// An archive of animated companions spawned inside OpenAI Codex. Synced live from codex-pet-share. Browse them, study their stats, then throw your favorite into the arena.
Codex is OpenAI's AI coding agent — a software engineer that lives in your terminal, IDE, browser, Slack, and now a desktop app. Originally launched in May 2025 as a cloud agent powered by codex-1, it went generally available in October 2025 and now runs on GPT-5-Codex, OpenAI's frontier coding model. It writes features, refactors entire codebases, runs tests, and ships PRs — in parallel, on its own.
$ npm i -g @openai/codex $ codex ▸ codex v1.0 — gpt-5-codex > hatch a pixel pet ✓ generating spritesheet… ✓ uploading to codex-arena… ◆ pet#Trump spawned ♥
In May 2026, OpenAI shipped Codex Pets — a playful new companion layer inside the Codex desktop app. You can hatch and name a pixel-art AI sidekick that pops up during coding sessions, chats via speech bubbles, and reacts to your work. Each pet is generated as a multi-state animated spritesheet (idle, running, waving, jumping, failed, review…) and can be shared to a community archive.
CODEX ARENA is the unofficial archive — every pet on this site comes straight from codex-pet-share, OpenAI's public feed of community-created Codex Pets. We mirror the spritesheets, derive deterministic battle stats from each pet's metadata, and let you fight them in Codex Arena, a 4-player free-for-all.
Generated as 9-row animated spritesheets by GPT-5-Codex.
Pulled from codex-pet-share every 10 minutes.
PWR/SPD/DEF/STA derived from likes, views, downloads.
Pick any pet and fight 4-player free-for-all online.
// Every claim on this page is sourced from OpenAI's public announcements, the Codex documentation, and the open codex-pet-share feed. CODEX ARENA is unofficial and not affiliated with OpenAI.
Overview of Codex, GPT-5-Codex, Cloud / CLI / IDE surfaces.
Original launch of the cloud agent powered by codex-1.
GA announcement, Slack & SDK integrations.
Reveal of GPT-5-Codex as the underlying model.
Public archive of community-hatched Codex Pets — mirrored here.
// OpenAI, Codex and GPT-5-Codex are trademarks of OpenAI. CODEX ARENA mirrors public sprite data for fan / archival use only.
352 fighters waiting in the archive. No login. No download. Just sprites and chaos.