Query Heimdall with tendermint-rpc

[royvardhan]

I'm developing a verifier that integrates with Peppermint and standard tendermint using the tendermint-rpc crate to fetch headers and consensus proofs, then delegates verification to tendermint-light-client-verifier. You can see my implementation here: https://github.com/polytope-labs/hyperbridge/pull/448/files

Current Implementation:
I'm querying the Heimdall RPC endpoint at https://polygon-heimdall-rpc.publicnode.com:443. Since there were response field mismatches between Heimdall's format and standard Tendermint types, I created a custom "peppermint client" to transform the responses for heimdall.

Issues I'm Facing:

1. Hash Mismatches: During verification, I'm encountering hash validator mismatches that cause my tests to fail. This suggests the response transformation or verification process has compatibility issues.

2. Response Format Compatibility: The field mismatches between Heimdall and standard Tendermint formats required custom transformation logic.

Questions:

1. What are the known differences between Heimdall's RPC responses and standard Tendermint that could cause hash mismatches during verification? Do I need to handle hashing differently in the verifier?

2. Is there an established crate or library specifically designed for handling Peppermint/Heimdall RPC responses that would eliminate the need for custom transformation logic?

Additionally, what's the recommended approach for integrating tendermint-light-client-verifier with Polygon's Heimdall consensus layer while maintaining compatibility?