Reconciliation Infrastructure You Can Actually Inspect
Settler is fully open source. The matching engine, evidence model, CLI, SDK, and self-host stack are all Apache 2.0. No gated core, no hidden runtime logic.
What's Open Source
Every component that processes, hashes, or moves your data is open source and auditable.
Reconciliation Engine
The deterministic matching core. Configurable rules, field-level tolerance, multi-source joins. Inspect every line of matching logic.
CLI
Run reconciliation jobs from the command line or CI. Pack inputs, execute runs, inspect output, verify evidence hashes.
TypeScript SDK
Typed client for creating jobs, polling runs, fetching mismatches, and exporting evidence. Integrates with any Node.js or Deno runtime.
Evidence Model
The hash-chain evidence schema is open and documented. Any system can verify Settler's output without running Settler itself.
Self-Host Stack
Docker Compose and Kubernetes targets ship with the repo. Self-host the full platform inside your own infrastructure.
Security Model
Tenant isolation, row-level security, and audit trail implementation are open for review. No security through obscurity.
Run it in 3 Minutes
Clone, install, and run the demo path to see deterministic reconciliation end-to-end. No database or API keys needed.
Clone the repo
git clone https://github.com/Hardonian/Settler.git && cd SettlerInstall dependencies
pnpm installRun the demo
pnpm demoInspect evidence output
cat examples/demo-output/evidence.jsonWhy Self-Host?
- Your financial data never leaves your network
- Deploy on your own cloud or on-premise infrastructure
- No per-seat pricing — scale without permission
- Audit the source code before trusting it with production data
- Customize matching rules and adapters for your specific data model
- No telemetry in self-hosted mode by default
Architecture
The OSS build exposes the full system architecture.
Data In
CSV, JSON, Parquet, webhook events, or any adapter-supported source. Inputs are deterministic and version-pinned.
Engine Core
Rules-based matching with configurable field tolerance, multi-source joins, and exception classification.
Evidence Out
SHA-256 hash chain over the full evidence payload. Mismatch report, variance log, and replay bundle.
Inspect the Source Before You Trust It
Financial infrastructure should be auditable. Read the code, run the tests, verify the evidence model.