Mining Considerations

Shield provides direct access to Bitcoin mining pools, but understanding how mining works can help you optimize your transaction strategy.

How Shield Works with Miners

Shield acts as a private channel between you and Bitcoin mining pools:

1. You submit a transaction to Shield

2. Shield validates your transaction and fee payment

3. Shield relays your transaction directly to partnered mining pools

4. Mining pools evaluate your transaction for inclusion in their next block

5. Your transaction is mined without ever entering the public mempool

Hashrate Coverage

The estimated_hashrate value returned by the /info endpoint represents the approximate percentage of the Bitcoin network hashrate that will accept your transaction at a specific fee rate.

For example:

• 0.65 means approximately 65% of Bitcoin's mining power will consider your transaction

• 0.95 means approximately 95% of Bitcoin's mining power will consider your transaction

Interpreting Hashrate Coverage

Hashrate Coverage	Expected Outcome
<50%	Transaction may take many blocks to confirm (potentially days)
50-70%	Transaction may confirm within several hours
70-90%	Transaction likely to confirm within a few hours
>90%	Transaction likely to confirm in the next few blocks

Block Time Variability

Bitcoin blocks are found approximately every 10 minutes on average, but individual block times can vary significantly:

• Some blocks may be found within seconds of each other

• Other times, it might take 30+ minutes to find a block

This natural variability means that even with high hashrate coverage, confirmation times can never be guaranteed precisely.

Mining Pool Selection

Shield works with multiple mining pools, each with its own policies:

• Pools may include / exclude transactions at their own discretion

• Certain pools may have minimum feerate requirements

• Pool hashrate share fluctuates over time

• Not all pools support RBF and CPFP

Shield automatically handles the routing of your transaction to appropriate pools based on your fee rate.

Transaction Replacement Considerations

If your transaction is taking too long to confirm, you may want to replace it with a higher-fee version. Important considerations:

1. Bitcoin transactions cannot be cancelled once submitted

2. You can only replace a transaction if it signals Replace-by-Fee (RBF)

3. The replacement transaction must pay a higher fee than the original

4. You'll need to create and sign a completely new transaction

Shield does not currently offer a direct replacement API - you would submit the new transaction as a separate request.

Block Template Inclusion

When miners receive your transaction through Shield:

1. They evaluate it against their current block template

2. If accepted, your transaction is added to their candidate block

3. If the miner finds a block, your transaction will be included

However, miners rebuild their block templates periodically, which can affect transaction inclusion. Transactions with higher fees are more likely to remain in the template during rebuilds.

Confirmation Strategies

Based on your confirmation needs, consider these strategies:

For Time-Critical Transactions

• Use the highest fee rate option

• Monitor for confirmation and be prepared with a higher-fee replacement

For Cost-Sensitive Transactions

• Use a moderate fee rate (70-80% hashrate coverage)

• Accept that confirmation may take several hours

For Lowest Cost

• Use the minimum fee rate accepted by Shield

• Understand that confirmation could take 24+ hours

Impact of Network Congestion

During periods of high network congestion:

• Fee rates across the network typically increase

• Shield's fee recommendations will adjust accordingly

• Consider checking the /info endpoint more frequently during these periods

Monitoring Your Transaction

After submission, you can monitor your transaction status:

• Use a block explorer to check for confirmation (once mined)

• Transaction will not appear in mempool explorers until confirmed (since it bypassed the public mempool)