summary: "@tryinget/pi-model-selection package overview." read_when:

• "Orienting to this package or directory before changing its behavior."

@tryinget/pi-model-selection

Shared Pi model-selection and auth-resolution primitives.

This is a top-level support package at packages/pi-model-selection, not a pi-interaction subpackage. Consumers should depend on @tryinget/pi-model-selection directly rather than depending on @tryinget/pi-interaction for model-selection helpers.

This package owns prompt-template-model-compatible model resolver semantics that are needed by more than one extension:

• exact modelId
• exact provider/modelId
• comma-separated fallback lists
• current-model preservation when the active model matches any candidate
• provider-priority ordering for ambiguous bare model IDs:
  1. openai-codex
  2. anthropic
  3. github-copilot
  4. openrouter
• auth-aware selection via getAvailable(), isUsingOAuth(), getApiKey(), and getApiKeyAndHeaders()
• optional { authentication: "host" } selection that uses getAvailable() when present but never returns or directly resolves credential material, for consumers that delegate the request to a host-owned completion boundary
• preservation of model-level headers in the default auth-resolution mode

It intentionally does not own prompt-template slash-command registration, compaction preset parsing, loops/workflows, or subagent execution.

Template baseline

This package was reconciled through ../pi-extensions-template in simple-package mode, then intentionally adapted as a root-managed support library. It keeps template lineage and baseline files such as .copier-answers.yml, biome.jsonc, policy/engineering-lane.json, and docs/engineering.local.md, but it deliberately omits package.json#pi.extensions and package.json#pi.prompts so it cannot register slash commands or package prompts by accident.