Foundation Layer Implementation
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Phase 1: Foundation Layer
The foundation layer establishes the minimum V6 base inside the current repository shape. This phase clarifies seams, validation gates, and ownership in packages/sdk, packages/babysitter-agent, and plugins/*. It does not commit V6 to creating deferred top-level packages.
Current-Package Seam Clarification
Runtime And Session Boundaries
- Clarify which runtime concerns already belong to
packages/babysitter-agent - Isolate Pi wrapper, session handling, and structured event concerns behind internal module seams before considering any package move
- Reduce filesystem assumptions only where current commands and tests prove the change is safe
- Record candidate extraction boundaries as ADR-backed slices rather than package commitments
Hook System
- Tighten programmatic hook responsibilities in the current SDK and plugin surfaces
- Verify hook registration, invocation, and acknowledgment flows against existing runtime behavior
- Add or update configuration only where the current CLI and plugin model already require it
Infrastructure Foundation
Compiler And Packaging Reality Checks
- Validate
agent-plugins-muxand related packaging flows against real plugin manifests and generated outputs - Document import and ownership seams that already exist in the repo instead of inventing new package boundaries
- Add compatibility notes for any rename or extraction candidate that survives Phase 0 decision framing
Platform Candidate Preparation
- Describe plugin-system responsibilities in current-package terms
- Identify which platform concerns are internal
packages/sdkorpackages/babysitter-agentcandidates versus actualplugins/*responsibilities - Treat filesystem abstraction and plugin registration work as candidate slices only when they can be validated independently
Deliverables
- Updated seam map for runtime, session, and hook responsibilities in current packages
- ADR-backed first executable slice for the accepted
@a5c-ai/babysitter-agentseam contract - ADR-ready candidate slices for any later extraction or rename still worth considering
- Hook and packaging flows validated against existing commands and plugin outputs
- Any reduced-filesystem claim stated with a baseline, command, and rollback note
Technical Validation
Documentation Consistency: Foundation work must remain consistent with V6 Architecture Specification and Package Specifications
Current-Behavior Checks: Use current build, test, and plugin packaging commands as the source of truth for whether a seam is real
Current Slice Command: npm run verify:v6:seams is the repo-level validation gate for the accepted seam-contract slice
Packaging Validation: Compare compiler changes against existing manifest and install surfaces
Performance Benchmarking: Any runtime or session target must cite a baseline command before it becomes a success criterion
Extraction Gate: No deferred package name becomes part of this phase without a decision record that changes its state in the core V6 docs
Explicit Non-Deliverables
This phase does not create @a5c-ai/agent-runtime or @a5c-ai/agent-platform. Those names remain deferred vocabulary unless later decision records promote a specific slice into scope.
Related Documents: Package Specifications | Testing Framework | Platform Layer