Claude Opus 5.5
Anthropic's first Claude 5.5 model. Fable-level on most work, about 40% cheaper than Opus 5. API id claude-opus-5-5.
Claude Opus 5.5 · 22 September 2026
Opus 5.5 builds on X
Anthropic shipped Claude Opus 5.5 on 22 September 2026. 41 first-party ships we cataloged, each with the original post.
Anthropic priced input at $4 per million tokens and output at $20, with cache reads at $0.20. They say that nets out about 40% cheaper than Opus 5 on typical agent work, and more than 30% faster. The model id is claude-opus-5-5. People used the extra headroom on games, labs, and films that are really programs.
Official note: Introducing Claude Opus 5.5. API: model overview. Announcement: the original post.
Antikythera
Underwater excavation game about the first computer. Single 3 MB HTML file. Everything you see and hear is generated in the browser.
Arkenfall
Open-world browser game. Terrain, creatures, boss, sound, and music all in code. No asset files.
Lemo-Opuscar
Open-source film style library for Opus 5.5. 39 styles, director guide, deterministic Canvas and WebGL frames. MIT.
Clearwater
Photographic shallow water in one HTML file. WebGL2 waves, refraction, caustics. The X video is a real-time capture.
Transformers
Cybertruck and Ferrari F1 that turn into robots. Three.js and WebGPU. Playable, MIT.
Noxe Pixel Engine
Browser engine that renders small 3D dioramas as pixel art, with time of day, weather, and sound. Made with Opus 5.5.
Bottle Studio
A bottle studio in the browser. Glass and light in one HTML file. Built with Opus 5.5. Open source.
Voidless
MCP that builds a Godot character from one chat: directions, a walk, a spell, and the effect.
GlideCut
Browser editor that zooms a screen recording where you click and type, then exports an MP4. Built with Opus 5.5. Open source.
HackerTube
YouTube picked from videos Hacker News keeps recommending. No login. Thumbnails are a frame from the middle of the video.
HackerTube TV
Native Android TV app for HackerTube. Pick a video and it plays on YouTube on the TV. Built with Opus 5.5.
PixelFX
Pixel effects written as code, with a skill that renders a clip and fixes the frames. Open source.
Daruma Desk
Mac desk of tasks drawn as daruma dolls. An eye fills in when you finish one. Built with Opus 5.5.
Zen Garden
Relaxing puzzle of Japanese gardens, drawn in code with Metal shaders. Built with Opus 5.5.
Chip Fab
Three.js tour of a chip fab. One speck of dust kills the wafer. Made with Opus 5.5.
STUFFED
Browser teddy-bear shooter. The game, the capture, and the song were made with Opus 5.5.
Solar System Atlas
A live 3D model of the solar system, with planets on their real orbits. Built with Opus 5.5.
Tidebreaker
Platformer with the atmosphere of Ori and a giant boss chase. Opus 5.5. Plays in the browser and on a phone.
Naga Studio
macOS app that remaps mouse buttons. Built with Opus 5.5, then open sourced.
Obelisk of Theodosius
The obelisk in Sultanahmet, readable. One HTML file, Three.js, Opus 5.5.
Obsidian
One monolith splits into 32,000 shards, then reforms as a cathedral and a whale. Opus 5.5 and Three.js. Public repo.
Bitcoin block rings
Live 3D map of every mined Bitcoin block, coiled like Saturn's rings from genesis to now. Opus 5.5 and Three.js.
Tension Type
Words held in a vacuum by thousands of threads. Drag them, strum them, they glow and snap. Live WebGL, one conversation with Opus 5.5.
Cybertruck steer-by-wire lab
Interactive 3D lab that shows how Cybertruck steer-by-wire works. Turn it yourself.
pixi-gomoku
Gomoku in the browser. Three AI levels, local two-player, room links, cross-device saves. MIT.
Sakutei
Japanese garden sandbox in the browser. Rake sand, set stones, waterfall, lanterns. Four styles and seasons.
AWM reborn
2009 Flash and Papervision 3D memorial wall, rebuilt in Three.js and Vite. Touch, mapping, and video conversion in one pass.
Read the Iron
You are a servitor on a Titan mecha, tending a huge actuator. The world happens around you. Browser game.
Crown and Claw
Medieval zoo tycoon. Economy, mythical beasts, terrain builder, staff. Two prompts, playable in the browser.
Lens lab
Interactive camera-focus lab. Move the ring and the glass elements shift the sharp plane through the scene.
shadow-garage
Software for silhouette plotters. Cut your own stickers. Opus 5.5, public repo.
claude-animation-skill
Node Canvas character rig, frame checks, and FFmpeg. The ant colony film has matching source.
opus-js-animations
Code-drawn paper-lightbox frames plus a spoken-word track. Matching project for the Shaml scene.
Mothership shooter
One HTML file, 936 lines. Waves, power-ups, combo, mothership every fifth wave. Music and lasers synthesized in the browser.
Akikan
Pick up the far cans or the near ones? Playable race with a making-of. Browser, no download.
Stickman (Opus 5.5)
Stickman fighter with character customization and skills. One HTML file from Opus 5.5. Playable.
netherspace
Low-effort platformer. An AI agent wakes up and reveals the world as he solves queries. Claude Opus 5.5.
S3GA Rally
Retro rally in the browser. C++ engine, no asset files. Opus 5.5, MIT, playable.
Videos people made with it
56 featured cases from a source-linked index of 182 reviewed posts. Films, explainers, and captures. Opus wrote code or directed tools. It did not paint the MP4 by itself.
Opus 5.5, in short
- What is Claude Opus 5.5?
- Anthropic's first Claude 5.5 model, released 22 September 2026. API id claude-opus-5-5. They say it performs at the level of Claude Fable 5.1 on most work and costs about 40% less to run than Opus 5.
- How much does it cost?
- API list price: $4 per million input tokens, $20 per million output, $0.20 per million cache reads. Fast mode is $8 / $40. We have not re-run those benches.
- Does it generate video?
- Not as pixels. Text and image in, text out. People get MP4s because Opus wrote the renderer, directed another video model, edited footage, or built an app they recorded. That catalog lives at /opus/videos.
- What counts as an Opus 5.5 build here?
- A public URL or repo posted on X by the person who made it, tagged to this drop. Playable games, labs, and production systems. Joke wrappers stay off the list.
