LemmaScript, a verification toolchain for TypeScript via Dafny
Details
- External ID
- 47849102
- Source
- HN
- Company
- —
- Product
- LemmaScript, a verification toolchain for TypeScript via Dafny
- Website domain
- github.com
- Launched
- April 21, 2026
- Cohort
- —
- Upvotes
- 5
- Upvotes percentile
- 0.11182519280205655
- Tags
- —
- Fetched at
- Sept. 7, 2026, 9:26 p.m.
- Updated at
- Sept. 7, 2026, 9:26 p.m.
Description
I created LemmaScript to compile TypeScript to a verification backend (Dafny or Lean) and prove properties on the systematically derived model. I'll keep developing this, but I have a few case studies already, and it looks quite promising, with the caveat that each case study pushed the development of the core further. I can support both greenfield and brownfield projects, and in many cases, verification can be in-place: the TypeScript source is just annotated and verified independently but runs as is.
Enrichment
- Theme
- niche developer utilities and toolchains
- Vertical
- Horizontal
- Function
- Dev tools
- Audience
- Developer
- AI stance
- Not AI
- Project type
- Hobby / open-source project
- Normalized one-liner
- formal verification for typescript via dafny
- Manually corrected
- False
Could you build this?
No Compiling dynamic TypeScript ASTs to formal verification languages like Dafny or Lean requires advanced compiler theory and formal semantics verification expertise.
What it would actually take: Building this requires designing a formal intermediate verification language, parsing TypeScript via Babel/swc, handling the impedance match between dynamic, mutable JavaScript semantics and purely functional or axiomatic proof targets (Dafny/Lean), and automatically synthesizing frame conditions and invariant specifications. This demands PhD-level expertise in programming languages, formal semantics, and SMT-backed verification tools.
Discussion
No comments on this launch.
Competitors
Other products that read as similar to this one — 84 launches clear the similarity bar, closest 8 shown.
Attention rank: #76 of 85 (itself plus its competitors, highest first — normalized so YC and Product Hunt are compared fairly).
Launched 171 days after the earliest competitor.
- Typical is TypeScript with type-safety at runtime · hn · 2026-01-11 · 8 upvotes · similarity 0.48
- TypeScript 6.0 · ph · 2026-03-24 · 156 upvotes · similarity 0.43
- Suites · hn · 2025-11-04 · 19 upvotes · similarity 0.43
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- SharpTS · hn · 2026-01-09 · 6 upvotes · similarity 0.42
- Crust · hn · 2026-03-17 · 95 upvotes · similarity 0.42
- The Tsonic Programming Language · hn · 2026-01-13 · 62 upvotes · similarity 0.41
- compiler · github · 2026-09-19 · 31 upvotes · similarity 0.41
Other launches for this product
- No other launches for this product.
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