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name: configuration-and-registry description: "Create, validate, merge, dump, and debug MMEngine Config/ConfigDict files and registry-driven object construction." disable-model-invocation: true metadata: disco-role: operating license: Apache 2.0

Configuration and Registry

Use this sub-skill when the task mentions MMEngine config files, config inheritance, Config or ConfigDict, custom_imports, lazy import, CLI overrides, Registry, build_from_cfg, DefaultScope, registry scope, or cross-library registry routing.

Runtime Map

• references/configuration-workflows.md: load, edit, merge, dump, validate, and inspect MMEngine configs safely.
• references/registry-reference.md: register classes/functions, build objects from config dictionaries, and reason about scopes.
• references/troubleshooting.md: map common config and registry symptoms to causes and fixes.
• scripts/inspect_config.py: safely parse a config file or inline config string, apply dotted overrides, and print top-level keys.

Start Here

1. For config file syntax, inheritance, environment/predefined variables, Config.fromfile, Config.fromstring, merge_from_dict, and dump, read references/configuration-workflows.md.
2. For Registry(...), register_module, Registry.build, build_from_cfg, default_args, _scope_, and init_default_scope, read references/registry-reference.md.
3. For failures such as missing type, unregistered modules, wrong default scope, list override errors, duplicate registration, or lazy/custom import confusion, read references/troubleshooting.md.
4. To validate a user-supplied config without training or building large objects, run python scripts/inspect_config.py --help from this sub-skill directory.

Boundaries

• Keep this sub-skill focused on mmengine.config, mmengine.registry, DefaultScope, config merging/dumping, and registry-driven object construction.
• Route full Runner train/val/test placement to ../runner-and-training/SKILL.md.
• Route dataset pipeline item semantics, data elements, and file IO backends to ../data-structures-and-io/SKILL.md.
• Route model step contracts, metrics, evaluator behavior, and inference/TTA contracts to ../models-metrics-and-inference/SKILL.md.
• Route logging, visualizer, distributed, device, and runtime utilities to ../runtime-utilities-and-visualization/SKILL.md.

Safe Operating Rules

• Prefer parsing and inspecting configs before building registry objects; building may import optional packages or instantiate user code.
• Treat custom_imports, pure-Python lazy imports, and registry locations as import triggers; review them before executing in an untrusted workspace.
• Do not depend on source checkout files; use the APIs and bundled helper script documented here.