Bitcoin Pocket Node

Bitcoin node in your pocket in under 20 minutes.

Turn any Android phone into a fully-validating Bitcoin full node. No server dependency, no ongoing tethering. Your phone becomes a sovereign Bitcoin node.

✅ Proven

Direct chainstate copy: full node at chain tip in ~20 minutes (167M UTXOs, 4 peers, instant)
AssumeUTXO alternative: full node in ~3 hours via cryptographically verified UTXO snapshot
4 Bitcoin implementations: Core 28.1, Core 30, Knots 29.3, Knots BIP 110. Switch with one tap, same chainstate
Phone stays cool, runs overnight without issues
~26 GB total disk with Lightning (11 GB chainstate + 2 GB pruned blocks + 13 GB block filters), ~13 GB without
BWT Electrum server for BlueWallet connectivity to your own node

Screenshots

Running on a Pixel 7 Pro with GrapheneOS

Node + On-chain wallet

Setup checklist	Electrum server	BlueWallet connected	BlueWallet wallet

Lightning

Lightning enabled	Connect Wallet	Zeus synced	Zeus Neutrino peer

Choose your implementation

Version picker

How It Works

Two bootstrap paths. Choose speed or trustlessness:

⚡ Path 1: Sync from Your Node (Direct Chainstate Copy) ~20 min

App connects to your home node (Umbrel, Start9, any Bitcoin node) via SSH
Briefly stops bitcoind, copies chainstate + block index + xor.dat + tip blocks
Creates stub files for historical blocks, starts bitcoind with checklevel=0
Instant full node at chain tip. No background validation, no catch-up

🔒 Path 2: Download from Internet (AssumeUTXO) ~3 hours

Download a UTXO snapshot (~9 GB) from your home node over LAN or the internet
App loads it via loadtxoutset (cryptographically verified by Bitcoin Core)
Phone syncs forward from the snapshot height (~25 min to load, ~2 hours to reach tip)
Background validation confirms everything independently from genesis

See Direct Chainstate Copy for a detailed comparison.

Version Selection

Your node, your rules. Choose which Bitcoin implementation runs on your phone:

Implementation	Size	Policy
Bitcoin Core 28.1	13 MB	Neutral: standard relay rules
Bitcoin Core 30	8.6 MB	Permissive: larger OP_RETURN data allowed
Bitcoin Knots 29.3	9 MB	Restrictive: filters non-standard transactions
Bitcoin Knots (BIP 110)	9 MB	Enforcement: consensus-level data restrictions, bit 4 signaling

All four share the same chainstate format. Switch without re-syncing. Tap "Change" on the dashboard, confirm, and the node restarts with the new binary.

BIP 110 (bip110.dev) temporarily limits arbitrary data embedding at the consensus level. Built from Dathon Ohm's reference implementation, signaling version bit 4 with a 55% activation threshold.

See Version Selection Design and BIP 110 Research for details.

Features

4 Bitcoin implementations with one-tap switching: Core 28.1, Core 30, Knots 29.3, Knots BIP 110
Two bootstrap paths: direct chainstate copy (~20 min) or AssumeUTXO (~3 hours)
BWT Electrum server so BlueWallet can query your own node
Lightning support via block filter copy from your home node, enabling Zeus Neutrino on localhost
Sovereign price discovery using UTXOracle (BTC/USD from on-chain data, no exchange APIs)
Mempool viewer with fee estimates, projected blocks, and transaction search
Wallet setup guide for BlueWallet and Zeus connection
Snapshot validation checks block hash before loading, auto-redownloads if wrong
Non-blocking snapshot load with progress tracking
Network-aware sync that auto-pauses on cellular and resumes on WiFi
VPN support: WireGuard/VPN connections treated as WiFi
Data budgets for WiFi and cellular
Battery saver pauses sync when unplugged below 50%
Auto-start on boot
Secure node pairing with restricted SFTP account (no access to your bitcoin data)
Setup checklist with auto-detection of completed steps
Live dashboard showing block height, sync progress, peers, mempool, disk usage
Partial mempool (50 MB) for fee estimation and cover traffic

Snapshot Sources

From Your Node (LAN)

Direct Chainstate Copy (fastest)

The app connects to your home node via SSH, briefly stops bitcoind, and copies:

chainstate/ (the UTXO set, ~11 GB)
blocks/index/ (block metadata, ~2 GB)
blocks/xor.dat (block file obfuscation key)
Tip block/rev files (latest block data)

Total transfer ~13 GB over LAN (~5 min). Node operational in ~20 minutes including setup.

AssumeUTXO Snapshot

Generates a UTXO snapshot using dumptxoutset rollback
Downloads via SFTP over LAN (~5 min for 9 GB)
Loads via loadtxoutset

The app tries saved pocketnode SFTP credentials first. If a snapshot already exists on the server, no admin credentials are needed.

From Internet

Download from https://utxo.download/utxo-910000.dat (9 GB). Same loadtxoutset flow, just a different download source. The snapshot is cryptographically verified against the block hash compiled into Bitcoin Core before loading.

Note: This path provides an on-chain node only. Lightning support requires block filters (~13 GB) which can be added later by copying from a home node via SSH.

Architecture

┌─────────────────────────────────────────────┐
│           Android App (Kotlin)              │
│                                             │
│  ┌──────────┐ ┌───────────┐ ┌───────────┐  │
│  │ Chainstate│ │  Network  │ │   Sync    │  │
│  │ Manager  │ │  Monitor  │ │ Controller│  │
│  └────┬─────┘ └─────┬─────┘ └─────┬─────┘  │
│       │             │             │         │
│  ┌────┴─────────────┴─────────────┴──────┐  │
│  │  bitcoind (ARM64), user selects:      │  │
│  │  Core 28.1 | Core 30 | Knots | BIP110│  │
│  │  Foreground service, local RPC        │  │
│  └──────────────┬────────────────────────┘  │
│                 │                           │
│  ┌──────────────┴──────────────────┐        │
│  │     BWT (Electrum server)       │        │
│  │     Local Electrum protocol     │        │
│  └──────────────┬──────────────────┘        │
│                 │                           │
└─────────────────┼───────────────────────────┘
                  │
     ┌────────────┼────────────┐
     │            │            │
Bitcoin P2P   BlueWallet   Electrum
 Network      (local)      clients

Security Model

Node Pairing (SSH Setup)

When you pair with your home node, the app creates a restricted pocketnode user:

SFTP-only. Cannot run commands, no shell access
Chroot jailed. Can only see /home/pocketnode/, nothing else
Zero data access. Cannot read your bitcoin data directory, wallet, configs, or logs
Root-owned copy scripts bridge the gap, copying only snapshot files to the SFTP location

Admin SSH credentials are never saved (username is saved for pre-fill convenience). Always prompted, used once, discarded.

You can view the pocketnode credentials and fully remove access from the app at any time.

Snapshot Verification

Snapshots are verified against block hashes compiled into the Bitcoin Core binary
The app also validates the snapshot file header before attempting to load
A tampered or wrong-height snapshot is rejected before any data is used
Background IBD independently validates everything from genesis (AssumeUTXO path)

Android Security

network_security_config.xml allows cleartext HTTP only to 127.0.0.1 (local RPC)
bitcoind runs as libbitcoind.so in jniLibs/ for GrapheneOS W^X compliance
No internet-facing ports. RPC and BWT Electrum are both localhost only

Lightning Support (Zeus)

The app can copy BIP 157/158 block filter indexes (~13 GB) from your home node, enabling Zeus to run as a fully sovereign Lightning wallet. Everything stays on localhost with no external dependencies.

How It Works

Tap "Add Lightning Support" on the dashboard
Enter your home node SSH credentials
The app detects block filters on your node, stops it briefly, archives filters alongside chainstate, downloads everything, and restarts your home node
Your phone's bitcoind restarts with blockfilterindex=1, peerblockfilters=1, listen=1, bind=127.0.0.1
Zeus connects via Neutrino to 127.0.0.1 for compact block filters

Zeus Setup

Install Zeus v0.12.2 from GitHub releases (v0.12.3+ has a SQLite bug that stalls sync at block 123,000)
Open Zeus, select Create embedded LND
Wait ~15 minutes on the boot animation while initial header sync completes (don't change settings yet)
Restart the app
Wait for the warning icon to appear at the top of the screen
Tap the warning icon to open node settings
Go to Embedded node > Peers > Neutrino Peers
Delete all default Neutrino peers
Add 127.0.0.1 as the only Neutrino peer
Restart Zeus. It connects to your local bitcoind and the wallet appears
To confirm: Settings > Embedded node > Peers > Neutrino Peers should show 127.0.0.1 as the only peer

Full Sovereign Stack

bitcoind (phone) --> block filters --> Zeus Neutrino --> Lightning wallet
         all on localhost, zero external dependencies

Target Platform

OS: GrapheneOS (or any Android 10+)
Hardware: Google Pixel devices (ARM64)
Default: Bitcoin Core v28.1 (non-controversial baseline)
Also bundled: Core 30, Knots 29.3, Knots BIP 110 (user selects from dashboard)
AssumeUTXO heights: 840k (upstream) + 880k, 910k (backported from Core 30)

Building

Prerequisites

macOS or Linux build machine
Android SDK + NDK r27
JDK 17
Bitcoin Core v28.1 source (with chainparams patch)

Build bitcoind for ARM64

See docs/build-android-arm64.md

Build the Android app

export ANDROID_HOME=/path/to/android-sdk
export JAVA_HOME=/path/to/jdk-17
./gradlew assembleDebug

Install

adb install -r app/build/outputs/apk/debug/app-debug.apk

App Structure

app/src/main/java/com/pocketnode/
├── service/
│   ├── BitcoindService.kt      # Foreground service managing bitcoind
│   ├── BwtService.kt           # BWT Electrum server service
│   └── SyncController.kt       # Network-aware sync pause/resume
├── network/
│   └── NetworkMonitor.kt       # WiFi/cellular/VPN detection + data tracking
├── snapshot/
│   ├── ChainstateManager.kt    # AssumeUTXO snapshot flow (generate/download/load)
│   ├── BlockFilterManager.kt   # Lightning block filter copy/remove
│   ├── NodeSetupManager.kt     # SSH setup + teardown
│   └── SnapshotDownloader.kt   # SFTP download with progress
├── ssh/
│   └── SshUtils.kt             # Shared SSH/SFTP utilities
├── rpc/
│   └── BitcoinRpcClient.kt     # Local bitcoind JSON-RPC (configurable timeouts)
├── ui/
│   ├── PocketNodeApp.kt        # Navigation + top-level routing
│   ├── NodeStatusScreen.kt     # Main dashboard
│   ├── SetupChecklistScreen.kt # Config mode setup wizard
│   ├── SnapshotSourceScreen.kt # Source picker
│   ├── ChainstateCopyScreen.kt # Snapshot load progress (4-step flow)
│   ├── ConnectWalletScreen.kt  # BlueWallet / Electrum / Zeus wallet connection guide
│   ├── BlockFilterUpgradeScreen.kt # Lightning block filter management
│   ├── DataUsageScreen.kt      # Data usage breakdown
│   ├── NetworkSettingsScreen.kt # Cellular/WiFi budgets
│   ├── NodeAccessScreen.kt     # View/remove node access
│   ├── NodeConnectionScreen.kt # Remote node connection setup
│   └── components/
│       ├── NetworkStatusBar.kt      # Sync status banner
│       └── AdminCredentialsDialog.kt # SSH creds prompt
├── oracle/
│   └── UTXOracle.kt            # Sovereign price discovery from on-chain data
└── util/
    ├── ConfigGenerator.kt      # Mobile-optimized bitcoin.conf
    ├── BinaryExtractor.kt      # Version selection, 4 bundled bitcoind binaries
    └── SetupChecker.kt         # Auto-detect completed setup steps

Documentation

Tested On

Device	SoC	Result
Pixel 7 Pro	Tensor G2	✅ Direct chainstate copy to chain tip, 167M UTXOs loaded via AssumeUTXO, phone stays cool

Known Issues

16KB page alignment warning on GrapheneOS (cosmetic only)
getblockchaininfo reports background validation progress, not snapshot chain tip (AssumeUTXO path only)
ARM64 Android emulator cannot run on x86 Mac, all testing requires real device
Direct chainstate copy: pruning ~5000 stub files takes ~15 minutes on first startup (optimizable)

License

MIT

Name		Name	Last commit message	Last commit date
Latest commit History 199 Commits
LICENSES		LICENSES
app		app
build/android-arm64		build/android-arm64
docs		docs
gradle/wrapper		gradle/wrapper
ndk-wrappers		ndk-wrappers
scripts		scripts
.gitignore		.gitignore
LICENSE		LICENSE
PLAN.md		PLAN.md
README.md		README.md
build.gradle.kts		build.gradle.kts
gradle.properties		gradle.properties
gradlew		gradlew
settings.gradle.kts		settings.gradle.kts

License

FreeOnlineUser/bitcoin-pocket-node

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Bitcoin Pocket Node

✅ Proven

Screenshots

How It Works

⚡ Path 1: Sync from Your Node (Direct Chainstate Copy) ~20 min

🔒 Path 2: Download from Internet (AssumeUTXO) ~3 hours

Version Selection

Features

Snapshot Sources

From Your Node (LAN)

Direct Chainstate Copy (fastest)

AssumeUTXO Snapshot

From Internet

Architecture

Security Model

Node Pairing (SSH Setup)

Snapshot Verification

Android Security

Lightning Support (Zeus)

How It Works

Zeus Setup

Full Sovereign Stack

Target Platform

Building

Prerequisites

Build bitcoind for ARM64

Build the Android app

Install

App Structure

Documentation

Tested On

Known Issues

License

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