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name: toolkit-backends description: "Choose, inspect, and troubleshoot OpenFF Toolkit optional backend wrappers and ToolkitRegistry behavior." disable-model-invocation: true metadata: disco-role: operating license: MIT

Toolkit Backends

Use this sub-skill when a task involves OpenFF Toolkit optional cheminformatics backends, wrapper availability, ToolkitRegistry precedence, GLOBAL_TOOLKIT_REGISTRY, toolkit_registry_manager, supported file formats, supported charge methods, or dependency/license failures for RDKit, OpenEye, AmberTools, OpenFF NAGL, or the built-in wrapper.

Start Here

1. Run python scripts/check_toolkit_backends.py --json when you need environment-specific backend facts.
2. Read references/backend-reference.md to choose wrappers, registries, optional installs, and supported file/charge capabilities.
3. Read references/troubleshooting.md when a wrapper is unavailable, a method cannot be resolved, a file format or charge method is unsupported, or OpenEye/RDKit behavior differs.

Routing Boundaries

• Handle backend readiness first: availability, registry construction, wrapper ordering, explicit toolkit_registry= use, and optional dependency guidance.
• Route molecule construction, file conversion, topology loading, force-field parameterization, and chemistry workflows back to the relevant OpenFF Toolkit domain sub-skill after backend selection is settled.
• Do not rely on global registry mutation unless the user specifically needs process-wide behavior; prefer explicit wrapper/registry arguments or toolkit_registry_manager for temporary changes.