Living Document Notice
Published 2026-09-18. The evolving architecture, revisions, and connected notes for this dispatch live in the Stax Digital Garden.
The Bosun Engine Roadmap
Summary
The development roadmap for the Bosun core engine is structured into three concrete engineering phases: deterministic parsing and CST representation, high-density graph indexing, and client-side WebAssembly execution. Each phase establishes explicit latency budgets and memory constraints prior to feature expansion.
By prioritizing memory ceilings and strict benchmark targets over superficial feature counts, the engine maintains predictable performance across desktop and web environments. This roadmap defines the technical milestones, interface specifications, and performance verification targets across engine releases.
Phase 1: Lossless Parser and CST Specification
The primary milestone delivers a lossless concrete syntax tree capable of deterministic round-trip serialization. Phase 1 replaces lossy ASTs with Tree-sitter incremental grammar evaluation and Rowan-style green-red trees.
Deliverables include:
- Integration of the Tree-sitter Markdown grammar with custom frontmatter scanner.
- Green-red tree implementation preserving trivia, comments, and line ending variations.
- Zero-copy YAML frontmatter validation with byte-span diagnostic reporting.
- Automated round-trip fuzz testing across 100,000 real-world notes.
The engine targets sub-150 microsecond incremental parse latency on 50,000-line Markdown documents, ensuring smooth typing response in interactive editing sessions. Concrete test gates enforce zero byte divergence when re-serializing unedited documents across Linux, macOS, and Windows filesystems.
Phase 2: Graph Engine and Compressed Indices
The second milestone focuses on relationship traversal across 50,000-note collections without heap exhaustion. Phase 2 delivers high-performance graph structures and disk cache synchronization.
Deliverables include:
- Compressed Sparse Row forward and backward graph indices.
- String interning symbol table reducing string metadata overhead.
- Embedded SQLite derived index cache with WAL mode and BLAKE3 incremental change detection.
- Sub-millisecond backlink and orphan query evaluation.
Memory consumption across 50,000 notes is constrained to less than 180 MB RSS, allowing background indexing to run continuously on low-spec hardware. Index serialization checkpoints are committed incrementally to NVMe storage to eliminate cold-start re-indexing overhead during application launch cycles.
Phase 3: WebAssembly Runtime and Sandbox Integration
The final milestone provides cross-platform execution across desktop daemons and browser workers. Phase 3 implements WebAssembly compilation and capability-based plugin execution.
Deliverables include:
- Zero-copy WASM linear memory bridge for JavaScript runtimes.
- Outrigger Protocol WASI runtime sandbox with deterministic fuel metering.
- Public C-ABI and TypeScript declaration bindings.
- Memory budget enforcement capping resident set size under 200 MB across full vaults.
Sandboxed plugins execute within bounded memory quotas with zero host filesystem access, preventing malicious code execution while supporting custom syntax transformations. The resulting WebAssembly artifact is optimized through link-time code elimination to maintain gzipped bundle sizes below 120 KB.
Target Latency Budgets and Architecture Milestones
The table below outlines target latency budgets and memory limits across all three roadmap milestones.
| Engine Milestone | Target Workload Scale | Latency Budget | Max RSS Ceiling | Verification Gate |
|---|---|---|---|---|
| Phase 1: CST Parser | 50,000 lines single file | < 150 μs incremental | < 50 MB heap | Zero-diff round-trip test |
| Phase 2: Graph Engine | 50,000 notes / 350k edges | < 50 μs 1-hop query | < 180 MB RSS | Cold startup < 50 ms |
| Phase 3: WASM Core | Web worker browser client | < 15 ms full parse | < 64 MB linear memory | Automated CI fuel trap test |
- Directus Target: bosunpkm-blog
- Garden Source Reference: MOC - Bosun PKM Engine, MOC - Bosun PKM Tools, MOC - Local-First Systems and Synchronization, MOC - Outrigger Protocol