Proposal: Adding debug_traceCall and debug_traceCallMany Support to Hedera Node

[yuval99g]

Background

As Hedera continues to expand its EVM compatibility and developer ecosystem, advanced debugging and transaction simulation capabilities are becoming increasingly important. In Ethereum and other EVM-based networks, RPC methods such as debug_traceCall and debug_traceCallMany are widely used by developers, tooling providers, and infrastructure services to gain deep visibility into transaction execution.

Currently, Hedera nodes do not expose equivalent tracing capabilities, which creates a gap for developers building sophisticated applications, debugging complex contract interactions, or operating simulation-heavy workflows.

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Problem Statement

Developers on Hedera lack:

• Detailed execution traces for contract calls without submitting transactions on-chain
• Multi-call simulation capabilities for batching and analyzing multiple calls efficiently
• Parity with Ethereum debugging tooling, limiting portability of existing tools and workflows

This results in:

• Reduced developer productivity
• Increased reliance on custom tooling or workarounds
• Friction when onboarding EVM developers to Hedera

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Proposed Solution

Introduce support for the following RPC methods in Hedera nodes:

1. debug_traceCall

Simulates a transaction call and returns a detailed execution trace, including:

• Opcode-level execution steps
• Gas usage per step
• Internal contract calls
• Storage reads/writes

2. debug_traceCallMany

Extends debug_traceCall to support batching multiple calls in a single request:

• Efficient simulation of multiple transactions
• Reduced RPC overhead
• Enables advanced use cases like bundle simulation and MEV-style analysis

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Expected Benefits

• Improved Developer Experience
  Developers can debug contracts more effectively and gain insights into execution behavior.

• Tooling Compatibility
  Enables easier integration with existing Ethereum tooling (e.g., Hardhat, Foundry, Tenderly-like systems).

• Advanced Use Cases
  Supports:

  • Transaction simulation pipelines
  • Batch analysis tools
  • Wallet and dApp pre-execution checks
  • Infrastructure providers offering tracing services

• Ecosystem Growth
  Reduces friction for EVM developers migrating to Hedera.

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Design Considerations

• Performance Impact
  Tracing is computationally expensive; should be:

  • Optional
  • Possibly restricted to archive/debug nodes

• Security & Abuse Prevention

  • Rate limiting or access control may be required
  • Avoid exposing excessive internal state that could be abused

• Trace Format Compatibility

  • Align with Ethereum’s existing trace formats where possible
  • Consider supporting popular tracers (e.g., callTracer, structLogs)

• Node Configuration

  • Feature flags to enable/disable tracing
  • Configurable depth and verbosity

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Open Questions

• Should tracing be enabled on all nodes or only specialized nodes?
• What level of compatibility with Ethereum tracing APIs should be targeted?
• How should resource usage and rate limiting be handled?
• Is there a need for custom Hedera-specific trace extensions?