Visual rules.
For everything airline.
A free, visual rules engine for airlines — flow-DSL graphs, typed node sockets, run it embedded or call the hosted instance.
Apache 2.0 · free to deploy & host. The same flow-DSL that powers the Open Tax Engine — usable on its own for any rule-shaped problem your airline has.
Powered by RuleForge.
70× faster than the <5ms target.
Measured on a laptop, fresh checkout, default config. Target was sub-5ms for typical 10–20-node graphs. We hit 70μs warm, 0.14ms p99.
Per rule evaluation, p50
On a laptop, 16 workers
Warm steady-state latency
vs the <5ms graph target
Methodology and full numbers at ruleforge.aerotoys.io/performance. Reproduce in under five minutes on your own hardware.
Why a rules engine?
Airline logic is rules, all the way down: fare conditions, fee triggers, eligibility, bundling, tax math, refund policy, ancillary inclusion, loyalty accrual. Every airline writes the same rule patterns in different code, and the rules drift from the policy documents that own them.
The Open Rules Engine — codenamed RuleForge — is a visual rule-graph editor and runtime that puts the policy back where it belongs: visible, testable, and authored by the team that owns the policy.
Flow-DSL graphs
Drag a node, wire a socket. Rules compose graphs, not procedural code. The shape of the graph is the documentation.
Typed node sockets
Inputs and outputs carry types. The editor refuses to wire incompatible nodes. Rule authors can't paint themselves into a corner.
Embed or host
Run the runtime inside your application for sub-millisecond evaluation, or call the hosted instance. Same engine, same outputs.
Apache 2.0
Free to deploy, free to host, free to fork. Your rules are yours; the runtime is the community's.
Test scenarios first
Every rule pack ships with scenario coverage. Change a rate, see which scenarios flip green or red — before you publish.
One DSL, many tools
The same flow-DSL powers the Open Tax Engine, and is the proposed core for the OOMS Lab. Learn it once, use it everywhere.
Anything rule-shaped.
Visually.
A non-exhaustive list of where airlines reach for rules — and where the Open Rules Engine is a better home for that logic than scattering it across microservices.
Fare rules
Conditions of carriage, advance purchase, minimum stay, fare combinability. Author the rules where the legal team can read them.
Fee logic
Change fees, refund fees, baggage charges, seat assignment fees. Conditional on cabin, route, loyalty tier, season.
Eligibility
Loyalty redemption, upgrade eligibility, fare promotions, codeshare permissions. Centralised, audited, time-bounded.
Bundling
Which products combine into which bundles, under what conditions. Same engine the OOMS Lab proposes for offer composition.
Tax math
The Open Tax Engine is a vertical slice on top of this engine — every airline tax rule is a graph in the Rules Engine.
Disruption rules
When a flight cancels, who gets rebooked where, with what compensation, on what timeline. Rule-shaped, not coded.
The full project site.
The visual editor, runtime, and SDKs
live on the dedicated site.
Open the editor in your browser, walk through example rule packs, read the node-type reference, or grab the runtime SDK for your language. Open for contributions.
Help us build the rules engine
airlines deserve.
Rule authors, policy owners, runtime engineers — and especially airlines with rule packs to seed. We'd love to hear from you.