Soljar — Platform Overview

soljar-overview-gist.md

Soljar — Platform Overview

Soljar is a Solana-native business finance platform. Crypto wallets, fiat banking, token swaps, invoicing, and payments — all in one product for freelancers and small businesses.

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Authentication & Wallets — Privy

• Users sign up with email only — no seed phrases, no extensions
• Privy auto-creates an embedded Solana wallet (real EOA keypair via MPC) for each user
• Auth via Privy identity tokens (JWTs) on every request
• Privy user ID = our database user ID (1:1 mapping)

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Banking & Fiat Rails — Bridge

Bridge handles all fiat ↔ crypto movement with full KYC compliance.

Deposits (Fiat → Crypto)

• Bridge creates a real bank account (account number + routing number) per user
• Incoming deposits auto-convert to USDC (ACH/Wire) or EURC (SEPA) on Solana
• Funds land directly in the user's embedded wallet
• Fee: 0.3% on deposits

Withdrawals (Crypto → Fiat)

• Users link their bank account (US ACH or EUR IBAN)
• Bridge generates a liquidation address — send USDC/EURC to it and funds auto-convert to fiat
• USD via ach_same_day, EUR via sepa
• Fee: 0.6% on withdrawals (~0.5% Bridge + ~0.1% platform)

KYC

• Required before any banking features
• Bridge handles the full identity verification (individual or business)

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Token Swaps & Market Data — Jupiter

Swaps (Jupiter Ultra API)

• Supports all routers: Iris (AMM), JupiterZ, DFlow, OKX DEX
• Privy EOA wallets support all routers including market maker co-signatures
• Flow: backend builds unsigned tx → client signs with Privy wallet → submit via Jupiter or directly to Solana
• Referral fee: 1% (100 bps) on swaps involving SOL, USDC, or USDT

Market Data (Jupiter Tokens API)

• Holdings — all token balances for a wallet
• Token search — by name, symbol, or address
• Trending tokens — by interval (5m, 1h, 6h, 24h)
• Token details — price, FDV, mcap, liquidity, volume, holder count, social links, security audit
• Shield — token safety warnings (mint authority, freeze authority, suspicious activity, etc.)

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Invoicing

Full invoicing engine for freelancers and businesses.

• Currencies: USDC or EURC
• Lifecycle: Draft → Sent → Viewed → Paid / Cancelled
• Line items, tax calculation, configurable payment terms
• Email delivery with PDF attachment
• Public payment page — anyone with the link can pay (no account needed)
• Paymaster-sponsored fees — Soljar pays Solana tx fees so the payer doesn't need SOL
• Payment validation via HMAC to prevent tampering
• Can also mark invoices as paid from bank deposits (Bridge integration)
• Business profiles, client management, invoice duplication

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Other Services

Service	Provider	Purpose
Transactions	Helius	On-chain tx history with balance change detection
Charts	Solana Tracker	OHLCV chart data for any token
Send	Solana RPC (Helius)	Direct wallet-to-wallet SOL/SPL transfers

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Revenue Model

Stream	Rate	How
Fiat deposits	0.3%	Bridge virtual account developer fee
Fiat withdrawals	0.6%	Bridge liquidation address developer fee
Token swaps	1%	Jupiter referral fee on SOL/USDC/USDT pairs
Invoice payments	Free	Soljar sponsors tx fees (~0.000005 SOL each)

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Tech Stack

Layer	Tech
Backend	Hono
Database	Drizzle ORM + PostgreSQL
Deployment	SST on AWS
Runtime	Bun
Blockchain	Solana mainnet
RPC	Helius

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External Dependencies

Service	What it does
Privy	Auth + embedded wallets
Bridge	KYC, fiat deposits, fiat withdrawals
Jupiter	Swaps, token data, holdings, safety
Helius	Solana RPC + transaction history
Solana Tracker	Chart data
AWS Lambda	Invoice PDF generation