Types Reference

This page summarizes the most important Rust and Cairo types used by HDP.

Rust input/output types

Type	Description	Location
`HDPDryRunInput`	Compiled class, params, injected state	`crates/types/src/lib.rs`
`HDPInput`	Compiled class, params, proofs, injected state	`crates/types/src/lib.rs`
`ProofsData`	`chain_proofs`, `state_proofs`, `unconstrained`	`crates/types/src/lib.rs`
`HDPDryRunOutput`	Task hash and output root fields	`crates/types/src/lib.rs`
`HDPOutput`	Task hash, output root, `mmr_metas`	`crates/types/src/lib.rs`
`MmrMetaOutput`	Poseidon or Keccak MMR metadata	`crates/types/src/lib.rs`
`StateProofs`	Injected state proof list	`crates/types/src/proofs/injected_state/`
`InjectedState`	Initial injected state map	`crates/types/src/lib.rs`
`UnconstrainedState`	Unconstrained data map	`crates/types/src/lib.rs`

Chain identifiers

Type	Description
`ChainIds`	Enum of supported chains
`ChainProofs`	Per-chain proof bundles
`HashingFunction`	Poseidon or Keccak

ProofsData (the proofs.json file) is structured as:

{
  "chain_proofs": [ ... ],
  "state_proofs": [ ... ],
  "unconstrained": { ... }
}

state_proofs is ordered and can include both read and write proofs.

Chain ID constants (Cairo)

The Cairo library exposes chain ID constants:

hdp_cairo::evm::{ETHEREUM_MAINNET_CHAIN_ID, ETHEREUM_TESTNET_CHAIN_ID, OPTIMISM_MAINNET_CHAIN_ID, OPTIMISM_TESTNET_CHAIN_ID}
hdp_cairo::starknet::{STARKNET_MAINNET_CHAIN_ID, STARKNET_TESTNET_CHAIN_ID}

Dry run keys

Dry run handlers collect keys in a DryRunKey enum:

Header, Account, Storage, Tx, Receipt for EVM
Starknet keys are tracked in the Starknet handler

Source: crates/dry_hint_processor/src/syscall_handler/

Injected state and unconstrained handlers also define their own DryRunKey enums for state actions and bytecode.

Cairo key structs

These are used when calling hdp_cairo APIs:

EVM: HeaderKey, AccountKey, StorageKey, BlockTxKey, BlockReceiptKey, LogKey
Starknet: HeaderKey, StorageKey

Output fields

The sound run output segment is decoded as:

task_hash_low, task_hash_high, output_root_low, output_root_high,
poseidon_len, keccak_len,
poseidon_metas (4 felts each), keccak_metas (5 felts each)

MmrMetaOutput is encoded as:

Poseidon: id, size, chain_id, root
Keccak: id, size, chain_id, root_low, root_high