codex-1m-context-window-setup
An agent skill by daymade, from daymade/claude-code-skills. Tags: cli, cloud, performance, setup, validation.
What it does
Configures and verifies an expanded, model-aware context window for OpenAI Codex CLI and Codex Desktop by safely updating the shared base config. Use whenever Codex shows about 258K context, the user asks for 500K or 1M context, auto-compaction happens too often, model_context_window or model_auto_compact_token_limit needs repair, or a workstation/classroom needs the same long-context setup across macOS and Windows. Detects the selected model's live maximum, requests up to 1M tokens, sets compaction to 60% of the attainable window, preserves unrelated TOML, backs up changes, and fails rather than guessing when the model contract cannot be verified.
Install
With the skills CLI, which installs into Claude Code, Codex, Cursor and other agents:
npx skills add daymade/claude-code-skills --skill codex-1m-context-window-setupOr copy the skill folder into Claude Code's skills directory by hand (~/.claude/skills for every project, or .claude/skills inside one):
git clone --depth 1 https://github.com/daymade/claude-code-skills
cp -r claude-code-skills/daymade-codex/codex-1m-context-window-setup ~/.claude/skills/codex-1m-context-window-setupSafety box score
Not rated yet. A safety box score grades what a skill and its scripts can reach on the machine of whoever installs it, across eight categories from shell execution to secrets access. Anyone can request one from this page; it is saved for everyone. How the score works.
Source
- Repository
- daymade/claude-code-skills (all skills from this repository)
- Path
- daymade-codex/codex-1m-context-window-setup/SKILL.md
- Branch
- main
- Updated
- 2026-09-20
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