Subagents Grow Up: Gemini Isolates Tool Boundaries While Codex Shares Trust by Default

Two agent platforms shipped subagent changes within hours of each other. One tightened what a child agent can see and use . The other tightened what a child agent can teach the rest of the system to trust . Same category. Very different instinct.

repo openai/codex main

6 source signals 3 repos source trail

> source trail / March 18, 2026 / Daily Edition

View Evidence Read Story

Edition File

All editions ›

This edition has one lead story and its evidence trail.

Recent Editions

Full history ›

May 25, 2026

Agent Reliability Is Moving Into the Test Rig

The newest source-readable trail points away from model mystique and toward the workflows that test, trace, serialize, and maintain agent behavior.

1 story 5 source signals 2 repos

May 24, 2026

Agent Runtimes Are Learning Where to Say No

After shipping more visible control planes, agent projects are now tightening the places where tools, plugins, credentials, chat context, and test runs are allowed to flow.

1 story 6 source signals 3 repos

May 23, 2026

Agent Runtimes Are Learning to Ship Their Control Plane

A set of Codex, Hermes Agent, Gemini CLI, and Crush commits shows agent tools packaging the machinery around the model: shells, platform adapters, context profiles, and skill catalogs.

1 story 13 source signals 5 repos

May 22, 2026

Agent Runtimes Are Making Their Limits Explicit

Recent Crush and LangChain changes show agent infrastructure turning hidden boundaries - shell permission, context overflow, and model token limits - into runtime contracts that users and developers can see.

1 story 8 source signals 2 repos

Agent Atlas

How AI Agents Work

The long-form map behind the daily paper: context, tools, loops, memory, delegation, safety, interface, and trust.

Open Atlas

1 article 3 repos detected 6 source signals 4 atlas drafts