Phase 2.5 — Tracks

Track A — Multi-Provider Adapters

Prove the Provider interface generalizes beyond OpenAI by implementing structurally different providers.

Status: Complete (G1.M1–M3 on main)

Preferred sequencing within track: 2.5.G1.M1 → 2.5.G1.M2 → 2.5.G1.M3

Related tracks: Track B uses TokenizerFamily from the capability registry.

2.5.G1.M1 — Anthropic Provider Adapter — completed
2.5.G1.M2 — Model Capability Registry — completed
2.5.G1.M3 — Self-Hosted LLM Adapter — completed

Track B — Tokenizer Registry

Accurate token counting across provider-specific tokenizers, required for downstream budget calculation.

Status: Complete (G2.M1)

Preferred sequencing within track: single milestone; depends on Track A capability registry for TokenizerFamily.

2.5.G2.M1 — Tokenizer Registry — completed

Track C — Response-Side Processing Pipeline

Typed response decode/re-encode pipeline enabling post-provider processing stages (usage normalization, metadata injection).

Preferred sequencing within track: 2.5.G3.M1 → 2.5.G3.M2 (streaming is design/spike after non-streaming seam)

Status: Complete (G3.M1–M2)

2.5.G3.M1 — Response Middleware Hook — completed
2.5.G3.M2 — Streaming Response Pipeline Design — completed

Track D — Pluggable Embedding Service

Abstract embedding behind a backend interface so the memory system can swap models without changing callers. Profile choice is a deployment setting; dimensionalities are not interchangeable without migration.

Status: Complete (G4.M1–M4 on main)

Preferred sequencing within track: 2.5.G4.M1 → 2.5.G4.M2 / 2.5.G4.M3 → 2.5.G4.M4

2.5.G4.M1 — Embedder Interface & Registry — completed
2.5.G4.M2 — TEI Backend — completed
2.5.G4.M3 — Hosted API Backend — completed
2.5.G4.M4 — Content-Hash Embedding Cache — completed

Track E — Schema Pre-Work

Migration-only, additive schema changes preparing Postgres for Phase 3's write pipeline — temporal validity, multi-label categories, relationship graph indexes. Migration sketches on linked milestones are orientation only and may change during schema work.

Status: Completed (G5.M1–M3)

Preferred sequencing within track: 2.5.G5.M1 → 2.5.G5.M2 → 2.5.G5.M3 (can run in parallel with Tracks A/B)

2.5.G5.M1 — Temporal Validity Columns — completed
2.5.G5.M2 — Multi-Label Category Support — completed
2.5.G5.M3 — Relationship Graph Readiness — completed

Track F — MCP Server Skeleton

Auth-boundary-scoped MCP server with stub tools, proving the resource-server auth boundary and audit-log wiring before Phase 3's real memory service exists.

Status: Completed

Preferred sequencing within track: single milestone; prefer after Track A auth/provider patterns are stable.

2.5.G6.M1 — MCP Server Skeleton — completed (ADR-0050)

Track G — Exit / Ops Pack-Up

Formal Phase 2.5 exit: local LGTM observability, multi-service verify gate, thin K8s observability chart, and roadmap sign-off before Phase 3.

Status: Completed

Preferred sequencing within track: single milestone after Tracks A–F.

2.5.G7 — Phase 2.5 Exit Gate — completed (ADR-0051)