Plugin Layout Slices

Plugin Layout Slices

A slice is one feature of a plugin, in one folder. This page shows what a slice folder holds, how its texts work, and how to add a slice. It follows Plugin Layout.

The Parts of a Slice

The handoff slice shows the usual parts:

src/plugins/claudetto/slices/handoff/
  slice.ts              the manifest: the name, the ladder line, and each part
  limits.ts             the bounds of the slice
  domain/               pure code: data and functions, no I/O
  adapters/mod.ts       mod handlers
  prompts/              the texts for Claude and for the user
  evals/handoff/        eval cases
  lab/compaction.test.ts  a hook lab test

Other slices add these parts when they need them.

Part	Use	Output in plugins/<plugin>/
slice.ts	Always. It exports slice, and slice.name equals the folder name	Lines in plugin.json, hooks.json, and register.ts
domain/	Pure logic, with no adapter import	slices/<s>/domain/
adapters/mod.ts	The functions that a mod handler runs	hooks/register.ts and slices/<s>/adapters/mod.ts
adapters/cli.ts	A CLI that exports main	bin/<bin>, a launcher, and slices/<s>/adapters/cli.ts
skills/<name>/SKILL.md	A skill	skills/<name>/SKILL.md
styles/<name>.md	An output style	output-styles/<name>.md
prompts/	Texts for Claude or the user	slices/<s>/prompts.ts
lab/*.test.ts	Hook lab tests	tests/*.test.ts, run by claude plugin test
evals/<case>/	Eval cases	evals/<case>/
limits.ts	The bounds of the slice	slices/<s>/limits.ts

The skills field of slice.ts declares the skills the slice ships.

The Prompt Files of a Slice

Each text of a slice that goes to Claude or to the user is a file in prompts/, not a string in the code. Examples are a deny reason, a notice, and the prompt of a side model. tools/generate/emit/prompts.ts writes the module prompts.ts from the folder. The code imports each text from ../prompts.ts.

Source	Export in prompts.ts
prompts/deny-reason.md	DENY_REASON, a string
A .md file with a parameter such as {{command}}	A function, such as DENY_REASON({ command }), that gives a string
prompts/automode.json	AUTOMODE, an object

• A lowercase name in double curly braces is a parameter. The code gives its value as a string at run time.
• An uppercase name in double curly braces is a value that the generator fills from limits.ts of the slice, or from VALUES in tools/generate/emit/fill.ts. A number gets the form 20,000.
• A line {{include name}} gives the text of src/fragments/name.md.
• The code keeps the choice between texts, the short labels, and the log lines.

Hook lab tests in lab/ import the texts from ../prompts.ts, and just generate changes the import to the module in the copy of the slice. The description of a plugin is description.md, with one sentence on each line, and just generate joins the lines into the manifest.

How to Add a Slice

1. Choose the plugin. A feature that costs tokens when unused, or that needs an outside tool, goes in an add-on (Add-Ons).
2. Create src/plugins/<plugin>/slices/<s>/slice.ts. Export slice with name set to the folder name and a ladder line. Add each part the slice needs, such as mod, cli, skills, or userConfig. The contract is in src/kernel/slice.ts.
3. Add the code. Put the logic in domain/ and the entry points in adapters/. Export each mod handler from adapters/mod.ts, and name it in run.
4. Add the texts. Put each skill in skills/<name>/SKILL.md, and each message in prompts/<name>.md.
5. Add the bounds to limits.ts of the slice, and shared bounds to src/kernel/budget.ts. Never put a bound in two files.
6. Add the tests. Put repository tests in tests/<folder>/<s>/ and hook lab tests in lab/. Name each hook eval in evals of its mod handler. Add a controls record for each hook.
7. For a new plugin, add src/plugins/<plugin>/plugin.ts that exports plugin, a description.md, and the name in src/marketplace.ts.
8. Run just generate, then just check. Commit the source and the generated files together.

The fixture of the generator tests is in tests/tools/generate/fixture/.

See Also

• Plugin Layout
• Architecture Generate
• Controls