The first group session of what we were still calling Spotlight Rules. I recapped why I forked Spectral: the Dutch and German governments have mandated it, and IBM, SAP and others have been quietly forking it because nobody trusts it has a roadmap. Then the group dug in. Mike Kistler talked about OpenAPI Initiative money going to tooling. Jakub Rożek, who spent years on Spectral at Stoplight, made the case for a conformance suite modeled on JSON Schema's. We covered licensing and trademark risk, the Stoplight-only dependencies, the JSONPath RFC mismatch, policy engines like OPA and Cedar, why rules should stay authorable in YAML, and which killer feature (MCP, agent skills, markdown linting) would get people to switch.
OpenLint · Session 2 of 6
Why Fork Spectral: Specification, Tooling, Conformance and Funding
August 21st, 2026 · 0:55:37
Spectral
Conformance
OpenAPI Initiative
Open Source Funding
JSONPath
What we worked through
Where the spec should end and the tooling begin
Swagger started as a config file for Swagger UI and Codegen and took years to become a specification. The OpenAPI Initiative’s charter keeps tooling out. The group liked treating the spec and the tools as separate lifecycles in one effort. Mike noted the OAI has floated grants for tools that serve its mission.
A conformance suite
Without a shared test suite, every implementation behaves a little differently and nobody can prove backwards compatibility. JSON Schema’s tiered suite, which validators in every language rely on, is the model to follow. The spec should reach a solid version one, with normative language and a conformance suite, before any major new features.
SmartBear, licensing and names
I have asked SmartBear to give Spectral to the OpenAPI Initiative and heard nothing back. The code is Apache 2.0, the specification should be Creative Commons, and the Spectral name is a trademark risk, which is why a rename is on the table.
Cleaning up the codebase
Spectral depends on Stoplight forks of libraries that haven’t been maintained in years. Cleaning up that technical debt is a good first job that can run alongside the ruleset work.
Hard problems in the rules format
Custom functions are tied to a language. Annotations and aliases could shortcut JSONPath, but the JSONPath RFC isn’t compatible with what Spectral uses, as Mike found when working on Overlays. Then there are formats, a fix-it function, and tests for the rules themselves.
Keeping rules human
Some enterprises have moved to OPA or Cedar, but Rego is steep. The group agreed that YAML and JSON rulesets are easy to author and review, even when an LLM writes the first draft.
The feature that makes people switch
Stability and a community roadmap come first. After that: linting MCP, agent skills and markdown. Mike added that we should teach people to layer AI on top of deterministic linting.