feat(rpc): Add support for the `EthTraceReplayBlockTransactions` V2 API by akaladarshi · Pull Request #6444 · ChainSafe/forest

akaladarshi · 2026-01-19T18:32:30Z

Summary of changes

Changes introduced in this pull request:

Adds support for the EthTraceReplayBlockTransactions V2 API
Small Refactor
Fix the discrepancy in EthTraceReplayBlockTransactions response

Reference issue to close (if applicable)

Closes#6308

Change checklist

I have performed a self-review of my own code,
I have made corresponding changes to the documentation. All new code adheres to the team's documentation standards,
I have added tests that prove my fix is effective or that my feature works (if possible),
I have made sure the CHANGELOG is up-to-date. All user-facing changes should be reflected in this document.

Summary by CodeRabbit

New Features
- Added a V2 Ethereum trace-replay RPC endpoint (new API path) returning the same trace items with updated parameters.
Changes
- Trace responses always include stateDiff and vmTrace (nullable) for compatibility.
- Improved validation and clearer error responses for trace type parameters.
- Aligned V1/V2 handling to a shared implementation for consistent results.
Tests
- Extended RPC test coverage and updated snapshots to include the V2 endpoint.

_{✏️ Tip: You can customize this high-level summary in your review settings.}

coderabbitai · 2026-01-19T18:32:47Z

Walkthrough

Adds a V2 RPC method EthTraceReplayBlockTransactionsV2, centralizes trace replay logic into a new async helper eth_trace_replay_block_transactions used by both V1 and V2, enforces V2 traceTypes validation, changes serialization to always emit state_diff and vm_trace (nullable), and updates tests, snapshots, and RPC registration.

Changes

Cohort / File(s)	Summary
RPC method implementation `src/rpc/methods/eth.rs`	Added `EthTraceReplayBlockTransactionsV2` (Params = `(ExtBlockNumberOrHash, Vec<String>)`, Ok = `Vec<EthReplayBlockTransactionTrace>`). Introduced `async fn eth_trace_replay_block_transactions<DB>(ctx, ts)` and updated V1 to delegate to it. V2 validates `traceTypes` and uses a V2 tipset resolver.
Types / serialization `src/rpc/methods/eth/types.rs`	Removed `#[serde(skip_serializing_if = "Option::is_none")]` from `state_diff` and `vm_trace` on `EthReplayBlockTransactionTrace`, so those fields serialize as `null` when absent.
RPC registration `src/rpc/mod.rs`	Registered `EthTraceReplayBlockTransactionsV2` in the `for_each_rpc_method` macro.
Tests & snapshots `src/tool/subcommands/api_cmd/api_compare_tests.rs`, `src/tool/subcommands/api_cmd/test_snapshots.txt`	Added test entry for V2 (`EthTraceReplayBlockTransactionsV2::request((ExtBlockNumberOrHash, Vec<String>))`) and replaced/added snapshot files for the V2 output.
Docs / changelog `CHANGELOG.md`	Documented the new API v2 method and the change to always include `stateDiff` and `vmTrace` (nullable) in responses.

Sequence Diagram(s)

mermaid
sequenceDiagram
participant Client
participant RPC as "RPC Method (V1/V2)"
participant Resolver as "Tipset Resolver"
participant Tracer as "Trace Executor"
participant DB as "DB / State Viewer"
participant Assembler as "Trace Assembler"

Client->>RPC: EthTraceReplayBlockTransactions request
RPC->>Resolver: resolve tipset (V1 or V2)
Resolver-->>RPC: tipset
RPC->>Tracer: execute traces for tipset
Tracer-->>RPC: raw trace results
RPC->>DB: resolve tx hashes & fetch state snapshots
DB-->>RPC: tx hashes / state
RPC->>Assembler: build envs, capture vm_trace/state_diff, assemble results
Assembler-->>Client: Vec

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~25 minutes

Possibly related PRs

feat: enable V2 API support for basic Eth and Filecoin RPC methods #6171 — related modifications to Eth trace replay and V2 API support for trace endpoints.
fix(rpc): register RPC methods for different versions into different modules #6219 — related RPC-versioning changes that add V2 method variants and registration.

Suggested reviewers

hanabi1224
sudo-shashank
LesnyRumcajs

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately describes the main change: adding V2 API support for EthTraceReplayBlockTransactions, which is the primary focus of all code modifications.
Linked Issues check	✅ Passed	The pull request successfully implements the EthTraceReplayBlockTransactions V2 endpoint as required by issue `#6308`, with a refactor and fixes included.
Out of Scope Changes check	✅ Passed	All changes are directly related to implementing the V2 API endpoint: adding the V2 variant, refactoring shared logic, updating types, and adjusting serialization behavior for Lotus compatibility.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

✨ Finishing touches

📝 Generate docstrings

_{Comment @coderabbitai help to get the list of available commands and usage tips.}

codecov · 2026-01-20T09:46:43Z

Codecov Report

❌ Patch coverage is 70.17544% with 17 lines in your changes missing coverage. Please review.
✅ Project coverage is 58.73%. Comparing base (1546c7c) to head (3f9cb65).
⚠️ Report is 3 commits behind head on main.

Files with missing lines	Patch %	Lines
src/rpc/methods/eth.rs	70.17%	10 Missing and 7 partials ⚠️

Additional details and impacted files

Files with missing lines	Coverage Δ
src/rpc/methods/eth/types.rs	`66.06% <ø> (ø)`
src/rpc/mod.rs	`24.47% <ø> (ø)`
src/rpc/methods/eth.rs	`67.67% <70.17%> (+0.01%)`	⬆️

... and 9 files with indirect coverage changes

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LesnyRumcajs · 2026-01-20T16:18:10Z


- let state = StateTree::new_from_root(ctx.store_owned(), &state_root)?;
+pub enum EthTraceReplayBlockTransactionsV2 {}
+impl RpcMethod<2> for EthTraceReplayBlockTransactionsV2 {


description?

I didn't notice this earlier that some of the other API's also doesn't have a Description, I will create an issue for this so we can add in all API's.

@coderabbitai create a issue for the adding Description to all the API's available in the forest.

🧩 Analysis chain
@akaladarshi I'll create a GitHub issue to track adding DESCRIPTION fields to all RPC methods in Forest.
🏁 Script executed:
#!/bin/bash # Create a GitHub issue for adding DESCRIPTION to all RPC methods gh issue create \ --repo ChainSafe/forest \ --title "Add DESCRIPTION to all RPC methods" \ --body "## Background Many RPC method implementations in Forest are missing the \`DESCRIPTION\` constant, which should provide documentation about what each method does. ## Task Add the \`DESCRIPTION\` field to all RPC method implementations throughout the codebase. This will improve API documentation and help users understand what each method does. ## Example \`\`\`rust impl RpcMethod<2> for EthTraceReplayBlockTransactions { const NAME: &'static str = \"Filecoin.EthTraceReplayBlockTransactions\"; const NAME_ALIAS: Option<&'static str> = Some(\"trace_replayBlockTransactions\"); const DESCRIPTION: Option<&'static str> = Some( \"Replays all transactions in a block returning the requested traces for each transaction.\", ); // ... } \`\`\` ## Context Related PR: `#6444` Related comment: https://github.com/ChainSafe/forest/pull/6444#discussion_r2709084181 cc: `@akaladarshi`" \ --assignee akaladarshi
Length of output: 47
@akaladarshi I've created issue #6460 to track adding DESCRIPTION fields to all RPC methods in Forest. The issue has been assigned to you and includes the context from this PR discussion.

LesnyRumcajs · 2026-01-20T16:21:45Z

+ ctx: Ctx<impl Blockstore + Send + Sync + 'static>,
+ (block_param, trace_types): Self::Params,
+ ) -> Result<Self::Ok, ServerError> {
+ if trace_types.as_slice() != ["trace"] {


is there a point in using anyhow here? Seems to me it'd be easier to define a new method on ServerError, e.g., ServerError::unsupported_params. It'd be cheaper.

I guess we can use the ServerError::invalid_params("only 'trace' is supported", None)

…snapshot tests

LesnyRumcajs · 2026-01-21T09:46:02Z

 #[serde(rename_all = "camelCase")]
 pub struct EthReplayBlockTransactionTrace {
 pub output: EthBytes,
- #[serde(skip_serializing_if = "Option::is_none")]


so this was incorrect?

what's the struct in Lotus?

Here is the lotus struct for this, and yeah I saw in the lotus snapshot response that the fields are set to null.

What's the Lotus snapshot response?

Lotus returns something like this:
"lotus_response": { "Ok": [ { "output": "0x0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000600000000000000000000000000000000000000000000000000000000000000000", "stateDiff": null, "trace": [ { "action": { "callType": "call", "from": "0xff00000000000000000000000000000000021cc9", "gas": "0xbdf9c", "input": "0x868e10c40000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000600000000000000000000000000000000000000000000000000000000000000000", "to": "0x0f96b5f075e13c3a552c1481a1ae00f9c042d58b", "value": "0x917bd023e0703660" }, "result": { "gasUsed": "0x12d48f", "output": "0x0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000600000000000000000000000000000000000000000000000000000000000000000" }, "subtraces": 0, "traceAddress": [], "type": "call" } ], "transactionHash": "0x77b925676c49edbc6096d6b67002202a11f8c0160cbba1fe40f4162cb734e598", "vmTrace": null },

Ok, cool, makes sense.

…PI (#6444)

akaladarshi force-pushed the akaladarshi/replay-block-tx-v2 branch from 62d9e13 to 1b2504aCompare January 20, 2026 08:59

akaladarshi marked this pull request as ready for review January 20, 2026 08:59

akaladarshi requested a review from a team as a code owner January 20, 2026 08:59

akaladarshi requested review from LesnyRumcajs and hanabi1224 and removed request for a teamJanuary 20, 2026 08:59

akaladarshi added the RPC requires calibnet RPC checks to run on CI label Jan 20, 2026

LesnyRumcajs reviewed Jan 20, 2026
View reviewed changes

akaladarshi added 4 commits January 21, 2026 00:38

Add EthTraceReplayBlockTransactionsV2 API support
10b6635

add api snapshot test
222b07b

fix eth replay block transaction response descrepancy and update the …
4386854
…snapshot tests

address comments
505c6f5

akaladarshi force-pushed the akaladarshi/replay-block-tx-v2 branch from 6cbc78a to 505c6f5Compare January 20, 2026 19:08

update changelog
0741774

LesnyRumcajs reviewed Jan 21, 2026
View reviewed changes

coderabbitaiBot mentioned this pull request Jan 22, 2026
Add DESCRIPTION to all RPC methods #6460
Closed

Merge branch 'main' into akaladarshi/replay-block-tx-v2
3f9cb65

LesnyRumcajs approved these changes Jan 22, 2026
View reviewed changes

LesnyRumcajs added this pull request to the merge queue Jan 22, 2026

github-merge-queueBot pushed a commit that referenced this pull request Jan 22, 2026
feat(rpc): Add support for the EthTraceReplayBlockTransactions V2 A…
09333d7
…PI (#6444)

github-merge-queueBot removed this pull request from the merge queue due to failed status checks Jan 22, 2026

akaladarshi added this pull request to the merge queue Jan 22, 2026

Merged via the queue into main with commit 3061897Jan 22, 2026
44 checks passed

akaladarshi deleted the akaladarshi/replay-block-tx-v2 branch January 22, 2026 19:33

sudo-shashank pushed a commit that referenced this pull request Jan 23, 2026
feat(rpc): Add support for the EthTraceReplayBlockTransactions V2 A…
b2df58c
…PI (#6444)

coderabbitaiBot mentioned this pull request Feb 5, 2026
fix: forge script bug #6541
Merged
6 tasks

coderabbitaiBot mentioned this pull request Feb 19, 2026
feat: Implement Forest.EthTraceCall#6412
Merged
4 tasks

This was referenced Mar 10, 2026
feat(api): Implement debug_traceTransaction API #6685
Closed
refactor: prepare for the changes in debug trace transaction #6731
Merged

coderabbitaiBot mentioned this pull request Mar 18, 2026
feat(api): Implement debug_traceTransaction API #6751
Merged
6 tasks

CopilotAI mentioned this pull request Jun 19, 2026
Add missing DESCRIPTION metadata across RPC methods #7199
Closed

coderabbitaiBot mentioned this pull request Jun 23, 2026
fix(eth): serialize empty lists as [] instead of null#7214
Merged
6 tasks

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Summary of changes

Reference issue to close (if applicable)

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