Agents SDK

What's new

A weekly digest for the changes worth posting: the headline, why it matters, and a clean changelog for what shipped.

This section turns the raw pace of product and docs work into something editorial: one clear weekly digest instead of a stream of scattered updates.

The idea is simple: keep the raw internal changelog as source material, then publish a lighter weekly roundup that turns the most important shipped work into something readable.

Week 15April 6-10, 2026Sandboxes / Runtime / Templates

Sandbox config opens up, and Claude Code runtime moves to ACP

Sandbox shape moved out of fixed template defaults: `cpuCount`, `memoryMB`, `timeoutMs`, and the `networkAllowOut`/`networkDenyOut` pair are now set in `agent.config.ts` or overridden per-call in the server SDKs. Claude Code sessions migrated from per-message SDK boot to a persistent ACP path inside the sandbox, so warm follow-ups reuse the same session instead of booting a fresh transformer each turn.

Also this week

  • `/agents/new` quickstart wizard (alpha)
  • `/community/agents` Agent Templates registry
  • runtime-tagged billing events on relay
  • mobile action bars on agent pages
Read the Week 15 digest
What's New - 21st Agents SDK Docs