API Reference

Architecture

Historical State Archive
- Accounts, blocks, and deltas are stored in Parquet for fast deterministic queries.
Historical State Archive
- Historical data may be stored locally or in S3-backed cold storage.
- There is no separate “request from S3” API. The same request path is used, and the system automatically resolves data availability across local storage and S3.
- The first request for a cold range can be slower due to data fetch and cache prewarm.
Hybrid S3 environment variables
- The following environment variables configure hybrid local + S3 history storage:
  - HYBRID_S3_HISTORY
  - S3_BUCKET
  - S3_PREFIX
  - S3_REGION
  - S3_SNAPSHOT_CACHE_MAX_BYTES
  - S3_OTHER_CACHE_MAX_BYTES
  - S3_MAX_PARALLEL_DOWNLOADS
Available Ranges
- Before creating a session, confirm the slot range of interest is available.
- curl https://<host>/available-ranges | jq
- This endpoint returns the ranges that can be used when creating a backtest session.
Management HTTP endpoints
- GET /health Returns 200 OK with body "ok".
- GET /ready Returns 200 OK when the server is accepting new sessions. Returns 503 when the server is draining and not accepting new sessions.
- GET /available-ranges Returns an array of objects describing available replay ranges:
- snapshotSlot
- snapshotSlotUtc
- bundleStartSlot
- bundleStartSlotUtc
- maxBundleEndSlot
- maxBundleEndSlotUtc
Replay Environment
- A Solana-compatible execution layer that replays historical transactions and applies injected ones.
Session Control Channel
- Connect to create and drive a backtest session. All messages on this channel use a custom JSON protocol.
- Endpoint: ws(s)://<host>/backtest
- Methods: createBacktestSession, attachBacktestSession, continue, closeBacktestSession
- Responses: sessionCreated, sessionAttached,readyForContinue, slotNotification, status (see variants below), success, completed, error
Sequenced Responses
- When disconnectTimeoutSecs > 0, responses are wrapped with a sequence id so clients can resume a session after reconnecting.
```
{
  "seqId": 123,
  "method": "status",
  "params": {
    "status": "decodedTransactions"
  }
}
```
- seqId is a monotonically increasing sequence number. Clients can pass their last received sequence when calling attachBacktestSession to resume the stream without replaying earlier messages.
Session startup
- Some sessions can take 2 to 3 minutes to become ready (for example when the bundle is not already cached). Keep the websocket connection open and wait for status updates.
Status variants
- During startup and execution, the server can produce the following status messages:
- PreparingBundle
- BundleReady
- DecodedTransactions
- AppliedAccountModifications
- ReadyToExecuteUserTransactions
- ExecutedUserTransactions
- ExecutingBlockTransactions
- ExecutedBlockTransactions
- ProgramAccountsLoaded
Per-Session RPC Channel
- Once a session is created, interact with the simulated Solana environment. Most methods conform to the standard Solana JSON-RPC interface.
- Endpoint: http(s):// or ws(s):// at /backtest/{session_id}
- Account state: getAccountInfo, getBalance, getMultipleAccounts, getProgramAccounts
- Chain state: getLatestBlockhash, getFeeForMessage, getSlot
- Transactions: simulateTransaction, sendTransaction, getTransaction
- Subscriptions: accountSubscribe, slotSubscribe, transactionSubscribe

Notes:
/backtest is authenticated by API key in production. /backtest/{session_id} is unauthenticated for per-session access.
ReadyToExecuteUserTransactions is the main status typically requires to wait for before sending or executing user transactions.
If your client script does strict parsing, make sure it can handle above mentioned status variants.

API Table

Method

Purpose

Surface

createBacktestSession

Start a backtest session and receive sessionId + rpcEndpoint.

Session control (WS)

continue

Execute a batch and advance slots; supports transactions + modifyAccountStates.

Session control (WS)

closeBacktestSession

Close and clean up a session.

Session control (WS)

attachBacktestSession

Reattach to an existing session and receive rpcEndpoint.

Session control (WS)

getAccountInfo

Fetch a single account at current slot.

Per-session RPC (HTTP)

getBalance

Fetch lamport balance for an account.

Per-session RPC (HTTP)

getMultipleAccounts

Fetch multiple accounts in one call.

Per-session RPC (HTTP)

getProgramAccounts

Fetch accounts owned by a program.

Per-session RPC (HTTP)

getLatestBlockhash

Get current slot blockhash.

Per-session RPC (HTTP)

getFeeForMessage

Get fee estimate for a message.

Per-session RPC (HTTP)

getSignatureStatuses

Fetch status for signatures.

Per-session RPC (HTTP)

getTransaction

Fetch transaction details (including logs).

Per-session RPC (HTTP)

simulateTransaction

Simulate a transaction without committing state.

Per-session RPC (HTTP)

sendTransaction

Execute a transaction immediately in the current slot.

Per-session RPC (HTTP)

getSlot

Get the current slot.

Per-session RPC (HTTP)

getAddressLookupTable

Fetch an ALT account.

Per-session RPC (HTTP)

modifyAccounts

Apply account overrides via RPC.

Per-session RPC (HTTP)

accountSubscribe

Stream account changes.