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devtools-import-boundary

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Enforce import boundaries inside the devtools scope. Use for any work in "devtools/**".

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Source SKILL.md: https://github.com/LedgerHQ/ledger-live/blob/HEAD/.agents/skills/devtools-import-boundary/SKILL.md

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DevTools import boundaries

Every @devtools/* package is self-contained. The only permitted cross-package import within the devtools scope is from @devtools/registry, and only from the two packages explicitly designed for it.

Rules

PackageMay import from @devtools/*
@devtools/shell@devtools/registry only
@devtools/bindings@devtools/registry only
@devtools/<tool>nothing from @devtools/*

All other @devtools/* → @devtools/* imports are forbidden.

Why

The devtools architecture decouples tools from the shell through the registry. The shell lazy-loads tools via metadata.loader; tools never know the shell exists. If a tool imports the shell or another tool directly:

  • The lazy-load boundary collapses — the tool is bundled eagerly.
  • A circular dependency becomes likely (tool → shell → registry → tool).
  • The tool can no longer be rendered standalone, outside the shell.

If bindings or shell import a tool package directly (instead of through the registry):

  • The registry's discriminated union is bypassed and TypeScript loses the narrowing guarantee on DevToolsConfig.
  • The import() split point disappears, defeating code-splitting.

Consequences of a violation

  • Tool imports shell or registry: The tool becomes coupled to shell internals; standalone rendering and unit-testing break.
  • Tool imports another tool: Cross-tool coupling; removing or renaming one tool requires editing the other.
  • Shell or bindings import a tool directly: Eager bundle; code-split lost; registry union integrity broken.

Correct pattern

Cross-cutting concerns (shared types, utilities) must not live in a tool package. Extract them to a standalone library with no @devtools/* scope, then import that from whichever packages need it.

App state and wiring for a tool arrive as props, built in @devtools/bindings — the single sanctioned bridge to Ledger Live internals. A tool that needs more data from the app gets new props, not a new import.

Documentation

When adding a new package under devtools/, its README.md must state:

  • Whether it may import from @devtools/registry (yes for shell and bindings, no for tool packages).
  • That it must not import any other @devtools/* package, with a pointer to this rule.