Rivet

Rivet Actors are the primitive for stateful workloads.

Built for AI agents, collaborative apps, and durable execution.

Open-source.

[Rivet @rivet_dev]

Say hello to agentOS (beta)

A portable open-source OS built just for agents. Powered by WASM & V8 isolates.

🔗 Embedded in your backend
⚡ ~6ms coldstarts, 32x cheaper than sbxs
📁 Mount anything as a file system (S3, SQLite, …)
🥧 Use Pi, Claude Code/Codex/Amp/OpenCode soon

[Rivet @rivet_dev]

We have passed over 10k stars✨

[Nathan Flurry 🔩 @NathanFlurry]

Memory of coding harnesses in agentOS (portable WASM OS for agents):

🥇 Codex (WASM): 122 MB
🥈 Pi (V8): 153 MB
🥉 Claude Code (V8): 316 MB

OpenCode & Amp coming soon

This is the memory for the *entire* VM, including bash, Node.js, Python, git fully loaded

[Rivet @rivet_dev]

Get started: https://t.co/io3GXVHR8x

[Rivet @rivet_dev]

Say hello to agentOS (beta)

A portable open-source OS built just for agents. Powered by WASM & V8 isolates.

🔗 Embedded in your backend
⚡ ~6ms coldstarts, 32x cheaper than sbxs
📁 Mount anything as a file system (S3, SQLite, …)
🥧 Use Pi, Claude Code/Codex/Amp/OpenCode soon

[Rivet @rivet_dev]

GitHub: https://t.co/v2u2N9Jbbk

[Nathan Flurry 🔩 @NathanFlurry]

🤘 Rivet Secure Exec (V8 isolates):

Securely execute Node.js anywhere (Railway, Vercel, Hetzner, Kubernetes)

vs

🔥 Firecracker (microVMs):

Full Linux operating system, but requires specialized infrastructure

[Rivet @rivet_dev]

Exciting launch powered by Rivet 🔩

[Advait Paliwal @advaitpaliwal]

Introducing Agent Computer

Cloud computers for AI agents in <0.5s with persistent disk, shared credentials, and SSH access

https://t.co/oYPPhqyN3z

[Rivet @rivet_dev]

@designrivet

[Nathan Flurry 🔩 @NathanFlurry]

Rivet Secure Exec v0.2.0 just got more secure

Process isolation now separates Node.js instances from the host

- Security → improved isolation against V8 0-days
- OOM protection → in case of over-provision
- Bun support → no longer tied to embedded V8

All written in Rust 🦀

[Nathan Flurry 🔩 @NathanFlurry]

Rivet Secure Exec 0.2.0 now has 2.8x faster coldstarts for Node.js execution without a sandbox

17.9 ms → 6.2ms (p99)
16.2ms → 4.0 ms (p50)

Instead of rebuilding the runtime every creation, V8 isolate snapshots let us clone a ready-to-go instance instantly – much like in KVM

[Rivet @rivet_dev]

Powered by Secure Exec ⚡️

[Hugo @hugorcd]

Just shipped something I'm really excited about in @𝗇𝗎𝗑𝗍𝗃𝗌/𝗆𝖼𝗉-𝗍𝗈𝗈𝗅𝗄𝗂𝗍: Code Mode.

The idea: instead of the LLM calling your MCP tools one at a time (and resending ALL tool descriptions every single round-trip), it writes JavaScript that orchestrates everything in one go.

Loops, conditionals, Promise.all, real control flow, not 8 separate LLM turns.

With 50 tools the token savings are insane: -81% on tool description overhead alone.

And the best part? Your existing tools don't change at all. One line:
`experimental_codeMode: true`

Runs in a secure V8 sandbox thanks to @rivet_dev's secure-exec, perfect timing with their launch yesterday.

https://t.co/eOOHnfRadH

[Nathan Flurry 🔩 @NathanFlurry]

Hot damn that was fast

Code Mode powered by Secure Exec SDK

Let LLMs execute JavaScript to call MCP/tool calls

- 81% reduction in tool usage
- Drop in replacement
- Real control flow

Adding this to our Code Mode docs 🤘

[Nathan Flurry 🔩 @NathanFlurry]

Secure Exec SDK gives agents an insanely customizable virtual OS

File system → persist to S3, SQLite, Postgres, etc
Network (outbound) → granular network control
Network (inbound) → dev servers (Hono, Express, etc)
Child process → custom tools