feat(l1): generate execution witnesses during payload execution

cmd/ethrex/cli.rs

@@ -280,6 +280,14 @@ pub struct Options {
         help_heading = "Block building options"
     )]
     pub gas_limit: u64,
+    #[arg(
+        long = "generate-witness",
+        action = ArgAction::SetTrue,
+        default_value = "false",
+        help = "Generate execution witnesses for received blocks.",
+        help_heading = "Node options"
+    )]
+    pub generate_witness: bool,
 }
 
 impl Options {
@@ -355,6 +363,7 @@ impl Default for Options {
             lookup_interval: Default::default(),
             extra_data: get_minimal_client_version(),
             gas_limit: DEFAULT_BUILDER_GAS_CEIL,
+            generate_witness: false,
         }
     }
 }

cmd/ethrex/initializers.rs

@@ -223,6 +223,7 @@ pub async fn init_rpc_api(
         log_filter_handler,
         opts.gas_limit,
         opts.extra_data.clone(),
+        opts.generate_witness,
     );
 
     tracker.spawn(rpc_api);

cmd/ethrex/l2/initializers.rs

@@ -68,6 +68,7 @@ fn init_rpc_api(
         rollup_store,
         log_filter_handler,
         gas_ceil.unwrap_or(DEFAULT_BUILDER_GAS_CEIL),
+        opts.generate_witness,
     );
 
     tracker.spawn(rpc_api);

crates/l2/networking/rpc/rpc.rs

@@ -87,6 +87,7 @@ pub async fn start_api(
     rollup_store: StoreRollup,
     log_filter_handler: Option<reload::Handle<EnvFilter, Registry>>,
     gas_ceil: u64,
+    generate_witness: bool,
 ) -> Result<(), RpcErr> {
     // TODO: Refactor how filters are handled,
     // filters are used by the filters endpoints (eth_newFilter, eth_getFilterChanges, ...etc)
@@ -110,6 +111,7 @@ pub async fn start_api(
             log_filter_handler,
             gas_ceil,
             block_worker_channel,
+            generate_witness,
         },
         valid_delegation_addresses,
         sponsor_pk,

crates/networking/rpc/debug/execution_witness.rs

@@ -234,6 +234,22 @@ impl RpcHandler for ExecutionWitnessRequest {
             blocks.push(block);
         }
 
+        if blocks.len() == 1 {
+            // Check if we have a cached witness for this block
+            let block = &blocks[0];
+            if let Some(witness) = context
+                .storage
+                .get_witness_by_number_and_hash(block.header.number, block.hash())?
+            {
+                let rpc_execution_witness =
+                    RpcExecutionWitness::try_from(witness).map_err(|e| {
+                        RpcErr::Internal(format!("Failed to create rpc execution witness {e}"))
+                    })?;
+                return serde_json::to_value(rpc_execution_witness)
+                    .map_err(|error| RpcErr::Internal(error.to_string()));
+            }
+        }
+
         let execution_witness = context
             .blockchain
             .generate_witness_for_blocks(&blocks)

crates/networking/rpc/engine/payload.rs

@@ -617,7 +617,37 @@ async fn handle_new_payload_v1_v2(
     }
 
     // All checks passed, execute payload
-    let payload_status = try_execute_payload(block, &context, latest_valid_hash).await?;
+    let payload_status = try_execute_payload(block.clone(), &context, latest_valid_hash).await?;
+
+    let block_hash = block.hash();
+    let block_number = block.header.number;
+
+    // Generate and store witness if required
+    if context.generate_witness {
+        let Ok(witness) = context
+            .blockchain
+            .generate_witness_for_blocks(&[block])
+            .await
+        else {
+            warn!(
+                %block_hash,
+                %block_number,
+                "Failed to generate witness for block. Skipping witness generation."
+            );
+            return Ok(payload_status);
+        };
+        _ = context
+            .storage
+            .store_witness(block_hash, block_number, witness)
+            .await
+            .inspect_err(|e| {
+                warn!(
+                    %block_hash,
+                    %block_number,
+                    "Failed to store witness for block: {e}. Skipping witness storage."
+                )
+            });
+    }
     Ok(payload_status)
 }
 

crates/networking/rpc/rpc.rs

@@ -176,6 +176,7 @@ pub struct RpcApiContext {
     pub log_filter_handler: Option<reload::Handle<EnvFilter, Registry>>,
     pub gas_ceil: u64,
     pub block_worker_channel: UnboundedSender<(oneshot::Sender<Result<(), ChainError>>, Block)>,
+    pub generate_witness: bool,
 }
 
 #[derive(Debug, Clone)]
@@ -281,6 +282,7 @@ pub async fn start_api(
     log_filter_handler: Option<reload::Handle<EnvFilter, Registry>>,
     gas_ceil: u64,
     extra_data: String,
+    generate_witness: bool,
 ) -> Result<(), RpcErr> {
     // TODO: Refactor how filters are handled,
     // filters are used by the filters endpoints (eth_newFilter, eth_getFilterChanges, ...etc)
@@ -303,6 +305,7 @@ pub async fn start_api(
         log_filter_handler,
         gas_ceil,
         block_worker_channel,
+        generate_witness,
     };
 
     // Periodically clean up the active filters for the filters endpoints.

crates/networking/rpc/test_utils.rs

@@ -246,6 +246,7 @@ pub async fn start_test_api() -> tokio::task::JoinHandle<()> {
             None,
             DEFAULT_BUILDER_GAS_CEIL,
             String::new(),
+            false,
         )
         .await
         .unwrap()
@@ -273,6 +274,7 @@ pub async fn default_context_with_storage(storage: Store) -> RpcApiContext {
         log_filter_handler: None,
         gas_ceil: DEFAULT_BUILDER_GAS_CEIL,
         block_worker_channel,
+        generate_witness: false,
     }
 }
 

crates/storage/api/tables.rs

@@ -87,7 +87,17 @@ pub const STORAGE_FLATKEYVALUE: &str = "storage_flatkeyvalue";
 
 pub const MISC_VALUES: &str = "misc_values";
 
-pub const TABLES: [&str; 17] = [
+/// Execution witnesses column family: [`Vec<u8>`] => [`Vec<u8>`]
+/// - [`Vec<u8>`] = Composite key
+///    ```rust,no_run
+///     // let mut composite_key = Vec::with_capacity(8 + 32);
+///     // composite_key.extend_from_slice(&block_number.to_be_bytes());
+///     // composite_key.extend_from_slice(block_hash.as_bytes());
+///    ```
+/// - [`Vec<u8>`] = `serde_json::to_vec(&witness)`
+pub const EXECUTION_WITNESSES: &str = "execution_witnesses";
+
+pub const TABLES: [&str; 18] = [
     CHAIN_DATA,
     ACCOUNT_CODES,
     BODIES,
@@ -105,4 +115,5 @@ pub const TABLES: [&str; 17] = [
     ACCOUNT_FLATKEYVALUE,
     STORAGE_FLATKEYVALUE,
     MISC_VALUES,
+    EXECUTION_WITNESSES,
 ];

crates/storage/store.rs

@@ -6,9 +6,9 @@ use crate::{
         StorageBackend,
         tables::{
             ACCOUNT_CODES, ACCOUNT_FLATKEYVALUE, ACCOUNT_TRIE_NODES, BLOCK_NUMBERS, BODIES,
-            CANONICAL_BLOCK_HASHES, CHAIN_DATA, FULLSYNC_HEADERS, HEADERS, INVALID_CHAINS,
-            MISC_VALUES, PENDING_BLOCKS, RECEIPTS, SNAP_STATE, STORAGE_FLATKEYVALUE,
-            STORAGE_TRIE_NODES, TRANSACTION_LOCATIONS,
+            CANONICAL_BLOCK_HASHES, CHAIN_DATA, EXECUTION_WITNESSES, FULLSYNC_HEADERS, HEADERS,
+            INVALID_CHAINS, MISC_VALUES, PENDING_BLOCKS, RECEIPTS, SNAP_STATE,
+            STORAGE_FLATKEYVALUE, STORAGE_TRIE_NODES, TRANSACTION_LOCATIONS,
         },
     },
     apply_prefix,
@@ -26,7 +26,7 @@ use ethrex_common::{
     types::{
         AccountInfo, AccountState, AccountUpdate, Block, BlockBody, BlockHash, BlockHeader,
         BlockNumber, ChainConfig, Code, ForkId, Genesis, GenesisAccount, Index, Receipt,
-        Transaction,
+        Transaction, block_execution_witness::ExecutionWitness,
     },
     utils::keccak,
 };
@@ -58,6 +58,9 @@ pub const STATE_TRIE_SEGMENTS: usize = 2;
 /// This will always be the amount yielded by snapshot reads unless there are less elements left
 pub const MAX_SNAPSHOT_READS: usize = 100;
 
+/// Maximum number of execution witnesses to keep in the database
+pub const MAX_WITNESSES: u64 = 128;
+
 // We use one constant for in-memory and another for on-disk backends.
 // This is due to tests requiring state older than 128 blocks.
 // TODO: unify these
@@ -1701,6 +1704,86 @@ impl Store {
         Ok(state_root)
     }
 
+    // Key format: block_number (8 bytes, big-endian) + block_hash (32 bytes)
+    fn make_witness_key(block_number: u64, block_hash: &BlockHash) -> Vec<u8> {
+        let mut composite_key = Vec::with_capacity(8 + 32);
+        composite_key.extend_from_slice(&block_number.to_be_bytes());
+        composite_key.extend_from_slice(block_hash.as_bytes());
+        composite_key
+    }
+
+    pub async fn store_witness(
+        &self,
+        block_hash: BlockHash,
+        block_number: u64,
+        witness: ExecutionWitness,
+    ) -> Result<(), StoreError> {
+        let key = Self::make_witness_key(block_number, &block_hash);
+        let value = serde_json::to_vec(&witness)?;
+        self.write(EXECUTION_WITNESSES, key, value)?;
+        // Clean up old witnesses (keep only last 128)
+        self.cleanup_old_witnesses(block_number).await
+    }
+
+    async fn cleanup_old_witnesses(&self, latest_block_number: u64) -> Result<(), StoreError> {
+        // If we have less than 128 blocks, no cleanup needed
+        if latest_block_number <= MAX_WITNESSES {
+            return Ok(());
+        }
+
+        let threshold = latest_block_number - MAX_WITNESSES;
+
+        // Get iterator for all witness keys
+        let db = self.backend.clone();
+        let old_witnesses =
+            tokio::task::spawn_blocking(move || -> Result<Vec<Vec<u8>>, StoreError> {
+                let tx = db.begin_read()?;
+                let iter = tx.prefix_iterator(EXECUTION_WITNESSES, &[])?;
+                let mut old_witnesses = Vec::new();
+
+                for result in iter {
+                    let (key, _) = result?;
+
+                    // Parse block number from key (first 8 bytes after prefix)
+                    let block_num_bytes: [u8; 8] = key[..8].try_into().map_err(|_| {
+                        StoreError::Custom("Failed to parse block number".to_string())
+                    })?;
+                    let block_number = u64::from_be_bytes(block_num_bytes);
+
+                    if block_number < threshold {
+                        old_witnesses.push(key.to_vec());
+                    }
+                }
+                Ok(old_witnesses)
+            })
+            .await
+            .map_err(|e| StoreError::Custom(format!("Task panicked: {}", e)))??;
+
+        // Delete old witnesses in batch
+        if !old_witnesses.is_empty() {
+            for key in old_witnesses {
+                self.delete(EXECUTION_WITNESSES, key)?;
+            }
+        }
+
+        Ok(())
+    }
+
+    pub fn get_witness_by_number_and_hash(
+        &self,
+        block_number: u64,
+        block_hash: BlockHash,
+    ) -> Result<Option<ExecutionWitness>, StoreError> {
+        let key = Self::make_witness_key(block_number, &block_hash);
+        match self.read(EXECUTION_WITNESSES, key)? {
+            Some(value) => {
+                let witness: ExecutionWitness = serde_json::from_slice(&value)?;
+                Ok(Some(witness))
+            }
+            None => Ok(None),
+        }
+    }
+
     pub async fn add_initial_state(&mut self, genesis: Genesis) -> Result<(), StoreError> {
         debug!("Storing initial state from genesis");
 

docs/CLI.md

@@ -54,7 +54,7 @@ Node options:
 
       --log.level <LOG_LEVEL>
           Possible values: info, debug, trace, warn, error
-          
+
           [env: ETHREX_LOG_LEVEL=]
           [default: INFO]
 
@@ -71,6 +71,9 @@ Node options:
 
           [default: 10000]
 
+      --generate-witness
+          Generate execution witnesses for received blocks.
+
 P2P options:
       --bootnodes <BOOTNODE_LIST>...
           Comma separated enode URLs for P2P discovery bootstrap.
@@ -102,14 +105,14 @@ P2P options:
           [default: 1000]
 
       --p2p.target-peers <MAX_PEERS>
-           Max amount of connected peers.
- 
-           [default: 100]
- 
+          Max amount of connected peers.
+
+          [default: 100]
+
       --p2p.lookup-interval <INITIAL_LOOKUP_INTERVAL>
           Initial Lookup Time Interval (ms) to trigger each Discovery lookup message and RLPx connection attempt.
-          
-         [default: 100]
+
+          [default: 100]
 
 RPC options:
       --http.addr <ADDRESS>