What is a Bitcoin node, and why run your own? Start9 explained

Running your own Bitcoin node lets you verify payments and retrieve wallet data without querying a third-party server. A hardware wallet stores private keys and signs transactions, but it does not verify the blockchain itself. To display your balance, transaction history and suggested fees, the wallet app on your computer or phone connects to a server. That server is usually run by the wallet manufacturer or a public Electrum server operator. An Electrum server finds blockchain transactions associated with wallet addresses.

Using the Start9 Server One as an example, we explain how a node works, what wallet servers can learn about you and how to connect a hardware wallet to your own server. We also look at node software, since its rules determine which blocks your node accepts.

How a Bitcoin node processes a payment

A Bitcoin node is a computer running software, usually Bitcoin Core, that downloads blocks starting with the first block from 2009 and checks them against the consensus rules. It verifies signatures, checks that coins have not been spent twice and ensures that new coin issuance and miner rewards follow Bitcoin’s rules. A node rejects any block that breaks even one rule, regardless of which mining pool found it.

The wallet app sends the node a transaction signed by your hardware wallet. If the transaction is valid and meets the node’s configured policy, the node adds it to its mempool, a pool of unconfirmed transactions, and relays it to other nodes. Once a miner includes the transaction in a block, every node that receives that block verifies it independently.

Node operators receive no reward for this verification. Unlike mining, it does not involve searching through hashes on specialized hardware, so a small, power-efficient PC is usually sufficient for a home node.

Archival and pruned nodes

An archival node stores the entire blockchain. According to Blockchain.com, this amounted to roughly 780 GB, excluding additional indexes, on October 21, 2026, having grown by about 83 GB over the previous 12 months. A pruned node also verifies the history, but deletes older blocks after checking them to keep stored block data within a set limit. Both are full nodes: they enforce the consensus rules while retaining different amounts of historical data.

The setup with electrs or Fulcrum described below requires an unpruned node. These services find transactions associated with addresses by processing the block history, so automatic deletion of old blocks must be disabled for this setup.

Which servers does your wallet contact?

To calculate your balance, the app needs to find transactions associated with your wallet addresses. Depending on how it connects, it sends the server either data used to look up individual addresses or an extended public key, known as an xpub, from which the account’s addresses can be derived. Private keys are not needed for these lookups and remain on the hardware device.

Ledger Wallet, formerly Ledger Live, uses Ledger’s infrastructure by default, while Trezor Suite uses Trezor’s servers. Sparrow and Electrum let you choose a public Electrum server or specify your own. If you use a public server, its operator receives your wallet queries regardless of who made your hardware wallet.

Those queries can allow the operator to link addresses and track their incoming payments, spending and balances. A direct connection also reveals your IP address. Combined with other information, including records held by an exchange that verified a customer’s identity through KYC, this may help identify the wallet owner. An IP address or an exchange withdrawal alone does not reveal your identity documents to the server operator.

The 2020 breach of Ledger’s online store customer database illustrates the consequences of exposing personal information. Attackers obtained the names, phone numbers and postal addresses of around 272,000 customers, who subsequently faced phishing attempts and threats. That incident involved customer records, which is a separate issue from what a server sees when a wallet queries the blockchain.

If revealing the size of your savings could put you or your family at risk, consider who can see your wallet queries. Combining financial information with personal details makes targeted phishing, blackmail and physical coercion of cryptocurrency owners easier.

Why run your own Bitcoin node?

Keeping blockchain queries private

When your wallet app connects only to your node, balance and transaction history queries go to your server. The wallet manufacturer and public Electrum server operators do not receive those queries. Your node exchanges blocks and transactions with other network participants without sending them a list of your wallet addresses.

You can configure your node to broadcast transactions through Tor to reduce the risk of linking them to your home IP address. However, your own node keeps queries private; the transactions themselves remain public. Connections visible on the blockchain do not disappear when you change how you connect.

Verifying payments independently

A third-party server can make mistakes, be compromised or provide false data. With your own node, you can independently verify that a transaction is included in a block that follows Bitcoin’s rules. This is especially useful for large payments, such as an over-the-counter (OTC) trade directly with a counterparty or a property sale settled in BTC. Your node shows the result of its own chain verification and the payment’s confirmation count, so you do not have to rely solely on a block explorer screenshot or another operator’s server.

Choosing consensus rules: the BIP-110 example

The rules in your node software determine which blocks it accepts. The consequences of this choice became apparent during the BIP-110 split in 2026, when some nodes stopped accepting blocks from the main chain.

Bitcoin Core 30.0, released in October 2025, changed the default relay policy for transactions containing OP_RETURN outputs, which can carry data. Some operators who opposed the relaxed limits chose Bitcoin Knots for its stricter mempool filters. These filters determine which unconfirmed transactions a node accepts and relays, but do not by themselves change the rules for validating blocks.

In May 2026, Knots v29.3.knots20260508 introduced support for BIP-110, also known as RDTS, or Reduced Data Temporary Softfork. The proposal introduced temporary restrictions on arbitrary data at the consensus level. A soft fork narrows the set of valid blocks: a node enforcing the new rules may reject a block that a node without those restrictions accepts. This is what distinguishes a consensus change from mempool filtering.

On August 8, 2026, at block height 961,632, RDTS entered a mandatory signaling period regardless of the level of miner support. Nodes enforcing RDTS rejected a block that lacked the required signal and followed a separate chain with a small share of the hashrate, or mining computing power. The main chain continued operating, but those nodes no longer showed confirmations for payments on it. Start9 documented the effects of the split on wallets, Lightning and other services that depend on a node.

According to the BIP-110 developers, the fork switched to the BLAKE2b mining algorithm on August 30 and has operated as a separate network since then. A payment on that fork must be checked separately from a BTC payment on Bitcoin’s main chain.

Before updating your node, read the release notes and check whether the update changes the consensus rules. If you use a third-party server, its operator chooses the software implementation and version.

What a node does not do

A Bitcoin node verifies the blockchain, but running one does not change how transactions get into blocks or remove the need to protect your private keys.

• Speed and fees. Running your own node does not give your transactions priority with miners. Confirmation time depends on the fee rate and competition for block space.
• Income. An ordinary Bitcoin node earns no rewards. A Lightning node, which serves a payment network built on top of Bitcoin, can earn routing fees, but income is usually modest for an individual with a few channels, and channel liquidity requires management.
• Private keys. In a hardware wallet setup, the node processes public data while the device holds the keys. If your seed phrase is compromised, running your own node will not stop an attacker from spending your coins.

Storing bitcoin “on a node” usually refers to Bitcoin Core’s built-in wallet. It can store private keys on the computer’s drive, in which case their protection depends on that computer’s security. For savings, keeping keys on a hardware wallet while retrieving and verifying payment data through your node is a more prudent arrangement.

Start9 and StartOS

You can install Bitcoin Core on an existing PC without buying a dedicated server. You will need to configure any additional Electrum server, backups and remote access yourself. The computer must stay on if you need the node around the clock. For occasional wallet use, you can start it when needed and wait for it to download and verify the blocks it missed.

StartOS, developed by US company Start9, simplifies the management of this setup. It is a Linux-based server operating system with a web interface you can open in a browser on your computer or phone. From there, you can install services from the marketplace, change settings and connect an Electrum server to Bitcoin Core so they work together. StartOS is open source and can be installed free of charge on compatible hardware you already own.

StartOS 0.4.0 introduced changes to networking and backups. Remote access is available through WireGuard on a compatible router or through StartTunnel; Tor is installed as a separate service. Differential backups save changes since the previous backup and support restoring data to another server.

Start9 Server One: a ready-made server for your node

Server One is a compact server with StartOS preinstalled, with specifications that vary by generation and configuration. We offer the Start9 Server One 2025 with an AMD Ryzen 7 5825U, 16 GB of DDR4 RAM and a 2 TB NVMe SSD. This configuration can run a Bitcoin node, an Electrum server and additional services such as a mempool explorer, Lightning or BTCPay Server, a system for accepting BTC payments without an intermediary.

The enclosure measures 11.4 × 10.6 × 3.75 cm and weighs around 370 g. The server has no Wi-Fi, so it connects to your router by Ethernet. We provide a one-year warranty on the Server One 2025, and the server also comes with lifetime support from Start9.

The blockchain and Electrum server index together can occupy around a terabyte, depending on the indexer and its settings. A 2 TB SSD is a reasonable starting point for a node used with a wallet, but you will need to monitor free space as the data grows. A 4 TB drive is useful if you also plan to run file storage or other services that retain large amounts of data. Lightning or BTCPay Server alone does not require a 4 TB drive.

How Server Pure differed

Start9 comparisons may also mention Server Pure, an earlier range of Intel-based servers with coreboot-based PureBoot firmware and Intel Management Engine disabled. Intel ME is a closed-source management subsystem with privileged access to platform components. These models appealed to users who wanted to reduce their reliance on closed-source firmware at the hardware level.

According to Start9’s current hardware list, sales of Server Pure 2026 ended in July. Both ranges can run a Bitcoin node, but compare the generation, configuration and support of the specific device you are considering, since the Server One name has also covered different models.

Start9 and the alternatives

You can run a home node on various types of hardware and management software. Your choice determines how much you will need to configure yourself.

• Bitcoin Core on an existing PC. If you already have a computer, this lets you get started without buying a separate device. You configure additional services and backups yourself, and the PC must stay on for continuous access.
• Raspberry Pi with a project such as RaspiBlitz. This suits users who want to build their own node with the help of a large community’s resources. For the Raspberry Pi 4, a reliable power supply, an SSD and a stable USB connection are particularly important. Initial synchronization can take considerably longer than on a modern mini PC.
• Umbrel. Offers browser-based management and a large app catalog. However, umbrelOS uses the PolyForm Noncommercial 1.0.0 license, which restricts commercial use. Its code is available to inspect, but the license does not meet the generally accepted definition of open source.
• StartOS. Combines open-source software with service management, backups and recovery through a web interface. Remote access is available through Tor, WireGuard or StartTunnel.

Choosing between Bitcoin Core, Knots (pre-RDTS) and Knots (RDTS)

In StartOS, distinguish between Bitcoin Core, Knots without RDTS and Knots builds that enforce RDTS. Available packages and upgrade paths depend on your StartOS version and the registry you use to install services. For a new server, the priority is to choose an implementation that validates Bitcoin’s main chain.

• Bitcoin Knots (RDTS). Builds enforcing BIP-110 split from the main chain in August 2026. Do not use them to verify incoming BTC payments on the main network.
• Bitcoin Knots (pre-RDTS) retains Knots’ filtering policy without enforcing BIP-110. The node stays on the main chain while applying stricter rules to the unconfirmed transactions it accepts into its mempool and relays. This lets operators limit the spread of unwanted data without adopting different consensus rules.
• Bitcoin Core is the main and most widely used Bitcoin implementation, supported by node services and wallet apps.

For a first node, we recommend Bitcoin Core from a current, compatible package. Knots (pre-RDTS) also works on the main network if you prefer its filtering policy.

To switch implementations in StartOS, open Marketplace, select the package you want and click Switch. If both the installed and selected versions support this transition, you can retain the downloaded blockchain data. Check the package description for requirements before switching, as the procedure depends on your StartOS version and installed service.

How to connect a hardware wallet to your own node

An Electrum-based setup has four components: Bitcoin node → Electrum server → wallet app → hardware device. The Electrum server indexes the blockchain so it can quickly find transactions in response to wallet queries. Bitcoin Core has no equivalent general-purpose address index, although Sparrow can also connect to it directly. We use an Electrum server below because this connection method works with several wallet apps.

StartOS offers electrs and Fulcrum. electrs has a smaller index, while Fulcrum generally handles large queries faster but needs more disk space. Initial indexing time depends on the hardware and service version. We choose Fulcrum for wallets with extensive transaction histories and for multisig setups, which require signatures from multiple keys to spend funds.

Ledger and Trezor: connecting through a wallet app

Your hardware wallet communicates with an app on your computer, and the app connects to the server. For Ledger devices, including the Ledger Flex, you can use Sparrow connected to your own node instead of Ledger Wallet’s default infrastructure.

Trezor devices, including the Trezor Safe 7, also work with Sparrow. If you prefer Trezor Suite, you can specify your own Electrum server in the Bitcoin settings. Wallet queries go to the server you select in the app; private keys remain on the device in either setup.

Keystone and Coldcard: transferring data without USB

The Keystone 3 Pro and Coldcard Q can work with Sparrow using QR codes or microSD, depending on the device’s capabilities and the selected mode. You import public account data into the app, which retrieves transaction history from your Electrum server. You then transfer the prepared transaction to the hardware wallet for signing and return the signed transaction to Sparrow for broadcast.

Blockstream Jade and BitBox02: using your own server in the companion app

For Blockstream Jade, including Jade Plus, you can specify your own Electrum server in the Blockstream app’s Bitcoin singlesig mode, a standard wallet requiring one signature. Check the requirements of other app modes before reusing these server settings.

The BitBox02 Bitcoin-only edition works with BitBoxApp, which supports connecting to your own Electrum server. You can also use BitBox02 with Sparrow if you want its transaction management features.

If you are choosing a device exclusively for BTC, our Bitcoin-only hardware wallet comparison explains the differences between models and firmware designed solely for bitcoin.

Sparrow supports many popular hardware wallets, multisig and manual selection of UTXOs, the unspent transaction outputs used to fund a payment. This gives you control over which coins you spend and which addresses you link in a single transaction.

How to check that you are connected to your server

In Sparrow, open Settings → Server → Private Electrum and check that it contains your server’s address: either a local address or an .onion address for Tor access. Click Test Connection to test the connection. Confirm that the test succeeds and the app receives up-to-date block data.

The toggle in the bottom-right corner indicates the connection type: yellow for a public server, green for Bitcoin Core and blue for a private Electrum server. In Trezor Suite and BitBoxApp, review the server settings and keep only the connections you intend to use. Some app features, such as exchange-rate lookups, may still rely on external services.

Running a Bitcoin node in Ukraine

Power outages

A sudden power loss while the node is writing to disk can corrupt its database. Verifying the database or rebuilding its indexes after such a failure can take hours or even days. Server One uses a 19 V power input; you can power it, your router and your provider’s optical network terminal from a UPS or portable power station using compatible power adapters. Runtime depends on the backup power source’s energy capacity and the combined consumption of the connected devices.

If you have no backup power, shut down the server through the StartOS interface before a scheduled outage and wait for it to power off normally. This reduces the risk of data corruption.

Initial synchronization and data usage

Initial synchronization can take many hours to several days. The node must download and verify blocks, so your internet connection, CPU and SSD all matter. Electrum server indexing takes additional time afterwards. As of October 2026, downloading the full history requires around 780 GB of incoming data, plus headroom for protocol overhead and repeat downloads. A stable connection without a restrictive data cap is preferable for the initial setup.

After that, the node downloads new blocks and sends data to other network participants. If your provider imposes a data cap, pay particular attention to outgoing traffic. Bitcoin Core has a setting to limit this volume; simply reducing the number of inbound connections may not be enough.

Access away from home

You can arrange remote access through Tor or a private VPN connection. For Tor, install the corresponding service in StartOS and create an .onion address for the interface you need. For WireGuard, you can use your router’s VPN server or StartTunnel, which also supports private access through WireGuard. StartTunnel can either expose services publicly on a domain or provide private access over a VPN.

If you have a public IP address, you can set up a WireGuard server on a compatible home router. Our GL.iNet VPN router comparison explains the differences between models that support this feature. If your provider uses CGNAT and inbound connections are unavailable, StartTunnel is an option. Choose a method your wallet supports, and do not expose Bitcoin RPC to the public internet: private access does not require this.

Interface labels and documentation

This guide uses the English menu labels found in Start9’s documentation. Knowing these labels helps when installing services, checking their status or contacting support. For unfamiliar terms, refer to the instructions for the specific service.

Who benefits from running a Bitcoin node?

Your own node is particularly useful if:

• You regularly accept BTC payments and want to verify incoming funds independently or use BTCPay Server to accept payments without an intermediary.
• You use multisig. A coordinator app such as Sparrow, Nunchuk or Specter queries data for the wallet’s addresses. Connecting the coordinator to your server keeps those queries from a third-party operator, preventing it from learning your wallet history through them.
• You need to limit disclosure of financial information. This is especially relevant if information about the size of your savings could expose you or your family to blackmail or physical coercion.

If you bought a small amount of BTC for long-term storage and rarely open your wallet, a dedicated server may not justify the time it requires. Sparrow connected through Tor offers a middle ground: the public server operator will not see your home IP address, but will still receive queries about your wallet addresses.

Getting started

These steps are for a new server running StartOS 0.4 and a singlesig Bitcoin wallet. In this example, we connect an already configured hardware wallet to a computer over USB and add it to Sparrow.

1. Prepare the server. A 2 TB SSD is a reasonable starting point for a Bitcoin node with an Electrum server. Connect the server to your router with an Ethernet cable and provide backup power if possible.
2. Initialize StartOS. From a computer on the same local network, open http://start.local. For a new server, select Start fresh, create a master password, save it in a password manager and give the server a name. When setup is complete, open its permanent address, such as https://myserver.local, replacing myserver with your chosen name.
3. Install the server’s root certificate. Download the Root CA through the StartOS web interface and add it to your operating system’s or browser’s trusted certificates, following the instructions for your platform. Reopen the server’s permanent address and confirm that the browser trusts the connection.
4. Install Bitcoin Core. Find Bitcoin Core in Marketplace, then install and start the service. To use electrs or Fulcrum, configure it to retain the full block history with pruning disabled. Wait for synchronization to finish and check the service status. Until synchronization is complete, the node will not have all the data needed to display your current balance.
5. Add Fulcrum or electrs. Install your chosen service from the marketplace, connect it to the installed Bitcoin Core service through its dependency settings and start it. Wait for indexing to finish. On the Interfaces tab, find the Electrum protocol connection. Copy the server address and port number, and check whether the connection uses TLS encryption.
6. Connect Sparrow to the server. Install the app from the official Sparrow website, open Settings → Server → Private Electrum and enter the server address and port. Enable Use SSL if the connection uses TLS; otherwise, leave it off. Click Test Connection. If the connection succeeds, Sparrow will show the server details and the latest block height. Once connected, the private Electrum server indicator will be blue.
7. Add your hardware wallet to Sparrow. Close the manufacturer’s companion app, connect and unlock the device, and open the Bitcoin app if you are using a Ledger. In Sparrow, select File → New Wallet, enter a name, click Create Wallet and choose the address type and account that match your wallet. Click Connected Hardware Wallet → Scan, select the device, confirm any required actions on it, then click Import Keystore → Apply. Set a password for the Sparrow wallet file. Sparrow receives public account data while private keys stay on the device: you do not need to enter your seed phrase on the computer. QR code and microSD workflows use separate import methods rather than Connected Hardware Wallet.
8. Check the account and address. If your wallet has an existing transaction history, make sure it appears correctly. On the Receive tab, click Display Address and compare the address in Sparrow with the one on the device’s screen. For an existing wallet, use the same account and the same passphrase, if one was configured. Only use the address to receive funds after completing these checks.
9. Back up StartOS. Connect an external drive, preferably formatted as EXT4, open System → Create Backup, select the drive, choose the services to include and click Done. Enter your master password to start the backup. Check the result and repeat the backup after significant changes. Blockchain data and indexes that can be downloaded or rebuilt may be excluded. If you use Lightning, configure separate channel data backups according to the installed service’s instructions. A StartOS backup alone may not be enough to recover those channels.

Final thoughts

Running your own Bitcoin node lets you verify payments and retrieve wallet history without querying a third-party server. The hardware wallet holds your keys and signs transactions, while the node verifies the blockchain according to its installed software. Alongside protecting your seed phrase, you therefore need to keep track of node updates and understand which chain it follows.

Start9 Server One with StartOS simplifies installation and maintenance through a browser. You can begin with Bitcoin Core, one Electrum server and a compatible wallet, with reliable power and backups in place. Add Lightning, BTCPay Server or other services when you have a specific use for them.