Prerequisites

• A Solana wallet — Phantom, Backpack, or Solflare all work.
• Switch the wallet to devnet (Phantom: Settings → Developer Settings → Change network).
• Some devnet SOL: airdrop from faucet.solana.com (~0.1 SOL is plenty).

1. Sign in

Go to usefillr.app/app. Pick a sign-in method — connect Phantom, or use email/Google/Twitter to get a Privy-managed embedded wallet.

2. Create a commitment

Click New in the nav, fill in:

• Target mint: the future-token mint address. For testing, use devnet USDC 4zMMC9srt5Ri5X14GAgXhaHii3GnPAEERYPJgZJDncDU.
• Payment mint: wSOL on devnet. The form auto-wraps SOL → wSOL inline.
• Payment amount: 0.01 SOL is enough for a smoke test.
• Max price per token: your ceiling, in payment-per-target. The fill will revert if Jupiter can't hit it.
• Min fill: minimum target tokens you'll accept.
• Trigger: choose Jupiter routable for “fill as soon as possible”, Time only for a strict timestamp, or Routable after for both conditions ANDed.
• Keeper bounty: the SOL the keeper earns on successful execution. 0.001 SOL is a fine default.
• Expiry: how long the commitment stays live. 7 days default; max 30.

Hit Create commitment. Your wallet pops a signature request. The transaction prepends 3 instructions to auto-wrap SOL→wSOL when needed, then calls fillr's create_commitment. Funds escrow to a fresh per-order PDA; you get a Solscan link in the success toast.

3. Watch the dashboard

Your active commitments appear at /app. Click into one to see the full state: status, trigger, max price, min fill, keeper bounty, expiry. On mainnet, a keeper will pick this up automatically when the swap becomes feasible.

4. Cancel or wait

You can cancel anytime before fill. The cancel button is on the detail page. Cancelling closes the commitment PDA, refunds the escrowed amount, and returns the rent.

That's the full user-facing surface. From here, read Commitments for the lifecycle state machine, or Architecture if you want to know what the program does under the hood.