2026.10.04 - Phase 3: Pi DCP Compact Markers

[lanhhoang]

• Compact markers replace verbose XML tags — every injectable user/assistant message now ends with a standalone @mN@, or @mN:P@ when a compression priority from 1 to 5 is assigned. On a 2,000-message clean workload this cut estimated metadata overhead from about 20,000 tokens to about 4,000. The injected format derives from a strict formatMessageMarker(ref, priority) that round-trips canonical refs through parseMessageRef and rejects noncanonical inputs or out-of-range priorities (src/utils/message-ids.ts, src/messages/inject.ts, tests/inject.test.ts, tests/message-ids.test.ts).
• Compact input is accepted and normalized to the canonical ref — parseBoundaryId now tries canonical m0001, then exact compact m1 / @m1@ / @m1:3@ / @m12:3@, then block bN. resolveBoundaryIndex re-runs the parsed index through formatMessageRef before comparing with SessionState.messageIds.byIndex, so a copied @m12:3@ resolves to the same stored message as m0012 rather than merely parsing. parseMessageRef itself stays canonical-only, block parsing rejects unsafe integers, and zero/negative/decimal/partial-padding/wrapped-padded inputs all return undefined (src/utils/message-ids.ts, src/compress/search.ts, tests/message-ids.test.ts, tests/compress-search.test.ts).
• Line-bounded sanitizer strips whole marker lines only — a new DCP_COMPACT_MARKER_LINE regex removes only complete or truncated markers (@m1@, @m1:3@, @m1, @m1:, @m1:2) on a line boundary, under LF or CRLF, with optional horizontal whitespace. The line boundary itself is preserved so surrounding prose is not concatenated. Inline @m1@, person@m1@example.com, @mention, and marker text inside a sentence are left untouched. Compact cleanup runs before the legacy XML fallbacks, which remain active for stored assistant output (src/messages/strip.ts, tests/strip.test.ts, tests/message-end.test.ts).
• Snapshot pairs are validated as canonical — parsePairs in src/state/persistence.ts switches from a permissive parseMessageRef(entry[1]) ?? 0 > 0 check to the strict isCanonicalMessageRef predicate. A compact persisted ref is discarded rather than normalized, nextRefIndex stays authoritative, the snapshot version is unchanged, and no stored map is migrated (src/state/persistence.ts, src/utils/message-ids.ts, tests/persistence.test.ts).
• Model-facing copy teaches the compact protocol — the system prompt documents @mN@, @mN:P@, and <dcp-system-reminder> as environment-injected metadata that must not be output, repeated, or invented; the message-mode tool description explains priority values and accepts the padded form as an alternative; the range tool and message tool descriptions use m1 / @m1@ examples while keeping bN block examples and the pruned/unavailable explanation. The legacy Choose a message ID (m0001)… error messages in normalizeEntries are now Choose a message marker (m1 or @m1@)… (src/prompts/system.ts, src/prompts/compress-message.ts, src/index.ts, src/compress/handler.ts, tests/index.test.ts, tests/integration.test.ts, tests/pipeline.test.ts, tests/compress-cycle.test.ts).
• Benchmark token gates are release-blocking — tests/benchmark.test.ts now asserts three deterministic budgets so a token regression fails pnpm check: injected-marker overhead on clean-2000-messages must stay at or below 6,000 tokens, and the repeated-tool-pairs-2000 and restored-nested-blocks-100 reduction ratios must stay within five percentage points of the retained 962873 / 1017575 and 1171 / 1291 baselines. Ratios are compared as exact fractions rather than rounded percentages, and elapsed-time reporting remains informational. The retained benchmarks/result.json was refreshed on Node 24.21.0 with the compact marker overhead now showing as -3,992 instead of -20,000 (tests/benchmark.test.ts, benchmarks/result.json, README.md).
• Version bump and docs refresh — version 0.7.0 → 0.8.0 (package.json); CHANGELOG.md adds a [0.8.0] - 2026-10-04 entry under Added / Changed / Removed covering compact markers, normalized lookup, line-bounded sanitization, snapshot canonical validation, and the dropped <dcp-message-id> XML formatter; README.md replaces the 0.7.0 block with a focused "What's new in 0.8.0" section and adds a "Message markers and IDs" reference table (package.json, CHANGELOG.md, README.md).
• Plan refresh and local-only ignore — the Phase 3 plan was tightened to match what shipped: the codec invariants, the line-bounded sanitizer rule, the canonical-only snapshot rule, and the high-index / invalid-input tables are all consistent with the implementation (docs/superpowers/plans/2026-10-03-phase-03-pi-dcp-compact-markers.md). .gitignore adds .DS_Store (.gitignore).

Automatic pruning timing, canonical padded references, the version-1 persisted snapshot shape, the generated schema, and Pi lifecycle hooks remain unchanged; no new runtime dependencies, no published Pi or OpenCode reference repositories, and no release workflow were touched. Verified end-to-end with pnpm check (format, warning-free lint, typecheck, tests) and pnpm benchmark (all three workloads complete within the new token gates; retained benchmarks/result.json refreshed on Node 24.21.0).