diff --git a/bin/client/src/comms/caching_oracle.rs b/bin/client/src/fault/caching_oracle.rs
similarity index 94%
rename from bin/client/src/comms/caching_oracle.rs
rename to bin/client/src/fault/caching_oracle.rs
index 8eac4670b6..f7fe610ff9 100644
--- a/bin/client/src/comms/caching_oracle.rs
+++ b/bin/client/src/fault/caching_oracle.rs
@@ -3,7 +3,7 @@
 //!
 //! [OracleReader]: kona_preimage::OracleReader
 
-use crate::{HINT_WRITER, ORACLE_READER};
+use super::{HINT_WRITER, ORACLE_READER};
 use alloc::{boxed::Box, sync::Arc, vec::Vec};
 use anyhow::Result;
 use async_trait::async_trait;
@@ -17,7 +17,7 @@ use spin::Mutex;
 ///
 /// [OracleReader]: kona_preimage::OracleReader
 #[derive(Debug, Clone)]
-pub struct CachingOracle {
+pub(crate) struct CachingOracle {
     /// The spin-locked cache that stores the responses from the oracle.
     cache: Arc<Mutex<LruCache<PreimageKey, Vec<u8>>>>,
 }
@@ -27,7 +27,7 @@ impl CachingOracle {
     /// responses in the cache.
     ///
     /// [OracleReader]: kona_preimage::OracleReader
-    pub fn new(cache_size: usize) -> Self {
+    pub(crate) fn new(cache_size: usize) -> Self {
         Self {
             cache: Arc::new(Mutex::new(LruCache::new(
                 NonZeroUsize::new(cache_size).expect("N must be greater than 0"),
diff --git a/bin/client/src/comms/mod.rs b/bin/client/src/fault/mod.rs
similarity index 58%
rename from bin/client/src/comms/mod.rs
rename to bin/client/src/fault/mod.rs
index 9627a174bc..b6689c0d10 100644
--- a/bin/client/src/comms/mod.rs
+++ b/bin/client/src/fault/mod.rs
@@ -1,10 +1,13 @@
-//! Contains the host <-> client communication utilities.
+//! Contains FPVM-specific constructs for the `kona-client` program.
 
 use kona_common::FileDescriptor;
 use kona_preimage::{HintWriter, OracleReader, PipeHandle};
 
 mod caching_oracle;
-pub use caching_oracle::CachingOracle;
+pub(crate) use caching_oracle::CachingOracle;
+
+mod precompiles;
+pub(crate) use precompiles::FPVMPrecompileOverride;
 
 /// The global preimage oracle reader pipe.
 static ORACLE_READER_PIPE: PipeHandle =
@@ -15,7 +18,7 @@ static HINT_WRITER_PIPE: PipeHandle =
     PipeHandle::new(FileDescriptor::HintRead, FileDescriptor::HintWrite);
 
 /// The global preimage oracle reader.
-pub static ORACLE_READER: OracleReader = OracleReader::new(ORACLE_READER_PIPE);
+pub(crate) static ORACLE_READER: OracleReader = OracleReader::new(ORACLE_READER_PIPE);
 
 /// The global hint writer.
-pub static HINT_WRITER: HintWriter = HintWriter::new(HINT_WRITER_PIPE);
+pub(crate) static HINT_WRITER: HintWriter = HintWriter::new(HINT_WRITER_PIPE);
diff --git a/bin/client/src/l2/precompiles/bn128_pair.rs b/bin/client/src/fault/precompiles/bn128_pair.rs
similarity index 96%
rename from bin/client/src/l2/precompiles/bn128_pair.rs
rename to bin/client/src/fault/precompiles/bn128_pair.rs
index 75c1dcffd6..091be7e977 100644
--- a/bin/client/src/l2/precompiles/bn128_pair.rs
+++ b/bin/client/src/fault/precompiles/bn128_pair.rs
@@ -1,8 +1,10 @@
 //! Contains the accelerated version of the `ecPairing` precompile.
 
+use crate::fault::{HINT_WRITER, ORACLE_READER};
 use alloc::{string::ToString, vec::Vec};
 use alloy_primitives::{keccak256, Address, Bytes};
 use anyhow::ensure;
+use kona_client::HintType;
 use kona_preimage::{HintWriterClient, PreimageKey, PreimageKeyType, PreimageOracleClient};
 use revm::{
     precompile::{
@@ -12,8 +14,6 @@ use revm::{
     primitives::{Precompile, PrecompileOutput, PrecompileResult},
 };
 
-use crate::{HintType, HINT_WRITER, ORACLE_READER};
-
 const ECPAIRING_ADDRESS: Address = u64_to_address(8);
 const PAIR_ELEMENT_LEN: usize = 64 + 128;
 
diff --git a/bin/client/src/l2/precompiles/ecrecover.rs b/bin/client/src/fault/precompiles/ecrecover.rs
similarity index 96%
rename from bin/client/src/l2/precompiles/ecrecover.rs
rename to bin/client/src/fault/precompiles/ecrecover.rs
index bbe96d7a81..3c8c78a202 100644
--- a/bin/client/src/l2/precompiles/ecrecover.rs
+++ b/bin/client/src/fault/precompiles/ecrecover.rs
@@ -1,16 +1,16 @@
 //! Contains the accelerated version of the `ecrecover` precompile.
 
+use crate::fault::{HINT_WRITER, ORACLE_READER};
 use alloc::{string::ToString, vec::Vec};
 use alloy_primitives::{keccak256, Address, Bytes};
 use anyhow::ensure;
+use kona_client::HintType;
 use kona_preimage::{HintWriterClient, PreimageKey, PreimageKeyType, PreimageOracleClient};
 use revm::{
     precompile::{u64_to_address, Error as PrecompileError, PrecompileWithAddress},
     primitives::{Precompile, PrecompileOutput, PrecompileResult},
 };
 
-use crate::{HintType, HINT_WRITER, ORACLE_READER};
-
 const ECRECOVER_ADDRESS: Address = u64_to_address(1);
 
 pub(crate) const FPVM_ECRECOVER: PrecompileWithAddress =
diff --git a/bin/client/src/l2/precompiles/kzg_point_eval.rs b/bin/client/src/fault/precompiles/kzg_point_eval.rs
similarity index 96%
rename from bin/client/src/l2/precompiles/kzg_point_eval.rs
rename to bin/client/src/fault/precompiles/kzg_point_eval.rs
index 38ae7fc390..91eff01d56 100644
--- a/bin/client/src/l2/precompiles/kzg_point_eval.rs
+++ b/bin/client/src/fault/precompiles/kzg_point_eval.rs
@@ -1,16 +1,16 @@
 //! Contains the accelerated version of the KZG point evaluation precompile.
 
+use crate::fault::{HINT_WRITER, ORACLE_READER};
 use alloc::{string::ToString, vec::Vec};
 use alloy_primitives::{keccak256, Address, Bytes};
 use anyhow::ensure;
+use kona_client::HintType;
 use kona_preimage::{HintWriterClient, PreimageKey, PreimageKeyType, PreimageOracleClient};
 use revm::{
     precompile::{u64_to_address, Error as PrecompileError, PrecompileWithAddress},
     primitives::{Precompile, PrecompileOutput, PrecompileResult},
 };
 
-use crate::{HintType, HINT_WRITER, ORACLE_READER};
-
 const POINT_EVAL_ADDRESS: Address = u64_to_address(0x0A);
 
 pub(crate) const FPVM_KZG_POINT_EVAL: PrecompileWithAddress =
diff --git a/bin/client/src/l2/precompiles/mod.rs b/bin/client/src/fault/precompiles/mod.rs
similarity index 97%
rename from bin/client/src/l2/precompiles/mod.rs
rename to bin/client/src/fault/precompiles/mod.rs
index e041f58fe5..1d8e6082f0 100644
--- a/bin/client/src/l2/precompiles/mod.rs
+++ b/bin/client/src/fault/precompiles/mod.rs
@@ -14,7 +14,7 @@ mod kzg_point_eval;
 
 /// The [PrecompileOverride] implementation for the FPVM-accelerated precompiles.
 #[derive(Debug)]
-pub struct FPVMPrecompileOverride<F, H>
+pub(crate) struct FPVMPrecompileOverride<F, H>
 where
     F: TrieDBFetcher,
     H: TrieDBHinter,
diff --git a/bin/client/src/kona.rs b/bin/client/src/kona.rs
index bba1039c17..5fa4ae162d 100644
--- a/bin/client/src/kona.rs
+++ b/bin/client/src/kona.rs
@@ -5,18 +5,21 @@
 #![no_std]
 #![cfg_attr(any(target_arch = "mips", target_arch = "riscv64"), no_main)]
 
+extern crate alloc;
+
 use alloc::sync::Arc;
 use alloy_consensus::Header;
 use kona_client::{
     l1::{DerivationDriver, OracleBlobProvider, OracleL1ChainProvider},
-    l2::{FPVMPrecompileOverride, OracleL2ChainProvider},
-    BootInfo, CachingOracle,
+    l2::OracleL2ChainProvider,
+    BootInfo,
 };
 use kona_common_proc::client_entry;
 use kona_executor::StatelessL2BlockExecutor;
 use kona_primitives::L2AttributesWithParent;
 
-extern crate alloc;
+pub(crate) mod fault;
+use fault::{CachingOracle, FPVMPrecompileOverride};
 
 /// The size of the LRU cache in the oracle.
 const ORACLE_LRU_SIZE: usize = 1024;
diff --git a/bin/client/src/l2/mod.rs b/bin/client/src/l2/mod.rs
index c2db9a8841..459e4dfe87 100644
--- a/bin/client/src/l2/mod.rs
+++ b/bin/client/src/l2/mod.rs
@@ -2,6 +2,3 @@
 
 mod chain_provider;
 pub use chain_provider::OracleL2ChainProvider;
-
-mod precompiles;
-pub use precompiles::FPVMPrecompileOverride;
diff --git a/bin/client/src/lib.rs b/bin/client/src/lib.rs
index 668e226430..3c11a076f8 100644
--- a/bin/client/src/lib.rs
+++ b/bin/client/src/lib.rs
@@ -10,14 +10,8 @@ pub mod l1;
 
 pub mod l2;
 
-pub mod hint;
+mod hint;
 pub use hint::HintType;
 
-mod comms;
-pub use comms::{CachingOracle, HINT_WRITER, ORACLE_READER};
-
-mod boot;
-pub use boot::{
-    BootInfo, L1_HEAD_KEY, L2_CHAIN_ID_KEY, L2_CLAIM_BLOCK_NUMBER_KEY, L2_CLAIM_KEY,
-    L2_OUTPUT_ROOT_KEY, L2_ROLLUP_CONFIG_KEY,
-};
+pub mod boot;
+pub use boot::BootInfo;
diff --git a/bin/host/src/kv/local.rs b/bin/host/src/kv/local.rs
index 2815d81088..23dce446de 100644
--- a/bin/host/src/kv/local.rs
+++ b/bin/host/src/kv/local.rs
@@ -3,7 +3,7 @@
 use super::KeyValueStore;
 use crate::cli::HostCli;
 use alloy_primitives::B256;
-use kona_client::{
+use kona_client::boot::{
     L1_HEAD_KEY, L2_CHAIN_ID_KEY, L2_CLAIM_BLOCK_NUMBER_KEY, L2_CLAIM_KEY, L2_OUTPUT_ROOT_KEY,
     L2_ROLLUP_CONFIG_KEY,
 };