Onchain round-up protocol

Auto-investspare change.

Buff is a lightweight SDK that turns every onchain transaction into a micro-investment. It rounds up the fee, invests the difference, and builds your users a portfolio — all behind the scenes.

Get started
$2.4M
Invested
140K+
Round-ups
18.6%
Returns
Portfolio
$012345678901234567890123456789.01234567890123456789
+12.4%
ETH
40%
BTC
30%
SOL
20%
USDC
10%
Swap SOL → USDC
$0.42 → $1.00
+$0.58
Jupiter Swap
$0.67 → $1.00
+$0.33
Stake SOL
$0.11 → $1.00
+$0.89
Mint NFT
$0.23 → $1.00
+$0.77
UniswapAaveOpenSeaLidoCurveJupiterRaydiumGMXUniswapAaveOpenSeaLidoCurveJupiterRaydiumGMX

Every gas fee
builds a portfolio

Step 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.

Step 02

Fee gets rounded up

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

Step 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.

Step 04

Portfolio compounds

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

Optimized for AI agentsdevelopers

No popups, no browser wallets. Just pass an API key and go.

01

Server-side ready

Built for Node.js, Deno, and serverless environments.

02

No browser required

Autonomous agents can transact without any UI.

03

One-line init

new Buff({ apiKey }) — that's the entire setup.

> new Buff({ apiKey })

Round up API payments automatically. Every HTTP 402 payment generates spare change.

01

Automatic capture

Hooks into the payment lifecycle silently.

02

Configurable thresholds

Round to nearest dollar, $5, or custom ceiling.

03

Zero UX friction

Users and agents never notice the round-up.

> buff.calculateRoundUp(cost)

Programmatic, deterministic, and exportable. Derive wallets from agent IDs.

01

Deterministic derivation

Same agent ID always produces the same wallet.

02

Non-custodial

Users own their keys. No custody risk.

03

Fully exportable

Move wallets between platforms freely.

> buff.deriveWallet(signature)
SKILL.md
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Integration

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.

Revenue sharing

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

integration.tsTypeScript
import{ Buff } from 'buff-protocol-sdk'
// Round up fees, auto-invest the difference
const buff = new Buff({
apiKey: 'your-api-key',
plan: 'sprout',
investInto: 'BTC',
})
// Get round-up instructions for any tx
const { instructions } = await buff.getWrapInstructions(usd, pk, bw)
$npm install buff-protocol-sdk
</>

Quick Start

Get Buff running in your app in under 5 minutes.

</>

Round-Ups

How round-ups work and how to configure them.

</>

Agent Wallets

Derive deterministic wallets from agent signatures.

</>

x402 Middleware

Auto round-up HTTP 402 payments for AI agents.

</>

React Guide

Integrate Buff into your React application.

</>

AI Agents

Build autonomous agents that invest spare change.

</>

SKILL.md

Let AI agents discover and use Buff automatically.

</>

Plans & Tiers

Round-up increments from $0.05 to $1.00.

Start building.

Free to integrate. Revenue from day one.

Get your API keyRead the docs

Available on Solana. More chains coming soon.

How it worksPlansSimulatorDocumentation↗Quick Start↗SDK Reference↗SKILL.mdTermsPrivacyGitHub↗
Buff

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