# Jsonforge: Schema Cards — JSON Schema Notebook

> JSON Schema Notebook (iPhone/iPad app by Robert Corbin.)

- Source: https://appshunter.io/ios/app/jsonforge-schema-cards/id6799455997 (this page in markdown: same URL + `.md`)
- Developer: [Robert Corbin](https://appshunter.io/developer/1890247992)
- Category: Developer Tools, Productivity
- Price: $4.99
- Age rating: 4+
- Requires: iOS 17.0 · 5 MB
- Languages: American English
- Released: 2026-09-16
- Data updated: 2026-09-20
- User reviews in markdown: https://appshunter.io/ios/app/jsonforge-schema-cards/id6799455997/reviews.md

## What is Jsonforge?

Before: a candidate JSON Schema tightens one field — say amount must now be greater than zero — and nobody on the team can say which of last month's real payloads would start failing. After: Jsonforge replays every captured payload against both the baseline and the candidate contract and hands you a verdict per file — stable, regression, recovered, or still failing — each backed by exact JSON Pointer evidence and a SHA-256 fingerprint.

The workflow is a flight recorder for API contracts. Keep a corpus of observed payloads beside two schema revisions, edit either side in the Schema Bay, and replay the corpus to watch the impact matrix recompute. When it is time to migrate documents, author an RFC 6902 patch in the Patch Lab and apply it with per-operation pre-state evidence and a generated inverse.

- Strict RFC 8259 parser that rejects duplicate keys and trailing commas instead of guessing
- JSON Schema 2020-12 subset validator that fails closed on unsupported keywords
- Structural contract diff separating required, type, and constraint changes
- Everything computes on this device; the binary contains no network client and your corpora never leave it
- RFC 6902 patch engine covering test, add, remove, replace, move, and copy with a provable inverse
- Revision snapshots with fingerprints you can restore and re-replay
- Evidence reports exported as Markdown or JSON through the share sheet
- Projects saved as portable .jsonforge packages via the Files app

Replay classifications describe how sample payloads evaluate against your schemas; they are informational and no substitute for your own release testing.


## Version history (last 1 release)

### 1.0 — 2026-09-16

No release notes.

## More apps by Robert Corbin

- [Daily Word Journey](https://appshunter.io/ios/app/daily-word-journey/id6761548266)
- [Hush Secret Text](https://appshunter.io/ios/app/hush-secret-text/id6761658175)
- [Renew Guard](https://appshunter.io/ios/app/renew-guard/id6761755447)
- [Receipt to PDF](https://appshunter.io/ios/app/receipt-to-pdf/id6761782025)
- [Route Your Pay](https://appshunter.io/ios/app/route-your-pay/id6761783719)
- [Tip Arbiter](https://appshunter.io/ios/app/tip-arbiter/id6761786879)

All apps by Robert Corbin: https://appshunter.io/developer/1890247992

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-09-20.*