test-alchemy.feerelayer.net
This relay pays the Solana network fee for your USDC transfer and charges 1% of the amount, minimum 0.002 USDC, inside the same transaction. Get a stuck transaction sponsored below, no API key, no account, and no code needed.
1. Paste a transaction
A base64 transaction you have already signed, with this relay set as the fee payer. Check it before you relay it.
Checking spends nothing and signs nothing. Relaying is final.
2. Or connect a wallet
Sign in your browser instead of pasting base64. The relay builds the transaction, your wallet signs it, and only then does the relay co-sign and send it.
Both addresses need an existing USDC account on Solana.
3. What it costs
This relay charges 1% with a minimum of 0.002 USDC. Worked out below as you type, in your browser, exactly the way the relay works it out.
| Total fee | 0.000000 |
|---|---|
| Relay (30%, floor 0.01 USDC) | 0.000000 |
| Operator (70%) | 0.000000 |
| Leaves your wallet | 0.000000 |
Amounts in USDC. A share shown as zero means that recipient gets nothing at this amount and no transfer is made to them.
4. Endpoints
Everything above is also available over HTTP. No API key, no account, no registration: the fee inside the transaction is what pays for the service, so there is nothing to sign up for.
| Endpoint | What it does |
|---|---|
GET https://test-alchemy.feerelayer.net/info | The policy of this relay, machine readable: the co-signer wallet to put at account slot 0, the fee rate, the minimum, and the declared fee recipients. Read it before you build, never hardcode a fee. |
POST https://test-alchemy.feerelayer.net/simulate | A dry run. Same body as /relay, same validator, same refusal messages, but it signs nothing and sends nothing. Use it while you are getting the shape right. |
POST https://test-alchemy.feerelayer.net/relay | The real thing: the relay co-signs your transaction and broadcasts it. Returns the signature. Final. |
POST https://test-alchemy.feerelayer.net/build | Hands back an unsigned transfer so a wallet can sign it. Convenience only: whatever it returns is re-validated from scratch when it comes back to /relay. |
GET https://feerelayer.net/relays.json | Every relay on this service, machine readable, if you would rather not hardcode this one. |
Start here, it costs nothing and tells you what this relay expects:
curl -s https://test-alchemy.feerelayer.net/infoThe full contract, every error string with its meaning, and worked examples for each endpoint: feerelayer.net/docs. The same as JSON: openapi.json. Whether this relay is answering right now: feerelayer.net/status.
This relay never holds your funds. It adds a fee-payer signature so the Solana network fee is covered, and takes its USDC fee inside the transaction you signed. You choose the recipient and the amount; the relay cannot change either.