Guide on using Opus 5.5 in Claude apps and Claude Code. Key practices include providing complete task descriptions with clear finish lines, removing unnecessary thinking prompts, allowing mid-run interruptions, specifying design constraints, and setting stop/go rules in CLAUDE.md files to optimize long-running workflows.
This guide explains how to work effectively with Opus 5.5 in Claude and Claude Code. Key practices include giving complete tasks with clear finish lines, removing explicit thinking prompts since Opus 5.5 thinks automatically, sending follow-ups during long runs, specifying design patterns to avoid, and setting rules in CLAUDE.md about when to stop for input versus continuing autonomously.
Claude Code now supports native AGENTS.md files as instruction files, configurable through four modes that control how AGENTS.md and CLAUDE.md files are loaded in the project context. The feature is built-in with settings accessible via /config or user configuration files.
A Hacker News discussion asking users to share their ChatGPT custom instructions in 2026, referencing a similar 2024 thread and noting significant model changes over two years.
Claude Code now supports AGENTS.md as a plugin that loads alternative instruction files based on configuration. The plugin offers four modes controlling whether CLAUDE.md, AGENTS.md, or both are loaded as project instructions, with behavior determined by the instructionFiles setting in user or managed configuration.