jsoncompat
a library to detect/fuzz breaking changes in JSON schemas
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HN · launched Apr 6, 2026 · 7 upvotes (top 61%) · 0 views
Niche: data and schema validation tools · 56 launches, 2 in the last 7 days ▼ -75% · Explore this niche →
Category and tags
- Horizontal
- Dev tools
- Developer
- Not AI
- Hobby / open-source project
Visit website ↗ Source listing ↗
More like this: all 56 launches in data and schema validation tools →
Could you build this?
Partial Writing a basic schema comparison tool is easy, but implementing a comprehensive, formal JSON Schema compatibility checker with automated fuzzing requires deep understanding of JSON Schema specification semantics and subtyping logic.
What it would actually take: The tool requires implementing a parser for JSON Schema drafts (draft-07, 2020-12) and evaluating schema containment/subtyping (determining whether Schema A is a subset of Schema B). The fuzzing component requires a grammar-based or constraint-solving synthetic data generator (e.g., hypothesis-style property testing) that finds edge-case payloads conforming to the old schema but rejected by the new one. High-level language tools (Rust or TypeScript) can be used, but correctly handling complex keywords like 'unevaluatedProperties', 'oneOf', and pattern regexes is notoriously difficult.
Discussion
1 comment analyzed.
Competitors
Other products that read as similar to this one : 1590 launches clear the similarity bar, closest 8 shown.
Attention rank: #907 of 1590 (itself plus its competitors, highest first, normalized so YC and Product Hunt are compared fairly).
Launched 157 days after the earliest competitor.
- change-order-extractor · github · 2026-10-18 · 65 upvotes · similarity 0.71
- genpark-dynamic-json-schema-tool-synthesizer-skill · github · 2026-09-29 · 7 upvotes · similarity 0.71
- genpark-structured-extract-schema-validator-skill · github · 2026-09-12 · 7 upvotes · similarity 0.66
- open-jev · github · 2026-09-16 · 19 upvotes · similarity 0.60
- bote · hn · 2026-06-18 · 5 upvotes · similarity 0.59
- jid · hn · 2026-03-27 · 9 upvotes · similarity 0.57
- genpark-structured-data-diff-patcher-skill · github · 2026-09-14 · 7 upvotes · similarity 0.57
- JSON Diff Checker · ph · 2026-10-14 · 1 upvotes · similarity 0.55
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