Round-up investing for humans & agents

Round up.
Auto-invest.

Buff rounds up every onchain transaction and auto-invests the spare change into crypto assets. A drop-in SDK for any platform — works for human users and AI agents alike.

Non-custodialOpen sourceSolana nativeAI agent ready
How it works

Every fee
builds a portfolio

Four steps. Zero friction. Every transaction fee becomes an investment in crypto assets.

01

Human or agent transacts

A user swaps tokens, an AI agent calls an API, or a bot sends a payment — any onchain action. Buff hooks into the transaction lifecycle silently.

Zero UX friction
02

Fee gets rounded up

The gas fee is rounded up to the nearest dollar (or configurable threshold). The difference is captured automatically.

Avg. $0.47 per tx
03

Spare change gets invested

The round-up difference is auto-invested into crypto assets — ETH, BTC, SOL, or a custom mix. Portfolio grows with every tx.

Auto-diversified
04

Portfolio compounds

Users build a diversified crypto portfolio passively. Fully withdrawable, fully transparent, fully onchain. Every tx counts.

100% non-custodial
Live on Solana

Built on
Solana.

Live on Solana today. More chains coming soon.

Solana
live
TVL
$180K
Ethereum
soon
Coming soon
Base
soon
Coming soon
Arbitrum
soon
Coming soon
SolanaEthereumBaseArbitrumSolanaEthereumBaseArbitrumSolanaEthereumBaseArbitrum
ArbitrumBaseEthereumSolanaArbitrumBaseEthereumSolanaArbitrumBaseEthereumSolana
Agent support

Built for
AI agents

Headless, programmatic, zero-friction. Let your agents round up and invest autonomously.

Headless SDK

No popups, no browser wallets. Just pass a keypair and go. Built for server-side and autonomous agents.

Buff.init({ agentKeypair })

x402 Middleware

Round up API payments automatically. Every HTTP 402 payment your agent makes can generate spare change for investing.

middleware: "x402-roundup"

Agent Wallets

Programmatic, deterministic, and exportable. Derive wallets from agent IDs with no browser or user interaction required.

wallet: "deterministic"
SKILL.md

Fetch this file from any agent to integrate Buff

For developers

Five lines.
That's it.

Buff is a lightweight TypeScript SDK that wraps any transaction provider. It rounds up the fee, invests the difference, and builds your users a portfolio — all behind the scenes.

Framework agnostic

Works with React, Vue, Svelte, or vanilla JS. No opinions, no lock-in.

Configurable thresholds

Round to nearest dollar, $5, or let users set their own ceiling.

Solana native

Built for Solana. Lightning fast, sub-cent fees. More chains coming soon.

Revenue sharing

Earn a cut of every round-up your platform generates. Aligned incentives.

TypeScriptintegration.ts
import{ Buff } from '@buff/sdk'
// Round up fees, auto-invest the difference
const buff = Buff.init({
platformId: 'your-platform-id',
chain: 'solana',
investInto: ['ETH', 'BTC', 'SOL'],
})
// Wrap any tx — Buff rounds up & invests
const tx = await buff.wrap(transaction)
$npm install @buff/sdk
The protocol

Investing in
every field

$0.0M
Total invested
across all portfolios
0K+
Round-ups
transactions processed
0
Integrations
platforms live
0.0%
Avg. return
portfolio performance

Trusted by leading protocols

UniswapAaveOpenSeaLidoCurveJupiterRaydiumGMXUniswapAaveOpenSeaLidoCurveJupiterRaydiumGMX

Start investing
spare change

Help your users build crypto portfolios from every transaction. Integrate Buff in minutes, not months.

Free to integrate — Revenue share on round-ups