Quickstart
Endpoints
Frankfurt, Germany: fra.nextblock.io
New York City, USA: ny.nextblock.io
Tip Wallets
Your TX must include a plain SOL Transfer IX to one of our tip wallets.
Tip Minimum: 0.001 SOL. Higher Tip = Higher Priority.
NextbLoCkVtMGcV47JzewQdvBpLqT9TxQFozQkN98pE
NexTbLoCkWykbLuB1NkjXgFWkX9oAtcoagQegygXXA2
NeXTBLoCKs9F1y5PJS9CKrFNNLU1keHW71rfh7KgA1X
NexTBLockJYZ7QD7p2byrUa6df8ndV2WSd8GkbWqfbb
neXtBLock1LeC67jYd1QdAa32kbVeubsfPNTJC1V5At
nEXTBLockYgngeRmRrjDV31mGSekVPqZoMGhQEZtPVG
NEXTbLoCkB51HpLBLojQfpyVAMorm3zzKg7w9NFdqid
nextBLoCkPMgmG8ZgJtABeScP35qLa2AMCNKntAP7Xc
gRPC
For those wishing to use gRPC, we have created sample docs. at our GitHub
Anti-MEV
To enable Anti-MEV, set frontRunningProtection: true in your request as shown:
curl -X 'POST'
'https://fra.nextblock.io/api/v2/submit'
-header "Authorization: $AUTH_HEADER"
-d '{ "transaction": {"content": "FtQ+KrJeNuiismV1Ke...DBABRQ=="}, "frontRunningProtection": true, }'
Priority Fees & Retries
If anti-MEV is enabled, priority fee does not matter, only the NextBlock Tip matters.
If anti-MEV is disabled, ensure you use a good priority fee to maintain a competitive position amongst others during block production. We recommend a minimum of 0.005 SOL priority fee for fast TXNs.
When sending without frontRunningProtection: true, your transaction is sent via all channels: our internal validator network, Jito Bundles, and as a normal transaction to upcoming leaders.
NextBlock's intelligent retry system actively tracks on-chain activity levels and adjusts dynamically to send transactions more aggressively during congestion and less aggressively during downtime. Simply send us the transaction once - we take care of the rest, no retries needed on your end.
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