Migration Mapping

What it does

When your agent uses it

• Documenting a migration project
• Tasks that involve Code migrations

Example prompts

• “/migration-mapping”

Requirements

• Compatibility (from SKILL.md): Requires completed migration with source and target code

Workflow steps

5 steps, taken from the first numbered list in SKILL.md.

1. 1Many-to-many mapping: A source file may map to multiple target files, and a target file may implement logic from multiple source files
2. 2Complete coverage: EVERY source file must appear as a key in the mapping
3. 3Complete target coverage: EVERY target file should appear as a value at least once
4. 4Empty arrays: If a source file has no corresponding target implementation, use an empty array []
5. 5Incremental: If a mapping file already exists, update it rather than replacing it

What it can do on your machine

Read from SKILL.md and the folder at commit d008b81. It shows what the files ask for, not the result of running them.

• Tool permissions

  Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.

  From allowed-tools in the SKILL.md frontmatter.

• Runs code

  No scripts in the folder and no shell commands in SKILL.md (its code samples are json).

  From the folder's file list and the shell code blocks in SKILL.md.

• Network

  No URLs in SKILL.md.

  From URLs in SKILL.md, links to its own repository left out.

• Credentials

  Names no API keys, tokens, secrets or passwords.

  From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

• Compatibility

  Requires completed migration with source and target code

  From compatibility in the SKILL.md frontmatter.

Context cost

Migration Mapping loads about 571 tokens when it runs. Until then it costs about 41 tokens; SKILL.md has 220 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it

~41

When it runs · the whole SKILL.md, loaded when a task matches

~571

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from OpenHands/extensions at commit d008b81, republished under its MIT licence (© OpenHands). 220 words, ~571 tokens.

name

migration-mapping

description

Create a mapping from source language files to target language files for code migrations. Use when evaluating or documenting a migration project.

compatibility

Requires completed migration with source and target code

license

MIT

triggers

migration mapping, source target mapping, file mapping

{
  "source_file_1.cbl": ["target_file_a.java", "target_file_b.java"],
  "source_file_2.cbl": ["target_file_c.java"],
  "source_file_3.cbl": []
}

{
  "CALC001.cbl": ["InvoiceCalculator.java", "TaxCalculator.java"],
  "CUST002.cbl": ["CustomerService.java", "CustomerRepository.java"],
  "UTIL003.cbl": ["StringUtils.java"],
  "SCREEN001.cbl": []
}

© OpenHands, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

Just SKILL.md in plugins/migration-scoring/skills/migration-mapping of OpenHands/extensions.

Open the folder on GitHubat commit d008b81