diff --git a/CHANGELOG.md b/CHANGELOG.md
index 315ac9b274d..c0d74847c4d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -35,6 +35,8 @@
 
 ### Fixed
 
+- [#7214](https://github.com/ChainSafe/forest/pull/7214): Aligned the `eth` transaction `accessList` field with go-ethereum/reth (typed: `[]`, legacy: omitted, never `null`).
+
 - [#7227](https://github.com/ChainSafe/forest/issues/7227): Fixed invalid `Filecoin.GasEstimateGasPremium` and `Filecoin.GasEstimateFeeCap` responses that were returning a fraction instead of an integer.
 
 ## Forest v0.33.7 "Shimmergloom"
diff --git a/docs/openrpc-specs/v0.json b/docs/openrpc-specs/v0.json
index 017db4222a3..93651fb1596 100644
--- a/docs/openrpc-specs/v0.json
+++ b/docs/openrpc-specs/v0.json
@@ -811,12 +811,9 @@
       "params": [],
       "result": {
         "name": "Filecoin.EthAccounts.Result",
-        "required": false,
+        "required": true,
         "schema": {
-          "type": [
-            "array",
-            "null"
-          ],
+          "type": "array",
           "items": {
             "type": "string"
           }
@@ -1100,12 +1097,9 @@
       ],
       "result": {
         "name": "Filecoin.EthGetBlockReceipts.Result",
-        "required": false,
+        "required": true,
         "schema": {
-          "type": [
-            "array",
-            "null"
-          ],
+          "type": "array",
           "items": {
             "$ref": "#/components/schemas/EthTxReceipt"
           }
@@ -1135,12 +1129,9 @@
       ],
       "result": {
         "name": "Filecoin.EthGetBlockReceiptsLimited.Result",
-        "required": false,
+        "required": true,
         "schema": {
-          "type": [
-            "array",
-            "null"
-          ],
+          "type": "array",
           "items": {
             "$ref": "#/components/schemas/EthTxReceipt"
           }
@@ -1753,12 +1744,9 @@
       ],
       "result": {
         "name": "Filecoin.EthTraceBlock.Result",
-        "required": false,
+        "required": true,
         "schema": {
-          "type": [
-            "array",
-            "null"
-          ],
+          "type": "array",
           "items": {
             "$ref": "#/components/schemas/EthBlockTrace"
           }
@@ -1780,12 +1768,9 @@
       ],
       "result": {
         "name": "Filecoin.EthTraceFilter.Result",
-        "required": false,
+        "required": true,
         "schema": {
-          "type": [
-            "array",
-            "null"
-          ],
+          "type": "array",
           "items": {
             "$ref": "#/components/schemas/EthBlockTrace"
           }
@@ -1820,12 +1805,9 @@
       ],
       "result": {
         "name": "Filecoin.EthTraceReplayBlockTransactions.Result",
-        "required": false,
+        "required": true,
         "schema": {
-          "type": [
-            "array",
-            "null"
-          ],
+          "type": "array",
           "items": {
             "$ref": "#/components/schemas/EthReplayBlockTransactionTrace"
           }
@@ -1847,12 +1829,9 @@
       ],
       "result": {
         "name": "Filecoin.EthTraceTransaction.Result",
-        "required": false,
+        "required": true,
         "schema": {
-          "type": [
-            "array",
-            "null"
-          ],
+          "type": "array",
           "items": {
             "$ref": "#/components/schemas/EthBlockTrace"
           }
@@ -6227,12 +6206,9 @@
       "params": [],
       "result": {
         "name": "eth_accounts.Result",
-        "required": false,
+        "required": true,
         "schema": {
-          "type": [
-            "array",
-            "null"
-          ],
+          "type": "array",
           "items": {
             "type": "string"
           }
@@ -6495,12 +6471,9 @@
       ],
       "result": {
         "name": "eth_getBlockReceipts.Result",
-        "required": false,
+        "required": true,
         "schema": {
-          "type": [
-            "array",
-            "null"
-          ],
+          "type": "array",
           "items": {
             "$ref": "#/components/schemas/EthTxReceipt"
           }
@@ -6530,12 +6503,9 @@
       ],
       "result": {
         "name": "eth_getBlockReceiptsLimited.Result",
-        "required": false,
+        "required": true,
         "schema": {
-          "type": [
-            "array",
-            "null"
-          ],
+          "type": "array",
           "items": {
             "$ref": "#/components/schemas/EthTxReceipt"
           }
@@ -7208,12 +7178,9 @@
       ],
       "result": {
         "name": "trace_block.Result",
-        "required": false,
+        "required": true,
         "schema": {
-          "type": [
-            "array",
-            "null"
-          ],
+          "type": "array",
           "items": {
             "$ref": "#/components/schemas/EthBlockTrace"
           }
@@ -7235,12 +7202,9 @@
       ],
       "result": {
         "name": "trace_filter.Result",
-        "required": false,
+        "required": true,
         "schema": {
-          "type": [
-            "array",
-            "null"
-          ],
+          "type": "array",
           "items": {
             "$ref": "#/components/schemas/EthBlockTrace"
           }
@@ -7275,12 +7239,9 @@
       ],
       "result": {
         "name": "trace_replayBlockTransactions.Result",
-        "required": false,
+        "required": true,
         "schema": {
-          "type": [
-            "array",
-            "null"
-          ],
+          "type": "array",
           "items": {
             "$ref": "#/components/schemas/EthReplayBlockTransactionTrace"
           }
@@ -7302,12 +7263,9 @@
       ],
       "result": {
         "name": "trace_transaction.Result",
-        "required": false,
+        "required": true,
         "schema": {
-          "type": [
-            "array",
-            "null"
-          ],
+          "type": "array",
           "items": {
             "$ref": "#/components/schemas/EthBlockTrace"
           }
@@ -7694,10 +7652,7 @@
         "type": "object",
         "properties": {
           "accessList": {
-            "type": [
-              "array",
-              "null"
-            ],
+            "type": "array",
             "items": {
               "$ref": "#/components/schemas/EthHash"
             }
diff --git a/docs/openrpc-specs/v1.json b/docs/openrpc-specs/v1.json
index 83c828becbd..b61aee70ae9 100644
--- a/docs/openrpc-specs/v1.json
+++ b/docs/openrpc-specs/v1.json
@@ -803,12 +803,9 @@
       "params": [],
       "result": {
         "name": "Filecoin.EthAccounts.Result",
-        "required": false,
+        "required": true,
         "schema": {
-          "type": [
-            "array",
-            "null"
-          ],
+          "type": "array",
           "items": {
             "type": "string"
           }
@@ -1092,12 +1089,9 @@
       ],
       "result": {
         "name": "Filecoin.EthGetBlockReceipts.Result",
-        "required": false,
+        "required": true,
         "schema": {
-          "type": [
-            "array",
-            "null"
-          ],
+          "type": "array",
           "items": {
             "$ref": "#/components/schemas/EthTxReceipt"
           }
@@ -1127,12 +1121,9 @@
       ],
       "result": {
         "name": "Filecoin.EthGetBlockReceiptsLimited.Result",
-        "required": false,
+        "required": true,
         "schema": {
-          "type": [
-            "array",
-            "null"
-          ],
+          "type": "array",
           "items": {
             "$ref": "#/components/schemas/EthTxReceipt"
           }
@@ -1745,12 +1736,9 @@
       ],
       "result": {
         "name": "Filecoin.EthTraceBlock.Result",
-        "required": false,
+        "required": true,
         "schema": {
-          "type": [
-            "array",
-            "null"
-          ],
+          "type": "array",
           "items": {
             "$ref": "#/components/schemas/EthBlockTrace"
           }
@@ -1772,12 +1760,9 @@
       ],
       "result": {
         "name": "Filecoin.EthTraceFilter.Result",
-        "required": false,
+        "required": true,
         "schema": {
-          "type": [
-            "array",
-            "null"
-          ],
+          "type": "array",
           "items": {
             "$ref": "#/components/schemas/EthBlockTrace"
           }
@@ -1812,12 +1797,9 @@
       ],
       "result": {
         "name": "Filecoin.EthTraceReplayBlockTransactions.Result",
-        "required": false,
+        "required": true,
         "schema": {
-          "type": [
-            "array",
-            "null"
-          ],
+          "type": "array",
           "items": {
             "$ref": "#/components/schemas/EthReplayBlockTransactionTrace"
           }
@@ -1839,12 +1821,9 @@
       ],
       "result": {
         "name": "Filecoin.EthTraceTransaction.Result",
-        "required": false,
+        "required": true,
         "schema": {
-          "type": [
-            "array",
-            "null"
-          ],
+          "type": "array",
           "items": {
             "$ref": "#/components/schemas/EthBlockTrace"
           }
@@ -6283,12 +6262,9 @@
       "params": [],
       "result": {
         "name": "eth_accounts.Result",
-        "required": false,
+        "required": true,
         "schema": {
-          "type": [
-            "array",
-            "null"
-          ],
+          "type": "array",
           "items": {
             "type": "string"
           }
@@ -6551,12 +6527,9 @@
       ],
       "result": {
         "name": "eth_getBlockReceipts.Result",
-        "required": false,
+        "required": true,
         "schema": {
-          "type": [
-            "array",
-            "null"
-          ],
+          "type": "array",
           "items": {
             "$ref": "#/components/schemas/EthTxReceipt"
           }
@@ -6586,12 +6559,9 @@
       ],
       "result": {
         "name": "eth_getBlockReceiptsLimited.Result",
-        "required": false,
+        "required": true,
         "schema": {
-          "type": [
-            "array",
-            "null"
-          ],
+          "type": "array",
           "items": {
             "$ref": "#/components/schemas/EthTxReceipt"
           }
@@ -7264,12 +7234,9 @@
       ],
       "result": {
         "name": "trace_block.Result",
-        "required": false,
+        "required": true,
         "schema": {
-          "type": [
-            "array",
-            "null"
-          ],
+          "type": "array",
           "items": {
             "$ref": "#/components/schemas/EthBlockTrace"
           }
@@ -7333,12 +7300,9 @@
       ],
       "result": {
         "name": "trace_filter.Result",
-        "required": false,
+        "required": true,
         "schema": {
-          "type": [
-            "array",
-            "null"
-          ],
+          "type": "array",
           "items": {
             "$ref": "#/components/schemas/EthBlockTrace"
           }
@@ -7373,12 +7337,9 @@
       ],
       "result": {
         "name": "trace_replayBlockTransactions.Result",
-        "required": false,
+        "required": true,
         "schema": {
-          "type": [
-            "array",
-            "null"
-          ],
+          "type": "array",
           "items": {
             "$ref": "#/components/schemas/EthReplayBlockTransactionTrace"
           }
@@ -7400,12 +7361,9 @@
       ],
       "result": {
         "name": "trace_transaction.Result",
-        "required": false,
+        "required": true,
         "schema": {
-          "type": [
-            "array",
-            "null"
-          ],
+          "type": "array",
           "items": {
             "$ref": "#/components/schemas/EthBlockTrace"
           }
@@ -7834,10 +7792,7 @@
         "type": "object",
         "properties": {
           "accessList": {
-            "type": [
-              "array",
-              "null"
-            ],
+            "type": "array",
             "items": {
               "$ref": "#/components/schemas/EthHash"
             }
diff --git a/docs/openrpc-specs/v2.json b/docs/openrpc-specs/v2.json
index d60e0dff492..2bbeb08a4f9 100644
--- a/docs/openrpc-specs/v2.json
+++ b/docs/openrpc-specs/v2.json
@@ -45,12 +45,9 @@
       "params": [],
       "result": {
         "name": "Filecoin.EthAccounts.Result",
-        "required": false,
+        "required": true,
         "schema": {
-          "type": [
-            "array",
-            "null"
-          ],
+          "type": "array",
           "items": {
             "type": "string"
           }
@@ -334,12 +331,9 @@
       ],
       "result": {
         "name": "Filecoin.EthGetBlockReceipts.Result",
-        "required": false,
+        "required": true,
         "schema": {
-          "type": [
-            "array",
-            "null"
-          ],
+          "type": "array",
           "items": {
             "$ref": "#/components/schemas/EthTxReceipt"
           }
@@ -369,12 +363,9 @@
       ],
       "result": {
         "name": "Filecoin.EthGetBlockReceiptsLimited.Result",
-        "required": false,
+        "required": true,
         "schema": {
-          "type": [
-            "array",
-            "null"
-          ],
+          "type": "array",
           "items": {
             "$ref": "#/components/schemas/EthTxReceipt"
           }
@@ -987,12 +978,9 @@
       ],
       "result": {
         "name": "Filecoin.EthTraceBlock.Result",
-        "required": false,
+        "required": true,
         "schema": {
-          "type": [
-            "array",
-            "null"
-          ],
+          "type": "array",
           "items": {
             "$ref": "#/components/schemas/EthBlockTrace"
           }
@@ -1014,12 +1002,9 @@
       ],
       "result": {
         "name": "Filecoin.EthTraceFilter.Result",
-        "required": false,
+        "required": true,
         "schema": {
-          "type": [
-            "array",
-            "null"
-          ],
+          "type": "array",
           "items": {
             "$ref": "#/components/schemas/EthBlockTrace"
           }
@@ -1054,12 +1039,9 @@
       ],
       "result": {
         "name": "Filecoin.EthTraceReplayBlockTransactions.Result",
-        "required": false,
+        "required": true,
         "schema": {
-          "type": [
-            "array",
-            "null"
-          ],
+          "type": "array",
           "items": {
             "$ref": "#/components/schemas/EthReplayBlockTransactionTrace"
           }
@@ -1081,12 +1063,9 @@
       ],
       "result": {
         "name": "Filecoin.EthTraceTransaction.Result",
-        "required": false,
+        "required": true,
         "schema": {
-          "type": [
-            "array",
-            "null"
-          ],
+          "type": "array",
           "items": {
             "$ref": "#/components/schemas/EthBlockTrace"
           }
@@ -1518,12 +1497,9 @@
       "params": [],
       "result": {
         "name": "eth_accounts.Result",
-        "required": false,
+        "required": true,
         "schema": {
-          "type": [
-            "array",
-            "null"
-          ],
+          "type": "array",
           "items": {
             "type": "string"
           }
@@ -1786,12 +1762,9 @@
       ],
       "result": {
         "name": "eth_getBlockReceipts.Result",
-        "required": false,
+        "required": true,
         "schema": {
-          "type": [
-            "array",
-            "null"
-          ],
+          "type": "array",
           "items": {
             "$ref": "#/components/schemas/EthTxReceipt"
           }
@@ -1821,12 +1794,9 @@
       ],
       "result": {
         "name": "eth_getBlockReceiptsLimited.Result",
-        "required": false,
+        "required": true,
         "schema": {
-          "type": [
-            "array",
-            "null"
-          ],
+          "type": "array",
           "items": {
             "$ref": "#/components/schemas/EthTxReceipt"
           }
@@ -2499,12 +2469,9 @@
       ],
       "result": {
         "name": "trace_block.Result",
-        "required": false,
+        "required": true,
         "schema": {
-          "type": [
-            "array",
-            "null"
-          ],
+          "type": "array",
           "items": {
             "$ref": "#/components/schemas/EthBlockTrace"
           }
@@ -2568,12 +2535,9 @@
       ],
       "result": {
         "name": "trace_filter.Result",
-        "required": false,
+        "required": true,
         "schema": {
-          "type": [
-            "array",
-            "null"
-          ],
+          "type": "array",
           "items": {
             "$ref": "#/components/schemas/EthBlockTrace"
           }
@@ -2608,12 +2572,9 @@
       ],
       "result": {
         "name": "trace_replayBlockTransactions.Result",
-        "required": false,
+        "required": true,
         "schema": {
-          "type": [
-            "array",
-            "null"
-          ],
+          "type": "array",
           "items": {
             "$ref": "#/components/schemas/EthReplayBlockTransactionTrace"
           }
@@ -2635,12 +2596,9 @@
       ],
       "result": {
         "name": "trace_transaction.Result",
-        "required": false,
+        "required": true,
         "schema": {
-          "type": [
-            "array",
-            "null"
-          ],
+          "type": "array",
           "items": {
             "$ref": "#/components/schemas/EthBlockTrace"
           }
@@ -2769,10 +2727,7 @@
         "type": "object",
         "properties": {
           "accessList": {
-            "type": [
-              "array",
-              "null"
-            ],
+            "type": "array",
             "items": {
               "$ref": "#/components/schemas/EthHash"
             }
diff --git a/src/lotus_json/vec.rs b/src/lotus_json/vec.rs
index 342139fa946..cbdafb6161c 100644
--- a/src/lotus_json/vec.rs
+++ b/src/lotus_json/vec.rs
@@ -2,6 +2,7 @@
 // SPDX-License-Identifier: Apache-2.0, MIT
 
 use super::*;
+use get_size2::GetSize;
 
 impl<T> HasLotusJson for Vec<T>
 // TODO(forest): https://github.com/ChainSafe/forest/issues/4032
@@ -37,7 +38,7 @@ where
 // while an empty `NotNullVec<T>` serializes into `[]`
 // this is a temporary workaround and will likely be deprecated once
 // other issues on serde of `Vec<T>` are resolved.
-#[derive(Debug, Clone, PartialEq, JsonSchema)]
+#[derive(Debug, Clone, Default, PartialEq, JsonSchema, GetSize)]
 pub struct NotNullVec<T>(pub Vec<T>);
 
 impl<T> HasLotusJson for NotNullVec<T>
@@ -60,6 +61,22 @@ where
     }
 }
 
+/// Deserialize `Option<NotNullVec<T>>`, mapping `null` and empty `[]` to `None`.
+///
+/// Generic `HasLotusJson for Option<T>` keeps `Some(NotNullVec([]))` on `[]`;
+/// Lotus sends `null` for empty access lists and we treat both as absent.
+pub fn deserialize_empty_not_null_opt<'de, T, D>(
+    deserializer: D,
+) -> Result<Option<NotNullVec<T>>, D::Error>
+where
+    T: Deserialize<'de>,
+    D: Deserializer<'de>,
+{
+    Ok(Option::<Vec<T>>::deserialize(deserializer)?
+        .filter(|l| !l.is_empty())
+        .map(NotNullVec))
+}
+
 #[test]
 fn snapshots() {
     assert_one_snapshot(json!([{"/": "baeaaaaa"}]), vec![::cid::Cid::default()]);
diff --git a/src/rpc/methods/eth.rs b/src/rpc/methods/eth.rs
index 5a98cf4e577..2c7d8bed3ba 100644
--- a/src/rpc/methods/eth.rs
+++ b/src/rpc/methods/eth.rs
@@ -26,7 +26,7 @@ use crate::eth::{
     EAMMethod, EVMMethod, EthChainId as EthChainIdType, EthEip1559TxArgs, EthLegacyEip155TxArgs,
     EthLegacyHomesteadTxArgs, parse_eth_transaction,
 };
-use crate::lotus_json::{HasLotusJson, lotus_json_with_self};
+use crate::lotus_json::{HasLotusJson, NotNullVec, lotus_json_with_self};
 use crate::message::{ChainMessage, MessageRead as _, MessageReadWrite as _, SignedMessage};
 use crate::networks::Height;
 use crate::prelude::*;
@@ -642,9 +642,14 @@ pub struct ApiEthTx {
     pub max_priority_fee_per_gas: Option<EthBigInt>,
     #[serde(skip_serializing_if = "Option::is_none", default)]
     pub gas_price: Option<EthBigInt>,
-    #[schemars(with = "Option<Vec<EthHash>>")]
-    #[serde(with = "crate::lotus_json")]
-    pub access_list: Vec<EthHash>,
+    #[schemars(with = "Vec<EthHash>")]
+    #[serde(
+        default,
+        skip_serializing_if = "Option::is_none",
+        serialize_with = "crate::lotus_json::serialize",
+        deserialize_with = "crate::lotus_json::deserialize_empty_not_null_opt"
+    )]
+    pub access_list: Option<NotNullVec<EthHash>>,
     pub v: EthBigInt,
     pub r: EthBigInt,
     pub s: EthBigInt,
@@ -846,7 +851,7 @@ impl RpcMethod<0> for EthAccounts {
     );
 
     type Params = ();
-    type Ok = Vec<String>;
+    type Ok = NotNullVec<String>;
 
     async fn handle(
         _: Ctx,
@@ -854,7 +859,7 @@ impl RpcMethod<0> for EthAccounts {
         _: &http::Extensions,
     ) -> Result<Self::Ok, ServerError> {
         // EthAccounts will always return [] since we don't expect Forest to manage private keys
-        Ok(vec![])
+        Ok(NotNullVec(vec![]))
     }
 }
 
@@ -1263,7 +1268,7 @@ fn eth_tx_from_native_message<DB: Blockstore>(
         gas: EthUint64(msg.gas_limit),
         max_fee_per_gas: Some(msg.gas_fee_cap.clone().into()),
         max_priority_fee_per_gas: Some(msg.gas_premium.clone().into()),
-        access_list: vec![],
+        access_list: Some(NotNullVec(vec![])),
         ..ApiEthTx::default()
     })
 }
@@ -1602,7 +1607,7 @@ impl RpcMethod<1> for EthGetBlockReceipts {
     );
 
     type Params = (BlockNumberOrHash,);
-    type Ok = Vec<EthTxReceipt>;
+    type Ok = NotNullVec<EthTxReceipt>;
 
     async fn handle(
         ctx: Ctx,
@@ -1615,6 +1620,7 @@ impl RpcMethod<1> for EthGetBlockReceipts {
             .await?;
         get_block_receipts(&ctx, ts, None)
             .await
+            .map(NotNullVec)
             .map_err(ServerError::from)
     }
 }
@@ -1631,7 +1637,7 @@ impl RpcMethod<2> for EthGetBlockReceiptsLimited {
     );
 
     type Params = (BlockNumberOrHash, ChainEpoch);
-    type Ok = Vec<EthTxReceipt>;
+    type Ok = NotNullVec<EthTxReceipt>;
 
     async fn handle(
         ctx: Ctx,
@@ -1644,6 +1650,7 @@ impl RpcMethod<2> for EthGetBlockReceiptsLimited {
             .await?;
         get_block_receipts(&ctx, ts, Some(limit))
             .await
+            .map(NotNullVec)
             .map_err(ServerError::from)
     }
 }
@@ -3580,7 +3587,7 @@ impl RpcMethod<1> for EthTraceBlock {
     const DESCRIPTION: Option<&'static str> = Some("Returns traces created at given block.");
 
     type Params = (BlockNumberOrHash,);
-    type Ok = Vec<EthBlockTrace>;
+    type Ok = NotNullVec<EthBlockTrace>;
     async fn handle(
         ctx: Ctx,
         (block_param,): Self::Params,
@@ -3590,7 +3597,9 @@ impl RpcMethod<1> for EthTraceBlock {
         let ts = resolver
             .tipset_by_block_number_or_hash(block_param, ResolveNullTipset::TakeOlder)
             .await?;
-        eth_trace_block(&ctx.state_manager, &ts).await
+        eth_trace_block(&ctx.state_manager, &ts)
+            .await
+            .map(NotNullVec)
     }
 }
 
@@ -3979,7 +3988,7 @@ impl RpcMethod<1> for EthTraceTransaction {
         Some("Returns the traces for a specific transaction.");
 
     type Params = (String,);
-    type Ok = Vec<EthBlockTrace>;
+    type Ok = NotNullVec<EthBlockTrace>;
     async fn handle(
         ctx: Ctx,
         (tx_hash,): Self::Params,
@@ -4000,7 +4009,7 @@ impl RpcMethod<1> for EthTraceTransaction {
             .into_iter()
             .filter(|trace| trace.transaction_hash == eth_hash)
             .collect();
-        Ok(traces)
+        Ok(NotNullVec(traces))
     }
 }
 
@@ -4017,7 +4026,7 @@ impl RpcMethod<2> for EthTraceReplayBlockTransactions {
     );
 
     type Params = (BlockNumberOrHash, Vec<String>);
-    type Ok = Vec<EthReplayBlockTransactionTrace>;
+    type Ok = NotNullVec<EthReplayBlockTransactionTrace>;
 
     async fn handle(
         ctx: Ctx,
@@ -4036,7 +4045,9 @@ impl RpcMethod<2> for EthTraceReplayBlockTransactions {
             .tipset_by_block_number_or_hash(block_param, ResolveNullTipset::TakeOlder)
             .await?;
 
-        eth_trace_replay_block_transactions(&ctx, &ts).await
+        eth_trace_replay_block_transactions(&ctx, &ts)
+            .await
+            .map(NotNullVec)
     }
 }
 
@@ -4089,7 +4100,7 @@ impl RpcMethod<1> for EthTraceFilter {
     const DESCRIPTION: Option<&'static str> =
         Some("Returns the traces for transactions matching the filter criteria.");
     type Params = (EthTraceFilterCriteria,);
-    type Ok = Vec<EthBlockTrace>;
+    type Ok = NotNullVec<EthBlockTrace>;
 
     async fn handle(
         ctx: Ctx,
@@ -4123,7 +4134,9 @@ impl RpcMethod<1> for EthTraceFilter {
                 return Err(EthErrors::limit_exceeded(max_block_range, range).into());
             }
         }
-        Ok(trace_filter(ctx, filter, from_block, to_block, ext).await?)
+        Ok(NotNullVec(
+            trace_filter(ctx, filter, from_block, to_block, ext).await?,
+        ))
     }
 }
 
@@ -4155,7 +4168,7 @@ async fn trace_filter(
             ext,
         )
         .await?;
-        for block_trace in block_traces {
+        for block_trace in block_traces.0 {
             if block_trace
                 .trace
                 .match_filter_criteria(filter.from_address.as_ref(), filter.to_address.as_ref())?
@@ -4209,6 +4222,59 @@ mod test {
         }
     }
 
+    #[rstest]
+    // Non-empty access list → JSON array.
+    #[case::populated_array(ApiEthTx { access_list: Some(NotNullVec(vec![EthHash::default()])), ..Default::default() }, Some(1))]
+    // `access_list: None` → field omitted.
+    #[case::explicit_none_omitted(ApiEthTx { access_list: None, ..Default::default() }, None)]
+    // Legacy tx → field omitted.
+    #[case::legacy_homestead_omitted(EthLegacyHomesteadTxArgs::default().into(), None)]
+    // Typed tx with no entries → `[]`.
+    #[case::eip1559_empty_array(EthEip1559TxArgs::default().into(), Some(0))]
+    fn access_list_serialization(#[case] tx: ApiEthTx, #[case] expected: Option<usize>) {
+        let json = serde_json::to_value(tx.into_lotus_json()).unwrap();
+        match expected {
+            Some(len) => assert_eq!(
+                json["accessList"]
+                    .as_array()
+                    .expect("accessList should serialize as an array")
+                    .len(),
+                len
+            ),
+            None => assert!(!json.as_object().unwrap().contains_key("accessList")),
+        }
+    }
+
+    #[rstest]
+    // `"accessList": null` → `None`.
+    #[case::null_to_none(Some(serde_json::Value::Null), None)]
+    // Omitted/Missing field → `None`.
+    #[case::missing_to_none(None, None)]
+    // `"accessList": []` → `None`.
+    #[case::empty_array_to_none(Some(serde_json::json!([])), None)]
+    // Non-empty array → `Some(...)`.
+    #[case::populated_array_to_some(
+        Some(serde_json::json!([EthHash::default()])),
+        Some(NotNullVec(vec![EthHash::default()]))
+    )]
+    fn access_list_deserialization(
+        #[case] access_list_value: Option<serde_json::Value>,
+        #[case] expected: Option<NotNullVec<EthHash>>,
+    ) {
+        let mut json = serde_json::to_value(ApiEthTx::default().into_lotus_json()).unwrap();
+        let obj = json.as_object_mut().unwrap();
+        match access_list_value {
+            Some(value) => {
+                obj.insert("accessList".into(), value);
+            }
+            None => {
+                obj.remove("accessList");
+            }
+        }
+        let tx = ApiEthTx::from_lotus_json(serde_json::from_value(json).unwrap());
+        assert_eq!(tx.access_list, expected);
+    }
+
     #[quickcheck]
     fn gas_price_result_serde_roundtrip(i: u128) {
         let r = EthBigInt(ethereum_types::U256::from(i));
diff --git a/src/rpc/methods/eth/eth_tx.rs b/src/rpc/methods/eth/eth_tx.rs
index 09107a2d76f..c16eca72a53 100644
--- a/src/rpc/methods/eth/eth_tx.rs
+++ b/src/rpc/methods/eth/eth_tx.rs
@@ -98,6 +98,7 @@ impl From<EthEip1559TxArgs> for ApiEthTx {
             v: v.into(),
             r: r.into(),
             s: s.into(),
+            access_list: Some(NotNullVec(vec![])),
             ..Default::default()
         }
     }
diff --git a/src/rpc/snapshots/forest__rpc__tests__rpc__v0.snap b/src/rpc/snapshots/forest__rpc__tests__rpc__v0.snap
index 7286ed2d616..42267792f50 100644
--- a/src/rpc/snapshots/forest__rpc__tests__rpc__v0.snap
+++ b/src/rpc/snapshots/forest__rpc__tests__rpc__v0.snap
@@ -493,11 +493,9 @@ methods:
     params: []
     result:
       name: Filecoin.EthAccounts.Result
-      required: false
+      required: true
       schema:
-        type:
-          - array
-          - "null"
+        type: array
         items:
           type: string
     paramStructure: by-position
@@ -506,11 +504,9 @@ methods:
     params: []
     result:
       name: eth_accounts.Result
-      required: false
+      required: true
       schema:
-        type:
-          - array
-          - "null"
+        type: array
         items:
           type: string
     paramStructure: by-position
@@ -867,11 +863,9 @@ methods:
           $ref: "#/components/schemas/BlockNumberOrHash"
     result:
       name: Filecoin.EthGetBlockReceipts.Result
-      required: false
+      required: true
       schema:
-        type:
-          - array
-          - "null"
+        type: array
         items:
           $ref: "#/components/schemas/EthTxReceipt"
     paramStructure: by-position
@@ -884,11 +878,9 @@ methods:
           $ref: "#/components/schemas/BlockNumberOrHash"
     result:
       name: eth_getBlockReceipts.Result
-      required: false
+      required: true
       schema:
-        type:
-          - array
-          - "null"
+        type: array
         items:
           $ref: "#/components/schemas/EthTxReceipt"
     paramStructure: by-position
@@ -906,11 +898,9 @@ methods:
           format: int64
     result:
       name: Filecoin.EthGetBlockReceiptsLimited.Result
-      required: false
+      required: true
       schema:
-        type:
-          - array
-          - "null"
+        type: array
         items:
           $ref: "#/components/schemas/EthTxReceipt"
     paramStructure: by-position
@@ -928,11 +918,9 @@ methods:
           format: int64
     result:
       name: eth_getBlockReceiptsLimited.Result
-      required: false
+      required: true
       schema:
-        type:
-          - array
-          - "null"
+        type: array
         items:
           $ref: "#/components/schemas/EthTxReceipt"
     paramStructure: by-position
@@ -1639,11 +1627,9 @@ methods:
           $ref: "#/components/schemas/BlockNumberOrHash"
     result:
       name: Filecoin.EthTraceBlock.Result
-      required: false
+      required: true
       schema:
-        type:
-          - array
-          - "null"
+        type: array
         items:
           $ref: "#/components/schemas/EthBlockTrace"
     paramStructure: by-position
@@ -1656,11 +1642,9 @@ methods:
           $ref: "#/components/schemas/BlockNumberOrHash"
     result:
       name: trace_block.Result
-      required: false
+      required: true
       schema:
-        type:
-          - array
-          - "null"
+        type: array
         items:
           $ref: "#/components/schemas/EthBlockTrace"
     paramStructure: by-position
@@ -1673,11 +1657,9 @@ methods:
           $ref: "#/components/schemas/EthTraceFilterCriteria"
     result:
       name: Filecoin.EthTraceFilter.Result
-      required: false
+      required: true
       schema:
-        type:
-          - array
-          - "null"
+        type: array
         items:
           $ref: "#/components/schemas/EthBlockTrace"
     paramStructure: by-position
@@ -1690,11 +1672,9 @@ methods:
           $ref: "#/components/schemas/EthTraceFilterCriteria"
     result:
       name: trace_filter.Result
-      required: false
+      required: true
       schema:
-        type:
-          - array
-          - "null"
+        type: array
         items:
           $ref: "#/components/schemas/EthBlockTrace"
     paramStructure: by-position
@@ -1707,11 +1687,9 @@ methods:
           type: string
     result:
       name: Filecoin.EthTraceTransaction.Result
-      required: false
+      required: true
       schema:
-        type:
-          - array
-          - "null"
+        type: array
         items:
           $ref: "#/components/schemas/EthBlockTrace"
     paramStructure: by-position
@@ -1724,11 +1702,9 @@ methods:
           type: string
     result:
       name: trace_transaction.Result
-      required: false
+      required: true
       schema:
-        type:
-          - array
-          - "null"
+        type: array
         items:
           $ref: "#/components/schemas/EthBlockTrace"
     paramStructure: by-position
@@ -1749,11 +1725,9 @@ methods:
             type: string
     result:
       name: Filecoin.EthTraceReplayBlockTransactions.Result
-      required: false
+      required: true
       schema:
-        type:
-          - array
-          - "null"
+        type: array
         items:
           $ref: "#/components/schemas/EthReplayBlockTransactionTrace"
     paramStructure: by-position
@@ -1774,11 +1748,9 @@ methods:
             type: string
     result:
       name: trace_replayBlockTransactions.Result
-      required: false
+      required: true
       schema:
-        type:
-          - array
-          - "null"
+        type: array
         items:
           $ref: "#/components/schemas/EthReplayBlockTransactionTrace"
     paramStructure: by-position
@@ -4806,9 +4778,7 @@ components:
       type: object
       properties:
         accessList:
-          type:
-            - array
-            - "null"
+          type: array
           items:
             $ref: "#/components/schemas/EthHash"
         blockHash:
diff --git a/src/rpc/snapshots/forest__rpc__tests__rpc__v1.snap b/src/rpc/snapshots/forest__rpc__tests__rpc__v1.snap
index 792db9214e2..f39fe8add37 100644
--- a/src/rpc/snapshots/forest__rpc__tests__rpc__v1.snap
+++ b/src/rpc/snapshots/forest__rpc__tests__rpc__v1.snap
@@ -488,11 +488,9 @@ methods:
     params: []
     result:
       name: Filecoin.EthAccounts.Result
-      required: false
+      required: true
       schema:
-        type:
-          - array
-          - "null"
+        type: array
         items:
           type: string
     paramStructure: by-position
@@ -501,11 +499,9 @@ methods:
     params: []
     result:
       name: eth_accounts.Result
-      required: false
+      required: true
       schema:
-        type:
-          - array
-          - "null"
+        type: array
         items:
           type: string
     paramStructure: by-position
@@ -862,11 +858,9 @@ methods:
           $ref: "#/components/schemas/BlockNumberOrHash"
     result:
       name: Filecoin.EthGetBlockReceipts.Result
-      required: false
+      required: true
       schema:
-        type:
-          - array
-          - "null"
+        type: array
         items:
           $ref: "#/components/schemas/EthTxReceipt"
     paramStructure: by-position
@@ -879,11 +873,9 @@ methods:
           $ref: "#/components/schemas/BlockNumberOrHash"
     result:
       name: eth_getBlockReceipts.Result
-      required: false
+      required: true
       schema:
-        type:
-          - array
-          - "null"
+        type: array
         items:
           $ref: "#/components/schemas/EthTxReceipt"
     paramStructure: by-position
@@ -901,11 +893,9 @@ methods:
           format: int64
     result:
       name: Filecoin.EthGetBlockReceiptsLimited.Result
-      required: false
+      required: true
       schema:
-        type:
-          - array
-          - "null"
+        type: array
         items:
           $ref: "#/components/schemas/EthTxReceipt"
     paramStructure: by-position
@@ -923,11 +913,9 @@ methods:
           format: int64
     result:
       name: eth_getBlockReceiptsLimited.Result
-      required: false
+      required: true
       schema:
-        type:
-          - array
-          - "null"
+        type: array
         items:
           $ref: "#/components/schemas/EthTxReceipt"
     paramStructure: by-position
@@ -1634,11 +1622,9 @@ methods:
           $ref: "#/components/schemas/BlockNumberOrHash"
     result:
       name: Filecoin.EthTraceBlock.Result
-      required: false
+      required: true
       schema:
-        type:
-          - array
-          - "null"
+        type: array
         items:
           $ref: "#/components/schemas/EthBlockTrace"
     paramStructure: by-position
@@ -1651,11 +1637,9 @@ methods:
           $ref: "#/components/schemas/BlockNumberOrHash"
     result:
       name: trace_block.Result
-      required: false
+      required: true
       schema:
-        type:
-          - array
-          - "null"
+        type: array
         items:
           $ref: "#/components/schemas/EthBlockTrace"
     paramStructure: by-position
@@ -1714,11 +1698,9 @@ methods:
           $ref: "#/components/schemas/EthTraceFilterCriteria"
     result:
       name: Filecoin.EthTraceFilter.Result
-      required: false
+      required: true
       schema:
-        type:
-          - array
-          - "null"
+        type: array
         items:
           $ref: "#/components/schemas/EthBlockTrace"
     paramStructure: by-position
@@ -1731,11 +1713,9 @@ methods:
           $ref: "#/components/schemas/EthTraceFilterCriteria"
     result:
       name: trace_filter.Result
-      required: false
+      required: true
       schema:
-        type:
-          - array
-          - "null"
+        type: array
         items:
           $ref: "#/components/schemas/EthBlockTrace"
     paramStructure: by-position
@@ -1748,11 +1728,9 @@ methods:
           type: string
     result:
       name: Filecoin.EthTraceTransaction.Result
-      required: false
+      required: true
       schema:
-        type:
-          - array
-          - "null"
+        type: array
         items:
           $ref: "#/components/schemas/EthBlockTrace"
     paramStructure: by-position
@@ -1765,11 +1743,9 @@ methods:
           type: string
     result:
       name: trace_transaction.Result
-      required: false
+      required: true
       schema:
-        type:
-          - array
-          - "null"
+        type: array
         items:
           $ref: "#/components/schemas/EthBlockTrace"
     paramStructure: by-position
@@ -1828,11 +1804,9 @@ methods:
             type: string
     result:
       name: Filecoin.EthTraceReplayBlockTransactions.Result
-      required: false
+      required: true
       schema:
-        type:
-          - array
-          - "null"
+        type: array
         items:
           $ref: "#/components/schemas/EthReplayBlockTransactionTrace"
     paramStructure: by-position
@@ -1853,11 +1827,9 @@ methods:
             type: string
     result:
       name: trace_replayBlockTransactions.Result
-      required: false
+      required: true
       schema:
-        type:
-          - array
-          - "null"
+        type: array
         items:
           $ref: "#/components/schemas/EthReplayBlockTransactionTrace"
     paramStructure: by-position
@@ -4875,9 +4847,7 @@ components:
       type: object
       properties:
         accessList:
-          type:
-            - array
-            - "null"
+          type: array
           items:
             $ref: "#/components/schemas/EthHash"
         blockHash:
diff --git a/src/rpc/snapshots/forest__rpc__tests__rpc__v2.snap b/src/rpc/snapshots/forest__rpc__tests__rpc__v2.snap
index 62911c06a72..c50b6d763fc 100644
--- a/src/rpc/snapshots/forest__rpc__tests__rpc__v2.snap
+++ b/src/rpc/snapshots/forest__rpc__tests__rpc__v2.snap
@@ -78,11 +78,9 @@ methods:
     params: []
     result:
       name: Filecoin.EthAccounts.Result
-      required: false
+      required: true
       schema:
-        type:
-          - array
-          - "null"
+        type: array
         items:
           type: string
     paramStructure: by-position
@@ -91,11 +89,9 @@ methods:
     params: []
     result:
       name: eth_accounts.Result
-      required: false
+      required: true
       schema:
-        type:
-          - array
-          - "null"
+        type: array
         items:
           type: string
     paramStructure: by-position
@@ -452,11 +448,9 @@ methods:
           $ref: "#/components/schemas/BlockNumberOrHash"
     result:
       name: Filecoin.EthGetBlockReceipts.Result
-      required: false
+      required: true
       schema:
-        type:
-          - array
-          - "null"
+        type: array
         items:
           $ref: "#/components/schemas/EthTxReceipt"
     paramStructure: by-position
@@ -469,11 +463,9 @@ methods:
           $ref: "#/components/schemas/BlockNumberOrHash"
     result:
       name: eth_getBlockReceipts.Result
-      required: false
+      required: true
       schema:
-        type:
-          - array
-          - "null"
+        type: array
         items:
           $ref: "#/components/schemas/EthTxReceipt"
     paramStructure: by-position
@@ -491,11 +483,9 @@ methods:
           format: int64
     result:
       name: Filecoin.EthGetBlockReceiptsLimited.Result
-      required: false
+      required: true
       schema:
-        type:
-          - array
-          - "null"
+        type: array
         items:
           $ref: "#/components/schemas/EthTxReceipt"
     paramStructure: by-position
@@ -513,11 +503,9 @@ methods:
           format: int64
     result:
       name: eth_getBlockReceiptsLimited.Result
-      required: false
+      required: true
       schema:
-        type:
-          - array
-          - "null"
+        type: array
         items:
           $ref: "#/components/schemas/EthTxReceipt"
     paramStructure: by-position
@@ -1224,11 +1212,9 @@ methods:
           $ref: "#/components/schemas/BlockNumberOrHash"
     result:
       name: Filecoin.EthTraceBlock.Result
-      required: false
+      required: true
       schema:
-        type:
-          - array
-          - "null"
+        type: array
         items:
           $ref: "#/components/schemas/EthBlockTrace"
     paramStructure: by-position
@@ -1241,11 +1227,9 @@ methods:
           $ref: "#/components/schemas/BlockNumberOrHash"
     result:
       name: trace_block.Result
-      required: false
+      required: true
       schema:
-        type:
-          - array
-          - "null"
+        type: array
         items:
           $ref: "#/components/schemas/EthBlockTrace"
     paramStructure: by-position
@@ -1304,11 +1288,9 @@ methods:
           $ref: "#/components/schemas/EthTraceFilterCriteria"
     result:
       name: Filecoin.EthTraceFilter.Result
-      required: false
+      required: true
       schema:
-        type:
-          - array
-          - "null"
+        type: array
         items:
           $ref: "#/components/schemas/EthBlockTrace"
     paramStructure: by-position
@@ -1321,11 +1303,9 @@ methods:
           $ref: "#/components/schemas/EthTraceFilterCriteria"
     result:
       name: trace_filter.Result
-      required: false
+      required: true
       schema:
-        type:
-          - array
-          - "null"
+        type: array
         items:
           $ref: "#/components/schemas/EthBlockTrace"
     paramStructure: by-position
@@ -1338,11 +1318,9 @@ methods:
           type: string
     result:
       name: Filecoin.EthTraceTransaction.Result
-      required: false
+      required: true
       schema:
-        type:
-          - array
-          - "null"
+        type: array
         items:
           $ref: "#/components/schemas/EthBlockTrace"
     paramStructure: by-position
@@ -1355,11 +1333,9 @@ methods:
           type: string
     result:
       name: trace_transaction.Result
-      required: false
+      required: true
       schema:
-        type:
-          - array
-          - "null"
+        type: array
         items:
           $ref: "#/components/schemas/EthBlockTrace"
     paramStructure: by-position
@@ -1418,11 +1394,9 @@ methods:
             type: string
     result:
       name: Filecoin.EthTraceReplayBlockTransactions.Result
-      required: false
+      required: true
       schema:
-        type:
-          - array
-          - "null"
+        type: array
         items:
           $ref: "#/components/schemas/EthReplayBlockTransactionTrace"
     paramStructure: by-position
@@ -1443,11 +1417,9 @@ methods:
             type: string
     result:
       name: trace_replayBlockTransactions.Result
-      required: false
+      required: true
       schema:
-        type:
-          - array
-          - "null"
+        type: array
         items:
           $ref: "#/components/schemas/EthReplayBlockTransactionTrace"
     paramStructure: by-position
@@ -1690,9 +1662,7 @@ components:
       type: object
       properties:
         accessList:
-          type:
-            - array
-            - "null"
+          type: array
           items:
             $ref: "#/components/schemas/EthHash"
         blockHash:
diff --git a/src/tool/subcommands/api_cmd/test_snapshots.txt b/src/tool/subcommands/api_cmd/test_snapshots.txt
index 310ed20b0bc..986cab5c856 100644
--- a/src/tool/subcommands/api_cmd/test_snapshots.txt
+++ b/src/tool/subcommands/api_cmd/test_snapshots.txt
@@ -46,7 +46,7 @@ filecoin_eam_statedecodeparams_1756139121347218.rpcsnap.json.zst
 filecoin_eam_statedecodeparams_1756139121347288.rpcsnap.json.zst
 filecoin_eam_statedecodeparams_1756139121347364.rpcsnap.json.zst
 filecoin_ethaccount_statedecodeparams_1756186350854913.rpcsnap.json.zst
-filecoin_ethaccounts_1737446676689764.rpcsnap.json.zst
+filecoin_ethaccounts_1782207886518096.rpcsnap.json.zst
 filecoin_ethaddresstofilecoinaddress_1740132538465536.rpcsnap.json.zst
 filecoin_ethbasefee_1778755118342258.rpcsnap.json.zst
 filecoin_ethblocknumber_1741272348346171.rpcsnap.json.zst
@@ -97,7 +97,7 @@ filecoin_ethgetstorageat_v2_finalized_1769611091511354.rpcsnap.json.zst
 filecoin_ethgetstorageat_v2_safe_1769611091439347.rpcsnap.json.zst
 filecoin_ethgetstorageat_v2_unknown_addr_1770288667897031.rpcsnap.json.zst
 filecoin_ethgettransactionbyblockhashandindex_1773159088537607.rpcsnap.json.zst
-filecoin_ethgettransactionbyblocknumberandindex_1740132538304408.rpcsnap.json.zst
+filecoin_ethgettransactionbyblocknumberandindex_1782207831415446.rpcsnap.json.zst
 filecoin_ethgettransactionbyblocknumberandindex_latest_1769103643171646.rpcsnap.json.zst
 filecoin_ethgettransactionbyblocknumberandindex_pending_1769103643171774.rpcsnap.json.zst
 filecoin_ethgettransactionbyblocknumberandindex_v2_1769103643172125.rpcsnap.json.zst