cas

# CAS Common Chemistry Query [CAS Common Chemistry](https://commonchemistry.cas.org/) for compound names, CAS Registry Numbers®, molecular formula, mass, SMILES, InChI, and experimental properties. Covers nearly 500,000 compounds (CC BY-NC 4.0). **API access:** Request a free API key at [https://www.cas.org/services/commonchemistry-api](https://www.cas.org/services/commonchemistry-api). The script works without a key for public endpoints; if CAS requires a key, set `CAS_API_KEY` or use `~/.scienceclaw/cas_config.json`. ## Overview - Search by compound name (supports trailing wildcard, e.g. `aspirin*`), CAS RN, SMILES, or InChI/InChIKey - Get detail: name, formula, mass, InChI, SMILES, experimental properties (e.g. melting point, density) - Reference: `references/cas-common-chemistry-api.md` ## Usage ### Search by name ```bash python3 {baseDir}/scripts/cas_search.py --query "aspirin" ``` ### Get detail by CAS Registry Number ```bash python3 {baseDir}/scripts/cas_search.py --cas "50-78-2" ``` ### Search with wildcard ```bash python3 {baseDir}/scripts/cas_search.py --query "atrazin*" ``` ### JSON output ```bash python3 {baseDir}/scripts/cas_search.py --query "caffeine" --format json ``` ## Parameters | Parameter | Description | Default | |-----------|-------------|---------| | `--query` | Name, SMILES, or InChI (name supports trailing *) | - | | `--cas` | CAS Registry Number (e.g. 50-78-2) | - | | `--max-results` | Max search results | 10 | | `--format` | summary, detailed, json | summary | ## Output - **Summary:** CAS RN, name, formula, molecular mass, SMILES - **Detailed:** Adds InChI, InChIKey, experimental properties, synonyms - **JSON:** Full API response ## Notes - Request API access: [CAS Common Chemistry API](https://www.cas.org/services/commonchemistry-api) - Optional: set `CAS_API_KEY` or config file if CAS requires authentication