Opentip

The open-source tip jar on Base. Send crypto to the developers who build the tools you use every day.

opentip.tech · GitHub · X / Twitter · support@opentip.tech

How it works

Find a repo — browse registered repositories on Opentip
Change one word in the URL — replace github.com with opentip.tech (or visit directly)
Send a tip — pay in ETH, USDC, or OAR
Developer claims — the repo owner sets a payout address and pulls tips on-chain

Opentip takes a 5% fee on each tip to keep the platform running. 95% goes directly to the developer. Minimum tip is $1 to prevent gas fees from eating small amounts.

Features

Multi-token tipping — send ETH, USDC, or OAR; tips stay in the token you send
Repo-level tips — tips are tied to a specific GitHub repository
Pull payments — developers set a payout address and claim when ready
Email verification — 6-digit code flow with brute-force protection
Password reset — email-based reset via Resend
AI-generated summaries — Groq-powered codebase analysis on each repo page
Developer profiles — public profiles with stats, contribution heatmaps, and social links
Leaderboard — top supporters ranked by lifetime USD tipped
Admin dashboard — contract controls, fee management, treasury, user management
GitHub OAuth — sign in with GitHub to verify repo ownership
Email/password auth — optional email signup with verification
Profile customization — upload profile picture and header image via Azure Blob Storage

Tech stack

Layer	Technology
Smart contract	Solidity 0.8.26, OpenZeppelin, Foundry
Frontend	Next.js 16, React 19, Tailwind CSS, TypeScript
Animation	Motion (Framer Motion)
Validation	Zod
Auth	NextAuth.js v4, GitHub OAuth, JWT
Database	PostgreSQL (Azure), Prisma ORM
Wallet	Opentip Smart Wallet (CDP Embedded, email OTP, same address everywhere) + Reown AppKit for external wallets, wagmi, viem
Indexer	Standalone Node.js, polls Base for events (Azure Container Apps)
RPC	Alchemy (recommended), Base public RPC
AI summaries	Groq API
Image uploads	Azure Blob Storage
Email	Resend
Hosting	Vercel (frontend), Azure Container Apps (indexer)

Project structure

opentip/
├── contracts/              Solidity smart contract + Foundry tests
│   ├── src/OpentipV2.sol   Multi-token contract (ETH, USDC, OAR)
│   ├── src/Opentip.sol     V1 contract (deprecated, USDC-only)
│   ├── test/               91 tests (36 V1 + 55 V2)
│   └── script/DeployV2.s.sol
├── frontend/               Next.js app (deployed to Vercel)
│   ├── app/                Pages, API routes, layouts
│   │   ├── [owner]/[repo]/ Public repo page (tip form + AI summary)
│   │   ├── admin/          Admin dashboard (owner-only controls)
│   │   ├── dashboard/      User dashboard (repos, account, profile)
│   │   ├── dev/[login]/    Public developer profile
│   │   ├── docs/           Documentation site
│   │   ├── verify-email/   Email verification (6-digit code)
│   │   ├── signin/         Sign in / sign up
│   │   ├── onboarding/     Repo onboarding flow
│   │   ├── activity/       Public tip activity feed
│   │   ├── repos/          Browse registered repos
│   │   ├── api/            REST API routes
│   │   └── legal/          Terms of Service, Privacy Policy
│   ├── components/         Shared UI components
│   ├── config/             Reown AppKit / wagmi configuration
│   ├── context/            React context providers
│   ├── lib/                Utilities (chain, auth, contracts, email, prices)
│   └── prisma/             Database schema
├── indexer/                Event indexer (polls contract, syncs to DB)
└── package.json            npm workspaces root

Quick start

Prerequisites

Node.js 20+
Foundry (for contracts)
PostgreSQL database

1. Clone & install

git clone https://github.com/opentiphq/opentip.git
cd opentip
npm install

2. Smart contract (Foundry)

cd contracts
forge install OpenZeppelin/openzeppelin-contracts --no-commit
forge test -vvv

# Deploy to Base Sepolia
cp .env.example .env   # fill in PRIVATE_KEY, BASE_SEPOLIA_RPC, ETHERSCAN_API_KEY
forge script script/DeployV2.s.sol:DeployV2 --rpc-url $BASE_SEPOLIA_RPC --broadcast

# Verify on Basescan
forge build && forge verify-contract <CONTRACT_ADDRESS> src/OpentipV2.sol:OpentipV2 --chain-id 84532

The contract is deployed and verified:

V2 (Multi-token, mainnet): 0xAf1b70F5BdDFfD64c5D7B971bA670e1ff65cB1bC — ETH, USDC, OAR
V1 (USDC-only, deprecated): 0xA45Be472a64eE6Daa093c6a975Cd8908C615d594
V2 (testnet): 0xeD13dB8234d437771e115419BF7498Ddef90Dc8D

Token addresses (mainnet):

USDC: 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913
OAR: 0x6F19171963b7095d039372d0962512259187E4e6

3. Database

# Set DATABASE_URL in frontend/.env and indexer/.env
cd indexer && npx prisma migrate dev --name init
cd ../frontend && npx prisma generate

4. Indexer

cd indexer
cp .env.example .env   # fill in DATABASE_URL, RPC_URL, CONTRACT_ADDRESS, START_BLOCK
npm run dev

The indexer polls the contract for events and syncs to PostgreSQL.

5. Frontend

cd frontend
cp .env.example .env   # fill in all required env vars (see below)
npm run dev            # http://localhost:3000

Environment variables

Frontend (`frontend/.env`)

Variable	Description
`DATABASE_URL`	PostgreSQL connection string (`?sslmode=require`)
`GITHUB_ID`	GitHub OAuth app client ID
`GITHUB_SECRET`	GitHub OAuth app client secret
`NEXTAUTH_SECRET`	Random string for JWT signing
`NEXTAUTH_URL`	`http://localhost:3000` (dev) or `https://opentip.tech` (prod)
`NEXT_PUBLIC_WALLETCONNECT_PROJECT_ID`	Reown/WalletConnect project ID
`NEXT_PUBLIC_CHAIN`	`baseSepolia` (testnet) or `base` (mainnet)
`NEXT_PUBLIC_BASE_SEPOLIA_CONTRACT`	Testnet contract address
`NEXT_PUBLIC_BASE_CONTRACT`	Mainnet contract address
`NEXT_PUBLIC_RPC_URL`	RPC endpoint for client-side wagmi/Reown (e.g. Alchemy)
`RPC_URL`	RPC endpoint for server-side admin routes
`START_BLOCK`	Contract deployment block for dev profile scanning
`GETLOGS_RANGE`	Max blocks per `eth_getLogs` call (default: 10 for Alchemy free tier)
`PRIVATE_KEY`	Owner wallet private key for on-chain admin transactions
`OWNER_ADDRESS`	Owner wallet address for admin auth
`REGISTRAR_PRIVATE_KEY`	Private key for EIP-712 registrar signer
`GROQ_API_KEY`	Groq API key for AI-generated repo summaries
`RESEND_API_KEY`	Resend API key (verification + password reset emails)
`RESEND_FROM`	Sender email address (e.g. `noreply@opentip.tech`)
`GITHUB_TOKEN`	GitHub personal access token for API requests
`NOTIFICATION_SECRET`	Shared secret for `POST /api/notifications/send` (same value as the indexer). Generate with `openssl rand -hex 32`
`AZURE_STORAGE_ACCOUNT`	Azure Blob Storage account name
`AZURE_STORAGE_KEY`	Azure Blob Storage access key

Indexer (`indexer/.env`)

Variable	Description
`DATABASE_URL`	PostgreSQL connection string
`RPC_URL`	RPC endpoint (e.g. `https://base-mainnet.g.alchemy.com/v2/YOUR_KEY`)
`CONTRACT_ADDRESS`	Deployed Opentip contract address
`START_BLOCK`	Block number to start indexing from
`POLL_MS`	Polling interval (default: 12000ms)
`CHAIN`	`base` (mainnet) or `baseSepolia` (testnet)
`GETLOGS_RANGE`	Max blocks per `eth_getLogs` call (default: 10)
`NOTIFICATION_API_URL`	Push endpoint (default: `https://opentip.tech/api/notifications/send`)
`NOTIFICATION_SECRET`	Shared secret sent as `x-notification-secret` (same value as the frontend)

Contract deploy (`contracts/.env`)

Variable	Description
`BASE_SEPOLIA_RPC`	Alchemy or public RPC for Base Sepolia
`BASE_RPC`	Alchemy or public RPC for Base mainnet
`PRIVATE_KEY`	Deployer wallet private key
`ETHERSCAN_API_KEY`	Basescan API key for contract verification
`TREASURY_ADDRESS`	Treasury wallet address (defaults to deployer)
`FEE_BPS`	Fee in basis points (default: 500 = 5%)
`REGISTRAR_SIGNER`	Address of the EIP-712 registrar signer

Architecture

Smart contract (`OpentipV2.sol`)

The on-chain contract handles:

Repo registration — EIP-712 signed registration with GitHub ownership verification
Multi-token tips — ETH, USDC, OAR, or any registered ERC-20 token
Payout claims — pull-payment pattern; developers set an address and claim all tokens at once
Fee collection — 5% fee routed to the treasury per token
Token management — admin can add/remove supported tokens
Stray ETH recovery — ETH sent outside receiveTipEth() is tracked and sweepable
Migration — V1 repos can be migrated to V2 via adminMigrateRepo() with a deadline
Admin controls — pause/unpause, fee adjustment, treasury and registrar key rotation

Key properties:

Ownable2Step — two-step ownership transfer for security
Pausable — emergency stop mechanism
ReentrancyGuard — prevents reentrancy attacks
EIP-712 — typed structured data for off-chain signature verification (domain version "2")
everAcceptedTokens — permanent record of all tokens that were ever tipped, ensures claimAll() works even after token removal

Indexer

A standalone Node.js service that:

Polls the contract for TipReceived, RepoRegistered, PayoutAddressUpdated, and other events
Syncs event data to PostgreSQL with idempotent upserts
Batches eth_getLogs calls with configurable block range (GETLOGS_RANGE)
Includes DB retry logic with exponential backoff
Runs on Azure Container Apps

Frontend

Next.js 16 app with:

App Router — file-based routing with layouts
Server Components — DB queries in server components (leaderboard, repo pages)
Turbopack — fast dev server and builds
Fluid responsive design — CSS clamp() for typography and spacing
Chain-driven config — single lib/chain.ts module controls all chain-specific values
Email verification — 6-digit code flow mandatory before onboarding
OTP input — 6-digit code input with auto-advance and paste support

Deployment

Vercel (frontend)

Connect your GitHub repo to Vercel
Set all environment variables in the Vercel dashboard
Deploy — npm run build runs automatically

Azure Container Apps (indexer)

# Build and push
cd indexer
docker build -t opentipregistry.azurecr.io/opentip-indexer:latest .
az acr login --name opentipregistry
docker push opentipregistry.azurecr.io/opentip-indexer:latest

# Update the container app
az containerapp update --name opentip-indexer --resource-group opentip --image opentipregistry.azurecr.io/opentip-indexer:latest

# Set env vars (if needed)
az containerapp update --name opentip-indexer --resource-group opentip --set-env-vars "RPC_URL=https://..." "GETLOGS_RANGE=10"

Contributing

See CONTRIBUTING.md or visit opentip.tech/tip/docs/contributing for setup instructions, code conventions, and PR guidelines.

License

MIT

Links

Website: opentip.tech
GitHub: github.com/opentiphq
X / Twitter: @opentip_tech
Email: support@opentip.tech
Contract V2 (mainnet): Basescan
Contract V1 (deprecated): Basescan
Contract (testnet): Basescan

Name		Name	Last commit message	Last commit date
.cursor/skills/verify-opentip		.cursor/skills/verify-opentip
.github/workflows		.github/workflows
contracts		contracts
frontend		frontend
indexer		indexer
scripts		scripts
.env.example		.env.example
.gitignore		.gitignore
.gitmodules		.gitmodules
AGENTS.md		AGENTS.md
README.md		README.md
package-lock.json		package-lock.json
package.json		package.json

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Opentip

How it works

Features

Tech stack

Project structure

Quick start

Prerequisites

1. Clone & install

2. Smart contract (Foundry)

3. Database

4. Indexer

5. Frontend

Environment variables

Frontend (`frontend/.env`)

Indexer (`indexer/.env`)

Contract deploy (`contracts/.env`)

Architecture

Smart contract (`OpentipV2.sol`)

Indexer

Frontend

Deployment

Vercel (frontend)

Azure Container Apps (indexer)

Contributing

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Opentip

How it works

Features

Tech stack

Project structure

Quick start

Prerequisites

1. Clone & install

2. Smart contract (Foundry)

3. Database

4. Indexer

5. Frontend

Environment variables

Frontend (frontend/.env)

Indexer (indexer/.env)

Contract deploy (contracts/.env)

Architecture

Smart contract (OpentipV2.sol)

Indexer

Frontend

Deployment

Vercel (frontend)

Azure Container Apps (indexer)

Contributing

License

Links

About

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Frontend (`frontend/.env`)

Indexer (`indexer/.env`)

Contract deploy (`contracts/.env`)

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