packages/ai/src/types.ts), model registry (models.generated.ts, 578 KB), stream parsing (packages/ai/src/utils/event-stream.ts), provider implementations (packages/ai/src/providers/: openai-completions, anthropic, bedrock-converse-stream, google, azure-openai, mistral, faux, etc.). Credential detection in packages/ai/src/env-api-keys.ts.
Exports: streamSimple, AssistantMessageEventStream, StreamOptions, Model, Api, Provider, KnownProvider. Provider subpath exports in packages/ai/package.json. Registered lazily in packages/ai/src/providers/register-builtins.ts.
Related: AI models, AI providers