Phases and roadmap

Bythos launches in two phases, set by what Elysium can provide. Phase 0 reads Elysium pools from mainnet day one. Phase 1 adds the HyperCore order book after the ArbOS upgrade.

Timeline

When	Milestone	Status
Now	Elysium Testnet (chain id 99801)	Phase 0 · pool sounding, with the Phase 1 interface stubbed
Nov 9, 2026	Elysium mainnet	Phase 0 · pool sounding
About 4 weeks after mainnet	ArbOS upgrade	Phase 1 · book sounding (after ArbOS upgrade)

The ArbOS upgrade date is set by Elysium, not by Bythos. The roughly 4-week gap is the current plan.

Phase 0 · pool sounding

Phase 0 runs from mainnet day one until the ArbOS upgrade.

• Sounding v0 reads Elysium pools only. It computes the exact executable output of a swap (getAmountOut), not a TWAP. The walk stops where the marginal price falls 15% below spot. See Sounding.
• Market condition: only tokens whose LP is locked in Horkos are accepted as Markets. A locked LP means the depth Sounding reads cannot be pulled out from under the Lines that rely on it.
• Trawl sells collateral through the Market's pool. If the pool cannot be read, the caller can repay the debt directly and receive collateral at 5% below TWAP30. See Trawl.
• Limits reflect pool depth only. For tokens that have already graduated to a HyperCore spot book, this understates their real depth, so limits are lower than they will be in Phase 1.

Phase 1 · book sounding (after ArbOS upgrade)

The ArbOS upgrade is planned to add two precompiles:

• EL1Read lets a smart contract read the entire HyperCore order book, every level, for free, in-block.
• EL1Write lets a smart contract submit trade-only intents to HyperCore.

With these, Bythos changes in three ways.

1. Sounding v1 adds the HyperCore bid book. Depth Value includes the bids on HyperCore as well as Elysium pools, walked level by level down to 15% below the best bid.
2. Existing Lines see their limits rise. A token with depth on both venues has a higher Depth Value once both are counted.
3. Trawl sells into HyperCore first. The fallback order becomes HyperCore intent, then pool swap, then collateral sale to the caller at a 5% discount. The venue that priced the position is the venue that liquidates it.

What stays the same

Markets read Sounding through the same ISounding interface in both phases. Its core call is:

function sound(address token, uint256 qty) external view returns (uint256 depthValue);

Contracts that consume sound(), such as the perps venue Shortcap can, keep the same call when book depth is added.

On testnet

The testnet build implements Phase 0. The Phase 1 contract SoundingV1 is deployed as a stub with the same interface; every call reverts with NotYetAvailable(). This keeps the integration surface fixed so that the move to Phase 1 is a change of data source, not of interface.

Testnet does not check the Horkos LP lock, so any token with a pool against WHYPE can get a Market there, given the tBYTHOS lock. Testnet state can be reset at any time. See Contracts and Risks.

If the upgrade is late

Phase 0 is a complete protocol on its own. If the ArbOS upgrade arrives later than planned, Bythos keeps running on pool sounding, with lower limits for graduated tokens, until book sounding is available.