| name | research-upstream-api |
| description | Research an upstream library's source code and documentation to understand its API surface, algorithms, and behavior before porting features to Krayon. Use when the user asks to port, implement, or add missing features from an external library (D3, Vega, Apache Commons Math, etc.), or when you need to understand how an upstream feature works before writing code. |
Research Upstream API
Before porting any feature into Krayon, research the upstream library to understand its API, algorithm, test fixtures, and license.
What to produce
Return a structured summary containing:
- Upstream library/module name, URL, and license
- List of symbols already present in the corresponding Krayon module
- List of symbols missing from Krayon
- For each missing symbol: brief description, algorithm notes, and links to the upstream source and test fixtures
D3-specific notes
Krayon's primary upstream is D3.
- Repos follow
https://github.com/d3/d3-<module> (e.g. d3-shape, d3-scale).
- Test files contain
[x, y] point arrays and expected SVG path strings — ideal gold data for Krayon tests.
- D3's curve protocol (
areaStart, areaEnd, lineStart, lineEnd, point) maps to Krayon's Curve interface
(startArea, endArea, startLine, endLine, point).
- Note configurable parameters (e.g.
bundle.beta(), cardinal.tension(), catmullRom.alpha()).
Tips
- Upstream test suites are the most reliable source of expected behavior. Always look for them.
- Note the upstream license — it will be needed for the NOTICE file.
- If the upstream uses
Double or 64-bit floats, note precision differences when porting to Kotlin Float.
