AI Coding GuidePractical, 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.https://aicoding-guide.com/enCLAUDE.md vs AGENTS.md vs GEMINI.md: keep one source of truth across three toolshttps://aicoding-guide.com/en/posts/context-files-comparison/https://aicoding-guide.com/en/posts/context-files-comparison/How Claude Code, Codex and Gemini CLI load their context files, and how to keep one source of truth with imports, context.fileName and symlinks instead of three copies.Fri, 11 Sep 2026 00:00:00 GMTCLAUDE.mdAGENTS.mdGEMINI.mdconfigurationcomparisonDoes # add to CLAUDE.md in Claude Code? What the current docs sayhttps://aicoding-guide.com/en/posts/claude-md-hash-shortcut/https://aicoding-guide.com/en/posts/claude-md-hash-shortcut/You typed # expecting it to append to CLAUDE.md, and nothing happened. Here is what the official docs actually say, and the three documented ways to add to CLAUDE.md.Fri, 11 Sep 2026 00:00:00 GMTClaude CodeCLAUDE.mdmemory/memoryGemini CLI vs Claude Code: free tier, context, configuration and permissionshttps://aicoding-guide.com/en/posts/gemini-cli-vs-claude-code/https://aicoding-guide.com/en/posts/gemini-cli-vs-claude-code/Gemini CLI and Claude Code compared on the parts that change slowly: the free tier, context handling, context files, permission control, extensibility and licensing.Fri, 11 Sep 2026 00:00:00 GMTGemini CLIClaude Codecomparisontool choiceInstalling Gemini CLI and writing GEMINI.md: getting started with a free Google accounthttps://aicoding-guide.com/en/posts/gemini-cli-setup-gemini-md/https://aicoding-guide.com/en/posts/gemini-cli-setup-gemini-md/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.Fri, 11 Sep 2026 00:00:00 GMTGemini CLIGEMINI.mdinstallationgetting startedAllow only some tools from an MCP server in Codex: enabled_tools, timeouts, and approval modeshttps://aicoding-guide.com/en/posts/codex-mcp-enabled-tools-timeout/https://aicoding-guide.com/en/posts/codex-mcp-enabled-tools-timeout/Restrict which tools an MCP server exposes to Codex with enabled_tools and disabled_tools, tune startup_timeout_sec and tool_timeout_sec, and require approval before tools run.Thu, 10 Sep 2026 00:00:00 GMTCodexMCPconfig.tomlenabled_toolstool_timeout_secCompact earlier or never: Claude Code's /autocompact, autoCompactWindow, and CLAUDE_AUTOCOMPACT_PCT_OVERRIDEhttps://aicoding-guide.com/en/posts/claude-code-autocompact-window/https://aicoding-guide.com/en/posts/claude-code-autocompact-window/How to change when Claude Code auto-compacts: /autocompact and autoCompactWindow, the --autocompact flag, the percent override, their precedence, and autoCompactEnabled.Thu, 10 Sep 2026 00:00:00 GMTClaude Codecompactionautocompactcontext windowenvironment variablesControl Codex web search with the web_search setting: disabled, cached, indexed, and livehttps://aicoding-guide.com/en/posts/codex-web-search-mode/https://aicoding-guide.com/en/posts/codex-web-search-mode/The four values of Codex CLI's web_search setting and their defaults, the --search flag for one-off use, why indexed reduces prompt injection risk, and how to restrict domains.Thu, 10 Sep 2026 00:00:00 GMTCodexconfig.tomlweb_searchweb searchsecurityFix Claude Code Bash timeouts and truncated output: BASH_DEFAULT_TIMEOUT_MS and bashOutputMaxCharshttps://aicoding-guide.com/en/posts/claude-code-bash-timeout-env/https://aicoding-guide.com/en/posts/claude-code-bash-timeout-env/Why Claude Code's Bash tool stops at 2 minutes or cuts long output, and how to tune it with BASH_DEFAULT_TIMEOUT_MS, BASH_MAX_TIMEOUT_MS, and bashOutputMaxChars.Thu, 10 Sep 2026 00:00:00 GMTClaude CodeBashtimeoutenvironment variablessettings.jsonGet a desktop or Slack notification when Codex finishes a turn: notify and tui.notificationshttps://aicoding-guide.com/en/posts/codex-notify-turn-complete/https://aicoding-guide.com/en/posts/codex-notify-turn-complete/Run a program when Codex CLI completes a turn with the notify setting, the JSON it receives, and how tui.notifications filters terminal notifications, with macOS/Linux examples.Thu, 10 Sep 2026 00:00:00 GMTCodexconfig.tomlnotifynotificationstuiHide or expand reasoning in Codex output: hide_agent_reasoning and model_reasoning_summaryhttps://aicoding-guide.com/en/posts/codex-hide-agent-reasoning/https://aicoding-guide.com/en/posts/codex-hide-agent-reasoning/The three Codex CLI settings that control reasoning display: hide_agent_reasoning, show_raw_agent_reasoning, and model_reasoning_summary, and how they differ from reasoning effort.Thu, 10 Sep 2026 00:00:00 GMTCodexconfig.tomlhide_agent_reasoningreasoningoutputKeep API keys out of the commands Codex runs: the shell_environment_policy settinghttps://aicoding-guide.com/en/posts/codex-shell-environment-policy/https://aicoding-guide.com/en/posts/codex-shell-environment-policy/Control which environment variables reach the commands Codex CLI runs with shell_environment_policy: inherit values, default handling of KEY/SECRET/TOKEN names, filters, and set.Thu, 10 Sep 2026 00:00:00 GMTCodexconfig.tomlshell_environment_policyenvironment variablessecurityLet Codex write outside the workspace in workspace-write mode: writable_roots and the /tmp ruleshttps://aicoding-guide.com/en/posts/codex-writable-roots/https://aicoding-guide.com/en/posts/codex-writable-roots/What Codex's workspace-write sandbox can write to by default (cwd, /tmp, $TMPDIR), how to add paths with writable_roots, how to exclude temp directories, and why .git is read-only.Thu, 10 Sep 2026 00:00:00 GMTCodexsandboxwritable_rootsworkspace-writeconfig.tomlLog which CLAUDE.md files Claude Code loads, and when, with the InstructionsLoaded hookhttps://aicoding-guide.com/en/posts/claude-code-instructions-loaded-hook/https://aicoding-guide.com/en/posts/claude-code-instructions-loaded-hook/Use the InstructionsLoaded hook to record every CLAUDE.md and .claude/rules/ file as it enters context: matcher values, input JSON fields, a logging example, and its limits.Thu, 10 Sep 2026 00:00:00 GMTClaude CodehooksInstructionsLoadedCLAUDE.mddebuggingManage Codex's "trust this folder?" prompt in config.toml with the projects trust_level settinghttps://aicoding-guide.com/en/posts/codex-project-trust-level/https://aicoding-guide.com/en/posts/codex-project-trust-level/How Codex records project trust under [projects."<absolute path>"] trust_level, what it ignores for untrusted projects (.codex/config.toml, hooks, rules), and its precedence.Thu, 10 Sep 2026 00:00:00 GMTCodexconfig.tomltrust_levelsecurityproject settingsOpen file references from Codex output directly in VS Code or Cursor with file_openerhttps://aicoding-guide.com/en/posts/codex-file-opener/https://aicoding-guide.com/en/posts/codex-file-opener/How the file_opener setting in Codex CLI turns cited file paths into clickable editor links: the values (vscode, vscode-insiders, windsurf, cursor, none) and terminal requirements.Thu, 10 Sep 2026 00:00:00 GMTCodexconfig.tomlfile_openerVS CodeCursorPin environment variables in Claude Code's settings.json with the env key: precedence and pitfallshttps://aicoding-guide.com/en/posts/claude-code-settings-env-block/https://aicoding-guide.com/en/posts/claude-code-settings-env-block/How the env key in Claude Code's settings.json works: it overrides shell variables, applies to every session and subprocess, and when a saved change reaches a running session.Thu, 10 Sep 2026 00:00:00 GMTClaude Codesettings.jsonenvironment variablesenvconfigurationRemove or customize the Co-Authored-By trailer Claude Code adds to commits with the attribution settinghttps://aicoding-guide.com/en/posts/claude-code-attribution-trailer/https://aicoding-guide.com/en/posts/claude-code-attribution-trailer/How to hide or rewrite the Co-Authored-By commit trailer and the PR attribution line with the attribution setting (commit, pr, sessionUrl), plus the deprecated includeCoAuthoredBy.Thu, 10 Sep 2026 00:00:00 GMTClaude CodegitCo-Authored-Byattributionsettings.jsonScope Claude Code rules to specific files with .claude/rules/ and paths frontmatterhttps://aicoding-guide.com/en/posts/claude-code-rules-path-scoped/https://aicoding-guide.com/en/posts/claude-code-rules-path-scoped/When CLAUDE.md gets long, move topics into .claude/rules/ and add paths frontmatter so a rule loads only when Claude touches matching files: glob syntax, timing, user-level rules.Thu, 10 Sep 2026 00:00:00 GMTClaude CodeCLAUDE.mdrulespathsmonorepoStop Claude Code loading other teams' CLAUDE.md files with claudeMdExcludeshttps://aicoding-guide.com/en/posts/claude-code-claude-md-excludes/https://aicoding-guide.com/en/posts/claude-code-claude-md-excludes/Keep a monorepo root or another team's CLAUDE.md out of your context with claudeMdExcludes: pattern syntax, which settings file to use, what cannot be excluded, and how to verify.Thu, 10 Sep 2026 00:00:00 GMTClaude CodeCLAUDE.mdclaudeMdExcludesmonoreposettings.jsonStop Codex saving conversation history to disk: history.persistence and where credentials are storedhttps://aicoding-guide.com/en/posts/codex-history-persistence-none/https://aicoding-guide.com/en/posts/codex-history-persistence-none/Keep Codex CLI from writing conversation history with history.persistence = "none", cap it with max_bytes, and choose where login credentials live with cli_auth_credentials_store.Thu, 10 Sep 2026 00:00:00 GMTCodexconfig.tomlhistoryprivacyauthenticationTurn off Claude Code auto memory or move it: autoMemoryEnabled and autoMemoryDirectoryhttps://aicoding-guide.com/en/posts/claude-code-auto-memory-disable/https://aicoding-guide.com/en/posts/claude-code-auto-memory-disable/What Claude Code's auto memory records and where, how to disable it with autoMemoryEnabled or CLAUDE_CODE_DISABLE_AUTO_MEMORY, how to relocate it, and the MEMORY.md load limit.Thu, 10 Sep 2026 00:00:00 GMTClaude Codeauto memoryautoMemoryEnabledautoMemoryDirectorysettings.jsonWhat Claude Code's /init puts in CLAUDE.md, and what to change afterwardshttps://aicoding-guide.com/en/posts/claude-md-init-command/https://aicoding-guide.com/en/posts/claude-md-init-command/What the /init command inspects and writes into CLAUDE.md, how it behaves when a file already exists, what to cut and add after generation, and how to confirm the file loads.Thu, 10 Sep 2026 00:00:00 GMTClaude CodeCLAUDE.md/initsetupWhen Claude Code deletes transcripts: the cleanupPeriodDays default and how to change retentionhttps://aicoding-guide.com/en/posts/claude-code-cleanup-period-days/https://aicoding-guide.com/en/posts/claude-code-cleanup-period-days/Claude Code stores transcripts in plain text under ~/.claude. What cleanupPeriodDays does (default 30 days, minimum 1), what the sweep deletes and skips, and how to stop writing.Thu, 10 Sep 2026 00:00:00 GMTClaude CodecleanupPeriodDaystranscriptsprivacysettings.jsonWhen does Claude Code load a CLAUDE.md in a subdirectory? Monorepo layout and how to checkhttps://aicoding-guide.com/en/posts/claude-md-subdirectory/https://aicoding-guide.com/en/posts/claude-md-subdirectory/When Claude Code loads a CLAUDE.md in a subdirectory, how it combines with the root file, a monorepo layout that keeps context small, and how to check with /memory.Thu, 10 Sep 2026 00:00:00 GMTClaude CodeCLAUDE.mdmonoreposubdirectoryWhy Codex reads only part of AGENTS.md: project_doc_max_bytes and fallback file nameshttps://aicoding-guide.com/en/posts/codex-agents-md-max-bytes-fallback/https://aicoding-guide.com/en/posts/codex-agents-md-max-bytes-fallback/How Codex discovers AGENTS.md (search order, AGENTS.override.md, the 32 KiB default cap, fallback names) and how project_doc_max_bytes and project_doc_fallback_filenames change it.Thu, 10 Sep 2026 00:00:00 GMTCodexAGENTS.mdproject_doc_max_bytesconfig.tomlmonorepoWhy the CLAUDE.md in a --add-dir directory is not loaded, and the setting that fixes ithttps://aicoding-guide.com/en/posts/claude-code-add-dir-claude-md/https://aicoding-guide.com/en/posts/claude-code-add-dir-claude-md/A --add-dir directory does not load its CLAUDE.md by default. What CLAUDE_CODE_ADDITIONAL_DIRECTORIES_CLAUDE_MD changes, which files it covers, and how to make it permanent.Thu, 10 Sep 2026 00:00:00 GMTClaude CodeCLAUDE.md--add-diradditionalDirectoriesenvironment variablesAdding MCP servers to Claude Code: claude mcp add versus .mcp.jsonhttps://aicoding-guide.com/en/posts/claude-code-mcp-servers-setup/https://aicoding-guide.com/en/posts/claude-code-mcp-servers-setup/Add and manage MCP servers in Claude Code: claude mcp add for stdio and HTTP servers, the local / project / user scopes, sharing via .mcp.json, authentication and troubleshooting.Wed, 09 Sep 2026 00:00:00 GMTClaude CodeMCPconfigurationintegrationsClaude Code permissions in settings.json: allow, deny and ask rules with real exampleshttps://aicoding-guide.com/en/posts/claude-code-settings-json-permissions/https://aicoding-guide.com/en/posts/claude-code-settings-json-permissions/Control what Claude Code may do without asking: allow / deny / ask rules in settings.json, the pattern syntax, scope precedence, and recommended setups for solo and team work.Wed, 09 Sep 2026 00:00:00 GMTClaude Codesettings.jsonpermissionssecurityCodex CLI approval modes versus sandbox modes: safe combinations for autonomous runshttps://aicoding-guide.com/en/posts/codex-approval-sandbox/https://aicoding-guide.com/en/posts/codex-approval-sandbox/What Codex CLI's approval policy and sandbox mode each control, what --full-auto really does, how to pin them in config.toml, and which pair fits research, daily work and CI.Wed, 09 Sep 2026 00:00:00 GMTCodexCodex CLIapprovalssandboxsecurityCodex vs Claude Code: pricing, permission models, config files and when to use whichhttps://aicoding-guide.com/en/posts/codex-vs-claude-code/https://aicoding-guide.com/en/posts/codex-vs-claude-code/OpenAI's Codex and Anthropic's Claude Code compared on what changes slowly: pricing, permission and sandbox design, AGENTS.md versus CLAUDE.md, cloud execution and CI.Wed, 09 Sep 2026 00:00:00 GMTCodexClaude Codecomparison