfg);
+}
+
 void
 overrideNetworkSettingsToMin(Application& app)
 {
@@ -7190,6 +7214,12 @@ TEST_CASE("Module cache", "[tx][soroban]")
     VirtualClock clock;
     auto cfg = getTestConfig(0);
     cfg.USE_CONFIG_FOR_GENESIS = false;
+    if (!isSorobanProtocolLinked(cfg, SOROBAN_PROTOCOL_VERSION))
+    {
+        SUCCEED("Skipping historical Soroban protocol test: requested "
+                "protocol is not linked in this build");
+        return;
+    }
 
     auto app = createTestApplication(clock, cfg);
 
@@ -7245,6 +7275,12 @@ TEST_CASE("Vm instantiation tightening", "[tx][soroban]")
     VirtualClock clock;
     auto cfg = getTestConfig(0);
     cfg.USE_CONFIG_FOR_GENESIS = false;
+    if (!isSorobanProtocolLinked(cfg, SOROBAN_PROTOCOL_VERSION))
+    {
+        SUCCEED("Skipping historical Soroban protocol test: requested "
+                "protocol is not linked in this build");
+        return;
+    }
 
     auto app = createTestApplication(clock, cfg);
 
@@ -7643,6 +7679,12 @@ TEST_CASE("Module cache across protocol versions", "[tx][soroban][modulecache]")
     // Start in p22
     cfg.TESTING_UPGRADE_LEDGER_PROTOCOL_VERSION =
         static_cast<int>(REUSABLE_SOROBAN_MODULE_CACHE_PROTOCOL_VERSION) - 1;
+    if (!testutil::isTestApplicationProtocolVersionSupported(cfg))
+    {
+        SUCCEED("Skipping historical Soroban protocol test: requested "
+                "protocol is not linked in this build");
+        return;
+    }
     auto app = createTestApplication(clock, cfg);
 
     // Deploy and invoke contract in protocol 22
@@ -8298,10 +8340,9 @@ TEST_CASE_VERSIONS("non-fee source account is recipient of payment in both "
 TEST_CASE("parallel txs", "[tx][soroban][parallelapply]")
 {
     auto cfg = getTestConfig();
-    cfg.LEDGER_PROTOCOL_VERSION =
-        static_cast<uint32_t>(PARALLEL_SOROBAN_PHASE_PROTOCOL_VERSION);
-    cfg.TESTING_UPGRADE_LEDGER_PROTOCOL_VERSION =
-        static_cast<uint32_t>(PARALLEL_SOROBAN_PHASE_PROTOCOL_VERSION);
+    auto testLedgerProtocolVersion = getParallelSorobanTestProtocolVersion();
+    cfg.LEDGER_PROTOCOL_VERSION = testLedgerProtocolVersion;
+    cfg.TESTING_UPGRADE_LEDGER_PROTOCOL_VERSION = testLedgerProtocolVersion;
     cfg.ENABLE_SOROBAN_DIAGNOSTIC_EVENTS = true;
 
     TmpDirManager tdm(std::string("metatest-soroban-") +
@@ -8543,6 +8584,14 @@ TEST_CASE("parallel txs", "[tx][soroban][parallelapply]")
     }
     SECTION("internal error")
     {
+        if (testLedgerProtocolVersion !=
+            static_cast<uint32_t>(PARALLEL_SOROBAN_PHASE_PROTOCOL_VERSION))
+        {
+            SUCCEED("Skipping p23 internal-error behavior: requested "
+                    "protocol is not linked in this build");
+            return;
+        }
+
         auto i1Spec =
             client.writeKeySpec("key2", ContractDataDurability::TEMPORARY);
         auto i1 = client.getContract().prepareInvocation(
@@ -8855,10 +8904,9 @@ TEST_CASE("Failed write still causes ttl observation",
           "[tx][soroban][parallelapply]")
 {
     auto cfg = getTestConfig();
-    cfg.LEDGER_PROTOCOL_VERSION =
-        static_cast<uint32_t>(PARALLEL_SOROBAN_PHASE_PROTOCOL_VERSION);
-    cfg.TESTING_UPGRADE_LEDGER_PROTOCOL_VERSION =
-        static_cast<uint32_t>(PARALLEL_SOROBAN_PHASE_PROTOCOL_VERSION);
+    auto testLedgerProtocolVersion = getParallelSorobanTestProtocolVersion();
+    cfg.LEDGER_PROTOCOL_VERSION = testLedgerProtocolVersion;
+    cfg.TESTING_UPGRADE_LEDGER_PROTOCOL_VERSION = testLedgerProtocolVersion;
     cfg.ENABLE_SOROBAN_DIAGNOSTIC_EVENTS = true;
 
     SorobanTest test(cfg);
@@ -8948,10 +8996,9 @@ TEST_CASE("Failed write still causes ttl observation",
 TEST_CASE("parallel txs hit declared readBytes", "[tx][soroban][parallelapply]")
 {
     auto cfg = getTestConfig();
-    cfg.LEDGER_PROTOCOL_VERSION =
-        static_cast<uint32_t>(PARALLEL_SOROBAN_PHASE_PROTOCOL_VERSION);
-    cfg.TESTING_UPGRADE_LEDGER_PROTOCOL_VERSION =
-        static_cast<uint32_t>(PARALLEL_SOROBAN_PHASE_PROTOCOL_VERSION);
+    auto testLedgerProtocolVersion = getParallelSorobanTestProtocolVersion();
+    cfg.LEDGER_PROTOCOL_VERSION = testLedgerProtocolVersion;
+    cfg.TESTING_UPGRADE_LEDGER_PROTOCOL_VERSION = testLedgerProtocolVersion;
     cfg.ENABLE_SOROBAN_DIAGNOSTIC_EVENTS = true;
 
     SorobanTest test(cfg);
@@ -9052,10 +9099,9 @@ TEST_CASE("delete non existent entry with parallel apply",
           "[tx][soroban][parallelapply]")
 {
     auto cfg = getTestConfig();
-    cfg.LEDGER_PROTOCOL_VERSION =
-        static_cast<uint32_t>(PARALLEL_SOROBAN_PHASE_PROTOCOL_VERSION);
-    cfg.TESTING_UPGRADE_LEDGER_PROTOCOL_VERSION =
-        static_cast<uint32_t>(PARALLEL_SOROBAN_PHASE_PROTOCOL_VERSION);
+    auto testLedgerProtocolVersion = getParallelSorobanTestProtocolVersion();
+    cfg.LEDGER_PROTOCOL_VERSION = testLedgerProtocolVersion;
+    cfg.TESTING_UPGRADE_LEDGER_PROTOCOL_VERSION = testLedgerProtocolVersion;
 
     SorobanTest test(cfg);
     ContractStorageTestClient client(test);
@@ -9405,10 +9451,9 @@ TEST_CASE("apply generated parallel tx sets", "[soroban][parallelapply]")
 {
     uint32 const MAX_TRANSACTIONS_PER_LEDGER = 500;
     auto cfg = getTestConfig();
-    cfg.LEDGER_PROTOCOL_VERSION =
-        static_cast<uint32_t>(PARALLEL_SOROBAN_PHASE_PROTOCOL_VERSION);
-    cfg.TESTING_UPGRADE_LEDGER_PROTOCOL_VERSION =
-        static_cast<uint32_t>(PARALLEL_SOROBAN_PHASE_PROTOCOL_VERSION);
+    auto testLedgerProtocolVersion = getParallelSorobanTestProtocolVersion();
+    cfg.LEDGER_PROTOCOL_VERSION = testLedgerProtocolVersion;
+    cfg.TESTING_UPGRADE_LEDGER_PROTOCOL_VERSION = testLedgerProtocolVersion;
     cfg.ENABLE_SOROBAN_DIAGNOSTIC_EVENTS = true;
 
     // This is required because we're setting the min stage count above one,
@@ -9528,10 +9573,9 @@ TEST_CASE("apply generated parallel tx sets", "[soroban][parallelapply]")
 TEST_CASE("parallel restore and extend op", "[tx][soroban][parallelapply]")
 {
     auto cfg = getTestConfig();
-    cfg.LEDGER_PROTOCOL_VERSION =
-        static_cast<uint32_t>(PARALLEL_SOROBAN_PHASE_PROTOCOL_VERSION);
-    cfg.TESTING_UPGRADE_LEDGER_PROTOCOL_VERSION =
-        static_cast<uint32_t>(PARALLEL_SOROBAN_PHASE_PROTOCOL_VERSION);
+    auto testLedgerProtocolVersion = getParallelSorobanTestProtocolVersion();
+    cfg.LEDGER_PROTOCOL_VERSION = testLedgerProtocolVersion;
+    cfg.TESTING_UPGRADE_LEDGER_PROTOCOL_VERSION = testLedgerProtocolVersion;
 
     SorobanTest test(cfg);
     ContractStorageTestClient client(test);
@@ -9646,10 +9690,9 @@ TEST_CASE("read-only bumps across threads", "[tx][soroban][parallelapply]")
 TEST_CASE("parallel restore and update", "[tx][soroban][parallelapply]")
 {
     auto cfg = getTestConfig();
-    cfg.LEDGER_PROTOCOL_VERSION =
-        static_cast<uint32_t>(PARALLEL_SOROBAN_PHASE_PROTOCOL_VERSION);
-    cfg.TESTING_UPGRADE_LEDGER_PROTOCOL_VERSION =
-        static_cast<uint32_t>(PARALLEL_SOROBAN_PHASE_PROTOCOL_VERSION);
+    auto testLedgerProtocolVersion = getParallelSorobanTestProtocolVersion();
+    cfg.LEDGER_PROTOCOL_VERSION = testLedgerProtocolVersion;
+    cfg.TESTING_UPGRADE_LEDGER_PROTOCOL_VERSION = testLedgerProtocolVersion;
 
     SorobanTest test(cfg);
     ContractStorageTestClient client(test);