Struct BundleBuilder 

pub struct BundleBuilder<'a> {
    pub payer: &'a Keypair,
    pub transactions_instructions: BundleInstructionSlots,
    pub lookup_tables: &'a [AddressLookupTableAccount],
    pub recent_blockhash: Hash,
    pub tip_lamports: u64,
    pub jitodontfront_pubkey: Option<&'a Pubkey>,
    pub compute_unit_limit: u32,
    pub tip_account: Pubkey,
    pub tip_mode: TipMode,
}

Mutable builder state used while constructing a bundle.

Fields

payer: &'a Keypair

Signing payer used for all compiled transactions.

transactions_instructions: BundleInstructionSlots

Fixed instruction slots (max 5).

lookup_tables: &'a [AddressLookupTableAccount]

Lookup tables used for v0 message compilation.

recent_blockhash: Hash

Recent blockhash used for all compiled messages.

tip_lamports: u64

Tip amount in lamports.

jitodontfront_pubkey: Option<&'a Pubkey>

Optional jitodontfront account to inject.

compute_unit_limit: u32

Compute unit limit prepended to each transaction.

tip_account: Pubkey

Randomly chosen Jito tip account for this build.

tip_mode: TipMode

Final tip placement mode selected during build.

Implementations

impl<'a> BundleBuilder<'a>

pub fn build(inputs: BundleBuilderInputs<'a>) -> Result<BuiltBundle, JitoError>

Builds a final BuiltBundle from fixed instruction slots.

Jito hard-limits bundles to MAX_BUNDLE_TRANSACTIONS (5), so this builder chooses tip placement based on remaining transaction capacity.

Build flow:

1. Compact sparse slots while preserving transaction order.
2. Optionally apply jitodontfront account rewriting.
3. Insert tip as separate tx when count < 5, or inline when count == 5.
4. Validate tip account is not in LUTs for inline mode.
5. Compile, sign, and size-check each transaction.

Returns JitoError for invalid bundle size, compile/sign failures, oversized transactions, and invalid LUT tip-account usage.

Trait Implementations

impl BundleSlotView for BundleBuilder<'_>

fn instruction_slots(&self) -> &BundleInstructionSlots

Returns the mutable builder’s current instruction slots view.

fn populated_count(&self) -> usize

Counts non-empty instruction slots.

fn last_populated_index(&self) -> Option<usize>

Returns the index of the last non-empty slot.