LazyPromise = Observable
Signals
Details
- External ID
- 46321852
- Source
- HN
- Company
- —
- Product
- LazyPromise = Observable
- Website domain
- github.com
- Launched
- Dec. 19, 2025
- Cohort
- —
- Upvotes
- 34
- Upvotes percentile
- 0.7471374045801527
- Tags
- —
- Fetched at
- Sept. 7, 2026, 9:25 p.m.
- Updated at
- Sept. 7, 2026, 9:25 p.m.
Description
A Promise-like primitive which is lazy/cancelable, has typed errors, and emits synchronously instead of on the microtask queue. In a way LazyPromise is what you get if you take an Observable and make it impossible to misuse it for what the Signals were built to do.
Enrichment
- Theme
- sleep, wake, and clock utilities
- Vertical
- Horizontal
- Function
- Dev tools
- Audience
- Developer
- AI stance
- Not AI
- Project type
- Hobby / open-source project
- Normalized one-liner
- signal library for reactive programming
- Manually corrected
- False
Could you build this?
Yes This is a scoped TypeScript/JavaScript reactive utility library implementing synchronous cancellation and lazy evaluation semantics. LLMs excel at generating compact algorithmic data structures and reactive primitives with thorough unit tests.
Discussion
10 comments analyzed.
Competitors mentioned: RxJS, AbortSignal API, SolidJS Signals, Angular Signals
Concerns raised: Two separate error channels introduce unwanted complexity, Learning curve for understanding LazyPromise as a primitive, Unclear practical advantage over simpler cancelable promise patterns
Feature requests: Better observability/logging of lazy promise execution
Competitors
Other products that read as similar to this one — 6 launches clear the similarity bar.
Attention rank: #2 of 7 (itself plus its competitors, highest first — normalized so YC and Product Hunt are compared fairly).
Looks like the first mover among its competitors.
- Lazy Alarm — Wake Up Your Brain · ph · 2026-09-29 · 1 upvotes · similarity 0.36
- The Event Loop, Visualized · ph · 2026-09-29 · 2 upvotes · similarity 0.35
- Vivere · Know your jobs are alive · ph · 2026-09-12 · 1 upvotes · similarity 0.34
- CodeDrift · hn · 2026-03-05 · 5 upvotes · similarity 0.31
- timedelaylock · ph · 2026-09-12 · 2 upvotes · similarity 0.31
- World Signal · ph · 2026-09-25 · 52 upvotes · similarity 0.30
Other launches for this product
- No other launches for this product.
Same idea, different domain
Nobody's really built a dev tools tool for Sales yet.