Vault Address Lookup

Smart-account addresses are derived one-way from an index (settings_seed):

settings = PDA(["smart_account", "settings", u128(seed)])
vault    = PDA(["smart_account", settings, "smart_account", account_index])

Given a vault address you can't recover its index — the derivation isn't invertible. But most users only ever saved their smart account (vault) address, and later need their index and settings address back (to fetch settings, run the lifecycle, etc.). Solace::SquadsSmartAccounts::VaultIndex solves this by precomputing the forward map once and inverting it locally.

When to use it

Reach for this when you have a vault address and need its settings_seed / settings account — typically recovering an account a user identifies only by the address that holds their funds. If you already have the index, you don't need it: just derive forward with get_settings_address / get_smart_account_address.

Building the table

VaultIndex.build derives the default vault (account_index 0) for every seed in 1..count and writes a compact binary table — one 32-byte vault pubkey per record, where the record at offset o is settings_seed = o + 1. The write is atomic, so an interrupted build never leaves a half-written file.

Parameter	Type	Required	Default	Description
count	Integer	no	500_000	Number of indices to cover (seeds 1..count).
path	String	no	default_path	Output file (default: vault-index.bin in the current directory).
progress	Proc	no	nil	Optional progress.call(done, count), invoked every 50k seeds.

require 'solace/squads_smart_accounts'

Solace::SquadsSmartAccounts::VaultIndex.build(
  count:    500_000,
  progress: ->(done, total) { puts "#{done} / #{total}" }
)
# => writes ./vault-index.bin

At 500,000 entries the file is ~16 MB and takes ~3 minutes to build (single-threaded). The pubkeys are high-entropy, so the file does not compress. Build it once and keep it.

Looking up an address

VaultIndex.lookup loads the table into an in-memory hash (once per path, memoized) and resolves a vault address. The settings address is re-derived from the recovered index.

Parameter	Type	Required	Default	Description
vault_address	#to_s	yes	—	The smart-account (vault) address to resolve.
path	String	no	default_path	The table file to read.

Returns { index:, settings_address: }, or nil if the address isn't in the table. Raises if the table file doesn't exist (build it first).

VaultIndex = Solace::SquadsSmartAccounts::VaultIndex

result = VaultIndex.lookup('EdMSvMoHfsemd2s7eHCrRnuM1dzPu2CpUrHJN98XYC9y')
# => { index: 1, settings_address: "41gqrPgijYycTaCCzKyLfvqikMEH9fzGCwZYAKQHvMbd" }

result[:index]            # => 1
result[:settings_address] # => the settings PDA for that account

Limitations

• Snapshot. The table covers indices 1..count. An address whose index is higher than count, or an account created after the build (the on-chain index keeps climbing), won't be found — rebuild with a larger count to extend coverage.
• Default vault only. Only the account_index 0 vault is indexed. A saved sub-vault address (account_index 1–255) won't match.
• Memory. Lookups load the whole table into a hash (tens of MB of RAM for the 500k table); it's memoized, so repeated lookups are O(1).