feat: add remote block prover as optional

CHANGELOG.md

@@ -22,6 +22,7 @@
 - [BREAKING] `CheckNullifiersByPrefix` now takes a starting block number (#707).
 - [BREAKING] Removed nullifiers from `SyncState` endpoint (#708).
 - [BREAKING] Added `batch_prover_url` to block producer configuration (#701).
+- [BREAKING] Added `block_prover_url` to block producer configuration (#719).
 
 ### Enhancements
 

README.md

@@ -185,14 +185,13 @@ or alternatively start the systemd service if that's how you wish to operate:
 systemctl start miden-node.service
 ```
 
-The `miden-node.toml` can be modified adding a batch prover URL, to delegate the batch proving:
+The node will use local provers for blocks and batches, but you can configure the node to use remote provers by adding the following to the `miden-node.toml` file in the `[block-producer]` section:
 
 ```toml
 batch_prover_url = "<BATCH_PROVER_URL>"
+block_prover_url = "<BLOCK_PROVER_URL>"
 ```
 
-If this variable is not set, the node will use a local batch prover.
-
 ### Monitoring and telemetry
 
 Please see our operator documentation [here](docs/operator.md).

bin/node/src/config.rs

@@ -28,6 +28,7 @@ struct NormalizedBlockProducerConfig {
     endpoint: Url,
     verify_tx_proofs: bool,
     batch_prover_url: Option<Url>,
+    block_prover_url: Option<Url>,
 }
 
 impl Default for NormalizedRpcConfig {
@@ -50,11 +51,13 @@ impl Default for NormalizedBlockProducerConfig {
             store_url: _,
             verify_tx_proofs,
             batch_prover_url,
+            block_prover_url,
         } = BlockProducerConfig::default();
         Self {
             endpoint,
             verify_tx_proofs,
             batch_prover_url,
+            block_prover_url,
         }
     }
 }
@@ -68,6 +71,7 @@ impl NodeConfig {
             store_url: store.endpoint.clone(),
             verify_tx_proofs: block_producer.verify_tx_proofs,
             batch_prover_url: block_producer.batch_prover_url,
+            block_prover_url: block_producer.block_prover_url,
         };
 
         let rpc = RpcConfig {
@@ -103,6 +107,7 @@ mod tests {
                     endpoint = "http://127.0.0.1:8080"
                     verify_tx_proofs = true
                     batch_prover_url = "http://127.0.0.1:8081"
+                    block_prover_url = "http://127.0.0.1:8082"
 
                     [rpc]
                     endpoint = "http://127.0.0.1:8080"
@@ -124,6 +129,7 @@ mod tests {
                         endpoint: Url::parse("http://127.0.0.1:8080").unwrap(),
                         verify_tx_proofs: true,
                         batch_prover_url: Some(Url::parse("http://127.0.0.1:8081").unwrap()),
+                        block_prover_url: Some(Url::parse("http://127.0.0.1:8082").unwrap()),
                     },
                     rpc: NormalizedRpcConfig {
                         endpoint: Url::parse("http://127.0.0.1:8080").unwrap(),

config/miden-node.toml

@@ -7,7 +7,9 @@ endpoint = "http://127.0.0.1:48046"
 # transaction queue.
 verify_tx_proofs = true
 # address of the remote batch prover service
-batch_prover_url = "http://127.0.0.1:8082/"
+batch_prover_url = "http://127.0.0.1:8081/"
+# address of the remote block prover service
+block_prover_url = "http://127.0.0.1:8082/"
 
 [rpc]
 # port defined as: sum(ord(c)**p for (p, c) in enumerate('miden-rpc', 1)) % 2**16

crates/block-producer/Cargo.toml

@@ -29,6 +29,7 @@ miden-objects = { workspace = true }
 miden-processor = { workspace = true }
 miden-proving-service-client = { git = "https://github.com/0xPolygonMiden/miden-base.git", branch = "next", features = [
   "batch-prover",
+  "block-prover",
 ] }
 miden-tx = { workspace = true }
 miden-tx-batch-prover = { git = "https://github.com/0xPolygonMiden/miden-base.git", branch = "next" }

crates/block-producer/src/block_builder/mod.rs

@@ -9,9 +9,11 @@ use miden_objects::{
     note::NoteHeader,
     MIN_PROOF_SECURITY_LEVEL,
 };
+use miden_proving_service_client::proving_service::block_prover::RemoteBlockProver;
 use rand::Rng;
 use tokio::time::Duration;
-use tracing::{instrument, Span};
+use tracing::{info, instrument, Span};
+use url::Url;
 
 use crate::{
     errors::BuildBlockError, mempool::SharedMempool, store::StoreClient, COMPONENT,
@@ -34,17 +36,25 @@ pub struct BlockBuilder {
     pub store: StoreClient,
 
     /// The prover used to prove a proposed block into a proven block.
-    pub block_prover: LocalBlockProver,
+    pub block_prover: BlockProver,
 }
 
 impl BlockBuilder {
-    pub fn new(store: StoreClient) -> Self {
+    /// Creates a new [`BlockBuilder`] with the given [`StoreClient`] and optional block prover URL.
+    ///
+    /// If the block prover URL is not set, the block builder will use the local block prover.
+    pub fn new(store: StoreClient, block_prover_url: Option<Url>) -> Self {
+        let block_prover = match block_prover_url {
+            Some(url) => BlockProver::new_remote(url),
+            None => BlockProver::new_local(MIN_PROOF_SECURITY_LEVEL),
+        };
+
         Self {
             block_interval: SERVER_BLOCK_FREQUENCY,
             // Note: The range cannot be empty.
             simulated_proof_time: Duration::ZERO..Duration::from_millis(1),
             failure_rate: 0.0,
-            block_prover: LocalBlockProver::new(MIN_PROOF_SECURITY_LEVEL),
+            block_prover,
             store,
         }
     }
@@ -190,10 +200,7 @@ impl BlockBuilder {
         &self,
         proposed_block: ProposedBlock,
     ) -> Result<ProvenBlock, BuildBlockError> {
-        let proven_block = self
-            .block_prover
-            .prove(proposed_block)
-            .map_err(BuildBlockError::ProveBlockFailed)?;
+        let proven_block = self.block_prover.prove(proposed_block).await?;
 
         self.simulate_proving().await;
 
@@ -352,3 +359,38 @@ impl TelemetryInjectorExt for ProvenBlock {
         span.set_attribute("block.commitments.transaction", header.tx_hash());
     }
 }
+
+// BLOCK PROVER
+// ================================================================================================
+
+pub enum BlockProver {
+    Local(LocalBlockProver),
+    Remote(RemoteBlockProver),
+}
+
+impl BlockProver {
+    pub fn new_local(security_level: u32) -> Self {
+        info!(target: COMPONENT, "Using local block prover");
+        Self::Local(LocalBlockProver::new(security_level))
+    }
+
+    pub fn new_remote(endpoint: impl Into<String>) -> Self {
+        info!(target: COMPONENT, "Using remote block prover");
+        Self::Remote(RemoteBlockProver::new(endpoint))
+    }
+
+    #[instrument(target = COMPONENT, skip_all, err)]
+    pub async fn prove(
+        &self,
+        proposed_block: ProposedBlock,
+    ) -> Result<ProvenBlock, BuildBlockError> {
+        match self {
+            Self::Local(prover) => {
+                prover.prove(proposed_block).map_err(BuildBlockError::ProveBlockFailed)
+            },
+            Self::Remote(prover) => {
+                prover.prove(proposed_block).await.map_err(BuildBlockError::RemoteProverError)
+            },
+        }
+    }
+}

crates/block-producer/src/config.rs

@@ -25,7 +25,14 @@ pub struct BlockProducerConfig {
     pub verify_tx_proofs: bool,
 
     /// URL of the remote batch prover.
+    ///
+    /// If not set, the block producer will use the local batch prover.
     pub batch_prover_url: Option<Url>,
+
+    /// URL of the remote block prover.
+    ///
+    /// If not set, the block producer will use the local block prover.
+    pub block_prover_url: Option<Url>,
 }
 
 impl Display for BlockProducerConfig {
@@ -38,7 +45,14 @@ impl Display for BlockProducerConfig {
             .as_ref()
             .map_or_else(|| "None".to_string(), ToString::to_string);
 
-        write!(f, ", batch_prover_url: \"{batch_prover_url}\" }}")
+        write!(f, ", batch_prover_url: \"{batch_prover_url}\" }}")?;
+
+        let block_prover_url = self
+            .block_prover_url
+            .as_ref()
+            .map_or_else(|| "None".to_string(), ToString::to_string);
+
+        write!(f, ", block_prover_url: \"{block_prover_url}\" }}")
     }
 }
 
@@ -53,6 +67,7 @@ impl Default for BlockProducerConfig {
                 .unwrap(),
             verify_tx_proofs: true,
             batch_prover_url: None,
+            block_prover_url: None,
         }
     }
 }

crates/block-producer/src/errors.rs

@@ -165,6 +165,8 @@ pub enum BuildBlockError {
     /// responses.
     #[error("nothing actually went wrong, failure was injected on purpose")]
     InjectedFailure,
+    #[error("failed to prove block with remote prover")]
+    RemoteProverError(#[source] RemoteProverError),
 }
 
 // Store errors

crates/block-producer/src/server.rs

@@ -82,7 +82,7 @@ impl BlockProducer {
 
         Ok(Self {
             batch_builder: BatchBuilder::new(config.batch_prover_url),
-            block_builder: BlockBuilder::new(store.clone()),
+            block_builder: BlockBuilder::new(store.clone(), config.block_prover_url),
             batch_budget: BatchBudget::default(),
             block_budget: BlockBudget::default(),
             state_retention: SERVER_MEMPOOL_STATE_RETENTION,