GPT-6 Astra in OpenCode 1.18.32
skills off
Zoom, inline player and more ways to view
The model's own page, run in a sandboxed frame only when you ask (a page that needs its own origin opens in a new tab on a separate demo site). Phones get a full-screen player capped at 1.5x pixel density (2x on larger screens) so it stays smooth; the original page runs uncapped. It starts in its auto-tour (T switches to play mode on a keyboard).
Wall time 33m 21sCost $6.88 reported
Generation timelapse
Generation timelapse (the agent's screen during the run, sped up). This is not the finished video. Download video (538 KB).
Review
No verdict yet.
The full review
OK. Finished on its own after 33.4 min.
Scores
AI judge
Not scored
No rubric for this prompt
Visitor votes and reviewer grades are not available yet.
- AI judge
- AI judge: the test runner (model claude-opus-5-5), scoring by visual review of the 1600 px render against the pre-registered rubric. No AI-judge score exists for this result: there is no rubric for this prompt, so no score is shown and none is made up.
- Visitors
- Public voting with a blind reveal is coming: you score the output first, then see the other scores.
- Reviewer
- The reviewer's own grade appears here once it is added.
Scores compare results for the same prompt only. AI-judge boards rank runs within one prompt, equal totals sharing a rank; scores from different prompts are never averaged.
Downloads
Files actually published for this run. Original output, site-made previews and post-run conversions are labelled separately.
The exact prompt
as run, 1,336 characters. Every result for this prompt
Build an explorable tropical island in Three.js. The island has white sand beaches, palm trees, a green hilly interior and a small fishing village of wooden huts with thatched roofs, joined to the sea by a long wooden pier with boats moored alongside. The ocean around it is animated, with waves, foam along the shore and clear shallow water over a reef where fish swim among corals and sea plants, fading to deep blue further out. Let the player switch between modes: walk on the island, swim at the surface, dive underwater (with underwater fog and caustic light), sail a small boat around the island, and fly a free camera. Add a time-of-day panel with a slider that moves the sun from morning through sunset to night, changing the sky, lighting and water colours, with stars and lit windows in the village at night. Show the controls on screen. Everything is built in code from Three.js geometry, shaders and materials; no external models or textures. Build it as index.html (plus any local asset files you create) in the current directory. Three.js may load from a pinned CDN. You may serve it locally and open it in headless chromium (/usr/bin/chromium, software WebGL, no GPU) to screenshot and inspect your own output, and iterate on your own before finishing. Close any browser you open as soon as you've taken your screenshot.
How it was made
Versions saved during the run
3 intermediate outputs, in the order the model wrote them.
Step by step
The prompt, every agent turn and tool call (tool name and a one-line summary; inputs and outputs are not shown), then the final message. The full transcript is 10.6 MB; it is published as a scrubbed, compressed download rather than shown on the page.
Show all 96 steps
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Download the full transcript OpenCode session export, 128 KB, gzip. Scrubbed: anything that looks like a key, token, e-mail address or phone number is replaced, and account details and the test machine's file paths are removed.
Cost breakdown
Headline cost $6.88, as reported by OpenCode (its own bill for the run). The list-price estimate from the token counts is $6.66.
| Tokens by type | Tokens | $ per 1M | Cost |
|---|---|---|---|
| Input (uncached) | 144 | $10.00 | $0.0014 |
| Cache write | 87,671 | $10.00 | $0.8767 |
| Cache read | 2,617,726 | $1.00 | $2.6177 |
| Output | 63,320 | $50.00 | $3.1660 |
| of which reasoning | 24,036 | billed as output |
- Total computed from tokens
- $6.6619
- Total reported by the harness
- $6.8811
- Difference
- Harness-reported $6.8811 vs list-price estimate $6.6619 (-3.2%); the harness figure is the headline.
OpenCode 1.18.32 reported its own total; token counts x list prices shown beside it. Cache writes priced at the input rate (the price table has no separate cache-write price). The harness reports reasoning tokens separately from output; here output includes them (39,284 visible + 24,036 reasoning), and both bill at the output rate.
Prices: Project price table (vendor list prices), 2026-09-22.
Run notes
- frozen prompt (rewritten): engine/prompts_rewritten/threejs_tidewater.txt: written by us from the recorded description (zero results)
- plain OpenCode config copy (providers only; no ECC instructions/agents)
- opencode export written to a file (not piped)
- Mode: interactive TUI in tmux (160x48), inside bubblewrap sandbox
- Isolation audit: outside paths seen