Abada Engine documentation

PostgreSQL is authoritative

Mutable workflow state is reconstructed inside each command. Replica-local memory caches only immutable parsed definitions.

Commands are atomic

Lock, validate, advance, persist, write history and outbox records, then commit as one workflow-state transaction.

Clusters coordinate through leases

Timers, external work, correlations and outbox delivery use durable rows, database locks and recoverable leases.

Contracts are executable

The BPMN subset, API v1, worker protocol, security model and migrations are backed by compatibility and PostgreSQL tests.

Documentation tracks

This site starts with two audiences:

1. Architecture explains system boundaries, state ownership, transaction behavior, cluster safety, security and the canonical BPMN model.
2. Developer guide explains how to navigate the repository, implement changes, evolve migrations and contracts, and select the required tests.

The end-user guide will be added later. Until then, this site deliberately does not mix engine internals with task-user or operator tutorials.

Current release boundary

These guides describe the 0.11.x line moving toward the 1.0 release candidate. PostgreSQL is the production source of truth, API v1 and worker protocol v1 are frozen, and multi-replica execution is certified for the documented BPMN subset. Conformance publication, rolling-upgrade evidence, security review, benchmarks and runbooks remain 1.0 RC gates.