Pyth#

solana_kit_pyth is off-chain client code for Pyth price data. It has four parts: Wormhole and accumulator wire parsing, legacy and receiver price accounts, an optional Hermes HTTP client, and builders for the receiver program's posting instructions. The default crate is no_std + alloc and uses the solana_kit_core bounded codecs, so the same parsing code runs natively, in the browser and under WASI.

Add the crate#

[dependencies]
solana_kit_core = { git = "https://github.com/pina-rs/solana_kit" }
solana_kit_pyth = { git = "https://github.com/pina-rs/solana_kit" }

The crate is unpublished (publish = false).

Wire messages#

Every parser takes a solana_kit_core::codecs::Limits value that caps the bytes and items it allocates.

use solana_kit_core::codecs::{Error, Limits};
use solana_kit_pyth::{
    PythPriceFeedMessage, parse_accumulator_update_data, parse_pyth_price_feed_message,
};

fn first_price(data: &[u8], limits: Limits) -> Result<PythPriceFeedMessage, Error> {
    let update = parse_accumulator_update_data(data, limits)?;
    let message = update.updates.first().ok_or(Error::InvalidValue)?.message;
    parse_pyth_price_feed_message(message, limits)
}

Payloads and variable-length byte fields borrow from your input. On one point this crate deliberately differs from the Dart reference. It follows the official AUWV format, which the pinned Dart helper rejects. The reasoning is in docs/parity/pyth-wire.md.

Price accounts#

decode_pyth_price_account decodes legacy price accounts into PythPriceAccount: exact integer samples, EMA state and an ordered list of publisher components, within your allocation limit. If you pass the slot your read was made at, it derives the effective status. More than PYTH_MAX_SLOT_DIFFERENCE (25) slots demotes the trading status, and the stored aggregate is left untouched.

decode_price_update_v2_account decodes receiver PriceUpdateV2 accounts. A full verification has a 133-byte prefix (PRICE_UPDATE_V2_FULL_SIZE) and a partial one has 134 bytes (PRICE_UPDATE_V2_PARTIAL_SIZE). The Dart decoder always requires 134. feed_id_hex returns the 64-digit lowercase feed ID.

Hermes#

Enable hermes to get the models and a client for Hermes' three GET routes. The client takes your REST transport, a subscriptions::Clock, a retry Policy and JSON Budgets:

use solana_kit_client::{rest, subscriptions::Clock};
use solana_kit_pyth::hermes::{Client, Policy, Service};

fn client<T: rest::Transport<Service>, C: Clock>(transport: T, clock: C) -> Client<T, C> {
    Client::new(transport, clock, Policy::default(), rest::Budgets::default())
}

UpdateOptions selects the Encoding and the parsed and ignore_invalid_price_ids flags. Policy::default() allows 5000 ms per attempt and three retries, with delays of 100, 200 and 400 ms. Only I/O failures, elapsed deadlines, HTTP 408 or 429, and statuses of 500 or above are retried. Policy::new rejects a zero timeout and more than MAX_HTTP_RETRIES (32) retries. Each losing exchange is dropped before the backoff starts.

Prices and confidence values are arbitrary-precision integers, capped at 8192 text bytes each. Price::approximate_f64 is the explicit lossy conversion. decode_price_update and decode_price_feeds decode stored responses with the same admission checks.

hermes::DEFAULT_BASE_URL is https://hermes.pyth.network. Bind the Hermes Service slot to an approved adapter such as NativeRest. The provider root, headers and bearer authentication all belong to that adapter.

Receiver instructions#

ReceiverInstruction builds post_update and post_update_atomic. Each has an exact Anchor discriminator, Borsh parameters and seven positional accounts:

use solana_kit_core::{Address, Instruction, codecs::{Error, Limits}};
use solana_kit_pyth::{
    MerklePriceUpdate, PostUpdateParams, ReceiverAccounts, ReceiverInstruction,
};

fn posted(
    accounts: ReceiverAccounts,
    encoded_vaa: Address,
    update: &MerklePriceUpdate<'_>,
) -> Result<Instruction, Error> {
    ReceiverInstruction::PostUpdate {
        accounts,
        encoded_vaa,
        params: PostUpdateParams::new(update),
    }
    .instruction(Limits::new(4096, 64))
}

ReceiverAccounts::new uses the standard receiver program, with the payer as write authority. Its fields are public, so you can override them. PYTH_SOLANA_RECEIVER_PROGRAM, PYTH_WORMHOLE_PROGRAM and PYTH_PUSH_ORACLE_PROGRAM match the pinned reference. random_treasury_id takes exactly one byte from an entropy callback you provide. The crate has no ambient RNG.

The builders do no I/O and no submission, and they authenticate nothing.

Status#

These slices cover the wire, accounts, Hermes and receiver instructions. They do not complete Pyth parity. The records are:

• docs/parity/pyth-wire.md
• docs/parity/pyth-accounts.md
• docs/parity/pyth-hermes.md
• docs/parity/pyth-receiver-instructions.md