Ruby implementation of Json Logic

[tavrelkate]

Hi team!

I’ve created a Ruby implementation of Json Logic: json-logic-rb. I wired it to the official tests.json suite and it passes 100%.

Why another implementation?
I noticed that Ruby didn’t have a well-organized to be extendable easily, actively maintained option lately, while Ruby is a great fit to spread and apply Json Logic efficiently across many services and companies.

My goals were (1) cover official cases providing all core operations and (2) to provide a clean extension interface so users can add custom operators without waiting for a new gem (library) release. This makes maintenance easier and lets pepole extend behavior locally, then propose it upstream.

I’d love to:
Have the gem listed on the official Json Logic site and/or “other implementations” to gather feedback, and participate in a community-driven spec and compatibility table to reduce gaps.

I also published a tiny companion: json-logic-rb-humanizable — translate Json Logic rules into readable sentences. It’s been useful for explaining rules to non-dev stakeholders and I think it can bring a value too.

Happy to align behavior or discuss implementation details.

Repo: https://github.com/tavrelkate/json-logic-rb
Gem: 0.1.0.beta1 October 06, 2025

Thanks for keeping the ecosystem going.

[TotalTechGeek]

Hey there! We'd love to include you in the list of implementations in the JSON Logic Community Organization! Sending an invite now!

Here's a list of some of the accepted proposals & tests for json-logic core: https://github.com/json-logic/.github/blob/main/ACCEPTED_PROPOSALS.md

These do introduce some new operators, but all behavior in JSON Logic Core should be backwards compatible with the original tests.json.

[TotalTechGeek]

The community initiative does not have access to that website at this time. We have acquired a couple of domains for the JSON Logic organization going forward. We hope to sync up with the original author.

[TotalTechGeek]

One of the plans though is to list pretty much every implementation and basically introduce a "CanIUse" type website to figure out operator compatibility & behaviors between implementations, as well as precision related details (decimal vs IEEE754, etc).

[tavrelkate]

This "CanIUse" would be amazing. To reduce the current alignment gaps, — not only in execution semantics, but also in the extensions API (e.g., #add_operation jwadhams/json-logic#24). @TotalTechGeek where can contributors discuss about that? Is there a central repo/issue where this matrix is being coordinated?

[TotalTechGeek]

We have this for discussion: https://github.com/orgs/json-logic/discussions/3
And a repo: https://github.com/json-logic/compat-tables

However, right now we're in the process of trying to get some other JSON Logic libraries to implement some of the proposals we've approved for Core.

Here are the tests that have been approved via proposals so far: https://github.com/json-logic/.github/tree/main/tests
And a table of accepted proposals here: https://github.com/json-logic/.github/blob/main/ACCEPTED_PROPOSALS.md

[tavrelkate]

Thank you for sharing @TotalTechGeek, looks great.

[codetiger]

Your humanize companion library seems interesting. Are you using it in any specific usecase, or just a POC?

[tavrelkate]

This use case is quick and simple: if you want to explain why JsonLogic returned a certain value to non-developers, it's better to use plain text instead of raw JSON. The "humanize" feature converts JSON rules into readable English sentences. The current implementation is quite basic and was originally created to automate message generation for complex rules — so users can understand what’s wrong with their input, for example.