Implementation Retrospective
What Went Smoothly
- Parallelization worked well - The foundation files (signal.ts, trigger.ts, handler.ts) and handlers (compaction.ts, struggling.ts) were implemented in parallel without issues. The spec's interface definitions were clear enough that agents could work independently.
- Pattern discovery - The initial exploration agent provided excellent context on Bus, Instance.state, and namespace patterns. This made subsequent implementation consistent with the codebase.
- TypeScript caught issues early - The type system immediately flagged that the SDK types also needed updating for the "lizard" trigger.
Issues Encountered
| Issue | Severity | Resolution |
|---|---|---|
| SDK types not updated | Medium | Had to update packages/sdk/js/src/v2/gen/types.gen.ts - spec didn't mention this |
| tool.complete trigger doesn't exist | Low | Removed from TriggerType enum and StrugglingHandler triggers |
| Module-level unsubscribes array | Medium | Changed to Instance.state() pattern for proper cleanup |
Spec Improvements Needed
- SDK Type Generation The spec doesn't mention that the SDK types are auto-generated from an OpenAPI schema. Adding "lizard" to CompactionTrigger in message-v2.ts isn't enough - the SDK needs updating too. Either:
- Note that packages/sdk/openapi.json needs updating
- Or note this is a manual sync step
- Remove tool.complete from TriggerType export const TriggerType = z.enum([ "message.user", "message.assistant",
- "tool.complete", // Event doesn't exist in codebase "periodic", ])
-
Instance.state for cleanup The spec shows a module-level array for cleanup: let unsubscribes: (() => void)[] = [] Should be: const state = Instance.state( () => ({ unsubscribes: [] as (() => void)[] }), async (s) => { /* cleanup */ } )
-
Handler model field unused The Definition.model: "haiku" | "fast" field is defined but never used - handlers call Provider.getSmallModel() directly. Either:
- Remove the field, or
- Use it to select model in a shared utility
- Missing initialization location Spec says "Initialize LizardBrain in server startup" but doesn't specify where. Should mention packages/opencode/src/project/bootstrap.ts.
Overall Assessment
Smooth implementation - The spec was well-designed with clear architecture diagrams and interface contracts. The 21 subtasks were appropriately scoped. Main friction was from details the spec couldn't anticipate (SDK types, missing events).
Estimated token efficiency: ~60% of tokens went to implementation, ~25% to exploration/review, ~15% to fixing issues. Parallelization saved significant wall-clock time on foundation and handler phases.