Settings and how-tos for Claude Code, Codex and Gemini CLI, verified against the official docs
Practical, verified guides to installing and configuring AI coding tools such as Claude Code, Codex and Gemini CLI: config files, permissions, hooks, MCP and recommended settings.
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- Claude CodeConfiguring and using Claude Code, Anthropic's coding agent for the terminal and VS Code
- CodexConfiguring and using OpenAI's Codex CLI, VS Code extension and cloud agent
- Gemini CLIConfiguring and using Google's Gemini CLI
- AI coding in generalCross-tool comparisons, security and workflow design
Latest & updated
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Codex CLI v0.164 adds /presets and inline /permissions arguments for permission profiles
v0.164.0 stores reusable prompts in ten /presets slots and lets /permissions pick a permission profile as an argument. Plus credential masking and hardened sandbox checks.
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Stop Claude Code reading your .env with a Read deny rule
A Read deny rule is the reliable way to keep .env out of the model's input. How to write the pattern, how depth and anchoring change its reach, and where deny stops working.
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This week in Claude Code, Codex and Gemini CLI (week of October 25, 2026)
Claude Code 2.1.309 lands a cluster of sandbox and permission-check bypass fixes, and Codex 0.164.0 adds /presets and credential masking. The ten changes from this week.
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Gemini CLI v0.65 enforces read-only settings in untrusted folders and adds OTLP headers
Only one of the 27 entries in v0.65.0 is a feature, custom OTLP headers. The rest covers untrusted folder settings, eager reads for @ references, and session resume fixes.
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Claude Code plan mode: review the plan before any file is touched
How to enter plan mode in Claude Code, how it differs from the other permission modes, the path from an approved plan to the code, and when a plan is worth the extra step.
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Gemini CLI v0.64 fixes the CPU hang on @ inside code and headless folder trust
v0.64.0 ships no new features. It fixes a hang where piping @scope/pkg into -p pinned the CPU at 100%, and a headless mode that treated untrusted folders as trusted.
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Installing Gemini CLI and writing GEMINI.md: getting started with a free Google account
Install Google's Gemini CLI, sign in with a Google account or API key, run your first task, and learn where GEMINI.md lives, how it is loaded, and how to check it with /memory.
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Codex CLI v0.163 turns Daybreak back on by default and makes /config searchable
v0.163.0 enables Daybreak by default for eligible accounts, adds search across /config, lets you steer a response mid-turn, and checks proxy permission before a DNS lookup.
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Claude Code starts in auto mode by default — all six permission modes compared
With v2.1.283 or later a terminal session starts in auto mode on every plan. What the six modes allow, and the two defaultMode values project settings ignore.
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Codex config.toml: set the model, model_reasoning_effort (low to ultra) and per-task profiles
Change model and reasoning effort in ~/.codex/config.toml (model_reasoning_effort = "high"), switch per-task profiles with --profile, and see which layer wins when settings overlap
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How to change reasoning effort in Codex CLI: model_reasoning_effort values and one-off overrides
How to change effort in Codex CLI: the model_reasoning_effort values (low, medium, high, xhigh, max, ultra) and how to set them in config.toml, with -c, or with /model.
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This week in Claude Code, Codex and Gemini CLI (week of October 18, 2026)
Claude Code now compacts idle conversations on its own, and Codex turned Daybreak back on by default. Plus the environment variables added in 2.1.299 to 2.1.302.