diff --git a/binaries/cuprated/src/rpc/blockchain.rs b/binaries/cuprated/src/rpc/blockchain.rs
index b96c5618..bda998c5 100644
--- a/binaries/cuprated/src/rpc/blockchain.rs
+++ b/binaries/cuprated/src/rpc/blockchain.rs
@@ -130,6 +130,24 @@ pub(super) async fn block_hash(
     Ok(hash)
 }
 
+/// [`BlockchainResponse::KeyImageSpent`]
+pub(super) async fn key_image_spent(
+    state: &mut CupratedRpcHandlerState,
+    key_image: [u8; 32],
+) -> Result<bool, Error> {
+    let BlockchainResponse::KeyImageSpent(is_spent) = state
+        .blockchain
+        .ready()
+        .await?
+        .call(BlockchainReadRequest::KeyImageSpent(key_image))
+        .await?
+    else {
+        unreachable!();
+    };
+
+    Ok(is_spent)
+}
+
 // FindBlock([u8; 32]),
 // FilterUnknownHashes(HashSet<[u8; 32]>),
 // BlockExtendedHeaderInRange(Range<usize>, Chain),
diff --git a/binaries/cuprated/src/rpc/helper.rs b/binaries/cuprated/src/rpc/helper.rs
index 43e6a427..d683ae91 100644
--- a/binaries/cuprated/src/rpc/helper.rs
+++ b/binaries/cuprated/src/rpc/helper.rs
@@ -8,7 +8,7 @@
 use std::sync::Arc;
 
 use anyhow::{anyhow, Error};
-use cuprate_rpc_types::misc::BlockHeader;
+use cuprate_rpc_types::misc::{BlockHeader, KeyImageSpentStatus};
 use futures::StreamExt;
 use tower::{Service, ServiceExt};
 
@@ -97,3 +97,17 @@ pub(super) async fn top_height(
     let height = chain_height.saturating_sub(1);
     Ok((height, hash))
 }
+
+/// TODO
+pub(super) async fn key_image_spent(
+    state: &mut CupratedRpcHandlerState,
+    key_image: [u8; 32],
+) -> Result<KeyImageSpentStatus, Error> {
+    if blockchain::key_image_spent(state, key_image).await? {
+        Ok(KeyImageSpentStatus::SpentInBlockchain)
+    } else if todo!("key image is spent in tx pool") {
+        Ok(KeyImageSpentStatus::SpentInPool)
+    } else {
+        Ok(KeyImageSpentStatus::Unspent)
+    }
+}
diff --git a/binaries/cuprated/src/rpc/json.rs b/binaries/cuprated/src/rpc/json.rs
index fd8cb89b..babfdc34 100644
--- a/binaries/cuprated/src/rpc/json.rs
+++ b/binaries/cuprated/src/rpc/json.rs
@@ -486,7 +486,8 @@ async fn relay_tx(
     state: CupratedRpcHandlerState,
     request: RelayTxRequest,
 ) -> Result<RelayTxResponse, Error> {
-    Ok(RelayTxResponse { status: todo!() })
+    todo!();
+    Ok(RelayTxResponse { status: Status::Ok })
 }
 
 /// <https://github.com/monero-project/monero/blob/cc73fe71162d564ffda8e549b79a350bca53c454/src/rpc/core_rpc_server.cpp#L3306-L3330>
diff --git a/binaries/cuprated/src/rpc/other.rs b/binaries/cuprated/src/rpc/other.rs
index d215ce29..b5650a5e 100644
--- a/binaries/cuprated/src/rpc/other.rs
+++ b/binaries/cuprated/src/rpc/other.rs
@@ -1,8 +1,8 @@
-use anyhow::Error;
+use anyhow::{anyhow, Error};
 
 use cuprate_rpc_types::{
     base::{AccessResponseBase, ResponseBase},
-    misc::Status,
+    misc::{KeyImageSpentStatus, Status},
     other::{
         GetAltBlocksHashesRequest, GetAltBlocksHashesResponse, GetHeightRequest, GetHeightResponse,
         GetLimitRequest, GetLimitResponse, GetNetStatsRequest, GetNetStatsResponse, GetOutsRequest,
@@ -22,7 +22,12 @@ use cuprate_rpc_types::{
     },
 };
 
-use crate::rpc::CupratedRpcHandlerState;
+use crate::{
+    rpc::CupratedRpcHandlerState,
+    rpc::{blockchain, helper},
+};
+
+use super::RESTRICTED_SPENT_KEY_IMAGES_COUNT;
 
 /// Map a [`OtherRequest`] to the function that will lead to a [`OtherResponse`].
 pub(super) async fn map_request(
@@ -77,12 +82,16 @@ pub(super) async fn map_request(
 
 /// <https://github.com/monero-project/monero/blob/cc73fe71162d564ffda8e549b79a350bca53c454/src/rpc/core_rpc_server.cpp#L486-L499>
 async fn get_height(
-    state: CupratedRpcHandlerState,
+    mut state: CupratedRpcHandlerState,
     request: GetHeightRequest,
 ) -> Result<GetHeightResponse, Error> {
+    let (height, hash) = helper::top_height(&mut state).await?;
+    let hash = hex::encode(hash);
+
     Ok(GetHeightResponse {
         base: ResponseBase::ok(),
-        ..todo!()
+        height,
+        hash,
     })
 }
 
@@ -110,12 +119,24 @@ async fn get_alt_blocks_hashes(
 
 /// <https://github.com/monero-project/monero/blob/cc73fe71162d564ffda8e549b79a350bca53c454/src/rpc/core_rpc_server.cpp#L1229-L1305>
 async fn is_key_image_spent(
-    state: CupratedRpcHandlerState,
+    mut state: CupratedRpcHandlerState,
     request: IsKeyImageSpentRequest,
 ) -> Result<IsKeyImageSpentResponse, Error> {
+    if state.restricted && request.key_images.len() > RESTRICTED_SPENT_KEY_IMAGES_COUNT {
+        return Err(anyhow!("Too many key images queried in restricted mode"));
+    }
+
+    let mut spent_status = Vec::with_capacity(request.key_images.len());
+
+    for hex in request.key_images {
+        let key_image = helper::hex_to_hash(hex)?;
+        let status = helper::key_image_spent(&mut state, key_image).await?;
+        spent_status.push(status.to_u8());
+    }
+
     Ok(IsKeyImageSpentResponse {
         base: AccessResponseBase::ok(),
-        ..todo!()
+        spent_status,
     })
 }