Crate replay_core 

replay-core

The engine for Replay — a time-travel debugger for Solana transactions.

The public surface is intentionally small:

• replay — one-shot replay of a mainnet transaction.
• fork — create a session you can mutate and re-execute.

Everything else is a private implementation detail. If you find yourself reaching for internals from outside this crate, that’s a signal to widen the public API here rather than bypass it.

Re-exports

pub use error::ReplayError;

pub use types::AccountDelta;

pub use types::AccountMutation;

pub use types::CpiFrame;

pub use types::FetchedTx;

pub use types::FrameAccount;

pub use types::LogDivergence;

pub use types::ProgramInfo;

pub use types::ProgramLoader;

pub use types::ReconstructedState;

pub use types::Trace;

pub use types::TraceDiff;

pub use types::TxContext;

pub use types::TxResult;

pub use rpc::HeliusClient;

pub use rpc::HeliusRpcClient;

pub use session::ForkedSession;

Modules

error

Error types. Fail loudly, fail specifically — every variant carries the context a user needs to understand and act on the failure.

fetch

Fetch a transaction and turn the raw Helius response into a structured TxContext ready for state reconstruction and replay.

idl

IDL-aware account decoder.

reconstruct

Reconstruct the pre-slot state of every account a transaction touches.

rpc

Helius RPC client. A trait + concrete impl so tests can mock.

session

ForkedSession — a replayable, mutable sandbox around a single transaction.

svm

The litesvm wrapper. Responsible for seeding reconstructed state, setting sysvars, and running the replay transaction.

trace

Trace tree builder. Takes a flat log list + execution result and produces a tree of CpiFrames, one per CPI invocation, nested according to call depth.

types

Shared data types.

Functions

decode_account_deltas

Walk trace.account_deltas and populate decoded_before / decoded_after (and idl_type_name when available) by running the decoder against each pre/post snapshot. Idempotent and side-effect-free outside the trace.

fork

Create a forked session seeded from a mainnet transaction.

replay

Replay a mainnet transaction against litesvm with historical state.