Internet Money (IMN)

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Overview

Internet Money (IMN) is an open-source, permissionless Layer-1 proof-of-work cryptocurrency designed for real-world merchant checkout and decentralized digital cash.

• ~5-Second Block Inclusion (0.2 BPS): Combines the GHOSTDAG ($k=8$) parallel block consensus model with 5,000 ms block times. Honest concurrent blocks merge into a single directed acyclic graph instead of being thrown away, and history older than 12 hours is final.
• Hallmark PoW (FishHash): The memory-hard FishHash algorithm from Iron Fish, with a seed specific to this network. Each hash makes random reads across a 4.6 GB dataset, which favours commodity GPU memory over custom chips. Nodes verify blocks from a 75 MB cache.
• Sub-1% Long-Term Inflation Floor: Strict 4-year halving cycle starting at 5.0 IMN/block, tapering down to a permanent 0.3125 IMN (about 0.83% annual inflation at year 16, declining) security subsidy floor to ensure permanent miner incentive without exorbitant user fees.
• Small Nodes: One block every five seconds, a 100 KB block limit and optional pruning keep a full verifying node within reach of a small VPS, using pure-Rust embedded redb storage.
• Merchant Stack: Every order gets an invoice number that the payer's wallet signs into the payment. The SDK (@imoney/sdk) and WooCommerce plugin report it as seen (under a second), in a block (about 5 seconds) or final, confirmed by the merchant's own node.

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⚙️ Key Specifications

Parameter	Value
Ticker	IMN
Consensus Engine	GHOSTDAG (blockDAG) with $k = 8$
Block Interval	5,000 ms (5 seconds)
Blocks Per Day	17,280
Blocks Per Year	6,307,200
Proof-of-Work Algorithm	Hallmark (FishHash with a network-specific seed)
Launch Block Reward	5 IMN per block (500,000,000 atoms)
Halving Cycle	Every 4 years (25,228,800 blocks)
Tail Emission Floor	0.3125 IMN per block (~1.97M IMN / year forever)
Decimal Precision	8 decimal places (1 IMN = 100,000,000 atoms)
Initial Year-1 Emission	~31,536,000 IMN

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📊 Emission & Halving Schedule

Era 0 (Years 0 - 4):    5.00000000 IMN / block  -->  126,144,000 IMN total
Era 1 (Years 4 - 8):    2.50000000 IMN / block  -->   63,072,000 IMN total
Era 2 (Years 8 - 12):   1.25000000 IMN / block  -->   31,536,000 IMN total
Era 3 (Years 12 - 16):  0.62500000 IMN / block  -->   15,768,000 IMN total
Era 4+ (Year 16+):      0.31250000 IMN / block  -->   Permanent Floor (<1% inflation tail)

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Workspace Architecture

The codebase is structured as a modular mono-repository:

• Core Protocol & Node (crates/):
  • crates/imoney-core: Addresses (imn:q...), Ed25519 signing, blocks and transactions with a canonical binary encoding, merkle roots.
  • crates/imoney-pow: Hallmark proof of work: a port of FishHash, checked against Iron Fish's reference implementation.
  • crates/imoney-emission: 4-year halving curve starting at 5 IMN/block down to 0.3125 IMN permanent floor.
  • crates/imoney-consensus: GHOSTDAG ordering rules ($k=8$), blue scores, and the difficulty rule.
  • crates/imoney-node: Full node daemon with embedded pure-Rust redb ACID storage, REST/WebSocket API, and TCP P2P gossip sync.
  • crates/imoney-miner: Reference multi-threaded miner CLI and benchmark.
  • crates/imoney-gpu-miner: OpenCL GPU miner. --list-devices shows the cards; --benchmark checks the card against the CPU and measures its hashrate.
  • crates/imoney-stratum: Stratum bridge between a node and mining software, and with --pool a complete small mining pool. See docs/STRATUM.md.

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🚀 Quick Start

Prerequisites

• Rust. The version is pinned in rust-toolchain.toml and installed automatically.

Build

git clone https://github.com/Internet-Money-Network/imoney.git
cd imoney
cargo build --release

Run a Node and Mine

# Start a node (wallet and dashboard at http://127.0.0.1:18556)
cargo run --release --bin imoney-node

# In another terminal: mine for that node with a graphics card, paying an address you control
cargo run --release --bin imoney-gpu-miner -- --node http://127.0.0.1:18556 --address imntest:q...

# Check the card against the CPU and measure its hashrate
cargo run --release --bin imoney-gpu-miner -- --benchmark

# For development: a private network with a small dataset, mined by the node's own CPU
cargo run --release --bin imoney-node -- --devnet mytest --auto-mine

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See docs/RUNNING-A-NODE.md for options, seed nodes, pruning and running a node for a shop. Building on Internet Money: the cookbook explains how it works and walks through reading the chain, sending, accepting payments, a paid API, shared wallets and mining, with examples you can run.

Exchanges, wallet developers and mining pools: see docs/INTEGRATION.md.

Rebuilding the browser pieces

The wallet's signing module and the SDK bundles are committed, so the node builds without extra tools. To regenerate them after changing crates/imoney-wasm or packages/imoney-sdk:

# Signing module (needs: rustup target add wasm32-unknown-unknown, cargo install wasm-bindgen-cli)
cargo build -p imoney-wasm --target wasm32-unknown-unknown --release
wasm-bindgen --target web --no-typescript --out-dir apps/imoney-wallet/pkg target/wasm32-unknown-unknown/release/imoney_wasm.wasm

# SDK bundles, and the copy shipped in the WooCommerce plugin
cd packages/imoney-sdk && npm install && npm test

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📜 License

Licensed under either of MIT or Apache-2.0 at your option, with one exception: crates/imoney-pow/src/fishhash.rs is a port of Iron Fish's FishHash implementation and is licensed under the MPL-2.0.

The licences cover the code. The Internet Money name and logo are covered by TRADEMARKS.md: forks are welcome, but a different network needs a different name.