What is the P2Pool sidechain?

The P2Pool sidechain is a separate record that Monero miners use to track their contributions and work out who should get paid. It runs alongside Monero’s main blockchain, but it is not a new coin, and it does not hold your mining earnings in a shared wallet.

A shared record of mining work

A blockchain is a record built from linked groups of data called blocks. Monero’s main blockchain records XMR transactions. P2Pool’s sidechain has a different job: it records evidence of the work you and other miners contribute.

That evidence is called a share. A share is a mining result that meets P2Pool’s work requirement, which is easier to meet than the requirement for a full Monero block.

You can think of the sidechain as a public scorecard:

• Your miner tries possible solutions to a mining puzzle.
• When it finds a result that qualifies as a P2Pool share, it sends that share to other participants.
• Those participants check it and, if valid, include it in their shared record.

Not every result your mining software calls a “share” necessarily becomes a sidechain share. The important ones for payment are the shares accepted into P2Pool’s accounting system.

How the sidechain leads to payment

P2Pool uses PPLNS, short for “pay per last N shares.” In everyday terms, it bases payments on accepted work within a recent window, rather than keeping a permanent balance for every miner.

Occasionally, a result also meets Monero’s much harder requirement. If the resulting block is accepted by the Monero network, it earns a real XMR reward.

The reward is divided according to the eligible shares in P2Pool’s payout window. The payments are written directly into the Monero block’s coinbase transaction—the special transaction that creates and distributes a mining reward.

This distinction matters:

• The sidechain records your contribution.
• Monero’s main blockchain records your actual payment.
• A pool operator does not collect the reward and later approve your withdrawal.

Your sidechain share is not a token you can sell or spend. It is evidence used to calculate a possible payout. If no Monero block is found while your share remains eligible, that share may earn nothing.

Why the extra chain matters

A traditional mining pool usually relies on a central server to track contributions and an operator to distribute earnings. P2Pool replaces that private accounting process with rules that participating computers check together.

The sidechain links shares using proof of work, meaning computational effort that others can verify. This makes it harder for someone to invent contributions or change the payment record.

It does not remove mining luck. Your payments still depend on finding qualifying shares and on P2Pool finding Monero blocks. It also does not make mining free: your hardware, electricity, and setup still matter.

What you need to know before joining

P2Pool has separate sidechains, including main and mini. They use the same basic approach but have different share difficulty levels and separate payout windows. Mini generally makes qualifying shares more attainable for smaller miners; easier shares do not guarantee higher earnings.

If you mine through a browser service, do not assume it uses P2Pool simply because it says “pool mining.” Check how it records work and sends payments.

P2Pool payouts are newly mined XMR, so they remain locked for 60 Monero blocks—roughly two hours, though block timing varies.

The bottom line

The P2Pool sidechain is a decentralized mining scorecard. It tracks eligible work, while Monero itself pays the rewards directly to miners.