₿ Simchain

A disposable Bitcoin regtest network that behaves like mainnet — non-empty blocks, real fee pressure, reorgs, network splits and propagation delay — so your application's tests need minimal changes to run on testnet or mainnet.

Guided tour

Feature walkthrough →

Every feature, one step at a time, with the commands to run and what you should see happen.

Preview

Control dashboard →

The real dashboard UI with sample data. Look around; the controls are inert.

Source

GitHub repository →

Code, full documentation, scenarios, and the issue tracker.

Try it in two commands

git clone https://github.com/danielemiliogarcia/simchain
cd simchain
./scripts/fresh-chain.sh --profile all-tools

Then open http://localhost:8090/ for the dashboard. The chain bootstraps to height 204 before settling into its normal block cadence.

What it gives you

Three real Bitcoin Core nodes in a P2P mesh. Two mine; the third has its wallet disabled and mining refused at the RPC layer — your production-like endpoint.
Blocks that are not empty, with a configurable mempool backlog and an economic fee floor built by paying for it, never by editing relay policy.
Chain events on demand — forced reorgs, true shorter-chain rewinds, and organic reorgs produced by partitioning the mesh and letting both halves mine.
Propagation faults — bounded latency and packet loss on P2P only, with automatic recovery.
Four ways to drive it — a dashboard, a CLI, a versioned HTTP API, and an MCP endpoint for coding agents, all over one operation set.
Repeatability — declarative YAML scenarios with CI checkpoints, and chain snapshots so you stop paying the bootstrap cost.

Simchain is a test environment for applications. It is not a consensus, miner, or network-scale testbed, and its results should not be read as testnet or mainnet network behaviour.

Documentation

README — install, configuration, profiles
FEATURES.md — every feature, linked to its reference doc
SETTINGS.md — every setting and what it does
SCENARIOS.md — scenario schema and CI checkpoints
RUNBOOK.md — handy one-liners