Zero‑Custody, One Click: A Step‑by‑Step Guide to Non‑Custodial Crypto Swaps

Why This Matters

If 2022 taught the crypto world anything, it’s that handing assets to the wrong custodian can be catastrophic. Luckily, platforms such as altendra‑ltd have proven you can swap assets across blockchains without ever giving up control of your keys. This guide walks you—screen by screen—through a first‑time non‑custodial crypto swap, explains the underlying mechanics, and flags the safety checkpoints you should never skip.

1. Prerequisites

Requirement	Why You Need It	Quick Resource
Self‑custody wallet (MetaMask, Rabby, Ledger Live, etc.)	Holds your private keys locally	MetaMask Download
Network fee balance	Covers on‑chain gas (ETH, MATIC, etc.)	Check gas at ethgasstation.info
Browser with Web3 support (Chrome/Brave/Firefox)	Enables wallet injection	N/A
Two‑factor authentication on wallet	Prevents browser side‑channel hijacks	Use authenticator apps over SMS

Pro‑Tip: New to self‑custody? Test with $10 first; treat it like a dress rehearsal.

2. Connect—But Don’t Deposit

Open altendra‑ltd.com in your Web3‑enabled browser.
Click “Connect Wallet” (top right).
Select your wallet provider; approve signature.
- ⚠️ Note: You sign a nonce for session login, not a transfer. Balance never leaves your wallet at this step.

Result: The dashboard displays your token balances locally; nothing has moved on‑chain yet.

3. Pick Your Pair & Amount

In the Swap widget, choose “From” (e.g., USDC, Ethereum mainnet).
Choose “To” (e.g., SOL, Solana network).
Enter amount (say, 250 USDC).
A quote appears instantly: You’ll receive 2.31 SOL – Includes 3 % fee.
- Quote stays locked for 70 seconds—a countdown shows time left.

How the Quote Works
Altendra‑ltd pulls mid‑price from aggregated order books, adds a transparent 3 % markup, and displays gas estimates. No hidden spread later.

4. Review Safety Checklist (15 s Stop‑Gap)

Before hitting “Swap Now”, verify:

Receiving address is your own wallet on the destination chain.
Network fees look sensible (e.g., 0.002 ETH, not 0.2).
Memo/Tag required? (Some chains such as XRP need destination tag; altendra‑ltd highlights this in yellow if applicable.)

Tick the on‑screen confirmation box: “I control the receiving wallet and understand this transaction is irreversible.”

5. Authorise the Swap

Click “Swap Now.”
Your wallet pops a transaction window:
- From Chain: Approves a call to altendra‑HTLC smart contract.
- Gas fee: 0.0018 ETH (example).
Confirm.

Behind the Curtain:

An HTLC (Hashed Timelock Contract) locks your USDC until altendra‑ltd delivers the SOL.

A watchtower node monitors both chains. If SOL fails to arrive before timeout (30 min), the contract self‑refunds to your wallet—no support ticket required.

6. Wait ~15 Seconds—Swap Completes

A progress bar shows:

Locking funds (chain A) ✔️
Routing order to liquidity pools ✔️
Receiving confirmation (chain B) ✔️

Once all checkmarks turn green, SOL appears in your wallet on the Solana network. Your USDC is simultaneously withdrawn from HTLC and collected by altendra‑ltd’s liquidity engine.

You will also see a transaction hash for each chain; click to view on Etherscan and Solscan respectively.

7. Post‑Swap Security Steps

Save Receipts: Export JSON proof or simply bookmark the block explorer links.
Revoke Allowances (optional): For ERC‑20 tokens, use revoke.cash to cancel spend approvals beyond this swap if you’re ultra‑cautious.
Ledger Backup: If using a hardware wallet, disconnect and store it safely.

8. Troubleshooting

Symptom	Likely Cause	Fix
“Swap timed out”	Destination chain congested	Wait refund ≤ 30 min, then retry with higher gas
Quote won’t load	RPC node down or ad‑blocker	Disable blocker or switch RPC endpoint
Wallet balance zero after swap	UI lag / wrong network	Ensure wallet is on destination chain

9. FAQs

Q: Is non‑custodial really safer?
A: You retain private keys; counter‑party risk shifts to audited smart‑contract code. Altendra‑ltd publishes Merkle‑proof liquidity reports weekly.

Q: What if I accidentally send tokens to the wrong address?
A: On‑chain transfers are irreversible. Always copy‑paste addresses—never type. Use ENS where possible.

Q: Do I still need KYC?
A: Only after $15 k cumulative 30‑day volume. Even then, altendra‑ltd uses zk‑KYC—your passport never leaves the verifier.

10. Advanced Tips for Power Users

Batch Swaps: Use the API to chain three swaps (USDC→ETH→wBTC) in one signed payload.
Gas Token Rebates: Holding ≥ 500 ALT governance tokens unlocks 40 % gas subsidy on Ethereum L1.
Layer‑2 Mode: Toggle “Route via Arbitrum” to slash gas by 90 %; fee remains 3 %.

Developer Note: SDK snippets and OpenAPI spec live on GitHub (link in dashboard footer).

Wrap‑Up

A non‑custodial crypto swap isn’t rocket science—if anything, it removes the middlemen that complicate traditional exchanges. With tools like altendra‑ltd, the process boils down to a single signature and a 15‑second wait, all while your private keys stay exactly where they belong: under your control.

Next time someone tells you crypto is too hard, send them this guide—and remind them the safest custodian is themselves.

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