Start and shuffle

_start_pasanaku runs automatically when the final participant joins. It freezes membership, normalizes collateral to the current vault rate, mints soulbound receipts, and opens round accounting.

Call flow

flowchart TD
  join[join fills roster] --> seed[seed from prevrandao]
  seed --> shuffle[Fisher-Yates shuffle]
  shuffle --> target[previewWithdraw pledge]
  target --> normalize[normalize each locked position]
  normalize --> mint[mint ERC-1155]
  mint --> active[started and updated timestamps]

Shuffle

Recipient order is not join order. The seed is:

keccak256(abi_encode(block.prevrandao, block.timestamp, token_id))

_shuffle_array runs a deterministic Fisher-Yates shuffle. After this point, participants[k] is the designated recipient of round k.

Pre-start normalization

Pool yield begins here—not at create or join.

For the current pledge asset amount, the contract computes:

target_shares = vault.previewWithdraw(pledge_assets)

Then for each participant:

Condition	Effect
locked > target_shares	Excess returns to free shares (pre-start appreciation)
locked < target_shares	Top up from free shares, or revert (pre-start collateral loss)
equal	No movement

Finally each participant is set to:

• _locked_shares = target_shares
• _locked_asset_basis = pledge_assets

Basis is recorded only after this normalization. That fixed principal is what end settlement later tries to return.

Activation side effects

• _mint_membership_token for every participant (_TOKEN_AMOUNT = 1)
• started = updated = block.timestamp
• _active_pasanaku_count += 1
• PasanakuStarted log

Round deposits and tick are valid only after started != 0.

Integrator implications

• Joining with the minimum free shares can still revert at start if the vault rate worsens before the roster fills.
• Holding extra free shares hedges pre-start share-price increases in the required pledge.
• Indexers should treat PasanakuStarted as the moment recipient positions become final.

See also

• ERC-1155 membership
• CONTEXT.md — Yield start
• tests/unitary/pasanaku/test_lifecycle.py, tests/unitary/erc1155/test_membership_mint.py