feat: add shared model utilities and OpenCode 2 (V2) support

[Majidalee1]

Summary

This PR adds support for OpenCode 2. It also moves model logic into one shared file. The shared file works for OpenCode 1 (V1) and OpenCode 2 (V2).

Problem

OpenCode 2 loads plugins in a new way. A plugin file must export { id, setup }. The current plugin.ts file exports a factory function instead. This function returns { config, auth }. This is the V1 format. OpenCode 2 cannot load this format. It shows this error:

SchemaError: Expected object, got async function commandcodePlugin()

The provider code already works with OpenCode 2. The files index.ts and src/model.ts implement the LanguageModelV3 interface from the AI SDK. The provider only needs a new V2 plugin file to register it.

Changes

1. Shared model utilities

• Add src/models.ts. This file loads and converts model data from models.json.
• Add these functions:
  • toConfigKey — creates a short, stable key for each model.
  • toV1ModelConfig — creates a model config for the V1 plugin.
  • toV2ModelDraft and toV2ModelMap — create model entries for the V2 catalog.
• Update plugin.ts to use the shared functions. The V1 plugin behavior does not change.
• Add tests in tests/unit/models.test.ts for all functions.

2. OpenCode 2 (V2) plugin entrypoint

• Add v2.ts. This file exports the V2 plugin as { id, setup }.
• The V2 plugin registers the commandcode provider through ctx.catalog.transform.
• The provider ID is aisdk:commandcode-go-opencode-provider. It has a default baseURL.
• Update package.json:
  • Add a new export path, ./v2.
  • Add v2.ts to the published files.
  • Set the version to 0.5.0.
• Update tsconfig.json to include v2.ts.
• Add tests in tests/unit/v2.test.ts. These tests check provider registration, settings overrides, and that all 21 models from models.json register with the correct shape.

3. Documentation

• Update README.md:
  • Add a new "OpenCode 2 (V2)" section. It explains how to install the plugin: plugins: ["commandcode-go-opencode-provider/v2"].
  • Explain how to set the API key. Use the /connect command or the COMMANDCODE_API_KEY variable.
  • Explain how to select a model.
  • Add a note: the old plugin/provider block still works for the OpenCode 1 (V1) CLI.
  • Add a local-development example. It uses a file:// path to the ./v2 entrypoint.
• Update opencode.json. Change the example config to the V2 format (plugins and providers).

How to use OpenCode 2 support

Add this to your config:

{
  "plugins": ["commandcode-go-opencode-provider/v2"]
}

You do not need a provider block. You do not need a hand-written model list.

Verification

• bun run typecheck passes.
• bun test tests/unit/ passes. It runs 90+ tests with 0 failures.
• The v2.ts plugin was tested in a live opencode2 instance. The provider and all 21 models registered correctly. This was checked through the /api/provider and /api/model endpoints.

Note on PR history

This PR replaces PR #15, PR #16, and PR #17. Those PRs formed a stack. GitHub does not allow a PR to use a fork branch as its base in the upstream repo. This blocks true stacking across a fork without push access to the upstream repo. This PR combines all three changes into one PR against main. PR #16 and PR #17 are now closed. Both point to this PR.