fskill-creator-migrate

Goal

Analyze a large or hard-to-maintain legacy skill directory into structured migration context while preserving behavior. This sub-skill only performs migration pre-analysis and does not directly write final functional skill files; final artifact generation, runtime capability provisioning, file writing, and validation are handled by the main fskill-creator.

Invoked by the main skill when the user has an existing monolithic skill and wants to "refactor into functional", "migrate to functional skill", or "restructure into functions/references/scripts".

Principles

• Preserve existing behavior first, then optimize structure.
• Load the whole legacy skill package, not only SKILL.md.
• Keep source section and file evidence so reviewers can trace migrated content.
• Only output migration_context; must not directly write target skill files.
• Duplicated rules, schemas, and vocabulary move to reference_plan.
• Existing references/, scripts/, and tools/ are inventoried before proposing splits.
• Deterministic parsing, formatting, validation, or mechanical transforms are identified as script_plan, to be generated or preserved later by the main skill.
• Optional viewers only enter tool_plan; final files are generated uniformly by the main skill's add_runtime_capabilities.

References

Resource	Load Timing	Purpose
shared_glossary	On demand	Stable migration terminology and output fields.
script_rules	Before proposing scripts	Rules for deciding what belongs in scripts/.

External Inputs

Field	Source	Description
legacy_skill_dir	user or repository	Path to the legacy skill directory containing SKILL.md.
legacy_skill_path	user or repository	Deprecated alias for legacy_skill_dir; may also be a direct path to SKILL.md, which resolves to its parent directory.
legacy_skill_content	user or repository	Existing skill markdown content when the directory is inaccessible.
migration_constraints	user	Constraints such as preserving file names, tone, or platform rules.
known_testcases	user or repository	Existing examples, traces, or expected behaviors.
existing_scripts	repository	Existing helper scripts associated with the legacy skill.
include_viewers	user	Whether to suggest generating tools/log_viewer.mjs and tools/tester_viewer.mjs.
script_runtime	environment	Whether this sub-skill's own Node.js scripts can be run.

Execution Pipeline

Step	Function	Purpose	Input	Output
1	load_legacy_skill	Load and normalize the legacy skill package.	legacy_skill_dir<br>legacy_skill_path<br>legacy_skill_content	legacy_skill
2	map_existing_behavior	Identify goals, rules, inputs, outputs, and behaviors that must be preserved.	legacy_skill<br>migration_constraints	behavior_map
3	propose_function_split	Propose function boundaries, script opportunities, optional viewer tools, and target file layout.	legacy_skill<br>behavior_map<br>script_rules<br>include_viewers<br>script_runtime	migration_proposal<br>script_plan<br>tool_plan
4	extract_shared_references	Move duplicated or shared rules into references.	legacy_skill<br>migration_proposal<br>script_plan	reference_plan

Output

The main skill combines the above outputs into:

Field	Description
migration_context.legacy_skill	Loaded source skill package data.
migration_context.behavior_map	Behaviors that must be preserved.
migration_context.migration_proposal	Function split and target structure proposal.
migration_context.reference_plan	Terms, rules, and schemas that should go into shared references.
migration_context.script_plan	Deterministic helpers to generate, preserve, or refactor.
migration_context.tool_plan	Optional viewer choices.
migration_context.source_evidence	Legacy source sections, companion files, and behavior preservation evidence.

Output Scope

Only output migration context; must not directly write target skill files or delete the legacy skill.