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@solana/sysvars

This package contains types and helpers for fetching and decoding Solana sysvars. It can be used standalone, but it is also exported as part of Kit @solana/kit.

More information about the available sysvars on Solana can be found in the docs
at .

All currently available sysvars can be retrieved and/or decoded using this
library.

Sysvar API

This package offers a simple API for working with sysvars.

One can fetch an encoded sysvar account using an RPC client.

``ts
const maybeEncodedClock = await fetchEncodedSysvarAccount(rpc, SYSVAR_CLOCK_ADDRESS);
maybeEncodedClock satisfies MaybeEncodedAccount<'SysvarC1ock11111111111111111111111111111111'>;
`

One can also attempt to fetch a JSON-parsed sysvar account.

`ts
const maybeJsonParsedClock = await fetchJsonParsedSysvarAccount(rpc, SYSVAR_CLOCK_ADDRESS);
maybeJsonParsedClock satisfies
| MaybeAccount
| MaybeEncodedAccount<'SysvarC1ock11111111111111111111111111111111'>;
`

Each sysvar within the library ships with its own
codec
for deserializing the account data.

You can pair this codec with the helpers from
@solana/accounts
to assert and decode sysvar account data.

`ts
// Fetch.
const clock = await fetchEncodedSysvarAccount(rpc, SYSVAR_CLOCK_ADDRESS);
clock satisfies MaybeEncodedAccount<'SysvarC1ock11111111111111111111111111111111'>;

// Assert.
assertAccountExists(clock);
clock satisfies EncodedAccount<'SysvarC1ock11111111111111111111111111111111'>;

// Decode.
const decodedClock = decodeAccount(clock, getSysvarClockDecoder());
decodedClock satisfies Account;
`

Each supported sysvar also ships with its own fetch-and-decode function to
perform the steps above and return the decoded sysvar data.

`ts
const clock: SysvarClock = await fetchSysvarClock(rpc);
`

Supported Sysvars:

This package supports the following Solana sysvars:

- Clock
- EpochRewards
- EpochSchedule
- Fees
- LastRestartSlot
- RecentBlockhashes
- Rent
- SlotHashes
- SlotHistory
- StakeHistory

The Instructions` sysvar is also supported but does not exist on-chain,
therefore has no corresponding module or codec.