CHAINS

Solana

Solana has the highest stablecoin throughput outside of EVM, the USDC float alone is in the billions and individual transactions clear in under a second for fractions of a cent. Tab supports it in v1 via a direct-pay flow that doesn't require an on-chain Tab program.

How the v1 Solana flow works

Note: the direct-pay flow described below is still live for the public checkout / pay-page surfaces, but Solana Smart Pay (further down) is now the default in-app path for tipping, subscriptions, and Smart Pay routing.

Every Tab user gets a Solana address derived from the same private key as their EVM address (Ed25519 instead of secp256k1). When a buyer pays, their Solana wallet (Phantom, Solflare, Backpack) signs one transactionthat contains two SPL transfers: 99% of the amount goes to the merchant's USDC ATA and 1% goes to the platform treasury's ATA. Solana's atomic-transaction guarantee means both transfers settle or neither does, the transaction itself replaces a router contract.

What this means for buyers

• Gas: ~$0.0001 in SOL, paid by the buyer. Cheaper than any EVM L2, effectively invisible.
• USDC mint: EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v (6 decimals).
• Wallets: Any wallet that exposes the Solana Wallet Standard works. Phantom, Solflare, Backpack.
• ATAs:If the merchant or treasury hasn't received USDC before, the buyer's transaction idempotently creates their token account in the same tx. Adds ~0.002 SOL of rent but no extra clicks.

What this means for merchants

• Signup: Identical. You pick a handle on the standard signup flow, and your Solana address auto-generates from your wallet seed alongside your EVM address.
• Payment links:When creating a link from the dashboard, choose “Solana” from the chain selector. Your settlement currency is USDC on Solana.
• Webhooks: Same shape as EVM, the order.completedevent fires when our cron picks up the Transfer on the treasury's ATA, and the order's txHash is the Solana signature (verifiable on Solscan).

Live deployed addresses

• Program ID: DvS3eW3GJGVJrvqMBtcsS8QtNoxzYtpB61Cx19Uz86xs (view on Solscan)
• Config PDA: DeGTa8K1Q1pGQTaknLaRNXR4WG1d11Ff3crV6ypEs6rL
• Fee recipient (treasury): 552531jSitQndRiiQK89ZshxvvRbEzSekQoniWpjSBr (view on Solscan)
• USDC mint: EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v
• Protocol fee: 100 bps (1%)

Solana Smart Pay (live)

Tab now has full Smart Pay parity on Solana through the Solana Foundation's audited Subscriptions Delegation Program (De1egAFMkMWZSN5rYXRj9CAdheBamobVNubTsi9avR44). A user signs onedelegation tx that lets Tab's executor pull USDC and wSOL up to a per-day cap; after that, outgoing payments are fully gasless from the user's perspective. Same UX as the 7702 flow on EVM, no second signature per spend.

Native SOL is held as wSOL inside the user's wallet so the program (which can only spend SPL tokens) can move it. Phantom, Solflare and Backpack auto-sum wSOL with native SOL in the UI, so the user just sees one “SOL” balance. Tab handles wrap/unwrap inside the spend tx.

When the user's Solana wallet has no SOL to cover the onboarding tx fees, Tab's /api/solana/top-upbridges native SOL from the user's EVM USDC balance via relay.link. The user signs once, Tab funds the Solana side automatically.

After enabling, users can top up the wSOL inside their delegation via the "Wrap balance" card on the panel — it calls POST /api/solana/wrap (kind: wrap | unwrap) which builds a relayer-paid wrap or full unwrap (close + recreate ATA so the recurring delegation keeps targeting a valid account). Both are gasless from the user's perspective.

A health probe at GET /api/diag/solana-subs reads both subscription programs and confirms their config PDAs are initialised. The dashboard subscription plan form auto-disables the Solana option in the chain dropdown when the probe reports unhealthy, so users never get stuck on a known-broken option.

Solana Subscriptions (live)

Recurring stablecoin payments work on Solana through a dedicated Tab Subscriptions Program with a zero-fee Personal tier (DpQSpSdnwRB1p7iK1b5TbL1F5YqtimGd9g32jWc4WyB7) and a 1%-fee Business tier (Ex1hBmDhmz8hZ7oYy4BKtt5jstEMCoeeshEA51swbXZa). Plans you create on the dashboard work identically to the EVM version, recurring charges are submitted by Tab's fee-payer relay so subscribers never need SOL for renewals.