MDS Roadmap — Post-v0.1.0 Progress Tracker

[dean0x]

MDS Roadmap

Master tracking issue for all planned work after the v0.1.0 release. Each item links to a detailed issue with its own PRD.

Status Key

• ✅ Complete
• 🚧 In Progress
• ⚪ Not Started

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v0.2.0 — Language Enrichment ✅

The core language gets the features users will hit first. Focus: make templates self-sufficient without external preprocessing.

• feat: built-in functions (upper, lower, join, trim, length, etc.) #53 — Built-in functions (upper, lower, join, trim, length, etc.)
• feat: default function arguments #54 — Default function arguments
• feat: logical operators in @if conditions (&&, ||) #55 — Logical operators in @if conditions (&&, ||)
• chore: re-enable wasm-opt for WASM size optimization #68 — Re-enable wasm-opt for WASM size optimization
• feat: expression support in @for and @if directives #74 — Expression support in @for and @if directives
• feat: frontmatter imports #75 — Frontmatter imports
• Add CODE_OF_CONDUCT.md (Contributor Covenant 2.1) #38 — Add CODE_OF_CONDUCT.md

Released: 2026-06-06 — v0.2.0

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v0.3.0 — Production Readiness ✅

Bridge MDS from "template language" to "production LLM input format." Add the developer workflow tooling that makes daily use pleasant.

Status (2026-06-28): All headline features and the full tech-debt sweep are merged to main. The tech-debt wave landed via PR #117 (88ddbcc); the structured-output feature evolved into the intrinsic output format (PR #118, breaking change) — output shape is decided by template content, with no --format flag or compileMessages API. Pre-release dogfooding (CLI, Node API 44/44, all four bundler apps) is green. Release pending: gh workflow run release.yml -f version=0.3.0.

Headline Features (Complete)

• feat: structured JSON output (chat message arrays) #56 — Structured output → shipped as the intrinsic output format: @message templates compile to a JSON array, all others to Markdown; mixed content is a hard error (mds::mixed_content)
• feat: mds watch command (file watcher with auto-recompile) #57 — mds watch command (file watcher with auto-recompile) — merged in feat(cli): add mds watch subcommand with auto-recompile on save #93
• feat: template inheritance (@extends / @block) #58 — Template inheritance (@extends / @block) — merged in feat(core): template inheritance via @extends / @block (#58) #95
• feat: verify & harden hot-reload (HMR) across bundler plugins — Vite, Rollup, Webpack, Rspack #94 — Hot-reload (HMR) across bundler plugins (Vite, Rollup, Webpack, Rspack) — merged in feat(ecosystem): verify & harden HMR across bundler plugins + add @mdscript/rspack-loader #105
• rspack-loader: verify @rspack/core 2.x compat and widen peer range to ^1.0.0 || ^2.0.0 #106 — rspack-loader: verify @rspack/core 2.x compat + widen peer to ^1.0.0 || ^2.0.0 — merged in feat(ecosystem): verify & harden HMR across bundler plugins + add @mdscript/rspack-loader #105

Tech-Debt Sweep (Complete)

Do-set — all 11 landed in PR #117 (88ddbcc) and verified on main 2026-06-28:

• tech-debt: Deduplicate arity-check logic across evaluator and validator #71 — Deduplicate arity-check logic across evaluator and validator
• tech-debt: Extract generic quote-aware byte scanner from parser_helpers.rs #72 — Extract generic quote-aware byte scanner from parser_helpers.rs
• Unify CondValue and Expr literal types #78 — Unify CondValue and Expr literal types
• Delegate parse_interpolation_expr to parse_expr_inner #79 — Delegate parse_interpolation_expr to parse_expr_inner
• tech-debt: Share @for loop machinery between text and messages modes #88 — Share @for loop machinery between text and messages modes
• tech-debt: Add resolver-backed compile_messages_file for CLI messages-mode symlink parity #89 — Messages-mode symlink parity — superseded by the intrinsic output format (single compile path; symlink rejection covered by mds-cli/tests/security.rs)
• tech-debt: Harden CLI/NAPI boundaries with escaping and injection tests #90 — Harden CLI/NAPI boundaries with escaping and injection tests
• tech-debt: Parse WASM return shape at FFI boundary #91 — Parse WASM return shape at FFI boundary (canonical method manifest / backend contract)
• tech-debt: Split resolver.rs into inheritance and frontmatter submodules #96 — Split resolver.rs into inheritance and frontmatter submodules
• tech-debt: Extract build_merged_extends_scope resolver helper #99 — Extract build_merged_extends_scope resolver helper
• tech-debt: Extract resolve_intermediate_base resolver helper #100 — Extract resolve_intermediate_base resolver helper

Already Closed (verified done):

• tech-debt: Eliminate O(N²) frontmatter accumulation in inheritance chains #98 — Eliminate O(N²) frontmatter accumulation in inheritance chains (done in feat: template inheritance (@extends / @block) #58)
• tech-debt: Carry per-node source identity for base-default block spans #101 — Carry per-node source identity for base-default block spans (panic-safety fixed; cosmetic follow-up → Cosmetic: improve base-source span precision in inheritance error reporting #115)
• Reduce parse_simple_condition complexity #80 — Reduce parse_simple_condition complexity (already implemented)
• Extract ScanState struct to consolidate duplicated quote/paren scanning #77 — Duplicate of tech-debt: Extract generic quote-aware byte scanner from parser_helpers.rs #72; consolidated to byte-scanner work

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v0.4.0 — Ecosystem Expansion

Expand reach beyond JS/TS. Add the quality-of-life tooling that mature languages provide.

• feat: Python bindings (PyO3) #59 — Python bindings (PyO3)
• feat: mds fmt — auto-formatter #60 — mds fmt (auto-formatter)
• feat: mds lint — static analysis and diagnostics #61 — mds lint (static analysis)
• feat: source maps for compiled output #62 — Source maps for compiled output
• tech-debt: reduce Value cloning in evaluate_expr Var lookups #81 — tech-debt: Reduce Value cloning in evaluate_expr Var lookups (deferred from v0.3.0)
• Cosmetic: improve base-source span precision in inheritance error reporting #115 — Cosmetic: improve base-source span precision in inheritance error reporting (split from tech-debt: Carry per-node source identity for base-default block spans #101)

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v0.5.0 — Advanced Features

Enable sharing and reuse across projects and teams.

• feat: URL-based imports (remote modules) #63 — URL-based imports (remote modules)
• feat: MDS package registry / prompt library ecosystem #64 — Package registry / prompt library ecosystem
• feat: MDS Runtime — on-read compilation via virtual filesystem #82 — MDS Runtime (on-read compilation via virtual filesystem)

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v1.0.0 — Editor Experience (Deferred)

Full editor integration. Intentionally last — language features and production readiness come before distribution overhead. These items require significant DevOps, testing, and maintenance investment beyond the code itself.

• feat: VS Code extension (TextMate injection grammar) #65 — VS Code extension (TextMate injection grammar)
• feat: Tree-sitter grammar (Neovim, Helix, Zed) #66 — Tree-sitter grammar (Neovim, Helix, Zed)
• feat: LSP server for MDS #67 — LSP server

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Completed Milestones

v0.2.0 (2026-06-06) ✅

• 18 built-in functions, default args, logical operators
• Expression support in @for and @if directives
• Frontmatter imports
• wasm-opt re-enabled (Binaryen v129, -Oz)
• Published to crates.io, npm (with SLSA provenance), and GitHub Releases

v0.1.0 (2026-05-31) ✅

• Core compiler (lexer, parser, resolver, validator, evaluator)
• CLI: build, check, init
• JS/TS ecosystem: WASM bindings, napi-rs, universal package, Vite/Rollup/Webpack plugins
• Automated release pipeline (workflow dispatch)
• 591+ tests, full CI/CD
• Published to crates.io, npm, and GitHub Releases

Notes

• Editor experience (v1.0.0) is intentionally deferred. Language enrichment and production readiness take priority — we want to ship features users can use before investing in distribution and tooling overhead.

[dean0x]

v0.2.0 Released — 2026-06-06

All language enrichment features shipped:

• mds-core + mds-cli → crates.io
• 8 npm packages → npmjs.com (with SLSA provenance)
• GitHub Release v0.2.0

Features: 18 built-in functions, default args, logical operators, expression directives, frontmatter imports, wasm-opt re-enabled.

Remaining on milestone: #38 (CODE_OF_CONDUCT.md), #71 and #72 (tech debt — moving to v0.3.0).