Composable Instructions

Venum's key differentiator: you get an unsigned transaction you can inspect and modify before signing, not an auto-submitted opaque blob.

The Problem with Jupiter

Jupiter API returns a fully serialized, opaque transaction. You can't:

• Add your own fee instruction
• Compose with a CPI (cross-program invocation)
• Bundle with other instructions in the same transaction
• Modify the compute budget
• Add a memo or custom program call

You either use their blob as-is, or you don't use it at all.

Venum's Approach

The /v1/swap/build endpoint returns an unsigned VersionedTransaction that you can deserialize, inspect, and extend before signing:

// Build the transaction — returns base64-encoded unsigned TX
const { transaction } = await fetch('https://api.venum.dev/v1/swap/build', {
  method: 'POST',
  headers: { 'Content-Type': 'application/json', 'x-api-key': API_KEY },
  body: JSON.stringify({
    inputMint: 'SOL',
    outputMint: 'USDC',
    amount: '1000000000',
    userPublicKey: wallet.publicKey.toString(),
  }),
}).then(r => r.json());

// Deserialize, modify, sign, submit
const tx = VersionedTransaction.deserialize(Buffer.from(transaction, 'base64'));
tx.sign([wallet]);

const { signature } = await fetch('https://api.venum.dev/v1/send', {
  method: 'POST',
  headers: { 'Content-Type': 'application/json', 'x-api-key': API_KEY },
  body: JSON.stringify({ transaction: Buffer.from(tx.serialize()).toString('base64') }),
}).then(r => r.json());

Use Cases

• Telegram bots — Add your own fee instruction to every swap
• dApps — Compose swap with your protocol's CPI
• Wallets — Bundle swap with account creation / closing
• Trading bots — Combine swap with Jito tip instruction
• Aggregators — Multi-hop through different DEXes in one TX