DEV Community: Daniel Carter

Taking USDT Payments with Taccoin: Payment Requests, Watch-Only Wallets and Receipts

Daniel Carter — Wed, 07 Oct 2026 09:18:52 +0000

By Daniel Carter

Disclosure: this article is sponsored by Taccoin and describes features that exist in the app today. Educational content, not financial advice. Written with the help of AI tools.

A small shop or freelancer taking USDT runs into the same three problems again and again: the customer asks which network to use, the amount arrives short, and the accountant wants to see payments without getting access to the money. Three features in Taccoin Wallet cover all three.

1. Payment requests: say exactly what you expect

A bare address does not tell the customer how much to pay, on which network, or for what. A payment request is a link and QR code that bundles:

The network: TRON (TRC-20), Ethereum (ERC-20) or BNB Chain (BEP-20).
The exact amount in USDT.
A title and optional note, for example "Invoice 21, logo design".
Your receiving address on that network.

The customer opens the link and sees the amount, network, token standard, note and address. If they use Taccoin, "Continue to pay" opens the send screen with everything pre-filled, and they confirm with their PIN. If the request has already been paid, they see a message with the transaction ID, so nobody pays twice by mistake.

Because a payment request asks for money and carries no secrets, you can share it in any chat.

2. Watch-only: let the accountant see, not spend

Add your shop's public address to another phone as a watch-only wallet. The person can see the balance and history but cannot send or swap; the app shows a clear banner saying so. Supported addresses: TRON (starting with T), Bitcoin, and EVM addresses starting with 0x.

Good uses:

Accountant: follows incoming payments with no control over funds.
Partner: sees the balance transparently.
You: track a cold wallet from your everyday phone without copying its phrase there.

3. Receipts: close the loop

When a payment lands, open the transaction details. You get a "Confirmed" badge, a link to the block explorer, and a Download receipt button. Attach the receipt to the invoice. You can also label the customer's address so you recognise it next time.

A simple setup for a small business

Keep a separate receiving wallet for the shop, apart from your personal funds.
Agree on the network with each customer, then send a payment request on that network.
Put the invoice number in the note so payments are easy to match.
Give your accountant the public address only, added as watch-only.
Don't deliver final work until you see the payment confirmed.

Learn more: wallet.taccoin.com

Taccoin Send-by-Link Q&A: How to Send USDT to Someone Without a Wallet

Daniel Carter — Tue, 06 Oct 2026 11:47:17 +0000

By Daniel Carter

Taccoin's "Send by link" feature lets you send USDT to someone by sharing a link, even if they don't have a wallet set up yet. It raises a lot of questions, so here they are, answered from how the feature actually works.

Q1: What is Taccoin's "Send by link"?

A: You choose an amount of USDT, the app creates a one-time link, and you share it by WhatsApp, Telegram or any messenger. Whoever opens the link can claim the USDT. It's meant for paying someone who doesn't have a crypto address ready, or doesn't know which network to pick.

Q2: Which networks does it support?

A: USDT on TRON (TRC-20) and on BNB Smart Chain (BEP-20). You pick the network with a tab at the top of the screen.

Q3: Who pays the fees, the sender or the receiver?

A: The sender. Before you create the link, Taccoin shows a breakdown: the amount they receive, the energy reserve (on TRON), the network reserve in TRX or BNB, any service fee, and the total taken from your wallet. The receiver gets the full amount shown on the link.

Q4: Are there limits on the amount?

A: Yes. The app shows the minimum and maximum for the selected network on the quote card before you create the link.

Q5: Does the receiver need to install Taccoin?

A: No. The link opens a claim page in the browser where they can paste an address on the right network and claim to it. If they do have Taccoin, the link opens in the app, where they can claim straight into their wallet or to another address.

Q6: Is the link itself safe to send?

A: Treat it like cash: whoever has the full link can claim the funds. The secret part of the link sits after the "#", which browsers don't send to the server. For extra protection, turn on the optional security code: the receiver must enter it before claiming, and you send the code separately, for example by a phone call or a different app.

Q7: Can I add a message?

A: Yes, there's an optional message field. The receiver sees it on the claim screen.

Q8: What if nobody claims the link?

A: Links expire after 7 days. You can track each one under "My transfers", where it shows a status such as "Ready to claim", "Claimed" or "Refunded". If a link hasn't been claimed, or it has expired, you can tap Refund to get the USDT back into your wallet.

Q9: Can the receiver cash out instead of keeping USDT?

A: For TRON links claimed in the Taccoin app, there's a "Cash out" option. The receiver enters their country code and phone number, and the USDT goes to Taccoin's local payments desk, which pays out in local currency. It only works in countries where the desk is currently buying USDT; otherwise the app says the country isn't available.

Q10: When should I not use a link?

A: When the receiver already has a wallet address on the right network, a normal send is simpler. Links shine when the other person is new to crypto, or when you don't want to risk them giving you the wrong network.

Learn more: wallet.taccoin.com

Disclosure: This article is sponsored by Taccoin and describes features that exist in the app today. Educational content, not financial advice. Written with AI tools.

Taccoin Security Q&A: Backups, PIN, Biometrics and What to Do If You Lose Your Phone

Daniel Carter — Tue, 06 Oct 2026 11:39:40 +0000

By Daniel Carter

Self-custody means you are the security team. These are the security questions people ask me most about the Taccoin wallet, with straight answers about what the app protects and what stays your responsibility.

Q1: Where are my keys stored when I use Taccoin?

A: On your phone, encrypted. Taccoin is a self-custody wallet: the 12-word recovery phrase and the keys derived from it never live on a company server. The upside is that nobody can freeze or lose your funds for you. The downside is that nobody can recover them for you either.

Q2: How is the app itself locked?

A: With a PIN, which is also required to confirm a transaction. If your phone supports it, you can turn on biometric unlock in settings and use your fingerprint or face instead of typing the PIN to open the app.

Q3: Can malware or a nosy app screenshot my recovery phrase?

A: Screenshots and screen recording are blocked on Taccoin's backup screen, and on the PIN and send screens too. That stops the most common accidental leak: a screenshot of the phrase that quietly syncs to a cloud photo library.

Q4: What backup options does Taccoin give me?

A: Two, and you can use both:

Write the 12 words down. The backup screen asks for your PIN before showing them.
Save an encrypted backup file, protected with your PIN, to Google Drive, Files or any folder you choose.

The screen tracks your progress ("1 of 2 completed") and recommends keeping the phrase in two separate places, for example paper at home and the encrypted file in your own cloud storage.

Q5: How do I know I wrote the phrase down correctly?

A: When you create a new wallet, Taccoin runs a short quiz asking for specific words from your phrase. A wrong answer restarts it. It takes thirty seconds and catches a mistake while you can still fix it.

Q6: I lost my phone. How do I get my Taccoin wallet back?

A: Install Taccoin on the new phone and restore the wallet, either by entering your 12-word phrase or by importing your backup file. If the file is encrypted, you'll need the PIN you used to protect it. Without the phrase or a usable backup file, the wallet can't be recovered by anyone.

Q7: What if someone messages me as "Taccoin support" and asks for my phrase?

A: It's a scam. Restoring, verifying a payment or "unlocking" an account never requires your recovery phrase. Anyone who asks for it, by chat, email or a "connect your wallet" page, is trying to empty your wallet.

Q8: How do I avoid address-poisoning scams?

A: Attackers send tiny transfers from addresses that look like ones you've used, hoping you'll copy the wrong one from your history. Taccoin lets you save recipients as named contacts and shows the contact's name next to the address in the confirm dialog. Send from your saved contacts instead of copying from transaction history. The app doesn't flag look-alike addresses on its own, so that habit matters.

Q9: Can I keep an eye on cold storage without putting its keys on my phone?

A: Yes. Add the cold-storage address as watch-only. Taccoin shows its balance and history, but there's nothing on the phone that could sign a transaction from it.

Q10: What's the one habit that matters most?

A: Two backups in two places, checked once. Everything else in this list helps, but a correct, offline copy of your phrase is what decides whether a lost phone is an inconvenience or a total loss.

Learn more: wallet.taccoin.com

Disclosure: This article is sponsored by Taccoin and describes features that exist in the app today. Educational content, not financial advice. Written with AI tools.

Taccoin USDT Q&A: TRC-20 vs BEP-20, Fees, and Sending Without TRX

Daniel Carter — Tue, 06 Oct 2026 11:37:27 +0000

By Daniel Carter

Most questions I get about the Taccoin wallet are really about USDT: which network to use, why fees change, and what happens when something is sent on the "wrong" chain. Here are the answers in one place.

Q1: Which USDT networks can I use in Taccoin?

A: USDT on TRON (TRC-20), BNB Smart Chain (BEP-20) and the other EVM networks the wallet supports, such as Ethereum, Polygon, Arbitrum, Optimism, Base and Avalanche. Each network shows its standard label (TRC-20, BEP-20, ERC-20 and so on) so you can tell them apart.

Q2: Is USDT on TRC-20 the same as USDT on BEP-20?

A: Same dollar value, different blockchains. They are separate tokens on separate networks, and a transfer only arrives if the sender and receiver use the same network. That's why Taccoin's receive screen makes you pick the network first and shows a banner like "Send USDT only via the TRON network" right above the QR code.

Q3: What do I need to pay fees on each network?

A: On EVM networks such as BNB Smart Chain, gas is paid in the network's native coin (BNB on BSC, ETH on Ethereum). Before you confirm, Taccoin checks that you have enough of it to cover gas. On TRON, fees are paid in TRX, or in USDT, as explained below.

Q4: I have USDT on TRON but zero TRX. Am I stuck?

A: No. For USDT on TRON, Taccoin lets you choose to pay the fee in TRX or in USDT. If you pick USDT, the app rents TRON Energy for the transfer and shows that cost in USDT before you confirm. It takes two signatures: one for the energy fee and one for the transfer.

Q5: Why does the same USDT transfer on TRON sometimes cost more?

A: TRON charges in "Energy", and sending USDT to an address that has never held USDT needs roughly twice the energy of sending to one that already holds it. So the same amount can cost noticeably more depending on the recipient. Taccoin calculates the estimate live and shows it on the send screen, in the summary and in the confirm dialog, and the confirm button stays disabled until an estimate exists.

Q6: Can I accidentally send USDT from TRON to a 0x address?

A: The send screen validates the address for the network you picked. A TRON send needs a T... address that passes a full checksum check; an EVM send needs 0x plus 40 hex characters. A mismatched address is rejected before you can continue.

Q7: Someone sent USDT on BEP-20 to my 0x address, but I expected Ethereum. Is it lost?

A: Usually not, if it's an EVM network Taccoin supports. All EVM networks share the same 0x address in your wallet, so the funds are on BNB Smart Chain under your address; switch to that network to see them. You'll need a little BNB for gas to move them. To avoid the confusion, share your address with the Share button, which includes the network name.

Q8: How do I ask for an exact USDT amount?

A: Use "Create payment request". It builds a link and QR code containing the amount, the network and an optional note, so the payer doesn't have to type anything.

Q9: Can I swap tokens inside Taccoin?

A: Yes, on the same EVM network only. There are no cross-chain swaps, so you can't, for example, convert TRC-20 USDT into BEP-20 USDT inside the app.

Q10: Which network should I pick for everyday transfers?

A: Ask the person you're paying which network their wallet or exchange expects, then use that one. For larger amounts, send a small test first. The cheapest network is useless if the receiver is watching a different one.

Learn more: wallet.taccoin.com

Disclosure: This article is sponsored by Taccoin and describes features that exist in the app today. Educational content, not financial advice. Written with AI tools.

Taccoin Wallet Q&A: 12 Questions People Ask Before Using It, Answered Honestly

Daniel Carter — Tue, 06 Oct 2026 11:29:59 +0000

By Daniel Carter

I've been using the Taccoin wallet on Android for a while, and friends keep asking me the same questions about it. Instead of answering them one by one in chat, here they are in one place, with honest answers, including the things Taccoin doesn't do.

Q1: What is Taccoin, in one sentence?

A: Taccoin is a self-custody mobile wallet: your keys are generated and stored encrypted on your phone, and you hold USDT and other coins on several networks from one 12-word recovery phrase.

Q2: Which networks does Taccoin support?

A: TRON, Bitcoin, and the EVM networks Ethereum, BNB Smart Chain, Polygon, Arbitrum, Optimism, Base and Avalanche. The EVM networks share one 0x address, TRON uses a T... address and Bitcoin uses a native SegWit bc1q... address, all derived from the same phrase.

Q3: Does Taccoin hold my funds or my recovery phrase?

A: No. The phrase and keys stay encrypted on your device. That also means there is no "forgot password" button: if you lose the phone and have no backup, nobody can restore the wallet for you.

Q4: How do I back up my Taccoin wallet?

A: The backup screen asks for your PIN first, then offers two options. You can write the 12 words down (screenshots and screen recording are blocked on that screen), or save a PIN-encrypted backup file to Drive, Files or any folder. The app tracks your progress ("1 of 2 completed") and recommends keeping the phrase in two separate places. When you create a new wallet, a short three-word quiz confirms you wrote it down correctly.

Q5: I only have USDT on TRON and no TRX. Can I still send it?

A: Yes. For USDT on TRON, Taccoin lets you choose whether to pay the fee in TRX or in USDT. If you pick USDT, the app rents TRON Energy for the transfer and shows that cost in USDT before you confirm. It takes two signatures: one for the energy fee and one for the transfer itself.

Q6: How does Taccoin help me avoid sending to the wrong address?

A: It validates the address format per network: 0x plus 40 hex characters on EVM chains, a full checksum check on TRON addresses, and valid mainnet addresses on Bitcoin. You can paste, scan a QR code or pick a saved recipient. The confirm dialog shows the contact's name next to a saved address and asks for your PIN. What it can't do is spot a look-alike address, so compare the full address or send from your saved contacts.

Q7: What do I share when someone wants to pay me?

A: On the receive screen, you pick the network first, and a banner reminds the sender which network to use. The Share button sends the asset, network and address together. If you need a specific amount, "Create payment request" builds a link and QR code with the amount, network and an optional note.

Q8: How do I know a payment actually arrived?

A: You get an incoming-transfer alert, and the transaction details screen shows a "Confirmed" badge, the amount, network, fee and transaction ID. It also has "View in explorer" (Tronscan, Etherscan, BscScan and others) and "Download receipt", which saves an image you can keep for your records.

Q9: Can I track a wallet without importing its keys?

A: Yes, with watch-only addresses. Add any TRON, Bitcoin or EVM public address, give it a name, and Taccoin shows its balance and history. You can't send from it, which is the point: there's nothing on the phone that could sign a transaction.

Q10: Is there a swap feature in Taccoin?

A: Yes, but it's limited to same-chain swaps on EVM networks. There are no cross-chain swaps and no BTC swaps inside the app.

Q11: What are the honest limitations?

No manual fee-rate control for Bitcoin; the app picks a rate targeting roughly 30-minute confirmation.
No coin control for BTC.
Swaps are same-chain EVM only.
The app doesn't flag look-alike addresses.
It's a mobile app; if you want a hardware wallet setup, use one alongside it.

Q12: Who is Taccoin a good fit for?

A: Someone who mainly holds USDT on TRON or BNB Smart Chain, wants a simple self-custody wallet with clear network warnings, and also wants to receive and send some BTC or ETH from the same recovery phrase. If you need advanced Bitcoin features, a dedicated Bitcoin wallet is the better tool.

Got a question I didn't cover? Ask it in the comments and I'll answer from my own use of the app.

Learn more: wallet.taccoin.com

Disclosure: This article is sponsored by Taccoin and describes features that exist in the app today. Educational content, not financial advice. Written with AI tools.

Bitcoin in a Multi-Chain Wallet: Native SegWit, Automatic Fees and Honest Limits

Daniel Carter — Tue, 06 Oct 2026 09:10:13 +0000

By Daniel Carter

Many "multi-chain" mobile wallets treat Bitcoin as an afterthought. Here's a plain look at how the Taccoin wallet handles BTC: what address type it uses, how fees are picked, and what it deliberately doesn't do.

One phrase, a native SegWit address

Your Bitcoin address is derived from the same 12-word recovery phrase that backs your TRON and EVM addresses. It's a native SegWit address (starting with bc1q), which generally means smaller transactions and lower fees than legacy formats.

Sending to any address type

You can send to legacy addresses (1...), P2SH addresses (3...) and bc1 addresses. The send screen validates that the recipient is a valid mainnet address before you can continue.

How the fee is chosen

The app reads mempool.space's recommended fee rate and targets confirmation in roughly 30 minutes. There's no slow/normal/fast picker; instead the estimated fee is shown before you confirm, and the confirm button stays disabled until an estimate is available. For most everyday transfers this removes a decision beginners often get wrong.

Balances and history

Balances and transaction history come from mempool.space. You can also add any Bitcoin address as watch-only to track it without importing keys.

What it doesn't do

No BTC swaps inside the app (swaps are same-chain EVM only).
No Bitcoin-based tokens.
No manual fee-rate control.

Who it suits

Someone who mostly holds USDT on TRON or BSC but also wants a straightforward place to receive and send some BTC, backed by the same recovery phrase. If you need coin control or custom fee rates, a dedicated Bitcoin wallet is the better tool.

Learn more: wallet.taccoin.com

Disclosure: This article is sponsored by Taccoin and describes features that exist in the app today. Educational content, not financial advice.

Watch-Only Addresses: Track Any Crypto Wallet Without Its Private Keys

Daniel Carter — Tue, 06 Oct 2026 08:34:21 +0000

By Daniel Carter

A watch-only address is one of the most underrated wallet features. You add a public address, and the wallet shows its balance and activity without ever holding the private key. Here's how it works in Taccoin and a few practical ways I use the idea.

What "watch-only" means technically

Blockchains are public. Anyone can read the balance of any address; only the private key can move funds. A watch-only entry stores just the public address, so the wallet can query balances and history but has nothing that could sign a transaction. If your phone is compromised, a watch-only entry gives an attacker nothing to spend.

Supported address types

TRON addresses (starting with T), for example to watch USDT-TRC20.
Bitcoin addresses (bc1...).
EVM addresses (0x...), which covers Ethereum, BSC, Polygon, Arbitrum, Optimism, Base and Avalanche.

You can give each one an optional name, such as "Cold storage" or "Shop wallet".

Practical uses

Monitor cold storage from your phone without importing its keys anywhere.
Track a business wallet that a partner or employee operates.
Keep an eye on a family member's wallet (with their consent) to help them spot unexpected activity.
Check a payment destination before and after sending, for example a supplier's address.

Adding one

Open the wallet list and choose to add a watch address.
Pick the network type (TRON, Bitcoin or EVM).
Paste the public address and optionally name it.
Save. You can now check its balance and history; if you try to send from it, the app tells you it's watch-only.

Things to keep in mind

You can't send from a watch-only address. That's the point.
Never paste a recovery phrase or private key into a "watch" field anywhere. Watching only ever needs the public address.
Remember that addresses are public: watching someone's address doesn't require their permission technically, so respect privacy.

Learn more: wallet.taccoin.com

Disclosure: This article is sponsored by Taccoin and describes a feature that exists in the app today. Educational content, not financial advice.

Getting Paid in USDT as a Freelance Developer in Türkiye: Networks, Fees and Cashing Out

Daniel Carter — Sun, 04 Oct 2026 16:09:47 +0000

A lot of developers in Türkiye work for clients in Europe, the Gulf or the US. Payment is where things get messy: international bank transfers take days, platforms take a cut, and by the time the money lands, the exchange rate has moved. More and more freelancers now ask to be paid in USDT.

This post is the practical guide I wish I had: how to pick a network, what it really costs, how to avoid the classic mistakes, and how to get from USDT back to lira.

1. Pick the network before you share an address

"Send me USDT" is not enough information. USDT exists on many chains, and they are not interchangeable:

Network	Address looks like	Typical fee to send	Notes
TRON (TRC20)	starts with `T`	0 to a few TRX, depends on energy	Most common for P2P in the region
BNB Chain (BEP20)	starts with `0x`	usually cents, paid in BNB	Same address as your other EVM chains
Ethereum (ERC20)	starts with `0x`	can be several dollars	Rarely worth it for invoices

Put the network in your invoice, in bold, next to the address. Something like: USDT on TRON (TRC20) only.

2. Understand what the fee actually is

On BNB Chain you pay gas in BNB. On TRON, a USDT transfer consumes energy; if you have none, the network burns TRX instead, which is why the "same" transfer can cost almost nothing or several TRX. If you send USDT often, use a wallet that can rent energy for the transfer instead of burning TRX.

3. Keep custody of your earnings

If the client pays straight into an exchange account, your income is only as available as that exchange's rules in your country. I prefer a self-custody wallet: a recovery phrase I hold, keys encrypted on my phone, and a PIN plus biometrics on top. Exchanges are fine for trading; your invoice address should be yours.

4. Avoid the four classic mistakes

Wrong network. The client sends BEP20 to a TRC20 address (or the reverse). Always confirm the network in writing.
No gas. USDT arrives on BNB Chain but you hold no BNB, so you cannot move it. Keep a small amount of the native coin on every chain you use.
Address poisoning. Scammers send dust from look-alike addresses so you copy the wrong one from history. Copy from your own receive screen, every time.
Skipping the test. For a new client, ask for a small test payment first.

5. Cashing out to lira

This is the step that matters most for freelancers. Options are exchanges, P2P marketplaces, or a wallet with a built-in local payment desk. With a desk, your USDT never leaves your custody until you place a sell order: you pick your country, choose a method the operator has enabled, send USDT, and receive lira to your local account. Whichever route you use, compare the rate you get to the market rate and check the current tax rules for freelance income in Türkiye.

The wallet I use

I use Taccoin: self-custody, one recovery phrase for Bitcoin, Ethereum, BNB Chain, Polygon, Arbitrum, Optimism, Base, Avalanche and TRON, built-in TRON energy for cheaper USDT transfers, and a local payments section that now lists Türkiye and nine European countries alongside the Arab region. Methods and rates are enabled per country, so check in the app what is live for Türkiye.

Disclosure: I am connected to the Taccoin project. This post is educational and not financial or tax advice.

TRON energy explained: why the same USDT transfer costs 0 or several TRX

Daniel Carter — Sun, 04 Oct 2026 14:27:20 +0000

If you have ever built anything that moves USDT on TRON, you have hit this question from users: "Why did my transfer cost almost nothing yesterday and several TRX today?" The answer is TRON's resource model, and it is worth understanding before you design fees in a wallet or payment flow.

Bandwidth and energy

TRON does not charge "gas" the way Ethereum does. Every transaction consumes two resources:

Bandwidth covers the raw size of the transaction. Every account gets a small free daily allowance, which usually covers simple TRX transfers.
Energy covers smart contract execution. USDT on TRON is a TRC20 contract, so every USDT transfer burns energy.

If the sender has energy (from staking TRX or from renting it), the transfer consumes that energy. If not, the network burns TRX from the sender to pay for it. That is where the "several TRX" comes from.

Why the cost changes per recipient

A USDT transfer() writes to the contract's balance mapping. Writing to a storage slot that already holds a value is cheaper than creating a new one. In practice:

Sending to an address that already holds USDT costs roughly 65k energy.
Sending to an address that has never held USDT costs roughly double, because a new storage slot is created.

So the same amount, from the same sender, can cost very different TRX depending on who receives it. Exact numbers drift with network parameters, so always estimate at send time rather than hard-coding.

What this means for wallet UX

Show the fee before confirmation. Estimate energy for the actual recipient and convert to TRX at current prices.
Check the TRX balance first. A user with 100 USDT and 0 TRX cannot send USDT at all unless energy is provided another way. This is the single most common support ticket for TRC20 wallets.
Consider energy rental. Renting energy for a single transfer is often cheaper than burning TRX. If you integrate a rental provider, handle the case where the rental arrives late or partially.
Let the payer be explicit. In flows where someone else receives the funds (gifts, payouts, claimable links), decide upfront who covers energy.

A real example: claimable links

I worked on the fee logic for Taccoin Wallet's send-by-link feature, where a sender locks USDT into a link and the receiver claims it later, possibly into a brand-new address. Because the receiver may have zero TRX and an empty address (the expensive case above), the sender pays the fees upfront: on TRON that is a small TRX amount plus a USDT reserve for energy, quoted before the link is created. On BNB Smart Chain the equivalent is a small BNB gas reserve. The receiver gets the full amount and never needs to acquire TRX first.

The general lesson: on TRON, "who pays energy, and is the recipient address new?" should be a first-class question in your design, not an afterthought.

Quick checklist

Estimate energy per recipient, not per token.
Block or warn on sends when TRX is insufficient.
Prefer rented or staked energy over burning TRX for high-volume flows.
Make the fee payer explicit in any flow involving a third party.

Disclosure: I am connected to the Taccoin project. This post was generated with AI tools. Numbers are approximate; verify current TRON network parameters before relying on them.

Claimable crypto links: why the secret lives after the #

Daniel Carter — Sun, 04 Oct 2026 12:54:22 +0000

Sending crypto to someone who has never installed a wallet is a surprisingly hard UX problem. You need their address, they need to pick the right network, and on chains like TRON or BNB Chain they also need a little native coin (TRX or BNB) just to move the token later.

One pattern that solves this is the claimable link: the sender creates a URL, shares it in WhatsApp or email, and whoever opens it can claim the funds. Here is how that works at the protocol level, and why the secret part of the link sits after the #.

1. An ephemeral wallet per link

When the sender creates a link, the app generates a fresh random private key on the device (32 bytes from a CSPRNG). That key controls a brand-new, single-use address on the target chain.

The sender then funds that address with:

the transfer amount (for example USDT), and
a small fee reserve, so the claim transaction can pay its own gas.

On BNB Chain the reserve is a bit of BNB. On TRON it is a little TRX to activate the account plus enough to cover energy for the USDT transfer. The key point: the sender pays the fees up front, so the receiver gets the full amount and never needs to hold a native coin.

2. The key travels in the URL fragment

The link looks roughly like this:

https://example.com/r/<link-id>#k=<key-material>

Everything after # is the fragment. Browsers never send the fragment to the server in the HTTP request. That gives a nice property: the backend can store the link ID, the ephemeral address, the amount and the expiry, while never seeing the key that can spend the funds.

The claim page reads location.hash in JavaScript, entirely client-side.

3. Claiming = signing on the receiver's device

When the receiver opens the link and chooses where to receive (a new wallet created on the spot, or an address they already own):

The page or app reconstructs the ephemeral key from the fragment.
It builds a transfer from the ephemeral address to the receiver's address.
It signs locally and hands the signed transaction to the server.
The server verifies it matches the link (right amount, right destination rules, not expired, not already claimed) and broadcasts it.

The server is a relay and a bookkeeper, not a custodian.

4. An optional second factor

A link in a chat is a bearer token: whoever has it can claim. To reduce the risk of a forwarded or leaked link, the fragment can carry the key XOR-ed with a value that is only released after the receiver enters a short security code. The sender shares that code over a different channel (a call, SMS, another app).

5. Expiry and refunds

Unclaimed links should not lock funds forever. After an expiry window (for example 7 days), the sender can sweep the ephemeral address back to their own wallet. Since the sender's device also kept the key, this needs no cooperation from the server beyond broadcasting.

Threat model in one table

Risk	Mitigation
Server breach	Server never stores the spending key
Link forwarded to the wrong person	Optional security code on a second channel
Receiver has no gas	Fee reserve pre-funded by the sender
Link never opened	Expiry + sender refund
Link posted publicly	Nothing technical helps: treat it like cash

Real-world example

This is the design behind send-by-link in Taccoin Wallet, the wallet I work on: USDT on TRON and BNB Chain, sender-paid fees, key in the #k= fragment, optional code, 7-day expiry with refund. There is a short write-up here: wallet.taccoin.com/en/features/send-by-link.

If you have built something similar (or found holes in this model), I would like to hear about it in the comments.

Disclosure: I work on Taccoin Wallet. This post was generated with AI tools. It is educational and not financial advice.