Jito Bundles

Core Concepts

Bundle Anatomy

A Jito bundle is a JSON-RPC request containing 1-5 base58-encoded signed transactions. The transactions execute sequentially and atomically within a single slot.

Bundle = [Tx1, Tx2, ..., TxN]  (N <= 5)

- All transactions must be signed
- Transactions execute in order: Tx1 → Tx2 → ... → TxN
- If ANY transaction fails, the ENTIRE bundle is dropped
- The tip instruction goes in the LAST transaction (last instruction)
- Bundle has ~2 slots (~800ms) to land before expiry

Tip Mechanism

Tips are SOL transfers to one of Jito's 8 tip accounts. The tip incentivizes validators to include your bundle.

# Tip is a standard SOL transfer instruction
tip_instruction = transfer(
    from_pubkey=your_wallet,
    to_pubkey=tip_account,      # One of 8 Jito tip accounts
    lamports=tip_amount          # Tip in lamports (1 SOL = 1e9 lamports)
)
# Add as the LAST instruction of the LAST transaction in the bundle

Tip accounts are fetched dynamically via getTipAccounts. Rotate through them to distribute load.

Block Engine Endpoints

Jito operates geographically distributed block engines. Choose the one closest to your infrastructure:

All endpoints accept JSON-RPC over HTTPS on port 443. The /api/v1/bundles path handles bundle operations.

API Methods

sendBundle

Submit a bundle of up to 5 transactions.

import httpx

BLOCK_ENGINE = "https://mainnet.block-engine.jito.wtf"

payload = {
    "jsonrpc": "2.0",
    "id": 1,
    "method": "sendBundle",
    "params": [
        [tx1_base58, tx2_base58],  # List of base58-encoded signed txs
    ]
}

resp = httpx.post(f"{BLOCK_ENGINE}/api/v1/bundles", json=payload)
data = resp.json()
bundle_id = data["result"]  # UUID string

getBundleStatuses

Check the landing status of submitted bundles (up to 5 bundle IDs per request).

payload = {
    "jsonrpc": "2.0",
    "id": 1,
    "method": "getBundleStatuses",
    "params": [[bundle_id]]
}
resp = httpx.post(f"{BLOCK_ENGINE}/api/v1/bundles", json=payload)
statuses = resp.json()["result"]["value"]
# Each status: {bundle_id, status, slot, transactions: [{signature, ...}]}
# status: "Invalid", "Pending", "Failed", "Landed"

getTipAccounts

Fetch the current list of Jito tip accounts.

payload = {
    "jsonrpc": "2.0",
    "id": 1,
    "method": "getTipAccounts",
    "params": []
}
resp = httpx.post(f"{BLOCK_ENGINE}/api/v1/bundles", json=payload)
tip_accounts = resp.json()["result"]  # List of 8 base58 pubkeys

getInflightBundleStatuses

Check status of bundles that haven't landed yet (in-flight).

payload = {
    "jsonrpc": "2.0",
    "id": 1,
    "method": "getInflightBundleStatuses",
    "params": [[bundle_id]]
}
resp = httpx.post(f"{BLOCK_ENGINE}/api/v1/bundles", json=payload)
# status: "Pending", "Failed", "Landed"

Bundle Construction Pattern

A typical bundle for a protected swap:

from solders.transaction import VersionedTransaction
from solders.message import MessageV0
from solders.instruction import Instruction
from solders.system_program import transfer, TransferParams
from solders.pubkey import Pubkey
import random

def build_protected_swap_bundle(
    swap_ix: Instruction,
    payer: Pubkey,
    tip_lamports: int,
    tip_accounts: list[str],
    recent_blockhash: str,
) -> list[VersionedTransaction]:
    """Build a 1-tx bundle: swap + tip in the same transaction.

    For simple swaps, a single-transaction bundle is sufficient.
    The tip instruction is appended as the last instruction.
    """
    # Pick a random tip account
    tip_account = Pubkey.from_string(random.choice(tip_accounts))

    # Tip instruction
    tip_ix = transfer(TransferParams(
        from_pubkey=payer,
        to_pubkey=tip_account,
        lamports=tip_lamports,
    ))

    # Build transaction with swap + tip
    msg = MessageV0.try_compile(
        payer=payer,
        instructions=[swap_ix, tip_ix],
        address_lookup_table_accounts=[],
        recent_blockhash=recent_blockhash,
    )
    tx = VersionedTransaction(msg, [keypair])
    return [tx]

Tip Sizing Guide

Dynamic tip calculation based on recent tip levels:

def calculate_dynamic_tip(
    base_tip: int = 10_000,
    urgency_multiplier: float = 1.0,
    recent_tip_percentile_50: int = 15_000,
) -> int:
    """Calculate tip based on urgency and recent network tips.

    Args:
        base_tip: Minimum tip in lamports.
        urgency_multiplier: 1.0 = normal, 2.0 = urgent, 5.0 = critical.
        recent_tip_percentile_50: Median tip from recent bundles.

    Returns:
        Tip amount in lamports.
    """
    dynamic_tip = max(base_tip, int(recent_tip_percentile_50 * urgency_multiplier))
    # Cap at 0.01 SOL to prevent accidents
    return min(dynamic_tip, 10_000_000)

Common Errors and Fixes

Landing Rate Optimization

Strategies to maximize bundle landing probability:

1. Multi-region submission: Send the same bundle to multiple block engines simultaneously. The first to reach the current leader wins.

2. Fresh blockhash: Use getLatestBlockhash with confirmed commitment immediately before building. Stale blockhashes are the #1 cause of dropped bundles.

3. Retry with backoff: If a bundle doesn't land within 2-3 seconds, rebuild with a fresh blockhash and resubmit. Do NOT resubmit with the same blockhash.

4. Adequate tipping: Under-tipped bundles are deprioritized. Monitor the network's tip distribution and tip at or above the 50th percentile for your urgency level.

5. Minimal bundle size: Fewer transactions = less simulation time = higher landing rate. Use single-transaction bundles when possible.

async def submit_with_retry(
    bundle_txs: list[str],
    endpoints: list[str],
    max_retries: int = 3,
) -> str | None:
    """Submit bundle to multiple endpoints with retry logic.

    Returns bundle_id if submitted, None if all retries exhausted.
    """
    for attempt in range(max_retries):
        # Submit to all endpoints in parallel
        async with httpx.AsyncClient() as client:
            tasks = [
                client.post(
                    f"{ep}/api/v1/bundles",
                    json={
                        "jsonrpc": "2.0", "id": 1,
                        "method": "sendBundle",
                        "params": [bundle_txs],
                    },
                    timeout=5.0,
                )
                for ep in endpoints
            ]
            # Process first successful response
            for resp in asyncio.as_completed(tasks):
                result = (await resp).json()
                if "result" in result:
                    return result["result"]

        # Wait before retry with fresh blockhash
        await asyncio.sleep(0.5 * (attempt + 1))
    return None

Safety Checklist (Execution)

Before submitting any bundle with real funds:

• Simulated all transactions individually via simulateTransaction
• Verified tip amount is reasonable (not accidentally SOL instead of lamports)
• Confirmed blockhash is fresh (< 60 seconds old)
• Verified all transactions are properly signed
• Checked wallet balance covers all transaction costs + tip
• Tested with devnet or --demo mode first
• Set maximum tip cap to prevent accidental overpayment

Files

References

• references/bundle_api.md — Complete JSON-RPC API reference with request/response schemas and error codes
• references/tip_strategies.md — Tip calculation strategies, dynamic tipping, cost optimization
• references/best_practices.md — Bundle construction patterns, landing rate optimization, common pitfalls

Scripts

• scripts/build_bundle.py — Bundle construction with tip instruction; --demo mode builds but does not submit
• scripts/check_bundle_status.py — Bundle status checking and tip account fetching; --demo mode uses mock responses