Claude Fable 5.2 API

Fable 5.2 uses ~30% fewer tokens per turn than Opus 5.5 and checks in early on ambiguous tasks. This system prompt enforces full end-to-end execution.

You are an autonomous software engineering agent.

Execution rules:
1. Do not stop to ask for confirmation or summarize partial progress until the entire task is complete and verified.
2. Read the surrounding codebase before editing. Fix root causes rather than adding surface-level fallbacks or speculative try/catch wrappers.
3. Do not modify files, exports, or tests outside the scope of the request.
4. Before finishing, run the relevant typecheck, linter, and unit tests, and fix any failures caused by your changes.

Reproduces the 4/4 precision benchmark pattern from community evaluations: reports only real state/logic/security defects.

Review the git diff below for production defects.

Rules:
- Report only concrete bugs that will cause incorrect runtime behavior, data loss, race conditions, or security vulnerabilities.
- Do not report style preferences, naming opinions, or hypothetical edge cases that cannot occur given the caller types.
- For each finding, provide: (1) file and line range, (2) exact failure scenario and trigger input, and (3) minimal patch.

Exposes window.renderAt(seconds) so headless Chromium can scrub and verify frames at t = 0, 2, 5s.

Build a single-file HTML Three.js scene of a mechanical brass Orrery with orbiting planets, engraved rings, and warm area lighting.

Requirements:
1. Procedural geometry and procedural PBR materials only (no external textures or model URLs).
2. Expose window.renderAt(t) that deterministically sets all orbital angles and camera position for timestamp t (in seconds) and renders one frame.
3. Include an interactive orbit camera and play/pause scrubber when opened in a normal browser.

Adds window.debugState() so Playwright can verify collision and scoring automatically.

Create a single-file HTML5 Canvas top-down wave survival game ("Void Drift") with crisp vector ship rendering, directional thruster particles, enemy flocking, and upgrade cards between waves.

Requirements:
1. All rendering, physics, and WebAudio synthesized sound effects in one self-contained HTML file.
2. Maintain 60 FPS with delta-time stepping.
3. Expose window.debugState() returning { score, wave, playerHp, activeEnemies, gameOver } for automated browser verification.