Replace the Vercel AI SDK with direct OpenAI SDK calls and a custom
AgentLoop. The AI SDK has zero runtime integration today, so removing
it costs nothing. Supply chain risk (2-5 releases/day, April 2026
Vercel breach, bus factor of 1) makes it a liability we don't need.
Key changes:
- ADR-018 accepted: openai package (zero runtime deps) replaces ai SDK
- AgentLoop handles multi-step tool execution explicitly (~300 LOC vs
AI SDK's ~2700 LOC streamText)
- Hub owns UIMessage/UIPart/ToolCallState types (extends ADR-016)
- Hub owns streaming protocol (subset of AI SDK's UIMessageChunk wire
format with step boundaries, error handling, usage tracking)
- operationToOpenAITool() maps TypeBox schemas directly, no adapter
- Trade-off: ~1100 LOC total new code for the savings of 6+ transitive
deps, supply chain risk, and release cadence coupling
Updates AGENTS.md constraints and dependencies, adds OQ-63/OQ-64/OQ-65
and Theme 11 (Inference & LLM Integration) to open questions.
glm-5.1
a248698f40