diff --git a/Cargo.lock b/Cargo.lock
index 35e1fe00fec50..de6b71a7b6638 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -23907,6 +23907,7 @@ dependencies = [
  "async-trait",
  "parity-scale-codec",
  "scale-info",
+ "sp-api",
  "sp-core 39.0.0",
  "sp-inherents",
  "sp-runtime",
diff --git a/cumulus/pallets/parachain-system/Cargo.toml b/cumulus/pallets/parachain-system/Cargo.toml
index 00417f5857b93..92331ec562bbd 100644
--- a/cumulus/pallets/parachain-system/Cargo.toml
+++ b/cumulus/pallets/parachain-system/Cargo.toml
@@ -118,3 +118,13 @@ try-runtime = [
 	"polkadot-runtime-parachains/try-runtime",
 	"sp-runtime/try-runtime",
 ]
+
+# Enables `TransactionIndex` host functions for parachain validation
+# without requiring maintenance of a transaction index.
+# However, the host environment (polkadot-prepare/execute-worker) still expects these functions to exist,
+# so we provide a replacement no-op implementation gated by this feature.
+#
+# Used by: `validate_block::implementation::validate_block`.
+#
+# Note: The parachain collator software is expected to use/include `transaction_index::HostFunctions`.
+transaction-index = []
diff --git a/cumulus/pallets/parachain-system/src/validate_block/implementation.rs b/cumulus/pallets/parachain-system/src/validate_block/implementation.rs
index 29905d921f375..3cde27324e8d4 100644
--- a/cumulus/pallets/parachain-system/src/validate_block/implementation.rs
+++ b/cumulus/pallets/parachain-system/src/validate_block/implementation.rs
@@ -122,6 +122,10 @@ where
 		sp_io::offchain_index::host_clear.replace_implementation(host_offchain_index_clear),
 		cumulus_primitives_proof_size_hostfunction::storage_proof_size::host_storage_proof_size
 			.replace_implementation(host_storage_proof_size),
+		#[cfg(feature = "transaction-index")]
+		sp_io::transaction_index::host_index.replace_implementation(host_transaction_index_index),
+		#[cfg(feature = "transaction-index")]
+		sp_io::transaction_index::host_renew.replace_implementation(host_transaction_index_renew),
 	);
 
 	let block_data = codec::decode_from_bytes::<ParachainBlockData<B::LazyBlock>>(block_data)
@@ -221,7 +225,6 @@ where
 		if overlay.storage(well_known_keys::CODE).is_some() && num_blocks > 1 {
 			panic!("When applying a runtime upgrade, only one block per PoV is allowed. Received {num_blocks}.")
 		}
-
 		run_with_externalities_and_recorder::<B, _, _>(
 			&backend,
 			&mut Default::default(),
@@ -539,3 +542,21 @@ fn host_default_child_storage_next_key(storage_key: &[u8], key: &[u8]) -> Option
 fn host_offchain_index_set(_key: &[u8], _value: &[u8]) {}
 
 fn host_offchain_index_clear(_key: &[u8]) {}
+
+/// Parachain validation does not require maintaining a transaction index,
+/// and indexing transactions does **not** contribute to the parachain state.
+/// However, the host environment still expects this function to exist,
+/// so we provide a no-op implementation.
+#[cfg(feature = "transaction-index")]
+fn host_transaction_index_index(_extrinsic: u32, _size: u32, _context_hash: [u8; 32]) {
+	// No-op host function used during parachain validation.
+}
+
+/// Parachain validation does not require maintaining a transaction index,
+/// and indexing transactions does **not** contribute to the parachain state.
+/// However, the host environment still expects this function to exist,
+/// so we provide a no-op implementation.
+#[cfg(feature = "transaction-index")]
+fn host_transaction_index_renew(_extrinsic: u32, _context_hash: [u8; 32]) {
+	// No-op host function used during parachain validation.
+}
diff --git a/prdoc/pr_11467.prdoc b/prdoc/pr_11467.prdoc
new file mode 100644
index 0000000000000..bd6c7b01fdb9d
--- /dev/null
+++ b/prdoc/pr_11467.prdoc
@@ -0,0 +1,14 @@
+title: "[stable2512] Backport #10662 - Bulletin as parachain missing features (partial)"
+doc:
+- audience: Runtime Dev
+  description: |-
+    Partial backport of #10662 to stable2512. This PR includes:
+    1. Add `transaction_index::HostFunctions` with NO-OP impl to the cumulus `ParachainSystem` `validate_block` for polkadot-prepare/execute-worker, gated behind the `transaction-index` feature.
+    2. Introduce the `TransactionStorageApi::retention_period` runtime API in `sp-transaction-storage-proof`.
+crates:
+- name: cumulus-pallet-parachain-system
+  bump: patch
+- name: pallet-transaction-storage
+  bump: patch
+- name: sp-transaction-storage-proof
+  bump: minor
diff --git a/substrate/frame/transaction-storage/Cargo.toml b/substrate/frame/transaction-storage/Cargo.toml
index 76a3de85ca9d0..baa0fec60a2f8 100644
--- a/substrate/frame/transaction-storage/Cargo.toml
+++ b/substrate/frame/transaction-storage/Cargo.toml
@@ -46,6 +46,7 @@ std = [
 	"sp-inherents/std",
 	"sp-io/std",
 	"sp-runtime/std",
+	"sp-transaction-storage-proof/std",
 	"tracing/std",
 ]
 runtime-benchmarks = [
diff --git a/substrate/primitives/transaction-storage-proof/Cargo.toml b/substrate/primitives/transaction-storage-proof/Cargo.toml
index 3e683ff7eeb7a..81e4188e1a7d9 100644
--- a/substrate/primitives/transaction-storage-proof/Cargo.toml
+++ b/substrate/primitives/transaction-storage-proof/Cargo.toml
@@ -19,6 +19,7 @@ targets = ["x86_64-unknown-linux-gnu"]
 async-trait = { optional = true, workspace = true }
 codec = { features = ["derive"], workspace = true }
 scale-info = { features = ["derive"], workspace = true }
+sp-api = { workspace = true }
 sp-core = { optional = true, workspace = true }
 sp-inherents.workspace = true
 sp-runtime.workspace = true
@@ -30,6 +31,7 @@ std = [
 	"async-trait",
 	"codec/std",
 	"scale-info/std",
+	"sp-api/std",
 	"sp-core/std",
 	"sp-inherents/std",
 	"sp-runtime/std",
diff --git a/substrate/primitives/transaction-storage-proof/src/lib.rs b/substrate/primitives/transaction-storage-proof/src/lib.rs
index 0dad6a748b385..db2bc9823f0f0 100644
--- a/substrate/primitives/transaction-storage-proof/src/lib.rs
+++ b/substrate/primitives/transaction-storage-proof/src/lib.rs
@@ -20,6 +20,8 @@
 
 #![cfg_attr(not(feature = "std"), no_std)]
 
+pub mod runtime_api;
+
 extern crate alloc;
 
 use core::result::Result;
diff --git a/substrate/primitives/transaction-storage-proof/src/runtime_api.rs b/substrate/primitives/transaction-storage-proof/src/runtime_api.rs
new file mode 100644
index 0000000000000..b7d920a8a8f61
--- /dev/null
+++ b/substrate/primitives/transaction-storage-proof/src/runtime_api.rs
@@ -0,0 +1,28 @@
+// This file is part of Substrate.
+
+// Copyright (C) Parity Technologies (UK) Ltd.
+// SPDX-License-Identifier: Apache-2.0
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 	http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//! Runtime API definition for the transaction storage proof processing.
+
+use sp_runtime::traits::NumberFor;
+
+sp_api::decl_runtime_apis! {
+	/// Runtime API trait for transaction storage support.
+	pub trait TransactionStorageApi {
+		/// Get the actual value of a retention period in blocks.
+		fn retention_period() -> NumberFor<Block>;
+	}
+}