Phase 21 — Rust port of scratchpad + tree-split primitives (companion to
the 2026-04-21 TS shipment). New crates/aibridge modules:
context.rs — estimate_tokens (chars/4 ceil), context_window_for,
assert_context_budget returning a BudgetCheck with
numeric diagnostics on both success and overflow.
Windows table mirrors config/models.json.
continuation.rs — generate_continuable<G: TextGenerator>. Handles the
two failure modes: empty-response from thinking
models (geometric 2x budget backoff up to budget_cap)
and truncated-non-empty (continuation with partial
as scratchpad). is_structurally_complete balances
braces then JSON.parse-checks. Guards the degen case
"all retries empty, don't loop on empty partial".
tree_split.rs — generate_tree_split map->reduce with running
scratchpad. Per-shard + reduce-prompt go through
assert_context_budget first; loud-fails rather than
silently truncating. Oldest-digest-first scratchpad
truncation at scratchpad_budget (default 6000 t).
TextGenerator trait (native async-fn-in-trait, edition 2024). AiClient
implements it; ScriptedGenerator test double lets tests inject canned
sequences without a live Ollama.
GenerateRequest gained think: Option<bool> — forwards to sidecar for
per-call hidden-reasoning opt-out on hot-path JSON emitters. Three
existing callsites updated (rag.rs x2, service.rs hybrid answer).
Phase 27 — Playbook versioning. PlaybookEntry gained four optional
fields (all #[serde(default)] so pre-Phase-27 state loads as roots):
version u32, default 1
parent_id Option<String>, previous version's playbook_id
superseded_at Option<String>, set when newer version replaces
superseded_by Option<String>, the playbook_id that replaced
New methods:
revise_entry(parent_id, new_entry) — appends new version, stamps
superseded_at+superseded_by on parent, inherits parent_id and sets
version = parent + 1 on the new entry. Rejects revising a retired
or already-superseded parent (tip-of-chain is the only valid
revise target).
history(playbook_id) — returns full chain root->tip from any node.
Walks parent_id back to root, then superseded_by forward to tip.
Cycle-safe.
Superseded entries excluded from boost (same rule as retired): filter
in compute_boost_for_filtered_with_role (both active-entries prefilter
and geo-filtered path), rebuild_geo_index, and upsert_entry's existing-
idx search. status_counts returns (total, retired, superseded, failures);
/status JSON reports active = total - retired - superseded.
Endpoints:
POST /vectors/playbook_memory/revise
GET /vectors/playbook_memory/history/{id}
Doc-sync — PHASES.md + PRD.md drifted from git after Phases 24-26
shipped. Fixes applied:
- Phase 24 marked shipped (commit b95dd86) with detail of observer
HTTP ingest + scenario outcome streaming. PRD "NOT YET WIRED"
rewritten to reflect shipped state.
- Phase 25 (validity windows, commit e0a843d) added to PHASES +
PRD.
- Phase 26 (Mem0 upsert + Letta hot cache, commit 640db8c) added.
- Phase 27 entry added to both docs.
- Phase 19.6 time decay corrected: was documented as "deferred",
actually wired via BOOST_HALF_LIFE_DAYS = 30.0 in playbook_memory.rs.
- Phase E/Phase 8 tombstone-at-compaction limit note updated —
Phase E.2 closed it.
Tests: 8 new version_tests in vectord (chain-metadata stamping,
retired/superseded parent rejection, boost exclusion, history from
root/tip/middle, legacy default round-trip, status counts). 25 new
aibridge tests (context/continuation/tree_split). Workspace total
145 green (was 120).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
