Helius hSOL$83.61-11.7% has released a beta API that shows what any Solana account looked like in the past, down to the effect of a single transaction. The Historical Accounts API returns an account's full state at the end of a past slot or straight after a chosen transaction. Helius's documentation says history starts on 7 September 2026, access is limited to Business plans and above, and calls cost 0 credits during the beta, with pricing subject to change.
Standard Solana RPC calls such as getAccountInfo only return an account as it is now. Before this launch, a developer who wanted last month's view of a liquidity pool, a lending vault or a wallet had to rebuild it by replaying transaction history. Helius announced the API on X on 14 November and pitched it for backtesting trades and simulating transactions against historical state: a strategy can now be tested against what a pool actually held at that moment.
How the Helius Historical Accounts API reads past Solana state
The Historical Accounts API adds two methods that work like familiar RPC calls with a point in time attached. getHistoricalAccountInfo returns one account at a past position, and getHistoricalTokenAccountsByOwner lists a wallet's SPL Token and Token-2022 accounts at a past position, page by page. Both run on mainnet only.
A query names its position in one of two ways:
- a slot on its own, which returns the account at the end of that slot, after every transaction and after writes that belong to no transaction, such as epoch rewards;
- a slot plus a transaction index, which returns the account immediately after that one transaction executed.
The second option is the finer tool. Solana packs many transactions into each slot, and a busy pool can change several times inside one. Reading an account on either side of a single transaction lets a developer debug a trade or see exactly what one transaction changed. Helius's docs list that use alongside wallet balances for audits, accounting and tax reporting, and reading a protocol's pools, vaults or oracles at a past slot.
Each response includes a lastUpdatedAt field, the position of the write that produced the state returned. The docs describe it as a cursor: step back one transaction from that position, query again, and repeat to walk an account's history backwards until the answer is null. A null means the account did not exist at that point, either because it had not been created yet or because it had been closed.
That last case matters on Solana, where closing an account removes it from current state. Owners often close unused token accounts because empty token accounts still hold a small deposit their owners can get back. After closure, a standard RPC node has nothing to return; the historical API can still show what the account held before it went.
The docs set rate limits apart from Helius's normal RPC limits: 100 requests a second for single-account reads and 10 a second for the token-account method. Responses come as base64, base64 with zstd compression, or parsed JSON.
Historical Accounts API coverage: epoch 1030 today, two years the goal
The archive reaches back about ten weeks at launch. History begins at slot 444,959,999 on 7 September 2026, the final slot of epoch 1029, and queries for earlier slots return an error, according to the Helius docs.
Nick Pennie, a Helius co-founder who oversees its data platform according to the company, called the archive "the most challenging engineering problem at Helius – ever" in a post on X. He wrote that the team had "compressed 116B account updates into 4TB", queryable in milliseconds, with "2yr+ history and more features dropping soon". Read alongside the docs, two years of history is Helius's stated target for coming releases; the beta itself starts on 7 September.
The volume behind that claim is easier to picture with our own numbers. Solana Compass counted about 8.3 billion account write operations on Solana in the 31 days from 14 October to 13 November, roughly 270 million a day. Each write leaves behind a version of an account that a standard RPC node no longer serves, and that turnover is what a point-in-time archive has to keep.
Solana accounts took between about 223 million and 309 million write operations a day over the month, averaging roughly 270 million, per Solana Compass.
View on Solana Compass →From balance-at to full account state: Helius's historical data push
The Historical Accounts API is the latest in a run of Helius history tools. In June Helius launched balance-at, which answers one question: a wallet's balance of one token at a past time. On 3 November it added the Parsed Events Scan API to search an address's transaction history on Helius's servers. The new API goes below both. It returns the raw account itself, so a developer can read a lending position, an oracle account or a pool's reserves exactly as they stood at that point.
Helius is not the only provider building this. Alchemy introduced its Solana Account Archive on 3 August 2026, and Alchemy's documentation says it answers getAccountInfo at any slot back to July 2025 on paid plans, with options to fetch an account's previous or next write. Alchemy's archive covers a longer window today and works at slot level; Helius's adds reads after an individual transaction inside a slot. For a backtest that turns on the order of trades within one slot, that is the difference that counts.
Point-in-time Solana account data for traders, accountants and protocol teams
Helius CEO Mert Mumtaz listed the uses as "historical defi positions, balances, closed accounts, taxes, backtesting, simulations" and wrote that "you can now read all of solana at any point in time". He opened the same post with "mass surveillance achieved", a joke landing four days after Helius put Privacy Rings on mainnet to encrypt balances and transfer amounts. The two launches sit on the same fact: Solana's ledger is public, and whatever is not encrypted can now be read as it stood on any day since early September.
For teams on Solana, the practical change is that a historical question becomes one call instead of an indexing project. A trading desk can replay a strategy against real pool states, an accountant can pull a wallet's token accounts on a year-end date, and a protocol team can see exactly what an exploit or a liquidation changed, transaction by transaction.
Three things are worth checking as the beta runs. The docs say parameters, pricing, response formats and coverage may all change, so the price once the 0-credit period ends is open. The backfill toward two years of history will decide whether the API can answer questions about earlier market events. And access is Business plans and above for now; whether it reaches cheaper plans is the line to watch for smaller teams.
