Provider Resolution — Reviewer Cluster

Scope

Subpath	Files	Role
src/main/ai/provider/	config.ts (495), endpoint.ts (99), factory.ts (17), constants.ts (14)	Provider config builder, endpoint resolver, derived helpers
provider/extensions.ts	(236)	All ProviderExtension.create(...) registrations
provider/custom/	aihubmix-provider.ts (167), newapi-provider.ts (151)	Aggregator-provider implementations
provider/	listModels.ts (559), listModelsSchemas.ts (232), listModels/vertex.ts	Per-provider model listing
Tests	__tests__/endpoint.test.ts (307)	Resolver coverage

Intent

v1 picked the @ai-sdk/* package by sniffing provider.id, provider.type, and apiHost. That worked for one-endpoint providers and broke for multi-endpoint relays (MiniMax, Silicon, AiHubMix — openai-chat-completions AND anthropic-messages under the same provider id). The most visible symptom was <think> tags leaking into translate output because an OpenAI-shape request hit an anthropic-format endpoint.

v2 introduces an explicit adapterFamily field per endpoint, computed once at row-write time, read at request time. The full design is in adapter-family.md and the reference at docs/references/ai/adapter-family.md.

This cluster bundles the resolver + the SDK-package wiring (extensions and custom providers). Claude Code is not a generic provider extension; it is only entered through the agent-session runtime.

Key changes

endpoint.ts (resolver)

Three pure functions:

• resolveEffectiveEndpoint(provider, model) — picks endpointType from model.endpointTypes[0] or provider.defaultChatEndpoint.
• resolveProviderVariant(baseProviderId, endpointType) — appends -chat / -responses suffix when ai-core registers a variant.
• resolveAiSdkProviderId(provider, endpointType) — the 6-line production resolver. Reads endpointConfigs[ep].adapterFamily, applies variant, falls back to openai-compatible.

54 test cases in __tests__/endpoint.test.ts.

config.ts (provider-to-SDK config)

providerToAiSdkConfig(provider, model) builds the { providerId, providerSettings } pair. Per-id branches build the SDK-specific settings shape:

• openai, anthropic, google, azure, etc. — standard apiKey + baseURL + headers.
• gateway — async, model-list dependent.
• aihubmix / newapi — pass through to the custom provider factories.

Provider extensions

provider/extensions.ts registers every @ai-sdk/* package Cherry uses via ProviderExtension.create(...). Each registration declares:

• name, aliases, variants
• create (the SDK factory)
• toolFactories (per-capability factories for webSearch, urlContext, etc.) — see the registry tool-capability section in docs/references/ai/core-architecture.md.
• supportsImageGeneration flag

Custom providers

• aihubmix (provider/custom/aihubmix-provider.ts) — relay across OpenAI / Anthropic / Google. Each model row carries model.provider = "aihubmix.<vendor>"; the registry's aggregator fallback in resolveToolCapability uses the suffix to find the right toolFactory.
• newapi — same shape, different relay backend.

Claude Code runtime helpers

Claude Code no longer registers a normal AI SDK provider extension. The Claude-specific runtime pieces live under src/main/ai/runtime/claudeCode/: the driver owns the SDK query, warm query reuse, SDK input queue, and stream adapter that converts agent SDK events into UI message chunks. settingsBuilder.ts builds ClaudeCodeSettings from an AgentSessionEntity — model selection, MCP server configs, allowed-tools list, prompt builder, proxy env, and OS shell quirks. agentSessionWarmup.ts then turns those settings into SDK query options using the agent session, provider, model, and latest persisted SDK session id.

listModels.ts

Per-provider model listing — fans out to OpenAI's /models, Anthropic's hardcoded list, Gemini's models.list, etc., normalises to the Model[] shape. listModelsSchemas.ts carries Zod schemas for the per- provider response bodies.

Invariants

• The resolver never reads apiHost to pick an adapter. Only adapterFamily and endpointType.
• Adding a new provider means: (a) register the extension, (b) add it to providerToAiSdkConfig's branch, (c) add the adapterFamily per endpoint in providers.json. No other touchpoint.
• claude-code runtime's buildClaudeCodeSessionSettings is the only path that reads agent session data — it must throw on orphan sessions (agentId === null) rather than fall back to defaults.

Validation

• __tests__/endpoint.test.ts — 54 cases incl. MiniMax regression, variant suffix application, unknown-family degradation
• Catalog tests in packages/provider-registry/src/__tests__/registry-utils.test.ts
• Migrator tests in src/main/data/migration/v2/migrators/mappings/__tests__/ProviderModelMappings.test.ts

Follow-ups (out of scope)

• The UI custom-provider form is queued — inferAdapterFamily is in place; UI wiring is one line when the form lands.
• claude-code retry on transient SDK errors — currently surfaces errors directly.