Endo Familiar, an O-cap based JavaScript agent sandbox
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HN · launched Apr 23, 2026 · 13 upvotes (top 33%) · 0 views
Niche: ai agent execution sandboxes · 137 launches, 6 in the last 7 days ▼ -25% · Explore this niche →
Category and tags
- Horizontal
- Dev tools
- Developer
- AI-native
- Hobby / open-source project
Visit website ↗ Source listing ↗
More like this: all 137 launches in ai agent execution sandboxes →
Could you build this?
No Implementing an Object-Capability (O-cap) based JavaScript sandbox requires deep programming language security semantics and virtual machine runtime internals.
What it would actually take: Building Endo Familiar requires implementing or embedding Hardened JavaScript (SES / Compartments) where primordial prototypes are frozen and capability references are strictly attenuated. It requires deep knowledge of the ECMAScript specification, memory isolation, and capability-based security architectures to prevent side-channel or prototype pollution escapes.
Discussion
3 comments analyzed.
Concerns raised: Capability dissemination beyond intended reach through bot networks, Agents sharing capabilities in cliques without reputation concerns, Safety non-compositionality in multi-agent capability systems, Managing capability escalation and transitive closure risks
Feature requests: Revocability of granted capabilities built in from start, Capability management across multi-agent scenarios
Competitors
Other products that read as similar to this one : 3289 launches clear the similarity bar, closest 8 shown.
Attention rank: #1069 of 3290 (itself plus its competitors, highest first, normalized so YC and Product Hunt are compared fairly).
Launched 176 days after the earliest competitor.
- Silos, An open source (MIT) CLI sandbox orchestrator for local agents · hn · 2026-11-12 · 5 upvotes · similarity 0.70
- Multi-agent coding assistant with a sandboxed Rust execution engine · hn · 2026-04-06 · 10 upvotes · similarity 0.67
- Lula · hn · 2026-03-23 · 5 upvotes · similarity 0.67
- TakoVM · hn · 2026-06-30 · 6 upvotes · similarity 0.66
- Veris · hn · 2026-05-07 · 9 upvotes · similarity 0.66
- The CLI for browser agents · hn · 2026-06-29 · 5 upvotes · similarity 0.64
- AgentNest, self-hosted sandboxes for AI agents · hn · 2026-07-23 · 12 upvotes · similarity 0.64
- Kyushu · hn · 2026-06-07 · 89 upvotes · similarity 0.64
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