Target Overrides

A target is a provider selected for a compiler run. compile.targets establishes the root plan; target overrides refine that plan or, at supported lower-level scopes, explicitly opt a provider back in.

Agent standards are not targets. Applicable adaptive source produces each adopted standard profile inherently. No agents target, root agents, plugin field, or frontmatter field enables or disables that floor; .skillset/subagents/ and defaults.<provider>.agents keep their project-agent meanings.

Distinguish Selection from Configuration

These layers have different jobs:

1. compile.targets establishes the root provider plan.
2. Root claude, codex, and cursor blocks configure provider output and inherit that plan unless explicitly enabled or disabled.
3. Target defaults fill omitted values for agents, plugins, rules, or skills.
4. Plugin and source-unit provider toggles refine one scope and may opt a provider back in.
5. A target-native island preserves a native file whose meaning is not portable.

These layers can change provider participation or a provider delta, but they do not suppress an applicable adopted Agent Instructions, Agent Skills, or Agent Plugins projection.

Do not add a bare top-level targets key. Keep root selection in compile.targets, and use lower-level provider toggles only for deliberate scoped divergence.

Configure Output Roots

Boolean output settings use Skillset’s default roots. An array includes named plugins or skills. Plugin objects can select include or enabled: false; skill objects also accept only selection fields. A nondefault plugin path is rejected because shared packages have fixed placement; custom placement is not yet supported:

compile:
  targets: [claude, codex]

claude:
  skills: true

codex:
  plugins:
    include: [review]
  skills:
    include: [review]

The fixed roots are .claude/skills, .agents/skills, and .cursor/skills. <target>.skills.path and skillset.outputs.skills.<target> are rejected. Shared plugin packages currently stay at plugins/<name>; custom placement through <target>.plugins.path or root plugins.output is not yet supported.

When compile.targets is present, a root provider object without enabled inherits that target set; an output-path object does not silently re-enable a provider. See the workspace schema for every accepted shape.

Set Reusable Defaults

The target-local form is canonical:

codex:
  defaults:
    skills:
      model: gpt-5

defaults.codex.skills is shorthand for the same layer. Defaults are supported for agents, plugins, rules, and skills; misspelled or unknown surfaces fail validation, and the retired instructions surface fails with its rules rewrite. Plugin defaults override workspace defaults, file-level target fields override plugin defaults, and provider fields override shared fields during the cascade.

Prefer Shared Intent

Start with a portable field whenever providers can preserve the same meaning. Add a provider field only for genuine divergence. Use provider source for provider-native files that should pass through to one provider rather than masquerade as portable configuration.

Tool allow and deny overlays have their own rules; configure them through tools policy.

Inspect the Result

Use skillset lookup to inspect provider and compatibility facts, skillset explain to trace one source unit, and skillset diff to preview generated changes. The support matrix is the current summary of cross-provider behavior.